Microbial communities on UV cabins in the dermatology service of a Spanish hospital: ecology and resistance to UV light and antibiotics

Microbial communities on UV cabins in the dermatology service of a Spanish hospital: ecology and resistance to UV light and antibiotics | Research Square window.SnipcartSettings = { analytics: { enabled: false } }; (function() { var accessVector = localStorage.getItem('access_vector') || ''; window.dataLayer = window.dataLayer || []; if (accessVector) { window.dataLayer.push({ user: { profile: { profileInfo: { snid: accessVector } } } }); } })(); (function(w,d,s,l,i){w[l]=w[l]||[];w[l].push({'gtm.start':new Date().getTime(),event:'gtm.js'});var f=d.getElementsByTagName(s)[0],j=d.createElement(s),dl=l!='dataLayer'?'&l='+l:'';j.async=true;j.src='https://www.googletagmanager.com/gtm.js?id='+i+dl;f.parentNode.insertBefore(j,f);})(window,document,'script','dataLayer','GTM-K279D39R'); Browse Preprints In Review Journals COVID-19 Preprints AJE Video Bytes Research Tools Research Promotion AJE Professional Editing AJE Rubriq About Preprint Platform In Review Editorial Policies Our Team Advisory Board Help Center Sign In Submit a Preprint Cite Share Download PDF Article Microbial communities on UV cabins in the dermatology service of a Spanish hospital: ecology and resistance to UV light and antibiotics Esther Molina-Menor, Nicolás Carlotto, Àngela Vidal-Verdú, Amparo Pérez-Ferriols, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-2800931/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 04 Sep, 2023 Read the published version in Scientific Reports → Version 1 posted 10 You are reading this latest preprint version Abstract Microorganisms colonize all possible ecological habitats, including those subjected to harsh stressors such as UV radiation. Hospitals, in particular the UV cabins used in phototherapy units, constitute an environment in which microbes are intermittently subjected to UV irradiation. This selective pressure, in addition to the frequent use of antibiotics by patients, may represent a threat in the context of the increasing problem of antimicrobial resistance. In this work, a collection of microorganisms has been established in order to study the microbiota associated to the inner and outer surfaces of UV cabins and to assess their resistance to UV light and the antibiotics frequently used in the Dermatology Service of a Spanish hospital. Our results show that UV cabins harbor a relatively diverse biocenosis dominated by typically UV-resistant microorganisms commonly found in sun-irradiated environments, such as Kocuria , Micrococcus or Deinococcus spp., but also clinically relevant taxa, such as Staphylococcus or Pseudomonas spp. The UV-radiation assays revealed that, although some isolates displayed some resistance, UV is not a major factor shaping the biocenosis living on the cabins, since a similar pool of resistant microorganisms was identified on the external surface of the cabins. Interestingly, some Staphylococcus spp. displayed resistance to one or more antibiotics, although the hospital reported no cases of antibiotic-resistance infections of the patients using the cabins. Finally, no association between UV and antibiotic resistances was found. Biological sciences/Microbiology/Communities Biological sciences/Microbiology/Communities/Metagenomics Biological sciences/Microbiology/Communities/Microbial ecology Biological sciences/Microbiology/Communities/Microbiome Biological sciences/Microbiology/Policy and public health in microbiology Figures Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Figure 7 Figure 8 Introduction Microorganisms (not only bacteria and archaea, but also eukaryotes) can resist both ultraviolet radiation and high doses of ionizing radiation [ 1 ]. UV-resistant organisms are widely distributed in many ecosystems, but they are particularly frequent on sun-irradiated environments such as building surfaces, deserts or solar panels [ 2 – 4 ]. Radiation-resistant bacteria belong to different taxonomic groups. Although some clades are known by their natural resistance to radiation and high temperatures, such as the Deinococcocota phylum (former Deinococcus-Thermus ), radiation-resistant bacteria are also represented in Pseudomonadota , Bacillota , Actinomycetota or Bacteroidota , previously Proteobacteria , Firmicutes , Actinobacteria and Bacteroidetes , respectively [ 5 ]. In addition to their general non-pathogenic condition, they can even contribute to other organisms, such as plants, fighting pathogenic microorganisms [ 6 ]. Pathogenic bacteria, in particular those causing health problems to humans and other animals, show different sensitivities to UV radiation [ 7 ]. In fact, irradiation is used as an antimicrobial strategy in different laboratory and hospital devices such as UV sterilization lamps and microbiology cabins [ 8 ]. Besides, UV light and other light-based strategies have been also proposed as potential strategies to treat microbial infections in patients [ 9 , 10 ]. However, UV sterilization has some limits as its efficiency depends on factors such as microbial species and state of cultures, or the nature of the surfaces, among others [ 7 , 11 ]. UV light covers the spectrum wavelength between 100 and 400 nm. It can be further subdivided into three regions: UVA (315–400 nm), UVB (280–315 nm) and UVC (100–280 nm) [ 12 ]. Each UV light range has a different effect on living organisms, being UVC the most energetic, and thus dangerous, radiation. However, solar radiation that reaches the Earth’s surface is UVB and UVA, as UVC is absorbed by the atmosphere [ 13 ]. Although UVB is also mainly filtered, the small fraction that gets to the surface causes different deleterious effects on the organisms, such as skin tanning and sunburns in animals. UVB light is directly absorbed by DNA molecules causing mutations, which is associated with the development of several types of skin cancer. Moreover, it is major responsible of killing airborne bacteria subjected to sunlight [ 14 ]. In contrast, UVA light is the most penetrating one and represents 95% of the UV light that reaches our planet’s surface. Its penetrating power has an impact on photoaging, but it can also contribute to DNA damage by interacting with already existing photoproducts [ 13 , 15 – 16 ]. The damaging effects of UV light is both direct (changes in biomolecules) and indirect, via the increase in reactive oxygen species (ROS). It includes changes in DNA, such as the formation of pyrimidine dimers, but also structural changes in proteins, lipids, and physiological stress that leads to loss of cell viability [ 16 – 18 ]. Interestingly, and beyond the antiseptic effect of UV treatment described above, both UVB and UVA, at controlled doses, can be used for therapeutic purposes to treat cutaneous affections. Phototherapy is the controlled use of light of different wavelengths to treat health problems, mostly skin disorders [ 19 ]. It is commonly used in new-borns developing jaundice, to treat the accumulation of bilirubin [ 20 ], but also in the treatment of psoriasis, chronic eczema, mycosis fungoides or vitiligo, among other diseases [ 21 – 22 ]. Antimicrobial resistance, AMR, has risen as one of the main threats for global health. Specifically, the World Health Organization (WHO) estimates that by 2050, around 10 million people will die from infections with no available treatments [ 23 ]. Although the selection of resistances is a natural phenomenon resulting from the imposed selective pressure of using antibiotics, their abuse and misuse, among other factors, has accelerated their spread [ 24 – 25 ]. Specifically, hospitals and intensive care units (ICUs) represent environments in which the risk of acquiring nosocomial multidrug resistant infections increases [ 26 ]. The systematic use of antibiotics in hospital environments, in addition to the abundance of more susceptible patients, favours the spread of AMR among microorganisms [ 27 ]. The studies regarding AMR and radiation mainly focus on the effect of IR on the degradation of both antibiotic products and the inactivation of gene synthesis [ 28 ], or the treatment of infections with specific IR [ 29 ]. Although there is some evidence that the use of radiation may favour the selection of antibiotic resistant bacteria, there are no previous reports on their study in phototherapy services [ 30 ]. In the present work, we aimed at studying the microbial diversity in a previously unreported niche: therapeutic UV light hospital cabins, and to explore whether there is a link between the origin of the samples (taken either inside or outside the cabins) and UV resistance. Additionally, we have explored the co-occurrence of UV resistance and antibiotic resistance. Such co-occurrence may be of special interest in order to inform UV-based antimicrobial and disinfection policies in hospital facilities [ 26 , 31 ]. Results Ecology and microbial diversity Culturable microbial collection and identification The establishment of a microbial collection resulted in the isolation of 169 strains. A total of 164 isolates were identified, of which 155 corresponded to bacterial species. The identification through 16S rRNA gene or ITS sequence sequencing revealed that the isolates belonged to 44 different genera, among which the genera Staphylococcus (29 isolates), Kocuria (17 isolates), Micrococcus (17 isolates) and Pseudomonas (11 isolates) were the most abundant ones. In contrast, genera Erwinia , Fredinandcohnia , Lysinibacillus , Mixta , Moraxella , Peribacillus , Pseudoxanthomonas , Rhodococcus , Robertmurraya , Roseomonas , Pantoea , Psychrobacillus , Domibacillus , Kosakonia , Ustilago , Cryptococcus , Cystobasidium and Rhodotorula were just represented by one isolate each (Fig. 1 A and 1 B). Taking into consideration the isolation source, 81 isolates originating from the inner surface of the cabins, being Staphylococcus (17 isolates) the most abundant genera. In contrast, 88 microbial isolates came from the outer surface of the cabins, among which Staphylococcus (12 isolates), Pseudomonas (11 isolates) and Kocuria (10 isolates) were the most abundant ones. Moreover, 14 genera were exclusively isolated from each location (inside and outside), whereas 16 were common for both sampling sites (Fig. 2 ). However, it has to be stressed that most of the “exclusive” taxa were represented by just one isolate, with the exception of Pseudomonas spp. When comparing the cabins, the four most abundant genera ( Staphylococcus , Kocuria , Micrococcus and Pseudomonas ), as well as Bacillus , were isolated from all of them and cabin two was the one with the highest number of exclusive taxa (11) regardless of the isolation source (Figure S1 C). However, the exclusivity inside and outside was similar (Figures S1 A and S1B). Next Generation Sequencing: high-throughput 16S rRNA gene sequencing Three different α-diversity indexes were calculated: richness, Shannon index and Simpson index. Richness refers to the total number of amplicon sequence variants (ASVs, or clones), Shannon measures the number of different taxa and their abundances, whereas Simpson quantifies how the sequences are distributed among ASV. That is, the number of bacteria per ASV. Although the α-diversity (ASV level) was higher in the samples from the outside than from the inside of the cabins, the Wilcoxon test did not find significant differences given the low number of replicates from each cabin and location. Similarly, the Shannon and Simpson indexes revealed higher diversity values for the outside of cabins two, three and four, but again, these results were not significantly different (Fig. 3 A, Figures S3A and S3B). The representation of the β-diversity in a principal component analysis (PCoA) showed that the outer surfaces of the cabins displayed higher similarities than the inner surfaces among cabins. Moreover, samples from both the inside and the outside of cabins one and two were similar in terms of microbial composition but plotted separately in the PCoA (Fig. 3 B). The PERMANOVA test confirmed that the microbiomes were significantly different both between cabins and sample locations. At the phylum level (updated according to the new nomenclature for prokaryotic phyla [ 32 ], all the samples displayed similar bacterial profiles, with Pseudomonadota , Actinomycetota and Bacillota as the predominant taxa. Moreover, Cyanobacteriota and Bacteroidota were also abundant, although not in the case of sample C4D1 (inside of cabin four) (Fig. 4 A and Figure S4A), in which Bacillota was the predominant phylum. However, none of the phyla was statistically more abundant in any of the cabins or locations (inside/outside) according to the DESeq2 test. At the genus level, the most similar cabins in terms of bacterial composition were cabin one and two. The genera Staphylococcus , Rubellimicrobium and Paracoccus were especially abundant there. Moreover, Pseudomonas , Kocuria , Sphingomonas and Corynebacterium were among the most abundant ones in the majority of the samples. Samples C1D3 (inside of cabin one), C3D1 (inside of cabin three) and C4D1 (inside of cabin four) were the most different ones (Fig. 3 B). In C1D3 there was a significant higher abundance of an unknown genus within the order Enterobacterales . In C3D1 there was higher abundance of Pseudomonas and an uncultured genus within the order Cyanobateriales . In C4D1 Halomonas was especially overrepresented, whereas Melittangium was characteristic for samples of cabin two (Fig. 4 B and Figure S4B). Furthermore, some genera were significantly more abundant outside the cabins, such as Oligella , Serratia , Cobetia and Carnobacterium , whereas only Providencia was more abundant inside them according to a DESeq2 test. Given the previous experience in irradiated environments, the knowledge on the natural skin microbiota, and the abundances found in the previous experiments, a selection of relevant taxa was analysed in order to determine whether there were differences in their distribution inside and outside. Moreover, the abundances of the top ten abundant genera were also plotted. That is, in alphabetical order, the genera Corynebacterium , Deinococcus , Hymenobacter , Kocuria , Micrococcus , Paracoccus , Pseudomonas , Rubellimicrobium , Sphingomonas and Staphylococcus (Fig. 5 and Figure S5). None of the studied genera revealed any significant difference on the distribution among locations, except for Staphylococcus (Fig. 5 C). Although Deinococcus was more abundant on the inner surfaces, these results were not significant according to the Wilcoxon test (Figure S5A). This tendency was also observed in the case of Sphingomonas (Figure S5D). Finally, in order to identify the most frequent species within Staphylococcus , successive BLAST were performed with the most abundant ASV. Among the 61 ASV identified as Staphylococcus , S. epidermitis and S. aureus were between the ten more abundant species, along with S. caprae , S. capitis , S. cohnii , and S. haemolyticus . Biological activity assays UV-radiation resistance assay The resistance to UV irradiation of the isolates from the subset of the microbial collection (Table S2) was assessed by quantifying the colony forming units (CFU) after treatments with 15 s and 30 s of exposure to UV. The survival rates were calculated by dividing the number of CFUs after irradiation between the CFUs observed in a non-exposed control replicate. Survival rates values close to 1 represented a high resistance to UV whereas close to 0 a low resistance to UV (Fig. 6 A). From the strains that were exclusively isolated inside the cabins, Kocuria polaris was the only one not showing a significant decrease of survival after 15 s of UV exposure. However, 30 s of exposure resulted in a sharp and significant decrease, with a survival rate close to 0. In contrast, Acinetobacter variabilis and Microbacterium esteraromaticum showed a linear decrease in the survival rate, with values after 15 s and 30 s close to 0.5 and 0 respectively, whereas, the survival rates of Frigoribacterium faeni, Lysinibacterium halotolerans, Paracoccus panacisoli and S. epidermitiss, showed a marked reduction to almost 0 after 15 s exposure to UV, revealing a high susceptibility to UV exposure. From the strains that were exclusively isolated outside the cabins, there were two of them showing no significant decrease of survival rate after 15 s exposure to UV: Arthrobacter agilis and Deinococcus ficus . Although 30 s exposure to UV led to a significant decrease in the survival rate, these two isolates showed a difference from K. polaris as the values were not close to 0, suggesting a mid-resistance to the treatment. This was especially evident for D. ficus with a survival rate at 30 s higher than 0.75. The rest of the group formed by Kocuria palustris , Priestia aryabhattai , Pseudomonas stutzeri , S. haemolyticus and Stenotrophomonas rhizophila showed survival rates significantly different to the control and with values close to 0 even with 15 s of UV exposure. Regarding the species that were isolated both inside and outside the cabins, all of them showed a similar output comparing the lineplot of the inside isolate to the outside isolate, revealing similar resistance patterns. The only exception was Micrococcus luteus , showing the outer strain a higher resistance to 15 s of exposure. Interestingly, the isolates of Arthrobacter bussei showed a similar output to the outer isolates A agilis and D. ficus , with survival rate values between 1 and 0.5 after 15 s and 30 s of UV exposure. Finally, Curtobacterium flaccumfaciens and Kocuria arsenatis also showed a considerable resistance after 15 s exposure to UV, whereas Bacillus altitudinis , S. cohnii and S. hominis showed a strong decrease in the resistance to UV treatment already at 15 s for both inside and outside isolates. To further test if the UV irradiation from the cabins could shape the surface-associated microbiome leading to an enrichment of UV resistant species in the inside of the cabins, we compared in Figs. 6 B and C the survival rates after 15 s and 30 s UV exposure, respectively, for all the isolates tested in Fig. 6 A. However, there was no clear evidence that supported this hypothesis. Although K. polaris inside showed the highest survival rate after 15 s, this was not significantly different to the next four species ( D. ficus , M. luteus , A. bussei and A. agilis ), which were isolated outside the cabins (Fig. 6 B). Moreover, a similar pattern was observed at 30 s of exposure, in which the significance group for the highest survival rates was formed by four isolates coming from the outer surfaces and two coming from the inner ones (Fig. 6 C). At the strain level, M. luteus and B. altitudinis isolated from outside displayed higher survival rates than the inside isolates, whereas C. flaccumfaciens behaved contrarily after 15 s UV exposure. In the case of the 30 s treatment, only B. altitudinis behaved differently between treatments, being more resistant the outer strain. Antibiotic resistance assay To study a possible occurrence of AMR in isolates from the microbiomes of the UV cabins, we tested the resistance to antibiotics of the isolates from the subset of the microbial collection (Table S2). Quality control strains were included in all the experiments and gave the expected MIC results (in µg/ml): E. coli for amoxiclavulanicc acid (AMC; 0.5–2), doxycycline (DXT; 0.5–2) and gentamicin (GEN; 0.25–1); and S. aureus for mupirocin (MUP; 0.06–0.25), azithromycin (AZM; 0.5–2) and clindamycin (CD; 0.06–0.25). The classification of the isolates as resistant (R) or sensitive (S) to the tested antibiotics was determined according to clinical breakpoints established by EUCAST (EUCAST Clinical Breakpoint Tables v.12.0), which classifies microorganisms into susceptible at standard doses (S), susceptible increased exposure (I) or resistant (R). However, there were not available data for some species or antibiotics given the environmental origin of the tested isolates. In those cases, only the MIC values are commented and further discussed. The six antibiotics revealed two different patterns. On the one hand, the tested strains showed variable susceptibilities to AMC, DXT, GEN, and CD (Figs. 7 A, B, C, F). In contrast, there was a clear cluster of resistant strains to MUP and AZM (Figs. 7 D and E). In the case of AMC, the majority of the tested isolates were sensitive (S or I) according to the EUCAST criteria, with the exception of S. rhizophila which was resistant (R, Fig. 7 A). In regard to DXT, S. hominis appeared as I, with a MIC value between 1 and 2 µg/ml, whereas the rest of the tested strains gave MIC values below 1 (Fig. 7 B). Similarly, most of the selected strains were S to GEN, with non-related species threshold stablished at 0.5 µg/ml, and 4 µg/ml for Pseudomonas spp. and Acinetobacter spp. However, in this case, S. hominis and S. rhizophila were R (Fig. 7 C). In the case of MUP and AZM, there was a significant cluster of R strains (Figs. 7 D and E, respectively), with interest on Staphylococcus spp. in both cases: S. haemolyticus for MUP (R threshold at 256 µg/ml) and S. hominis , S. epidermitis , S. cohnii and S. haemolyticus for AZM (R threshold at 2 µg/ml). Moreover, both S. cohnii isolates displayed MIC values above the breakpoint established for Staphylococcus spp. for CD (Fig. 7 F). As for the strains with no registry of their resistances, their MIC values were diverse. AMC median MIC values ranged from 3 to 0.01, with the highest value at 6 µg/ml. DXT values ranged from 1.5 to 0.016, with the highest point on 4 µg/ml. GEN values varied from 2 to 0.016, being 3 µg/ml the top value. MUP values were from 1536, the top score, to 0.064 µg/ml. AZM values ranged from 384 (highest value) to 0.01 µg/ml, and CD values were from 384 (highest score) to 0.01 µg/ml. Phylogenetic interpretation From the phylogenetic perspective, there was found out a clear tendency on Actinomycetota to resist UV. In contrast, species within the phylum Bacillota appeared as the most sensitive to this treatment. Regarding antibiotics, as stated above, there was not a significant enrichment on resistant isolates. However, MIC values were diverse. Specifically, there is interest on the resistances displayed by staphylococci to DXT, GEN, MUP, AZM and CD. Although the displayed values may appear as high, the available literature on clinical specimens did not catalogue most of them as resistant. Discussion In the present work, we analysed the microbiomes associated to the inner and external surfaces of UV cabins used in the Dermatology Service of the Hospital General Universitario de Valencia to treat skin pathologies. First, we wanted to shed light on whether the UV irradiation shaped the microbial communities of the cabins. Second, we wanted to explore the possible correlation between UV light-resistance and resistance to antibiotics commonly used to treat skin pathologies. For this, we used a double strategy based in culture-dependent (culturomics, colony identification and biological activity tests) and independent techniques (high-throughput 16S rRNA gene sequencing). From the culturomics point of view, the microbial profiles we found are moderately diverse and include both environmental and human associated microbial taxa (Fig. 1 A). From the most abundant taxa to the least, the high abundances of Staphylococcus , and to a lesser extent of Micrococcus and Bacillus , are not surprising since these genera are naturally present on the human skin [ 33 – 34 ]. Moreover, Kocuria and Pseudomonas have also been associated with skin disorders, such as psoriasis, and some Arthrobacter species are opportunistic human pathogens, such as A. creatinolyticus or A. woluwensis , or have been isolated from human clinical specimens [ 35 – 38 ]. However, both Kocuria and Arthrobacter species inhabit soils, being, thus, common environmental species [ 2 ], and the large genus Bacillus not only includes pathogenic species such as B. cereus or B. anthracis , but is also a typical environmental species in different natural habitats [ 39 – 40 ]. Some of these genera are also known by their tolerance to biotic and abiotic stressors. Specifically, Micrococcus spp. and Kocuria spp. have been isolated from polar environments and reported to be resistant to radiation [ 41 – 44 ], whereas Arthrobacter spp. are present in hot deserts [ 2 , 45 – 46 ]. Moreover, Bacillus spp. are well known by their tolerance to stress given their ability to form resistance spores [ 47 ]. From the clinical point of view, we found relevant to analyze the presence of some health-threatening genera, such as Acinetobacter or Pseudomonas . Both genera have been described to have an innate adaptation ability, including the acquisition of antibiotic resistances [ 48 – 50 ]. Among them, A. baumanii and P. aeruginosa strains fall into the ESKAPE group of multi-drug resistant bacteria [ 51 – 52 ]. Moreover, other present genera such as Rhodococcus , Roseomonas or Stenotrophomonas host species that cause infection to immunocompromised patients, and Cryptococcus spp. have been reported to cause opportunistic infections [ 52 – 56 ]. Apart from the above-described ones, there is also a less abundant representation of some environmental-associated taxa, many of which have been isolated from varied environments such as Deinococcus , Domibacillus , Pantoea or Sphingomonas [ 57 – 60 ]. Others have been linked to isolated cases of fungaemia, bacteremia or sepsis, such as Aureobasidium , Kosakonia , Lysinibacillus or Massilia [ 61 – 64 ]. However, Massilia is also a common soil-inhabitant [ 65 – 66 ]. Regarding fungi, the ones we isolated in pure culture belonged to the genera Aureobasidium (five isolates), Ustilago , Cystobasidium , Rhodotorula and Cryptococcus (the last four represented by just one isolate). Despite the low number of fungal isolates selected, the fact that the yeast genera Aureobasidium , Rhodotorula and Cryptococcus had previously been reported to inhabit different hospital facilities is in accordance with our results [ 67 ]. The comparison of the isolation surface (inside or outside the cabins) revealed similar microbiomes. However, the existence of a cluster of exclusive genera in each location reveals some differences from the culturable point of view. The dominance of Staphylococcus in both isolation sources is in accordance with its widely known role in skin pathology [ 68 ]. In contrast, Pseudomonas , a sensitive genus, is only detected outside [ 69 ]. Curiously, all six isolates identified as Frigoribacterium spp. were isolated from the inner surfaces of the cabins (Fig. 1 A). This genus was first described as a psychrophilic genus isolated from dust in a cattle barn in Finland [ 70 ]. As revealed by high-throughput 16S rRNA gene sequencing, the all the cabins and locations display similar taxonomic profiles in terms of α-diversity. However, in terms β-diversity some differences are observed at the genus level (Figs. 3 A and 3 B). The fact that cabin one (working in UVA) and cabin two (working in UVB) are the most similar ones suggests that UV does not have a significant effect in shaping the microbial biocenosis in our studies (Fig. 3 B). At the phylum level, the predominant phyla found ( Pseudomonadota , Actinomycetota and Bacillota ) are in accordance with the already described profiles found in hospitals by other authors. Moreover, the comparison of the microbial profiles found in the samples at the genus level with those of hospitals is also in accordance with previous studies, particularly due to the presence of Staphylococcus , Pseudomonas , Acinetobacter and Streptococcus (Figs. 4 A and 4 B) [ 27 , 71 ]. Interestingly, the presence of the genera Rubellimicrobium , Deinococcus , Bacillus , Hymenobacter and Sphingomonas is in line with the already described microbial communities living on solar panels [ 3 ]. This may suggest that the studied microbiomes are a combination of both highly-irradiated surfaces, such as solar panels, and hospital environments. Although, at the genus level, there are differences between both cabins and locations (Fig. 4 B), the most relevant genera according to their environmental or clinical interest do not show significant differences in their distribution, with the exception of Staphylococcus (Fig. 5 C). Finally, the genera Rubellimicrobium , Paracoccus and Corynebacterium are among the most abundant genera through NGS whereas they are completely absent in the strain collection (Figs. 4 B and 1 A, respectively). Biases in culturing techniques are well-known and our results support the importance of combining both culture-dependent and culture-independent techniques in microbial ecology. We tested the hypothesis that the resistance to UV irradiation of the species isolated inside the cabins would be higher than that of the species isolated outside the cabins. However, our results did not support this statement (Fig. 6 ). All the strains isolated exclusively from the inner surfaces showed a significant decrease in the survival rate after 15 s or 30 s of UV irradiation, with the only exception being K. polaris at 15 s of UV irradiation treatment. Similarly, in the group of isolates obtained exclusively from the outer surfaces there were only two strains whose survival did not decrease significantly after 15 s of UV exposure: A. agilis and D. ficus . Moreover, in the comparison of species isolated from both the inner and outer surfaces of the cabins, no relevant differences were found out. There was only one outside M. luteus isolate displaying higher resistance that the inner strain (Fig. 6 ). This suggests that, in this case, UV exposure is no causing an adaptive response for bacteria (Fig. 6 A). According to this experiment, the most resistant strains were A. bussei, A. agilis, K. polaris, D. ficus and M. luteus (Figs. 6 B and 6 C). Some Kocuria strains have been reported as highly resistant to different types of radiation, as well as to synthesize carotenoids and encode genes related to oxidative stress [ 41 , 44 , 72 – 74 ]. Moreover, Deinococcus spp. have been extensively studied for its high resistance to radiation, which is a result of a combination of mechanisms such as robust DNA repair systems regulatory proteins, enzymatic and non-enzymatic antioxidant strategies [ 74 – 75 ]. On its part, the genus Arthrobacter hosts several multi-resistant species to different abiotic stressors [ 76 – 77 ]. Specifically, A. agilis has been reported to produce the C50 carotenoid bacterioruberin [ 78 ]. Finally, Micrococcus spp. have DNA repair mechanisms fundamental on their resistance to UV light [ 79 – 80 ], and M. luteus strains have been reported to resist high doses of gamma radiation [ 42 ]. These taxa are, thus, highly resistant to radiation and other stresses, and naturally inhabit soil and desert-like environments [ 2 – 3 ]. Even though for most of the strains the survival rate after UV treatment was significantly reduced compared to the non-irradiated control, many of them showed mid-viability after 15 s of treatment. This is the case of A. variabilis and M. esteraromaticum , isolated from the inner surfaces of the cabins, and A. bussei, C. flaccumfaciens and K. arsenatis , isolated both from the inside and the outside. Some Acinetobacter species have demonstrated to be able to cope with oxidative stress [ 81 – 82 ]. Moreover, the genus Microbacterium has extensive background on UV resistance and carotenoid synthesis as well [ 83 – 85 ]. In contrast, less has been described about Curtobacterium spp., but still there are reports on their tolerance to UV [ 86 ]. The reasons for the absence of an enrichment on resistant species inside the cabins may be varied (Figs. 6 A and 6 B). On the one hand, both surfaces are accessible to patients, which may be in contact constantly with both surfaces. This would explain also the high similarities found in terms of diversity. Moreover, the stress to which they are subjected (short pulses of UV light) may be less intense than the stress tested under laboratory conditions. From this perspective, the species tested may not represent a threaten. As stated in the introduction, hospitals and sanitary environments increase the population of multidrug resistant pathogens. Considering that the surface of UV-cabins is constantly in contact with patients with skin pathologies, many of them with complementary treatments with antibiotics, and that the use of radiation may favor the selection of antibiotic resistant bacteria [ 30 ], we hypothesized that the isolates taken from the inside and the outside of these cabins may present an altered susceptibility to antibiotics. In this regard, we assessed the antibiotic resistance of the isolates from Table S2 to six antibiotics widely used in dermatology: AMC, DXT, GEN, MUP, AZM and CD (Fig. 7 ). The classification of the strains as sensitive or resistant has been done according to the European Committee on Antimicrobial Susceptibility (EUCAST) as expressed in the instructions of the MTS. The presence of some resistant strains is confirmed, with special interest on the genus Staphylococcus . In this regard, there were found isolates resistant to DXT and GEN ( S. hominis isolated from outside), MUP ( S. haemolyticus ), AZM (both S. cohnii isolates, S. haemolyticus and S. hominis from inside) and CD (both S. cohnii ). The resistance to MUP is remarkable, as this antibiotic is specifically used in the treatment of topic dermal infections by Gram-positive cocci, which also explains the resistance values displayed by most of the tested strains (which are not Gram-positive cocci). Moreover, the resistance of S. haemolyticus to MUP has been already reported and is mediated by the gene mupA [ 87 ], and the rest of the mentioned staphylococci have reports on their multi-resistances [ 88 – 90 ]. There were some differences between strains isolated from different surfaces belonging to the same species, such as the case of S. hominis : the inside isolate is resistant to AZM whereas the outside one is resistant to DXT and GEN. As for S. rhizophila , our strain showed resistance to AMC, and there are reports on their multi-resistance to many antibiotics [ 91 ]. Regarding the strains for which a breakpoint has not been established, no susceptibilities can be assigned. Taken together, the results obtained from both resistance assays (UV and antibiotics) reveal that most of microorganisms are not resistant to the antibiotics tested. Those that are, which are the staphylococci, do not show UV-resistance. The rest of the isolates we tested lack clinical interest as they are not common human pathogens. Therefore, the microbial community of the cabins is mainly composed of antibiotic-sensitive micro-organisms which display a diverse sensitivity to UV light, and a few potential pathogenic microorganisms that are sensitive to UV light (and that should thus be eliminated easily with UV-based sterilization devices). Moreover, the lack of reports of infections associated with the cabins supports a lack of substantial threat in their microbial content. However, the combination of the presence in the cabins of some microbial pathogens and the presence of antibiotic resistant genes poses an obvious potential problem linked to horizontal gene transfer (Fig. 8 ). Methods Sample collection Dust samples from the inner and the outer surfaces of four UVA and UVB cabins were taken in June 2021, in the Dermatology Service of the Hospital General of Valencia, Spain. The cabins sampled were: 1) PUVA 700 Waldmann (Villingen-Schwenningen, Germany), 2) UV7001K UVA/UVB Waldmann (Villingen-Schwenningen, Germany), 3) and 4) UV7002 UVA/UVB Waldmann (Villingen-Schwenningen, Germany). Samples (in duplicate or triplicate) were obtained by scrubbing the surface with a sterile swab (FLOQSwabs TM hDNA Free, Copan Flock Technologies SRL, Brescia, Italy) and immediately stored in sterile tubes with 500 µL of Phosphate Buffer Saline (PBS) 1X until processed in the laboratory. Isolation of microbial strains Samples were thoroughly shaken with vortex. As most samples were very clear, suggesting a low microbial load, 20 µL of the direct suspensions were spread on Petri dishes in duplicate, on five different culture media: TSA (composition in g/L: 15.0 tryptone, 5.0 soya peptone, 5.0 sodium chloride, 15.0 agar), Nutrient Agar (composition in g/L: peptone 5.0, meat extract 3.0, agar 15.0), Columbia Blood (catalogue number: CM0331B, ThermoFisher Scientific Inc., Massachusetts, USA), R2A (composition in g/L: 1 peptone, 0.5 yeast extract, 0.5 dextrose, 0.5 soluble starch, 0.3 dipotassium phosphate, 0.05 magnesium phosphate, 0.3 sodium pyruvate, 15.0 agar) and Yeast Mold (composition in g/L: malt extract 3.0, yeast extract 3.0, dextrose/glucose 10.0, peptone soybean 5.0, agar 15.0). Samples were incubated at 25 and 37 °C for one week. Colonies were then selected according to morphological traits, such as colour or shape, and isolated independently by re-streaking on fresh media. When pure cultures were obtained, strains were cryopreserved as glycerol stocks (12 % glycerol in their isolation media) at -80 °C until required. Colony identification (16S rRNA/ITS gene sequencing) Microbial biomass from grown plates of pure cultures was suspended in 100 µL of Milli-Q sterile water. Cells were lysed by heat shock in two cycles of boiling-freezing steps. PCR was carried out for the taxonomic identification through 16S rRNA gene sequencing. Colony PCR and amplicon precipitation were carried out following the procedures previously described by Molina-Menor et al. (2021) [2]. Sequencing was performed with Sanger by Eurofins Genomics (Ebersberg, Germany). Trev tool (Staden Package, 2002) was used to manually edit 16S rRNA sequences in order to eliminate low-quality base calls. Sequences where then compared by EzBioCloud 16S rRNA BLAST tool to nucleotide databases. The sequences have been deposited under the GenBank/EMBL/DDBJ accession numbers OQ221901-OQ222055 (bacterial sequences) and OQ208835-OQ208843 (fungal sequences). Redundancy of the isolates was checked among the ones with the same identification that had been isolated from the same sample and media by Blast to Blast (https://blast.ncbi.nlm.nih.gov/Blast.cgi). The identifications are listed in Table S1. High-throughput 16S rRNA gene sequencing (metataxonomics) Total DNA extraction was carried out with the DNease PowerSoil kit (MO BIO laboratories, Carlsbad, CA, USA). In order to consider potential microbial contamination of the reagents used, two negative controls consisting of pure water, instead of samples, and processed with the same kit were included. Given that very low DNA concentrations were obtained, the amplification of the 16S rRNA gene through PCR was carried out following the protocol described by Molina-Menor et al. (2021) [2]. For those samples failing to be amplified with 16S rRNA gene primers, a PCR with ITS region primers ITS3 and ITS4 [92] was carried out under the following conditions: initial step at 95 °C for 5 min, followed by 30 cycles of 30 s at 94 °C for denaturation, 30 s at 53 °C for annealing and 30 s at 72 °C for elongation, and a final step of elongation of 5 min at 72 °C. Samples with a clear amplification band in the electrophoresis gel were selected for sequencing, ensuring the representation of all four cabins and sampling points (inside and outside). The samples selected consisted of: three samples from inside and two from outside cabin one, two samples from inside and two from outside cabin two, one sample from inside and one sample from outside cabin three, and one sample from inside and one sample from outside cabin four. Both sequencing (Illumina) and the bioinformatic analysis were carried out by Darwin Bioprospecting Excellence SL (Paterna, Spain). Rarefaction curves were plotted to check the sequencing depth (Figure S2). UV-radiation resistance assay Based on the microbial identifications, a subset of isolates was selected from the collection to further perform UV irradiation and antibiotic resistance assays (from now on, sub-collection). Isolates from the most represented taxa were selected considering to have (1) a wide diversity of genera tested for each surface and (2) species that were isolated both from the inside and outside of the cabins (Table S2). Liquid cell cultures of selected isolates were serially diluted in PBS to an OD 600 of 10 -4 /10 -5 in order to obtain isolated colonies after inoculation on R2A agar plates. Aliquots of 100 µl of the cultures were plated in triplicate. Two replicates were then exposed to UVC light for 15 s or 30 s, while the other replicate was the non-irradiated control. UVC irradiation was performed with a VILBER LOURMAT UV lamp emitting 354 nm light with an intensity of 340 mW/cm 2 at 15 cm of distance. Plates were incubated at 30 °C and colonies were counted 24 to 72 h post inoculation depending on each strain. Number of colonies in the irradiated plates were compared to the number of colonies in the control non-irradiated plates. Antibiotic resistance assay Minimum Inhibitory Concentration (MIC) tests were carried out with the commercial MIC Test Strip (MTS) by Liofilchem SRL (Roseto degli Abruzzi (TE), Italy). Amoxicillin*-clavulanic acid (2/1) (ref: 920240, 0.016-256 mg/L), azithromycin (ref: 920300, 0.016-256 mg/L), clindamycin (ref: 920720, 0.016-256 mg/L), doxycycline (ref: 921560, 0.016-256 mg/L), gentamicin (ref: 920090, 0.016-256 mg/L) and mupirocin (ref: 920380, 0.064-1024 mg/L) were selected among the antibiotics that are commonly used in the Dermatology Service of the Hospital General of Valencia (AMC: amoxicillin-clavulanic acid; AZM: azithromycin; CD: clindamycin; DXT: doxycycline; GEN: gentamycin; MUP: mupirocin). Growth on Mueller Hinton-agar media was tested prior to the assay in order to ensure that all the strains were able to grow on it. The experiment was carried out following the manufacturer’s instructions, using OD 600 instead of McFarland turbidity standards to assess cell concentration. For this, PBS cell-resuspensions for each strain were diluted to OD 600 0.1, 0.5 and 1, and 100 ml were plated on Mueller Hinton agar plates. We selected the dilution for inoculation for each strain based on confluent cell-growth after 24, 48 and 72 h incubation at 30 °C. MIC was registered 24 h, 48 h and 72 h for each sample. The quality check strains were Staphylococcus aureus (ATCC 29213 – WDCM 00131) for AZM, MUP and CD; and Escherichia coli ( ATCC25922 – WDCM 00013) for DXT, AMC and GEN. The strains were purchased from DSMZ (German Collection of Microorganisms and Cell Cultures, Leibniz Institute, Braunschweig, Germany). The MICs for control strains showed minor changes throughout the three days that lasted each replicate, but they were always inside the expected range as referred by the manufacturer. The results were interpreted following the manufacturer’s instructions, according to the European Committee on Antimicrobial Susceptibility testing (EUCAST) (EUCAST Clinical Breakpoint Tables v.12.0). Phylogenetic tree The 16S rRNA gene sequences of the type strains of the subcollection (Table S2) were retrieved from EzBioCloud (www.ezbiocloud.net). Phylogenetic analysis was carried out with MEGA11 software (v.11.0.13). Sequences were aligned with MUSCLE algorithm and the phylogenetic tree was constructed using the Neighbour Joining method [93]. The branch pattern reliability was checked with bootstrap analysis based on 100 replicates with nucleotide p-distance substitution model including transitions and transversion. Declarations ACKNOWLEDGMENTS We are thankful to Daniel Torrent and Adriel Latorre-Pérez from Darwin Bioprospecting Excellence SL for their assistance and help with the bioinformatic analysis. We thank Lorena Martínez and Cristina Calabuig for their help with the establishment and identification of the microbial collection. AUTHOR CONTRIBUTIONS E.M.M., A.P.F, G.P.P and M.P. conceived the work. E.M.M., N.C, À.V.V. carried out the experimental procedures. E.M.M., N.C, À.V.V, A.P.F, G.P. and M.P. analysed the results, wrote and approved the manuscript. All the authors agree to publish the manuscript. DATA AVAILABILITY STATEMENT The 16S rRNA gene sequences have been deposited under the GenBank/EMBL/DDBJ accession numbers OQ221901-OQ222055 (bacterial sequences) and OQ208835-OQ208843 (fungal sequences). ADDITIONAL INFORMATION EMM and ÀVV are funded with a Formación del Profesorado Universitario (FPU) fellowship from the Spanish Ministry of Universities, with references FPU17/04184 and FPU18/02578, respectively. NC is funded with MICRO4BIOGAS project (reference ID101000470, funded by European Union's Horizon 2020 research and innovation program). The authors declare no conflict of interest. References Shuryak I. (2019). Review of microbial resistance to chronic ionizing radiation exposure under environmental conditions. Journal of environmental radioactivity , 196 , 50–63. https://doi.org/10.1016/j.jenvrad.2018.10.012 Molina-Menor, E., Gimeno-Valero, H., Pascual, J., Peretó, J., & Porcar, M. (2021). High Culturable Bacterial Diversity From a European Desert: The Tabernas Desert. Frontiers in microbiology , 11 , 583120. https://doi.org/10.3389/fmicb.2020.583120 Tanner, K., et al. (2020). Extremophilic microbial communities on photovoltaic panel surfaces: a two-year study. Microb. Biotechnol. 13, 1819–1830. doi: 10.1111/1751-7915.13620 Ragon, M., Restoux, G., Moreira, D., Møller, A. P., & López-García, P. (2011). Sunlight-exposed biofilm microbial communities are naturally resistant to chernobyl ionizing-radiation levels. PloS one , 6 (7), e21764. https://doi.org/10.1371/journal.pone.0021764 Yu, L. Z., Luo, X. S., Liu, M., & Huang, Q. (2015). Diversity of ionizing radiation-resistant bacteria obtained from the Taklimakan Desert. Journal of basic microbiology , 55 (1), 135–140. https://doi.org/10.1002/jobm.201300390 Arrigoni, E., Antonielli, L., Pindo, M., Pertot, I., & Perazzolli, M. (2018). Tissue age and plant genotype affect the microbiota of apple and pear bark. Microbiological research , 211 , 57–68. https://doi.org/10.1016/j.micres.2018.04.002 Jaiaue, P., et al (2022). Mathematical Modeling for Evaluating Inherent Parameters Affecting UVC Decontamination of Indicator Bacteria. Applied and environmental microbiology , 88 (7), e0214821. https://doi.org/10.1128/aem.02148-21 Moore, G., et al. (2012). Use of UV-C radiation to disinfect non-critical patient care items: a laboratory assessment of the Nanoclave Cabin. BMC infectious diseases , 12 , 174. https://doi.org/10.1186/1471-2334-12-174 Cieplik, F., et al. (2018). Antimicrobial photodynamic therapy - what we know and what we don't. Critical reviews in microbiology , 44 (5), 571–589. https://doi.org/10.1080/1040841X.2018.1467876 Rezaie, A., et al. (2020). Ultraviolet A light effectively reduces bacteria and viruses including coronavirus. PloS one , 15 (7), e0236199. https://doi.org/10.1371/journal.pone.0236199 Wang, M., Ateia, M., Awfa, D., & Yoshimura, C. (2021). Regrowth of bacteria after light-based disinfection - What we know and where we go from here. Chemosphere , 268 , 128850. https://doi.org/10.1016/j.chemosphere.2020.128850 World Health Organization, WHO (9 th March 2016). Radiation: Ultraviolet (UV) radiation. https://www.who.int/news-room/questions-and-answers/item/radiation-ultraviolet-(uv) Hargreaves, A., Taiwo, F. A., Duggan, O., Kirk, S. H., & Ahmad, S. I. (2007). Near-ultraviolet photolysis of β-phenylpyruvic acid generates free radicals and results in DNA damage. Journal of Photochemistry and Photobiology B: Biology , 89 (2-3), 110-116 Madronich, S., Björn, L. O., and McKenzie, R. L. (2018). Solar UV radiation and microbial life in the athmosphere. Photochem. Photobiol. Sci ., 17, 1918. Battie, C., et al. (2014). New insights in photoaging, UVA induced damage and skin types. Experimental dermatology , 23 Suppl 1 , 7–12. https://doi.org/10.1111/exd.12388 Richa, Sinha, R. P., & Häder, D. P. (2015). Physiological aspects of UV-excitation of DNA. Topics in current chemistry , 356 , 203–248. https://doi.org/10.1007/128_2014_531 Johann To Berens, P., & Molinier, J. (2020). Formation and Recognition of UV-Induced DNA Damage within Genome Complexity. International journal of molecular sciences , 21 (18), 6689. https://doi.org/10.3390/ijms21186689 Llabrés, M., Agustí, S., Alonso-Laita, P., & Herndl, G. J. (2010). Synechococcus and Prochlorococcus cell death induced by UV radiation and the penetration of lethal UVR in the Mediterranean Sea. Marine Ecology Progress Series , 399 , 27-37. Rathod DG, Muneer H, Masood S. Phototherapy. [Updated 2022 Oct 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK563140/ Woodgate, P., & Jardine, L. A. (2015). Neonatal jaundice: phototherapy. BMJ clinical evidence, 2015, 0319. Bae, J. M., et al. (2017). Phototherapy for Vitiligo: A Systematic Review and Meta-analysis. JAMA dermatology , 153 (7), 666–674. https://doi.org/10.1001/jamadermatol.2017.0002 Torres, A. E., Lyons, A. B., Hamzavi, I. H., & Lim, H. W. (2021). Role of phototherapy in the era of biologics. Journal of the American Academy of Dermatology , 84 (2), 479–485. https://doi.org/10.1016/j.jaad.2020.04.095 Mancuso, G., Midiri, A., Gerace, E., & Biondo, C. (2021). Bacterial Antibiotic Resistance: The Most Critical Pathogens. Pathogens (Basel, Switzerland) , 10 (10), 1310. https://doi.org/10.3390/pathogens10101310 Coculescu, B.I. (2009). Antimicrobial resistance induced by genetic changes. J. Med. Life , 2 , 114–123. Collignon, P., & Beggs, J. J. (2019). Socioeconomic Enablers for Contagion: Factors Impelling the Antimicrobial Resistance Epidemic. Antibiotics (Basel, Switzerland) , 8 (3), 86. https://doi.org/10.3390/antibiotics8030086 Strich, J. R., & Palmore, T. N. (2017). Preventing Transmission of Multidrug-Resistant Pathogens in the Intensive Care Unit. Infectious disease clinics of North America , 31 (3), 535–550. https://doi.org/10.1016/j.idc.2017.05.010 ElRakaiby, M. T., Gamal-Eldin, S., Amin, M. A., & Aziz, R. K. (2019). Hospital Microbiome Variations As Analyzed by High-Throughput Sequencing. Omics: a journal of integrative biology , 23 (9), 426–438. https://doi.org/10.1089/omi.2019.0111 Chu, L., et al. (2020). Degradation of antibiotics and inactivation of antibiotic resistance genes (ARGs) in Cephalosporin C fermentation residues using ionizing radiation, ozonation and thermal treatment. Journal of hazardous materials , 382 , 121058. https://doi.org/10.1016/j.jhazmat.2019.121058 van Dijk, B., et al. (2020). Treating infections with ionizing radiation: a historical perspective and emerging techniques. Antimicrobial resistance and infection control , 9 (1), 121. https://doi.org/10.1186/s13756-020-00775-w Álvarez-Molina, A., et al. (2020). Selection for Antimicrobial Resistance in Foodborne Pathogens through Exposure to UV Light and Nonthermal Atmospheric Plasma Decontamination Techniques. Applied and environmental microbiology , 86 (9), e00102-20. https://doi.org/10.1128/AEM.00102-20 Dancer S. J. (2014). Controlling hospital-acquired infection: focus on the role of the environment and new technologies for decontamination. Clinical microbiology reviews , 27 (4), 665–690. https://doi.org/10.1128/CMR.00020-14 Oren, A., & Garrity, G. M. (2021). Valid publication of the names of forty-two phyla of prokaryotes. International journal of systematic and evolutionary microbiology , 71 (10), 10.1099/ijsem.0.005056. https://doi.org/10.1099/ijsem.0.005056 Byrd, A. L., Belkaid, Y., and Segre, J. A. (2018). The human skin microbiome. Nature reviews. Microbiology , 16 (3), 143–155. Tang, V. H., et al. (2013). Skin-associated Bacillus, staphylococcal and micrococcal species from the house dust mite, Dermatophagoides pteronyssinus and bacteriolytic enzymes. Experimental & applied acarology , 61 (4), 431–447. https://doi.org/10.1007/s10493-013-9712-8 Li, S. Y., et al. (2021). Arthrobacter woluwensis Bacteremia: A Clinical and Genomic Report. Pathogens (Basel, Switzerland) , 10 (4), 443. https://doi.org/10.3390/pathogens10040443 Nabal-Díaz, S., García-Lechuz Moya, J. M., Mormeneo Bayo, S., & Millán Lou, M. I. (2020). Arthrobacter creatinolyticus: An emerging human pathogen causing urinary tract infection. Enfermedades infecciosas y microbiologia clinica (English ed.) , 38 (2), 88–89. https://doi.org/10.1016/j.eimc.2019.02.003 Mages, I. S., Frodl, R., Bernard, K. A., & Funke, G. (2008). Identities of Arthrobacter spp. and Arthrobacter -like bacteria encountered in human clinical specimens. Journal of clinical microbiology , 46 (9), 2980–2986. https://doi.org/10.1128/JCM.00658-08 Stehlikova, Z., et al. (2019). Dysbiosis of Skin Microbiota in Psoriatic Patients: Co-occurrence of Fungal and Bacterial Communities. Frontiers in microbiology , 10 , 438. Ehling-Schulz, M., Lereclus, D., & Koehler, T. M. (2019). The Bacillus cereus Group: Bacillus Species with Pathogenic Potential. Microbiology spectrum , 7 (3), 10.1128/microbiolspec.GPP3-0032-2018. https://doi.org/10.1128/microbiolspec.GPP3-0032-2018 Ren, W., et al. (2022). Cross-habitat distribution pattern of Bacillus communities and their capacities of producing industrial hydrolytic enzymes in Paracel Islands: Habitat-dependent differential contributions of the environment. Journal of environmental management , 323 , 116252. https://doi.org/10.1016/j.jenvman.2022.116252 Asgarani, E., Soudi, M. R., Borzooee, F., & Dabbagh, R. (2012). Radio-resistance in psychrotrophic Kocuria sp. ASB 107 isolated from Ab-e-Siah radioactive spring. Journal of environmental radioactivity , 113 , 171–176. https://doi.org/10.1016/j.jenvrad.2012.04.009 Deng, W., et al. (2016). Radiation-Resistant Micrococcus luteus SC1204 and Its Proteomics Change Upon Gamma Irradiation. Current microbiology , 72 (6), 767–775. https://doi.org/10.1007/s00284-016-1015-y Liu, H., Xu, Y., Ma, Y., & Zhou, P. (2000). Characterization of Micrococcus antarcticus sp. nov., a psychrophilic bacterium from Antarctica. International journal of systematic and evolutionary microbiology , 50 Pt 2 , 715–719. https://doi.org/10.1099/00207713-50-2-715 Reddy, G. S. N., et al. (2003). Kocuria polaris sp. nov., an orange-pigmented psychrophilic bacterium isolated from an Antarctic cyanobacterial mat sample. International journal of systematic and evolutionary microbiology , 53 (Pt 1), 183–187. https://doi.org/10.1099/ijs.0.02336-0 Hu, Q. W., et al. (2016). Arthrobacter deserti sp. nov., isolated from a desert soil sample. International journal of systematic and evolutionary microbiology , 66 (5), 2035–2040. https://doi.org/10.1099/ijsem.0.000986 Ye, J. J., et al. (2020). Arthrobacter mobilis sp. nov., a novel actinobacterium isolated from Cholistan desert soil. International journal of systematic and evolutionary microbiology , 70 (10), 5445–5452. https://doi.org/10.1099/ijsem.0.004431 Saxena, A. K., Kumar, M., Chakdar, H., Anuroopa, N., & Bagyaraj, D. J. (2020). Bacillus species in soil as a natural resource for plant health and nutrition. Journal of applied microbiology , 128 (6), 1583–1594. https://doi.org/10.1111/jam.14506 Maslova, O., Mindlin, S., Beletsky, A., Mardanov, A., & Petrova, M. (2022). Plasmids as Key Players in Acinetobacter Adaptation. International journal of molecular sciences , 23 (18), 10893. https://doi.org/10.3390/ijms231810893 Silby, M. W., Winstanley, C., Godfrey, S. A., Levy, S. B., & Jackson, R. W. (2011). Pseudomonas genomes: diverse and adaptable. FEMS microbiology reviews , 35 (4), 652–680. https://doi.org/10.1111/j.1574-6976.2011.00269.x Zhao, W. H., & Hu, Z. Q. (2012). Acinetobacter: a potential reservoir and dispenser for β-lactamases. Critical reviews in microbiology , 38 (1), 30–51. https://doi.org/10.3109/1040841X.2011.621064 De Oliveira, D. M. P., et al. (2020). Antimicrobial Resistance in ESKAPE Pathogens. Clinical microbiology reviews , 33 (3), e00181-19. https://doi.org/10.1128/CMR.00181-19 Lee, K., Yong, D., Jeong, S. H., & Chong, Y. (2011). Multidrug-resistant Acinetobacter spp.: increasingly problematic nosocomial pathogens. Yonsei medical journal , 52 (6), 879–891. https://doi.org/10.3349/ymj.2011.52.6.879 Brooke J. S. (2012). Stenotrophomonas maltophilia : an emerging global opportunistic pathogen. Clinical microbiology reviews , 25 (1), 2–41. https://doi.org/10.1128/CMR.00019-11 Ioannou, P., Mavrikaki, V., & Kofteridis, D. P. (2020). Roseomonas species infections in humans: a systematic review. Journal of chemotherapy (Florence, Italy) , 32 (5), 226–236. https://doi.org/10.1080/1120009X.2020.1785742 Majidzadeh, M., & Fatahi-Bafghi, M. (2018). Current taxonomy of Rhodococcus species and their role in infections. European journal of clinical microbiology & infectious diseases: official publication of the European Society of Clinical Microbiology , 37 (11), 2045–2062. https://doi.org/10.1007/s10096-018-3364-x May, R. C., Stone, N. R., Wiesner, D. L., Bicanic, T., & Nielsen, K. (2016). Cryptococcus: from environmental saprophyte to global pathogen. Nature reviews. Microbiology , 14 (2), 106–117. https://doi.org/10.1038/nrmicro.2015.6 Dorado-Morales, P., et al. (2016). A highly diverse, desert-like microbial biocenosis on solar panels in a Mediterranean city. Scientific reports , 6 , 29235. https://doi.org/10.1038/srep29235 Lee, J. H., Jung, J. H., Kim, M. K., & Lim, S. (2022). Deinococcus taeanensis sp. nov., a Radiation-Resistant Bacterium Isolated from a Coastal Dune. Current microbiology , 79 (11), 334. https://doi.org/10.1007/s00284-022-03044-8 Verma, A., et al. (2017). Domibacillus mangrovi sp. nov. and Domibacillus epiphyticus sp. nov., isolated from marine habitats of the central west coast of India. International journal of systematic and evolutionary microbiology , 67 (8), 3063–3070. https://doi.org/10.1099/ijsem.0.002085 Walterson, A. M., & Stavrinides, J. (2015). Pantoea: insights into a highly versatile and diverse genus within the Enterobacteriaceae. FEMS microbiology reviews , 39 (6), 968–984. https://doi.org/10.1093/femsre/fuv027 Ali, G. A., Ibrahim, E. B., Doiphode, S. H., & Goravey, W. (2022). Massilia timonae bacteremia: An unusual pathogen of septic abortion. IDCases , 29 , e01592. https://doi.org/10.1016/j.idcr.2022.e01592 Bhatti, M. D., et al. (2017). Identification and Whole Genome Sequencing of the First Case of Kosakonia radicincitans Causing a Human Bloodstream Infection. Frontiers in microbiology , 8 , 62. https://doi.org/10.3389/fmicb.2017.00062 Morioka, H., et al. (2022). Lysinibacillus fusiformis bacteremia: Case report and literature review. Journal of infection and chemotherapy: official journal of the Japan Society of Chemotherapy , 28 (2), 315–318. https://doi.org/10.1016/j.jiac.2021.10.030 Verdecia, J., Jankowski, C. A., Reynolds, M. L., McCarter, Y., & Ravi, M. (2022). Fungemia due to Aureobasidium pullulans . Medical mycology case reports , 37 , 26–28. https://doi.org/10.1016/j.mmcr.2022.06.004 Baek, J. H., et al. (2022). Massilia soli sp. nov., isolated from soil. International journal of systematic and evolutionary microbiology , 72 (2), 10.1099/ijsem.0.005227. https://doi.org/10.1099/ijsem.0.005227 Li, C., et al. (2021). Massilia rhizosphaerae sp. nov., a rice-associated rhizobacterium with antibacterial activity against Ralstonia solanacearum . International journal of systematic and evolutionary microbiology , 71 (9), 10.1099/ijsem.0.005009. https://doi.org/10.1099/ijsem.0.005009 Arroyo, M. G., et al. (2020). Broad Diversity of Fungi in Hospital Water. TheScientificWorldJournal , 2020 , 9358542. https://doi.org/10.1155/2020/9358542 Oliveira W.F., et al. (2018). Staphylococcus aureus and Staphylococcus epidermidis infections on implants. J Hosp Infect. 98, 111-7 Miller, C. D., Mortensen, W. S., Braga, G. U., & Anderson, A. J. (2001). The rpoS gene in Pseudomonas syringae is important in surviving exposure to the near-UV in sunlight. Current microbiology , 43 (5), 374–377. https://doi.org/10.1007/s002840010319 Kämpfer, P., et al. (2000). Frigoribacterium faeni gen. nov., sp. nov., a novel psychrophilic genus of the family Microbacteriaceae. International journal of systematic and evolutionary microbiology , 50 Pt 1 , 355–363. https://doi.org/10.1099/00207713-50-1-355 Rampelotto, P.H., Sereia, A.F.R., de Oliveira, L.F.V., Margis, R. (2019) Exploring the Hospital Microbiome by High-Resolution 16S rRNA Profiling. Int. J. Mol. Sci , 20 , 3099 Chander, A. M., et al. (2017). Genome Sequence of Kocuria polaris Strain CD08_4, an Isolate from the Duodenal Mucosa of a Celiac Disease Patient. Genome announcements , 5 (43), e01158-17. https://doi.org/10.1128/genomeA.01158-17 Metwally, R. A., El-Sersy, N. A., El Sikaily, A., Sabry, S. A., & Ghozlan, H. A. (2022). Optimization and multiple in vitro activity potentials of carotenoids from marine Kocuria sp. RAM1. Scientific reports , 12 (1), 18203. https://doi.org/10.1038/s41598-022-22897-4 Tian, B., & Hua, Y. (2010). Carotenoid biosynthesis in extremophilic Deinococcus-Thermus bacteria. Trends in microbiology , 18 (11), 512–520. https://doi.org/10.1016/j.tim.2010.07.007 Lim, S., Jung, J. H., Blanchard, L., & de Groot, A. (2019). Conservation and diversity of radiation and oxidative stress resistance mechanisms in Deinococcus species. FEMS microbiology reviews , 43 (1), 19–52. https://doi.org/10.1093/femsre/fuy037 Hernández-Fernández, G., Galán, B., Carmona, M., Castro, L., & García, J. L. (2022). Transcriptional response of the xerotolerant Arthrobacter sp. Helios strain to PEG-induced drought stress. Frontiers in microbiology , 13 , 1009068. https://doi.org/10.3389/fmicb.2022.1009068 Romaniuk, K., Golec, P., & Dziewit, L. (2018). Insight Into the Diversity and Possible Role of Plasmids in the Adaptation of Psychrotolerant and Metalotolerant Arthrobacter spp. to Extreme Antarctic Environments. Frontiers in microbiology , 9 , 3144. https://doi.org/10.3389/fmicb.2018.03144 Flegler, A., & Lipski, A. (2021). The C 50 carotenoid bacterioruberin regulates membrane fluidity in pink-pigmented Arthrobacter species. Archives of microbiology , 204 (1), 70. https://doi.org/10.1007/s00203-021-02719-3 Tao, K., Noda, A., & Yonei, S. (1987). The roles of different excision-repair mechanisms in the resistance of Micrococcus luteus to UV and chemical mutagens. Mutation research , 183 (3), 231–239. https://doi.org/10.1016/0167-8817(87)90005-8 Zherebtsov, S. V., & Tomilin, N. V. (1982). The roles of different repair mechanisms in the ultraviolet resistance of Micrococcus luteus . Biochimica et biophysica acta , 698 (3), 295–302. https://doi.org/10.1016/0167-4781(82)90160-9 Di Capua, C., Bortolotti, A., Farías, M. E., & Cortez, N. (2011). UV-resistant Acinetobacter sp. isolates from Andean wetlands display high catalase activity. FEMS microbiology letters , 317 (2), 181–189. https://doi.org/10.1111/j.1574-6968.2011.02231.x Ghosh, A., Goyal, A., & Jain, R. K. (2007). Study of methanol-induced phenotypic changes in a novel strain of Acinetobacter lwoffii. Archives of microbiology , 188 (5), 533–539. https://doi.org/10.1007/s00203-007-0268-z Han, S. R., Kim, K. H., Ahn, D. H., Park, H., & Oh, T. J. (2016). Complete genome sequence of carotenoid-producing Microbacterium sp. strain PAMC28756 isolated from an Antarctic lichen. Journal of biotechnology , 226 , 18–19. https://doi.org/10.1016/j.jbiotec.2016.03.034 Reis-Mansur, M. C. P. P., et al. (2019). Carotenoids from UV-resistant Antarctic Microbacterium sp. LEMMJ01. Scientific reports , 9 (1), 9554. https://doi.org/10.1038/s41598-019-45840-6 Zhang, W., et al. (2010). Microbacterium radiodurans sp. nov., a UV radiation-resistant bacterium isolated from soil. International journal of systematic and evolutionary microbiology , 60 (Pt 11), 2665–2670. https://doi.org/10.1099/ijs.0.017400-0 Ellington, A. J., Bryan, N. C., Christner, B. C., & Reisch, C. R. (2021). Draft Genome Sequences of Actinobacterial and Betaproteobacterial Strains Isolated from the Stratosphere. Microbiology resource announcements , 10 (50), e0100921. https://doi.org/10.1128/MRA.01009-21 Eltwisy, H. O., Twisy, H. O., Hafez, M. H., Sayed, I. M., & El-Mokhtar, M. A. (2022). Clinical Infections, Antibiotic Resistance, and Pathogenesis of Staphylococcus haemolyticus . Microorganisms , 10 (6), 1130. https://doi.org/10.3390/microorganisms10061130 Kloos, W. E., et al. (1998). Staphylococcus hominis subsp. novobiosepticus subsp. nov., a novel trehalose- and N-acetyl-D-glucosamine-negative, novobiocin- and multiple-antibiotic-resistant subspecies isolated from human blood cultures. International journal of systematic bacteriology , 48 Pt 3 , 799–812. https://doi.org/10.1099/00207713-48-3-799 Lienen, T., et al. (2021). Multidrug-resistant Staphylococcus cohnii and Staphylococcus urealyticus isolates from German dairy farms exhibit resistance to beta-lactam antibiotics and divergent penicillin-binding proteins. Scientific reports , 11 (1), 6075. https://doi.org/10.1038/s41598-021-85461-6 Mendoza-Olazarán, S., et al. (2015). Antibiotic Susceptibility of Biofilm Cells and Molecular Characterisation of Staphylococcus hominis Isolates from Blood. PloS one, 10(12), e0144684. https://doi.org/10.1371/journal.pone.0144684 Jałowiecki, Ł.,et al. (2017). Using phenotype microarrays in the assessment of the antibiotic susceptibility profile of bacteria isolated from wastewater in on-site treatment facilities. Folia microbiologica , 62 (6), 453–461. https://doi.org/10.1007/s12223-017-0516-9 White, T., Bruns, T., Lee, S., Taylor, J. (1990). Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. PCR-protocols a guide to methods and applications. Edited by: Innis MA, Gelfand DH, Sninski JJ, White TJ. 1990, San Diego: Academic press, 315-322 Saitou N, Nei M. (1987). The neighbor-joining method: A new method for reconstructing phylogenetic trees. Mol Biol Evol, 4, 406–425 Additional Declarations No competing interests reported. Supplementary Files SUPPLEMENTARYMATERIALHVG.docx Cite Share Download PDF Status: Published Journal Publication published 04 Sep, 2023 Read the published version in Scientific Reports → Version 1 posted Editorial decision: Major revision 01 Aug, 2023 Reviews received at journal 15 Jul, 2023 Reviewers agreed at journal 24 Apr, 2023 Reviews received at journal 22 Apr, 2023 Reviewers agreed at journal 19 Apr, 2023 Reviewers invited by journal 19 Apr, 2023 Editor assigned by journal 19 Apr, 2023 Editor invited by journal 15 Apr, 2023 Submission checks completed at journal 15 Apr, 2023 First submitted to journal 11 Apr, 2023 You are reading this latest preprint version Research Square lets you share your work early, gain feedback from the community, and start making changes to your manuscript prior to peer review in a journal. As a division of Research Square Company, we’re committed to making research communication faster, fairer, and more useful. We do this by developing innovative software and high quality services for the global research community. Our growing team is made up of researchers and industry professionals working together to solve the most critical problems facing scientific publishing. Also discoverable on Platform About Our Team In Review Editorial Policies Advisory Board Help Center Resources Author Services Accessibility API Access RSS feed Manage Cookie Preferences © Research Square 2026 | ISSN 2693-5015 (online) Privacy Policy Terms of Service Do Not Sell My Personal Information {"props":{"pageProps":{"initialData":{"identity":"rs-2800931","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Article","associatedPublications":[],"authors":[{"id":192055967,"identity":"a86498ec-61c9-4fde-8698-e0c75980ef22","order_by":0,"name":"Esther Molina-Menor","email":"","orcid":"","institution":"University of Valencia","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Esther","middleName":"","lastName":"Molina-Menor","suffix":""},{"id":192055968,"identity":"8ec18fac-bc94-4995-b35c-c95e4c65e4f4","order_by":1,"name":"Nicolás Carlotto","email":"","orcid":"","institution":"University of Valencia","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Nicolás","middleName":"","lastName":"Carlotto","suffix":""},{"id":192055969,"identity":"c3173153-1de4-4540-9e87-c216b16c64fd","order_by":2,"name":"Àngela Vidal-Verdú","email":"","orcid":"","institution":"University of Valencia","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Àngela","middleName":"","lastName":"Vidal-Verdú","suffix":""},{"id":192055970,"identity":"6b312399-73d3-4be7-a540-ee26c8af68ef","order_by":3,"name":"Amparo Pérez-Ferriols","email":"","orcid":"","institution":"Consorcio Hospital General de Valencia","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Amparo","middleName":"","lastName":"Pérez-Ferriols","suffix":""},{"id":192055971,"identity":"831f2fed-4c5e-4101-8311-c5f922f0f372","order_by":4,"name":"Gemma Pérez-Pastor","email":"","orcid":"","institution":"Consorcio Hospital General de Valencia","correspondingAuthor":false,"submittingAuthor":false,"prefix":"","firstName":"Gemma","middleName":"","lastName":"Pérez-Pastor","suffix":""},{"id":192055972,"identity":"2c04eb1b-b94f-4d6e-9f9b-fedb935b1879","order_by":5,"name":"Manuel Porcar","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA0UlEQVRIiWNgGAWjYNCCAhijgmgtBjDGGZK1MLYRoVi3/ewxiQ8GDHn80ocffq6cdzixgb39AV4tZmfy0iRnGDAUS/alGUue3QbUwnPGAL+WAzlm0jwGDIkbzvAwSDZuO2zMIJGD32Fm59+YSf+BaGH+2TgHqEX+OQGH3QDawgDRwibZ2HBYjkGCgYDDbrwxtuwxkCiW7GEzs2w4li7HxpNDQMv5HMMbPyps8vh5mB/fbKix5uFnP47fYVAgkQBnshGjHgQSCKoYBaNgFIyCkQsARdI+zEsJz2wAAAAASUVORK5CYII=","orcid":"","institution":"University of Valencia","correspondingAuthor":true,"submittingAuthor":false,"prefix":"","firstName":"Manuel","middleName":"","lastName":"Porcar","suffix":""}],"badges":[],"createdAt":"2023-04-11 08:14:36","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-2800931/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-2800931/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1038/s41598-023-40996-8","type":"published","date":"2023-09-04T15:02:20+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":35896382,"identity":"5c235328-48da-4a04-9fee-3e12b80fce3f","added_by":"auto","created_at":"2023-04-17 21:18:13","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":263979,"visible":true,"origin":"","legend":"\u003cp\u003eCulturable microbial diversity. A) Histogram showing the number of strains isolated from inside (blue) and outside (yellow) the cabins. The genera are listed in alphabetical order. Non-identified isolates (NID) are also included. B) Lineplot representing the number of strains isolated from inside (green) and outside (orange) from the most abundant to the less abundant.\u003c/p\u003e","description":"","filename":"Onlinefloatimage1.png","url":"https://assets-eu.researchsquare.com/files/rs-2800931/v1/336dca8307efd10f85bb20fb.png"},{"id":35896386,"identity":"e16a4dda-d5b4-4106-a189-9f7cb5a4e6b5","added_by":"auto","created_at":"2023-04-17 21:18:13","extension":"png","order_by":2,"title":"Figure 2","display":"","copyAsset":false,"role":"figure","size":159892,"visible":true,"origin":"","legend":"\u003cp\u003eVenn diagram showing the exclusive and shared cultured genera isolated from inside and outside the cabins.\u003c/p\u003e","description":"","filename":"Onlinefloatimage2.png","url":"https://assets-eu.researchsquare.com/files/rs-2800931/v1/93229163d3b84dd59a4cf678.png"},{"id":35896381,"identity":"e1bde8cb-aeab-4a99-97da-c3638ca015c9","added_by":"auto","created_at":"2023-04-17 21:18:13","extension":"png","order_by":3,"title":"Figure 3","display":"","copyAsset":false,"role":"figure","size":73304,"visible":true,"origin":"","legend":"\u003cp\u003eMicrobial diversity in the cabins. A) α-diversity at the ASV level (clones) observed through Wilcoxon test and measured by Shannon and Simpson indexes. B) PCoA showing the β-diversity of the samples from four different cabins both from inner and outer surfaces. Control samples corresponding to the DNA extraction kits used are included.\u003c/p\u003e","description":"","filename":"Onlinefloatimage3.png","url":"https://assets-eu.researchsquare.com/files/rs-2800931/v1/06c85a5d99b24dad62675e5e.png"},{"id":35896383,"identity":"c787ca2d-1dba-4c64-bd8e-e4db53d9cfbb","added_by":"auto","created_at":"2023-04-17 21:18:13","extension":"png","order_by":4,"title":"Figure 4","display":"","copyAsset":false,"role":"figure","size":104370,"visible":true,"origin":"","legend":"\u003cp\u003eRelative abundances (%) of bacteria in the sampled cabins as deduced by high-throughput 16S rRNA gene sequencing. A) Relative abundances at the phylum level. B) Relative abundances at the genus level.\u003c/p\u003e","description":"","filename":"Onlinefloatimage4.png","url":"https://assets-eu.researchsquare.com/files/rs-2800931/v1/ebee1d850e10d48306b2d6ab.png"},{"id":35896920,"identity":"ed949aa3-b6fe-435e-b2f6-ad67e230ac69","added_by":"auto","created_at":"2023-04-17 21:26:13","extension":"png","order_by":5,"title":"Figure 5","display":"","copyAsset":false,"role":"figure","size":188781,"visible":true,"origin":"","legend":"\u003cp\u003eRelative abundances (%) at the genus level of specific taxa based on their abundance and relevance for the study. A) Abundance of Rubellimicrobium. B) Abundance of Paracoccus. C) Abundance of Staphylococcus. D) Abundance of Pseudomonas. E) Abundance of Micrococcus. F) Abundance of Kocuria.\u003c/p\u003e","description":"","filename":"Onlinefloatimage5.png","url":"https://assets-eu.researchsquare.com/files/rs-2800931/v1/c523f0f45c77d444aac1074f.png"},{"id":35896384,"identity":"fb8afa11-4e51-4f5d-baa3-7145b3f5745d","added_by":"auto","created_at":"2023-04-17 21:18:13","extension":"png","order_by":6,"title":"Figure 6","display":"","copyAsset":false,"role":"figure","size":295628,"visible":true,"origin":"","legend":"\u003cp\u003eSurvival rate of bacterial isolates after UV-irradiation treatment. A) Lineplots showing the survival rate of cell suspensions for each of the selected isolates. Results for isolates of the same species that were taken from the inside and the outside of the UV cabins are plotted in the same facets to facilitate the comparison. The mean is depicted with a circle and standard deviation is depicted with vertical black lines. t-tests for the difference of the mean to a theoretical survival rate value of 1 were performed for 15 s and 30 s groups. Significance is stated as filled circles for p\u0026lt;0.05. B-C) Survival rate of all the strains for treatments with 15 s (B) or 30 s (C) exposure to UV irradiation. Kruskal Wallis test was performed to assess the differences among all the survival rates. Each dot represents a replicate, while the black columns represent the average. Isolates with the same letter above the column are not statistically different (p≥0.05). Isolates taken both outside and inside samples are underlined. Results for all the panels were obtained from 4 replicates for each isolate.\u003c/p\u003e","description":"","filename":"Onlinefloatimage6.png","url":"https://assets-eu.researchsquare.com/files/rs-2800931/v1/7ec7c84d5492c62a3b0b1281.png"},{"id":35896387,"identity":"a0a54205-c0c7-4799-998e-04f4cc6d2d49","added_by":"auto","created_at":"2023-04-17 21:18:13","extension":"png","order_by":7,"title":"Figure 7","display":"","copyAsset":false,"role":"figure","size":667906,"visible":true,"origin":"","legend":"\u003cp\u003eMinimum Inhibitory Concentration (MIC) test strips (MTSs) displaying the resistance of bacterial isolates to antibiotics commonly used in the Dermatology Service of the HGUV. A) Amoxicillin clavulanic acid (AMC). B) Doxycycline (DXT). C) Gentamicin (GEN). D) Mupirocin (MUP). E) Azithromycin (AZM). F) Clindamycin (CD). Kruskal Wallis test was performed to assess for differences among MIC values. Each dot represents a replicate, while the number over the dots states the median value for each isolate. Isolates with the same letter above the column are not statistically different from each other (p≥0.05). Isolates taken both from outside and inside the cabins are underlined. Reference strains are depicted with black dots. Expected MIC range for reference strains in µg/ml: AMC 2 – 8; MUP 0.06 – 0.25; CD 0.06 – 0.25; AZM 0.5 – 2; GEN 0.25 – 1; DXT 0.5 – 2. Results for MTSs were obtained from 3 replicates for each isolate.\u003c/p\u003e","description":"","filename":"Onlinefloatimage7.png","url":"https://assets-eu.researchsquare.com/files/rs-2800931/v1/4da7e0c496b6cffd489a8562.png"},{"id":35896388,"identity":"ec64eb16-c59d-4878-b995-8946c5de8724","added_by":"auto","created_at":"2023-04-17 21:18:13","extension":"png","order_by":8,"title":"Figure 8","display":"","copyAsset":false,"role":"figure","size":258071,"visible":true,"origin":"","legend":"\u003cp\u003eHeatmap assessing correlating the phylogenetic distance of bacterial isolates and the results of biological tests (15 s of UV irradiation and antibiotic MIC tests). UV-resistance is divided in to five categories based on non-overlapping significance groups from figure 6. MIC values are divided into five categories based on non-overlapping significance groups from figure 7. Figures and significance groups [very high - high - medium - low - very low]: UV Fig 6B [ab - e - XX - h - kl], AMC Fig 8A [a - de - ghij - l - n], DXT Fig 8B [ab - XX - c - XX - fh], GEN Fig 8C [a - e - hi - k - mn], MUP Fig 8D [ab - cde - g - i - kl ], AZM Fig 8E [ab - d - XX - f - hk], CD Fig 8F [ab - e - XX - h - kl]. XX depicts non-used classification level.\u003c/p\u003e","description":"","filename":"Onlinefloatimage8.png","url":"https://assets-eu.researchsquare.com/files/rs-2800931/v1/d0223f202733754f0f750c34.png"},{"id":42947363,"identity":"00a14a6d-abfa-486e-af30-bbf3047ff9da","added_by":"auto","created_at":"2023-09-11 15:08:44","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2259255,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-2800931/v1/b6bb26f7-c176-4479-a294-4180872fa3de.pdf"},{"id":35896389,"identity":"d4896890-ab15-4ef1-b8ff-44f6a722e147","added_by":"auto","created_at":"2023-04-17 21:18:13","extension":"docx","order_by":2,"title":"","display":"","copyAsset":false,"role":"supplement","size":3754220,"visible":true,"origin":"","legend":"","description":"","filename":"SUPPLEMENTARYMATERIALHVG.docx","url":"https://assets-eu.researchsquare.com/files/rs-2800931/v1/655d8d79bf6c1ce45ed8cdf6.docx"}],"financialInterests":"No competing interests reported.","formattedTitle":"Microbial communities on UV cabins in the dermatology service of a Spanish hospital: ecology and resistance to UV light and antibiotics","fulltext":[{"header":"Introduction","content":"\u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eMicroorganisms (not only bacteria and archaea, but also eukaryotes) can resist both ultraviolet radiation and high doses of ionizing radiation [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e]. UV-resistant organisms are widely distributed in many ecosystems, but they are particularly frequent on sun-irradiated environments such as building surfaces, deserts or solar panels [\u003cspan additionalcitationids=\"CR3\" citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR4\" class=\"CitationRef\"\u003e4\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eRadiation-resistant bacteria belong to different taxonomic groups. Although some clades are known by their natural resistance to radiation and high temperatures, such as the \u003cem\u003eDeinococcocota\u003c/em\u003e phylum (former \u003cem\u003eDeinococcus-Thermus\u003c/em\u003e), radiation-resistant bacteria are also represented in \u003cem\u003ePseudomonadota\u003c/em\u003e, \u003cem\u003eBacillota\u003c/em\u003e, \u003cem\u003eActinomycetota\u003c/em\u003e or \u003cem\u003eBacteroidota\u003c/em\u003e, previously \u003cem\u003eProteobacteria\u003c/em\u003e, \u003cem\u003eFirmicutes\u003c/em\u003e, \u003cem\u003eActinobacteria\u003c/em\u003e and \u003cem\u003eBacteroidetes\u003c/em\u003e, respectively [\u003cspan citationid=\"CR5\" class=\"CitationRef\"\u003e5\u003c/span\u003e]. In addition to their general non-pathogenic condition, they can even contribute to other organisms, such as plants, fighting pathogenic microorganisms [\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e].\u003c/p\u003e \u003cp\u003ePathogenic bacteria, in particular those causing health problems to humans and other animals, show different sensitivities to UV radiation [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. In fact, irradiation is used as an antimicrobial strategy in different laboratory and hospital devices such as UV sterilization lamps and microbiology cabins [\u003cspan citationid=\"CR8\" class=\"CitationRef\"\u003e8\u003c/span\u003e]. Besides, UV light and other light-based strategies have been also proposed as potential strategies to treat microbial infections in patients [\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. However, UV sterilization has some limits as its efficiency depends on factors such as microbial species and state of cultures, or the nature of the surfaces, among others [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e, \u003cspan citationid=\"CR11\" class=\"CitationRef\"\u003e11\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eUV light covers the spectrum wavelength between 100 and 400 nm. It can be further subdivided into three regions: UVA (315\u0026ndash;400 nm), UVB (280\u0026ndash;315 nm) and UVC (100\u0026ndash;280 nm) [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e]. Each UV light range has a different effect on living organisms, being UVC the most energetic, and thus dangerous, radiation. However, solar radiation that reaches the Earth\u0026rsquo;s surface is UVB and UVA, as UVC is absorbed by the atmosphere [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e]. Although UVB is also mainly filtered, the small fraction that gets to the surface causes different deleterious effects on the organisms, such as skin tanning and sunburns in animals. UVB light is directly absorbed by DNA molecules causing mutations, which is associated with the development of several types of skin cancer. Moreover, it is major responsible of killing airborne bacteria subjected to sunlight [\u003cspan citationid=\"CR14\" class=\"CitationRef\"\u003e14\u003c/span\u003e]. In contrast, UVA light is the most penetrating one and represents 95% of the UV light that reaches our planet\u0026rsquo;s surface. Its penetrating power has an impact on photoaging, but it can also contribute to DNA damage by interacting with already existing photoproducts [\u003cspan citationid=\"CR13\" class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan citationid=\"CR15\" class=\"CitationRef\"\u003e15\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe damaging effects of UV light is both direct (changes in biomolecules) and indirect, via the increase in reactive oxygen species (ROS). It includes changes in DNA, such as the formation of pyrimidine dimers, but also structural changes in proteins, lipids, and physiological stress that leads to loss of cell viability [\u003cspan additionalcitationids=\"CR17\" citationid=\"CR16\" class=\"CitationRef\"\u003e16\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR18\" class=\"CitationRef\"\u003e18\u003c/span\u003e]. Interestingly, and beyond the antiseptic effect of UV treatment described above, both UVB and UVA, at controlled doses, can be used for therapeutic purposes to treat cutaneous affections.\u003c/p\u003e \u003cp\u003ePhototherapy is the controlled use of light of different wavelengths to treat health problems, mostly skin disorders [\u003cspan citationid=\"CR19\" class=\"CitationRef\"\u003e19\u003c/span\u003e]. It is commonly used in new-borns developing jaundice, to treat the accumulation of bilirubin [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e20\u003c/span\u003e], but also in the treatment of psoriasis, chronic eczema, mycosis fungoides or vitiligo, among other diseases [\u003cspan citationid=\"CR21\" class=\"CitationRef\"\u003e21\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR22\" class=\"CitationRef\"\u003e22\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAntimicrobial resistance, AMR, has risen as one of the main threats for global health. Specifically, the World Health Organization (WHO) estimates that by 2050, around 10\u0026nbsp;million people will die from infections with no available treatments [\u003cspan citationid=\"CR23\" class=\"CitationRef\"\u003e23\u003c/span\u003e]. Although the selection of resistances is a natural phenomenon resulting from the imposed selective pressure of using antibiotics, their abuse and misuse, among other factors, has accelerated their spread [\u003cspan citationid=\"CR24\" class=\"CitationRef\"\u003e24\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR25\" class=\"CitationRef\"\u003e25\u003c/span\u003e]. Specifically, hospitals and intensive care units (ICUs) represent environments in which the risk of acquiring nosocomial multidrug resistant infections increases [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e]. The systematic use of antibiotics in hospital environments, in addition to the abundance of more susceptible patients, favours the spread of AMR among microorganisms [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe studies regarding AMR and radiation mainly focus on the effect of IR on the degradation of both antibiotic products and the inactivation of gene synthesis [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e28\u003c/span\u003e], or the treatment of infections with specific IR [\u003cspan citationid=\"CR29\" class=\"CitationRef\"\u003e29\u003c/span\u003e]. Although there is some evidence that the use of radiation may favour the selection of antibiotic resistant bacteria, there are no previous reports on their study in phototherapy services [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eIn the present work, we aimed at studying the microbial diversity in a previously unreported niche: therapeutic UV light hospital cabins, and to explore whether there is a link between the origin of the samples (taken either inside or outside the cabins) and UV resistance. Additionally, we have explored the co-occurrence of UV resistance and antibiotic resistance. Such co-occurrence may be of special interest in order to inform UV-based antimicrobial and disinfection policies in hospital facilities [\u003cspan citationid=\"CR26\" class=\"CitationRef\"\u003e26\u003c/span\u003e, \u003cspan citationid=\"CR31\" class=\"CitationRef\"\u003e31\u003c/span\u003e].\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e"},{"header":"Results","content":"\u003cdiv id=\"Sec3\" class=\"Section2\"\u003e \u003ch2\u003eEcology and microbial diversity\u003c/h2\u003e \u003cdiv id=\"Sec4\" class=\"Section3\"\u003e \u003ch2\u003eCulturable microbial collection and identification\u003c/h2\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eThe establishment of a microbial collection resulted in the isolation of 169 strains. A total of 164 isolates were identified, of which 155 corresponded to bacterial species. The identification through 16S rRNA gene or ITS sequence sequencing revealed that the isolates belonged to 44 different genera, among which the genera \u003cem\u003eStaphylococcus\u003c/em\u003e (29 isolates), \u003cem\u003eKocuria\u003c/em\u003e (17 isolates), \u003cem\u003eMicrococcus\u003c/em\u003e (17 isolates) and \u003cem\u003ePseudomonas\u003c/em\u003e (11 isolates) were the most abundant ones. In contrast, genera \u003cem\u003eErwinia\u003c/em\u003e, \u003cem\u003eFredinandcohnia\u003c/em\u003e, \u003cem\u003eLysinibacillus\u003c/em\u003e, \u003cem\u003eMixta\u003c/em\u003e, \u003cem\u003eMoraxella\u003c/em\u003e, \u003cem\u003ePeribacillus\u003c/em\u003e, \u003cem\u003ePseudoxanthomonas\u003c/em\u003e, \u003cem\u003eRhodococcus\u003c/em\u003e, \u003cem\u003eRobertmurraya\u003c/em\u003e, \u003cem\u003eRoseomonas\u003c/em\u003e, \u003cem\u003ePantoea\u003c/em\u003e, \u003cem\u003ePsychrobacillus\u003c/em\u003e, \u003cem\u003eDomibacillus\u003c/em\u003e, \u003cem\u003eKosakonia\u003c/em\u003e, \u003cem\u003eUstilago\u003c/em\u003e, \u003cem\u003eCryptococcus\u003c/em\u003e, \u003cem\u003eCystobasidium\u003c/em\u003e and \u003cem\u003eRhodotorula\u003c/em\u003e were just represented by one isolate each (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA and \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eB).\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eTaking into consideration the isolation source, 81 isolates originating from the inner surface of the cabins, being \u003cem\u003eStaphylococcus\u003c/em\u003e (17 isolates) the most abundant genera. In contrast, 88 microbial isolates came from the outer surface of the cabins, among which \u003cem\u003eStaphylococcus\u003c/em\u003e (12 isolates), \u003cem\u003ePseudomonas\u003c/em\u003e (11 isolates) and \u003cem\u003eKocuria\u003c/em\u003e (10 isolates) were the most abundant ones. Moreover, 14 genera were exclusively isolated from each location (inside and outside), whereas 16 were common for both sampling sites (Fig.\u0026nbsp;\u003cspan refid=\"Fig2\" class=\"InternalRef\"\u003e2\u003c/span\u003e). However, it has to be stressed that most of the \u0026ldquo;exclusive\u0026rdquo; taxa were represented by just one isolate, with the exception of \u003cem\u003ePseudomonas\u003c/em\u003e spp. When comparing the cabins, the four most abundant genera (\u003cem\u003eStaphylococcus\u003c/em\u003e, \u003cem\u003eKocuria\u003c/em\u003e, \u003cem\u003eMicrococcus\u003c/em\u003e and \u003cem\u003ePseudomonas\u003c/em\u003e), as well as \u003cem\u003eBacillus\u003c/em\u003e, were isolated from all of them and cabin two was the one with the highest number of exclusive taxa (11) regardless of the isolation source (Figure \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003eC). However, the exclusivity inside and outside was similar (Figures \u003cspan refid=\"MOESM1\" class=\"InternalRef\"\u003eS1\u003c/span\u003eA and S1B).\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec5\" class=\"Section3\"\u003e \u003ch2\u003eNext Generation Sequencing: high-throughput 16S rRNA gene sequencing\u003c/h2\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eThree different α-diversity indexes were calculated: richness, Shannon index and Simpson index. Richness refers to the total number of amplicon sequence variants (ASVs, or clones), Shannon measures the number of different taxa and their abundances, whereas Simpson quantifies how the sequences are distributed among ASV. That is, the number of bacteria per ASV. Although the α-diversity (ASV level) was higher in the samples from the outside than from the inside of the cabins, the Wilcoxon test did not find significant differences given the low number of replicates from each cabin and location. Similarly, the Shannon and Simpson indexes revealed higher diversity values for the outside of cabins two, three and four, but again, these results were not significantly different (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA, Figures S3A and S3B).\u003c/p\u003e \u003cp\u003eThe representation of the β-diversity in a principal component analysis (PCoA) showed that the outer surfaces of the cabins displayed higher similarities than the inner surfaces among cabins. Moreover, samples from both the inside and the outside of cabins one and two were similar in terms of microbial composition but plotted separately in the PCoA (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eB). The PERMANOVA test confirmed that the microbiomes were significantly different both between cabins and sample locations.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eAt the phylum level (updated according to the new nomenclature for prokaryotic phyla [\u003cspan citationid=\"CR32\" class=\"CitationRef\"\u003e32\u003c/span\u003e], all the samples displayed similar bacterial profiles, with \u003cem\u003ePseudomonadota\u003c/em\u003e, \u003cem\u003eActinomycetota\u003c/em\u003e and \u003cem\u003eBacillota\u003c/em\u003e as the predominant taxa. Moreover, \u003cem\u003eCyanobacteriota\u003c/em\u003e and \u003cem\u003eBacteroidota\u003c/em\u003e were also abundant, although not in the case of sample C4D1 (inside of cabin four) (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eA and Figure S4A), in which \u003cem\u003eBacillota\u003c/em\u003e was the predominant phylum. However, none of the phyla was statistically more abundant in any of the cabins or locations (inside/outside) according to the DESeq2 test.\u003c/p\u003e \u003cp\u003eAt the genus level, the most similar cabins in terms of bacterial composition were cabin one and two. The genera \u003cem\u003eStaphylococcus\u003c/em\u003e, \u003cem\u003eRubellimicrobium\u003c/em\u003e and \u003cem\u003eParacoccus\u003c/em\u003e were especially abundant there. Moreover, \u003cem\u003ePseudomonas\u003c/em\u003e, \u003cem\u003eKocuria\u003c/em\u003e, \u003cem\u003eSphingomonas\u003c/em\u003e and \u003cem\u003eCorynebacterium\u003c/em\u003e were among the most abundant ones in the majority of the samples. Samples C1D3 (inside of cabin one), C3D1 (inside of cabin three) and C4D1 (inside of cabin four) were the most different ones (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eB). In C1D3 there was a significant higher abundance of an unknown genus within the order \u003cem\u003eEnterobacterales\u003c/em\u003e. In C3D1 there was higher abundance of \u003cem\u003ePseudomonas\u003c/em\u003e and an uncultured genus within the order \u003cem\u003eCyanobateriales\u003c/em\u003e. In C4D1 \u003cem\u003eHalomonas\u003c/em\u003e was especially overrepresented, whereas \u003cem\u003eMelittangium\u003c/em\u003e was characteristic for samples of cabin two (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eB and Figure S4B). Furthermore, some genera were significantly more abundant outside the cabins, such as \u003cem\u003eOligella\u003c/em\u003e, \u003cem\u003eSerratia\u003c/em\u003e, \u003cem\u003eCobetia\u003c/em\u003e and \u003cem\u003eCarnobacterium\u003c/em\u003e, whereas only \u003cem\u003eProvidencia\u003c/em\u003e was more abundant inside them according to a DESeq2 test.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eGiven the previous experience in irradiated environments, the knowledge on the natural skin microbiota, and the abundances found in the previous experiments, a selection of relevant taxa was analysed in order to determine whether there were differences in their distribution inside and outside. Moreover, the abundances of the top ten abundant genera were also plotted. That is, in alphabetical order, the genera \u003cem\u003eCorynebacterium\u003c/em\u003e, \u003cem\u003eDeinococcus\u003c/em\u003e, \u003cem\u003eHymenobacter\u003c/em\u003e, \u003cem\u003eKocuria\u003c/em\u003e, \u003cem\u003eMicrococcus\u003c/em\u003e, \u003cem\u003eParacoccus\u003c/em\u003e, \u003cem\u003ePseudomonas\u003c/em\u003e, \u003cem\u003eRubellimicrobium\u003c/em\u003e, \u003cem\u003eSphingomonas\u003c/em\u003e and \u003cem\u003eStaphylococcus\u003c/em\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003e and Figure S5). None of the studied genera revealed any significant difference on the distribution among locations, except for \u003cem\u003eStaphylococcus\u003c/em\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eC). Although \u003cem\u003eDeinococcus\u003c/em\u003e was more abundant on the inner surfaces, these results were not significant according to the Wilcoxon test (Figure S5A). This tendency was also observed in the case of \u003cem\u003eSphingomonas\u003c/em\u003e (Figure S5D).\u003c/p\u003e \u003cp\u003eFinally, in order to identify the most frequent species within \u003cem\u003eStaphylococcus\u003c/em\u003e, successive BLAST were performed with the most abundant ASV. Among the 61 ASV identified as \u003cem\u003eStaphylococcus\u003c/em\u003e, \u003cem\u003eS. epidermitis\u003c/em\u003e and \u003cem\u003eS. aureus\u003c/em\u003e were between the ten more abundant species, along with \u003cem\u003eS. caprae\u003c/em\u003e, \u003cem\u003eS. capitis\u003c/em\u003e, \u003cem\u003eS. cohnii\u003c/em\u003e, and \u003cem\u003eS. haemolyticus\u003c/em\u003e.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec6\" class=\"Section3\"\u003e \u003ch2\u003eBiological activity assays\u003c/h2\u003e \u003cdiv id=\"Sec7\" class=\"Section4\"\u003e \u003ch2\u003eUV-radiation resistance assay\u003c/h2\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eThe resistance to UV irradiation of the isolates from the subset of the microbial collection (Table S2) was assessed by quantifying the colony forming units (CFU) after treatments with 15 s and 30 s of exposure to UV. The survival rates were calculated by dividing the number of CFUs after irradiation between the CFUs observed in a non-exposed control replicate. Survival rates values close to 1 represented a high resistance to UV whereas close to 0 a low resistance to UV (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eA).\u003c/p\u003e \u003cp\u003eFrom the strains that were exclusively isolated inside the cabins, \u003cem\u003eKocuria polaris\u003c/em\u003e was the only one not showing a significant decrease of survival after 15 s of UV exposure. However, 30 s of exposure resulted in a sharp and significant decrease, with a survival rate close to 0. In contrast, Acinetobacter variabilis and Microbacterium esteraromaticum showed a linear decrease in the survival rate, with values after 15 s and 30 s close to 0.5 and 0 respectively, whereas, the survival rates of Frigoribacterium faeni, Lysinibacterium halotolerans, Paracoccus panacisoli and S. epidermitiss, showed a marked reduction to almost 0 after 15 s exposure to UV, revealing a high susceptibility to UV exposure.\u003c/p\u003e \u003cp\u003eFrom the strains that were exclusively isolated outside the cabins, there were two of them showing no significant decrease of survival rate after 15 s exposure to UV: \u003cem\u003eArthrobacter agilis\u003c/em\u003e and \u003cem\u003eDeinococcus ficus\u003c/em\u003e. Although 30 s exposure to UV led to a significant decrease in the survival rate, these two isolates showed a difference from \u003cem\u003eK. polaris\u003c/em\u003e as the values were not close to 0, suggesting a mid-resistance to the treatment. This was especially evident for \u003cem\u003eD. ficus\u003c/em\u003e with a survival rate at 30 s higher than 0.75. The rest of the group formed by \u003cem\u003eKocuria palustris\u003c/em\u003e, \u003cem\u003ePriestia aryabhattai\u003c/em\u003e, \u003cem\u003ePseudomonas stutzeri\u003c/em\u003e, \u003cem\u003eS. haemolyticus\u003c/em\u003e and \u003cem\u003eStenotrophomonas rhizophila\u003c/em\u003e showed survival rates significantly different to the control and with values close to 0 even with 15 s of UV exposure.\u003c/p\u003e \u003cp\u003eRegarding the species that were isolated both inside and outside the cabins, all of them showed a similar output comparing the lineplot of the inside isolate to the outside isolate, revealing similar resistance patterns. The only exception was \u003cem\u003eMicrococcus luteus\u003c/em\u003e, showing the outer strain a higher resistance to 15 s of exposure. Interestingly, the isolates of \u003cem\u003eArthrobacter bussei\u003c/em\u003e showed a similar output to the outer isolates \u003cem\u003eA agilis\u003c/em\u003e and \u003cem\u003eD. ficus\u003c/em\u003e, with survival rate values between 1 and 0.5 after 15 s and 30 s of UV exposure. Finally, \u003cem\u003eCurtobacterium flaccumfaciens\u003c/em\u003e and \u003cem\u003eKocuria arsenatis\u003c/em\u003e also showed a considerable resistance after 15 s exposure to UV, whereas \u003cem\u003eBacillus altitudinis\u003c/em\u003e, \u003cem\u003eS. cohnii\u003c/em\u003e and \u003cem\u003eS. hominis\u003c/em\u003e showed a strong decrease in the resistance to UV treatment already at 15 s for both inside and outside isolates.\u003c/p\u003e \u003cp\u003eTo further test if the UV irradiation from the cabins could shape the surface-associated microbiome leading to an enrichment of UV resistant species in the inside of the cabins, we compared in Figs.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eB and C the survival rates after 15 s and 30 s UV exposure, respectively, for all the isolates tested in Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eA. However, there was no clear evidence that supported this hypothesis. Although \u003cem\u003eK. polaris\u003c/em\u003e inside showed the highest survival rate after 15 s, this was not significantly different to the next four species (\u003cem\u003eD. ficus\u003c/em\u003e, \u003cem\u003eM. luteus\u003c/em\u003e, \u003cem\u003eA. bussei\u003c/em\u003e and \u003cem\u003eA. agilis\u003c/em\u003e), which were isolated outside the cabins (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eB). Moreover, a similar pattern was observed at 30 s of exposure, in which the significance group for the highest survival rates was formed by four isolates coming from the outer surfaces and two coming from the inner ones (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eC). At the strain level, \u003cem\u003eM. luteus\u003c/em\u003e and \u003cem\u003eB. altitudinis\u003c/em\u003e isolated from outside displayed higher survival rates than the inside isolates, whereas \u003cem\u003eC. flaccumfaciens\u003c/em\u003e behaved contrarily after 15 s UV exposure. In the case of the 30 s treatment, only \u003cem\u003eB. altitudinis\u003c/em\u003e behaved differently between treatments, being more resistant the outer strain.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv id=\"Sec8\" class=\"Section3\"\u003e \u003ch2\u003eAntibiotic resistance assay\u003c/h2\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eTo study a possible occurrence of AMR in isolates from the microbiomes of the UV cabins, we tested the resistance to antibiotics of the isolates from the subset of the microbial collection (Table S2). Quality control strains were included in all the experiments and gave the expected MIC results (in \u0026micro;g/ml): E. coli for amoxiclavulanicc acid (AMC; 0.5\u0026ndash;2), doxycycline (DXT; 0.5\u0026ndash;2) and gentamicin (GEN; 0.25\u0026ndash;1); and S. aureus for mupirocin (MUP; 0.06\u0026ndash;0.25), azithromycin (AZM; 0.5\u0026ndash;2) and clindamycin (CD; 0.06\u0026ndash;0.25). The classification of the isolates as resistant (R) or sensitive (S) to the tested antibiotics was determined according to clinical breakpoints established by EUCAST (EUCAST Clinical Breakpoint Tables v.12.0), which classifies microorganisms into susceptible at standard doses (S), susceptible increased exposure (I) or resistant (R). However, there were not available data for some species or antibiotics given the environmental origin of the tested isolates. In those cases, only the MIC values are commented and further discussed.\u003c/p\u003e \u003cp\u003eThe six antibiotics revealed two different patterns. On the one hand, the tested strains showed variable susceptibilities to AMC, DXT, GEN, and CD (Figs.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e7\u003c/span\u003eA, B, C, F). In contrast, there was a clear cluster of resistant strains to MUP and AZM (Figs.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e7\u003c/span\u003eD and E).\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003cp\u003eIn the case of AMC, the majority of the tested isolates were sensitive (S or I) according to the EUCAST criteria, with the exception of \u003cem\u003eS. rhizophila\u003c/em\u003e which was resistant (R, Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e7\u003c/span\u003eA). In regard to DXT, \u003cem\u003eS. hominis\u003c/em\u003e appeared as I, with a MIC value between 1 and 2 \u0026micro;g/ml, whereas the rest of the tested strains gave MIC values below 1 (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e7\u003c/span\u003eB). Similarly, most of the selected strains were S to GEN, with non-related species threshold stablished at 0.5 \u0026micro;g/ml, and 4 \u0026micro;g/ml for \u003cem\u003ePseudomonas\u003c/em\u003e spp. and \u003cem\u003eAcinetobacter\u003c/em\u003e spp. However, in this case, \u003cem\u003eS. hominis\u003c/em\u003e and \u003cem\u003eS. rhizophila\u003c/em\u003e were R (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e7\u003c/span\u003eC).\u003c/p\u003e \u003cp\u003eIn the case of MUP and AZM, there was a significant cluster of R strains (Figs.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e7\u003c/span\u003eD and E, respectively), with interest on \u003cem\u003eStaphylococcus\u003c/em\u003e spp. in both cases: \u003cem\u003eS. haemolyticus\u003c/em\u003e for MUP (R threshold at 256 \u0026micro;g/ml) and \u003cem\u003eS. hominis\u003c/em\u003e, \u003cem\u003eS. epidermitis\u003c/em\u003e, \u003cem\u003eS. cohnii\u003c/em\u003e and \u003cem\u003eS. haemolyticus\u003c/em\u003e for AZM (R threshold at 2 \u0026micro;g/ml). Moreover, both \u003cem\u003eS. cohnii\u003c/em\u003e isolates displayed MIC values above the breakpoint established for \u003cem\u003eStaphylococcus\u003c/em\u003e spp. for CD (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e7\u003c/span\u003eF).\u003c/p\u003e \u003cp\u003eAs for the strains with no registry of their resistances, their MIC values were diverse. AMC median MIC values ranged from 3 to 0.01, with the highest value at 6 \u0026micro;g/ml. DXT values ranged from 1.5 to 0.016, with the highest point on 4 \u0026micro;g/ml. GEN values varied from 2 to 0.016, being 3 \u0026micro;g/ml the top value. MUP values were from 1536, the top score, to 0.064 \u0026micro;g/ml. AZM values ranged from 384 (highest value) to 0.01 \u0026micro;g/ml, and CD values were from 384 (highest score) to 0.01 \u0026micro;g/ml.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003cdiv id=\"Sec9\" class=\"Section3\"\u003e \u003ch2\u003ePhylogenetic interpretation\u003c/h2\u003e \u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eFrom the phylogenetic perspective, there was found out a clear tendency on \u003cem\u003eActinomycetota\u003c/em\u003e to resist UV. In contrast, species within the phylum \u003cem\u003eBacillota\u003c/em\u003e appeared as the most sensitive to this treatment. Regarding antibiotics, as stated above, there was not a significant enrichment on resistant isolates. However, MIC values were diverse. Specifically, there is interest on the resistances displayed by \u003cem\u003estaphylococci\u003c/em\u003e to DXT, GEN, MUP, AZM and CD. Although the displayed values may appear as high, the available literature on clinical specimens did not catalogue most of them as resistant.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003e \u003c/p\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Discussion","content":"\u003cp\u003e \u003cdiv class=\"BlockQuote\"\u003e \u003cp\u003eIn the present work, we analysed the microbiomes associated to the inner and external surfaces of UV cabins used in the Dermatology Service of the Hospital General Universitario de Valencia to treat skin pathologies. First, we wanted to shed light on whether the UV irradiation shaped the microbial communities of the cabins. Second, we wanted to explore the possible correlation between UV light-resistance and resistance to antibiotics commonly used to treat skin pathologies. For this, we used a double strategy based in culture-dependent (culturomics, colony identification and biological activity tests) and independent techniques (high-throughput 16S rRNA gene sequencing).\u003c/p\u003e \u003cp\u003eFrom the culturomics point of view, the microbial profiles we found are moderately diverse and include both environmental and human associated microbial taxa (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA). From the most abundant taxa to the least, the high abundances of \u003cem\u003eStaphylococcus\u003c/em\u003e, and to a lesser extent of \u003cem\u003eMicrococcus\u003c/em\u003e and \u003cem\u003eBacillus\u003c/em\u003e, are not surprising since these genera are naturally present on the human skin [\u003cspan citationid=\"CR33\" class=\"CitationRef\"\u003e33\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR34\" class=\"CitationRef\"\u003e34\u003c/span\u003e]. Moreover, \u003cem\u003eKocuria\u003c/em\u003e and \u003cem\u003ePseudomonas\u003c/em\u003e have also been associated with skin disorders, such as psoriasis, and some \u003cem\u003eArthrobacter\u003c/em\u003e species are opportunistic human pathogens, such as \u003cem\u003eA. creatinolyticus\u003c/em\u003e or \u003cem\u003eA. woluwensis\u003c/em\u003e, or have been isolated from human clinical specimens [\u003cspan additionalcitationids=\"CR36 CR37\" citationid=\"CR35\" class=\"CitationRef\"\u003e35\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR38\" class=\"CitationRef\"\u003e38\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eHowever, both \u003cem\u003eKocuria\u003c/em\u003e and \u003cem\u003eArthrobacter\u003c/em\u003e species inhabit soils, being, thus, common environmental species [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e], and the large genus \u003cem\u003eBacillus\u003c/em\u003e not only includes pathogenic species such as \u003cem\u003eB. cereus\u003c/em\u003e or \u003cem\u003eB. anthracis\u003c/em\u003e, but is also a typical environmental species in different natural habitats [\u003cspan citationid=\"CR39\" class=\"CitationRef\"\u003e39\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR40\" class=\"CitationRef\"\u003e40\u003c/span\u003e]. Some of these genera are also known by their tolerance to biotic and abiotic stressors. Specifically, \u003cem\u003eMicrococcus\u003c/em\u003e spp. and \u003cem\u003eKocuria\u003c/em\u003e spp. have been isolated from polar environments and reported to be resistant to radiation [\u003cspan additionalcitationids=\"CR42 CR43\" citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e], whereas \u003cem\u003eArthrobacter\u003c/em\u003e spp. are present in hot deserts [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR45\" class=\"CitationRef\"\u003e45\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR46\" class=\"CitationRef\"\u003e46\u003c/span\u003e]. Moreover, \u003cem\u003eBacillus\u003c/em\u003e spp. are well known by their tolerance to stress given their ability to form resistance spores [\u003cspan citationid=\"CR47\" class=\"CitationRef\"\u003e47\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eFrom the clinical point of view, we found relevant to analyze the presence of some health-threatening genera, such as \u003cem\u003eAcinetobacter\u003c/em\u003e or \u003cem\u003ePseudomonas\u003c/em\u003e. Both genera have been described to have an innate adaptation ability, including the acquisition of antibiotic resistances [\u003cspan additionalcitationids=\"CR49\" citationid=\"CR48\" class=\"CitationRef\"\u003e48\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR50\" class=\"CitationRef\"\u003e50\u003c/span\u003e]. Among them, \u003cem\u003eA. baumanii\u003c/em\u003e and \u003cem\u003eP. aeruginosa\u003c/em\u003e strains fall into the ESKAPE group of multi-drug resistant bacteria [\u003cspan citationid=\"CR51\" class=\"CitationRef\"\u003e51\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e]. Moreover, other present genera such as \u003cem\u003eRhodococcus\u003c/em\u003e, \u003cem\u003eRoseomonas\u003c/em\u003e or \u003cem\u003eStenotrophomonas\u003c/em\u003e host species that cause infection to immunocompromised patients, and \u003cem\u003eCryptococcus\u003c/em\u003e spp. have been reported to cause opportunistic infections [\u003cspan additionalcitationids=\"CR53 CR54 CR55\" citationid=\"CR52\" class=\"CitationRef\"\u003e52\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR56\" class=\"CitationRef\"\u003e56\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eApart from the above-described ones, there is also a less abundant representation of some environmental-associated taxa, many of which have been isolated from varied environments such as \u003cem\u003eDeinococcus\u003c/em\u003e, \u003cem\u003eDomibacillus\u003c/em\u003e, \u003cem\u003ePantoea\u003c/em\u003e or \u003cem\u003eSphingomonas\u003c/em\u003e [\u003cspan additionalcitationids=\"CR58 CR59\" citationid=\"CR57\" class=\"CitationRef\"\u003e57\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR60\" class=\"CitationRef\"\u003e60\u003c/span\u003e]. Others have been linked to isolated cases of fungaemia, bacteremia or sepsis, such as \u003cem\u003eAureobasidium\u003c/em\u003e, \u003cem\u003eKosakonia\u003c/em\u003e, \u003cem\u003eLysinibacillus\u003c/em\u003e or \u003cem\u003eMassilia\u003c/em\u003e [\u003cspan additionalcitationids=\"CR62 CR63\" citationid=\"CR61\" class=\"CitationRef\"\u003e61\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR64\" class=\"CitationRef\"\u003e64\u003c/span\u003e]. However, \u003cem\u003eMassilia\u003c/em\u003e is also a common soil-inhabitant [\u003cspan citationid=\"CR65\" class=\"CitationRef\"\u003e65\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR66\" class=\"CitationRef\"\u003e66\u003c/span\u003e]. Regarding fungi, the ones we isolated in pure culture belonged to the genera \u003cem\u003eAureobasidium\u003c/em\u003e (five isolates), \u003cem\u003eUstilago\u003c/em\u003e, \u003cem\u003eCystobasidium\u003c/em\u003e, \u003cem\u003eRhodotorula\u003c/em\u003e and \u003cem\u003eCryptococcus\u003c/em\u003e (the last four represented by just one isolate). Despite the low number of fungal isolates selected, the fact that the yeast genera \u003cem\u003eAureobasidium\u003c/em\u003e, \u003cem\u003eRhodotorula\u003c/em\u003e and \u003cem\u003eCryptococcus\u003c/em\u003e had previously been reported to inhabit different hospital facilities is in accordance with our results [\u003cspan citationid=\"CR67\" class=\"CitationRef\"\u003e67\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe comparison of the isolation surface (inside or outside the cabins) revealed similar microbiomes. However, the existence of a cluster of exclusive genera in each location reveals some differences from the culturable point of view. The dominance of \u003cem\u003eStaphylococcus\u003c/em\u003e in both isolation sources is in accordance with its widely known role in skin pathology [\u003cspan citationid=\"CR68\" class=\"CitationRef\"\u003e68\u003c/span\u003e]. In contrast, \u003cem\u003ePseudomonas\u003c/em\u003e, a sensitive genus, is only detected outside [\u003cspan citationid=\"CR69\" class=\"CitationRef\"\u003e69\u003c/span\u003e]. Curiously, all six isolates identified as \u003cem\u003eFrigoribacterium\u003c/em\u003e spp. were isolated from the inner surfaces of the cabins (Fig.\u0026nbsp;\u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA). This genus was first described as a psychrophilic genus isolated from dust in a cattle barn in Finland [\u003cspan citationid=\"CR70\" class=\"CitationRef\"\u003e70\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eAs revealed by high-throughput 16S rRNA gene sequencing, the all the cabins and locations display similar taxonomic profiles in terms of α-diversity. However, in terms β-diversity some differences are observed at the genus level (Figs.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eA and \u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eB). The fact that cabin one (working in UVA) and cabin two (working in UVB) are the most similar ones suggests that UV does not have a significant effect in shaping the microbial biocenosis in our studies (Fig.\u0026nbsp;\u003cspan refid=\"Fig3\" class=\"InternalRef\"\u003e3\u003c/span\u003eB).\u003c/p\u003e \u003cp\u003eAt the phylum level, the predominant phyla found (\u003cem\u003ePseudomonadota\u003c/em\u003e, \u003cem\u003eActinomycetota\u003c/em\u003e and \u003cem\u003eBacillota\u003c/em\u003e) are in accordance with the already described profiles found in hospitals by other authors. Moreover, the comparison of the microbial profiles found in the samples at the genus level with those of hospitals is also in accordance with previous studies, particularly due to the presence of \u003cem\u003eStaphylococcus\u003c/em\u003e, \u003cem\u003ePseudomonas\u003c/em\u003e, \u003cem\u003eAcinetobacter\u003c/em\u003e and \u003cem\u003eStreptococcus\u003c/em\u003e (Figs.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eA and \u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eB) [\u003cspan citationid=\"CR27\" class=\"CitationRef\"\u003e27\u003c/span\u003e, \u003cspan citationid=\"CR71\" class=\"CitationRef\"\u003e71\u003c/span\u003e]. Interestingly, the presence of the genera \u003cem\u003eRubellimicrobium\u003c/em\u003e, \u003cem\u003eDeinococcus\u003c/em\u003e, \u003cem\u003eBacillus\u003c/em\u003e, \u003cem\u003eHymenobacter\u003c/em\u003e and \u003cem\u003eSphingomonas\u003c/em\u003e is in line with the already described microbial communities living on solar panels [\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. This may suggest that the studied microbiomes are a combination of both highly-irradiated surfaces, such as solar panels, and hospital environments. Although, at the genus level, there are differences between both cabins and locations (Fig.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eB), the most relevant genera according to their environmental or clinical interest do not show significant differences in their distribution, with the exception of \u003cem\u003eStaphylococcus\u003c/em\u003e (Fig.\u0026nbsp;\u003cspan refid=\"Fig5\" class=\"InternalRef\"\u003e5\u003c/span\u003eC).\u003c/p\u003e \u003cp\u003eFinally, the genera \u003cem\u003eRubellimicrobium\u003c/em\u003e, \u003cem\u003eParacoccus\u003c/em\u003e and \u003cem\u003eCorynebacterium\u003c/em\u003e are among the most abundant genera through NGS whereas they are completely absent in the strain collection (Figs.\u0026nbsp;\u003cspan refid=\"Fig4\" class=\"InternalRef\"\u003e4\u003c/span\u003eB and \u003cspan refid=\"Fig1\" class=\"InternalRef\"\u003e1\u003c/span\u003eA, respectively). Biases in culturing techniques are well-known and our results support the importance of combining both culture-dependent and culture-independent techniques in microbial ecology.\u003c/p\u003e \u003cp\u003eWe tested the hypothesis that the resistance to UV irradiation of the species isolated inside the cabins would be higher than that of the species isolated outside the cabins. However, our results did not support this statement (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). All the strains isolated exclusively from the inner surfaces showed a significant decrease in the survival rate after 15 s or 30 s of UV irradiation, with the only exception being \u003cem\u003eK. polaris\u003c/em\u003e at 15 s of UV irradiation treatment. Similarly, in the group of isolates obtained exclusively from the outer surfaces there were only two strains whose survival did not decrease significantly after 15 s of UV exposure: \u003cem\u003eA. agilis\u003c/em\u003e and \u003cem\u003eD. ficus\u003c/em\u003e. Moreover, in the comparison of species isolated from both the inner and outer surfaces of the cabins, no relevant differences were found out. There was only one outside \u003cem\u003eM. luteus\u003c/em\u003e isolate displaying higher resistance that the inner strain (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003e). This suggests that, in this case, UV exposure is no causing an adaptive response for bacteria (Fig.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eA).\u003c/p\u003e \u003cp\u003eAccording to this experiment, the most resistant strains were \u003cem\u003eA. bussei, A. agilis, K. polaris, D. ficus\u003c/em\u003e and \u003cem\u003eM. luteus\u003c/em\u003e (Figs.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eB and \u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eC). Some \u003cem\u003eKocuria\u003c/em\u003e strains have been reported as highly resistant to different types of radiation, as well as to synthesize carotenoids and encode genes related to oxidative stress [\u003cspan citationid=\"CR41\" class=\"CitationRef\"\u003e41\u003c/span\u003e, \u003cspan citationid=\"CR44\" class=\"CitationRef\"\u003e44\u003c/span\u003e, \u003cspan additionalcitationids=\"CR73\" citationid=\"CR72\" class=\"CitationRef\"\u003e72\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR74\" class=\"CitationRef\"\u003e74\u003c/span\u003e]. Moreover, \u003cem\u003eDeinococcus\u003c/em\u003e spp. have been extensively studied for its high resistance to radiation, which is a result of a combination of mechanisms such as robust DNA repair systems regulatory proteins, enzymatic and non-enzymatic antioxidant strategies [\u003cspan citationid=\"CR74\" class=\"CitationRef\"\u003e74\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR75\" class=\"CitationRef\"\u003e75\u003c/span\u003e]. On its part, the genus \u003cem\u003eArthrobacter\u003c/em\u003e hosts several multi-resistant species to different abiotic stressors [\u003cspan citationid=\"CR76\" class=\"CitationRef\"\u003e76\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR77\" class=\"CitationRef\"\u003e77\u003c/span\u003e]. Specifically, \u003cem\u003eA. agilis\u003c/em\u003e has been reported to produce the C50 carotenoid bacterioruberin [\u003cspan citationid=\"CR78\" class=\"CitationRef\"\u003e78\u003c/span\u003e]. Finally, \u003cem\u003eMicrococcus\u003c/em\u003e spp. have DNA repair mechanisms fundamental on their resistance to UV light [\u003cspan citationid=\"CR79\" class=\"CitationRef\"\u003e79\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR80\" class=\"CitationRef\"\u003e80\u003c/span\u003e], and \u003cem\u003eM. luteus\u003c/em\u003e strains have been reported to resist high doses of gamma radiation [\u003cspan citationid=\"CR42\" class=\"CitationRef\"\u003e42\u003c/span\u003e]. These taxa are, thus, highly resistant to radiation and other stresses, and naturally inhabit soil and desert-like environments [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR3\" class=\"CitationRef\"\u003e3\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eEven though for most of the strains the survival rate after UV treatment was significantly reduced compared to the non-irradiated control, many of them showed mid-viability after 15 s of treatment. This is the case of \u003cem\u003eA. variabilis\u003c/em\u003e and \u003cem\u003eM. esteraromaticum\u003c/em\u003e, isolated from the inner surfaces of the cabins, and \u003cem\u003eA. bussei, C. flaccumfaciens\u003c/em\u003e and \u003cem\u003eK. arsenatis\u003c/em\u003e, isolated both from the inside and the outside. Some \u003cem\u003eAcinetobacter\u003c/em\u003e species have demonstrated to be able to cope with oxidative stress [\u003cspan citationid=\"CR81\" class=\"CitationRef\"\u003e81\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR82\" class=\"CitationRef\"\u003e82\u003c/span\u003e]. Moreover, the genus \u003cem\u003eMicrobacterium\u003c/em\u003e has extensive background on UV resistance and carotenoid synthesis as well [\u003cspan additionalcitationids=\"CR84\" citationid=\"CR83\" class=\"CitationRef\"\u003e83\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR85\" class=\"CitationRef\"\u003e85\u003c/span\u003e]. In contrast, less has been described about \u003cem\u003eCurtobacterium\u003c/em\u003e spp., but still there are reports on their tolerance to UV [\u003cspan citationid=\"CR86\" class=\"CitationRef\"\u003e86\u003c/span\u003e].\u003c/p\u003e \u003cp\u003eThe reasons for the absence of an enrichment on resistant species inside the cabins may be varied (Figs.\u0026nbsp;\u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eA and \u003cspan refid=\"Fig6\" class=\"InternalRef\"\u003e6\u003c/span\u003eB). On the one hand, both surfaces are accessible to patients, which may be in contact constantly with both surfaces. This would explain also the high similarities found in terms of diversity. Moreover, the stress to which they are subjected (short pulses of UV light) may be less intense than the stress tested under laboratory conditions. From this perspective, the species tested may not represent a threaten.\u003c/p\u003e \u003cp\u003eAs stated in the introduction, hospitals and sanitary environments increase the population of multidrug resistant pathogens. Considering that the surface of UV-cabins is constantly in contact with patients with skin pathologies, many of them with complementary treatments with antibiotics, and that the use of radiation may favor the selection of antibiotic resistant bacteria [\u003cspan citationid=\"CR30\" class=\"CitationRef\"\u003e30\u003c/span\u003e], we hypothesized that the isolates taken from the inside and the outside of these cabins may present an altered susceptibility to antibiotics. In this regard, we assessed the antibiotic resistance of the isolates from Table S2 to six antibiotics widely used in dermatology: AMC, DXT, GEN, MUP, AZM and CD (Fig.\u0026nbsp;\u003cspan refid=\"Fig8\" class=\"InternalRef\"\u003e7\u003c/span\u003e). The classification of the strains as sensitive or resistant has been done according to the European Committee on Antimicrobial Susceptibility (EUCAST) as expressed in the instructions of the MTS.\u003c/p\u003e \u003cp\u003eThe presence of some resistant strains is confirmed, with special interest on the genus \u003cem\u003eStaphylococcus\u003c/em\u003e. In this regard, there were found isolates resistant to DXT and GEN (\u003cem\u003eS. hominis\u003c/em\u003e isolated from outside), MUP (\u003cem\u003eS. haemolyticus\u003c/em\u003e), AZM (both \u003cem\u003eS. cohnii\u003c/em\u003e isolates, \u003cem\u003eS. haemolyticus\u003c/em\u003e and \u003cem\u003eS. hominis\u003c/em\u003e from inside) and CD (both \u003cem\u003eS. cohnii\u003c/em\u003e). The resistance to MUP is remarkable, as this antibiotic is specifically used in the treatment of topic dermal infections by Gram-positive cocci, which also explains the resistance values displayed by most of the tested strains (which are not Gram-positive cocci). Moreover, the resistance of \u003cem\u003eS. haemolyticus\u003c/em\u003e to MUP has been already reported and is mediated by the gene \u003cem\u003emupA\u003c/em\u003e [\u003cspan citationid=\"CR87\" class=\"CitationRef\"\u003e87\u003c/span\u003e], and the rest of the mentioned staphylococci have reports on their multi-resistances [\u003cspan additionalcitationids=\"CR89\" citationid=\"CR88\" class=\"CitationRef\"\u003e88\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR90\" class=\"CitationRef\"\u003e90\u003c/span\u003e]. There were some differences between strains isolated from different surfaces belonging to the same species, such as the case of \u003cem\u003eS. hominis\u003c/em\u003e: the inside isolate is resistant to AZM whereas the outside one is resistant to DXT and GEN. As for \u003cem\u003eS. rhizophila\u003c/em\u003e, our strain showed resistance to AMC, and there are reports on their multi-resistance to many antibiotics [\u003cspan citationid=\"CR91\" class=\"CitationRef\"\u003e91\u003c/span\u003e]. Regarding the strains for which a breakpoint has not been established, no susceptibilities can be assigned.\u003c/p\u003e \u003c/div\u003e \u003c/p\u003e \u003cp\u003eTaken together, the results obtained from both resistance assays (UV and antibiotics) reveal that most of microorganisms are not resistant to the antibiotics tested. Those that are, which are the staphylococci, do not show UV-resistance. The rest of the isolates we tested lack clinical interest as they are not common human pathogens. Therefore, the microbial community of the cabins is mainly composed of antibiotic-sensitive micro-organisms which display a diverse sensitivity to UV light, and a few potential pathogenic microorganisms that are sensitive to UV light (and that should thus be eliminated easily with UV-based sterilization devices). Moreover, the lack of reports of infections associated with the cabins supports a lack of substantial threat in their microbial content. However, the combination of the presence in the cabins of some microbial pathogens and the presence of antibiotic resistant genes poses an obvious potential problem linked to horizontal gene transfer (Fig.\u0026nbsp;\u003cspan refid=\"Fig10\" class=\"InternalRef\"\u003e8\u003c/span\u003e).\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003e\u003cstrong\u003eSample collection\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eDust samples from the inner and the outer surfaces of four UVA and UVB cabins were taken in June 2021, in the Dermatology Service of the Hospital General of Valencia, Spain. The cabins sampled were: 1) PUVA 700 Waldmann (Villingen-Schwenningen, Germany), 2) UV7001K UVA/UVB Waldmann (Villingen-Schwenningen, Germany), 3) and 4) UV7002 UVA/UVB Waldmann (Villingen-Schwenningen, Germany). Samples (in duplicate or triplicate) were obtained by scrubbing the surface with a sterile swab (FLOQSwabs\u003csup\u003eTM\u003c/sup\u003e hDNA Free, Copan Flock Technologies SRL, Brescia, Italy) and immediately stored in sterile tubes with 500 \u0026micro;L of Phosphate Buffer Saline (PBS) 1X until processed in the laboratory.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eIsolation of microbial strains\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eSamples were thoroughly shaken with vortex. As most samples were very clear, suggesting a low microbial load, 20 \u0026micro;L of the direct suspensions were spread on Petri dishes in duplicate, on five different culture media: TSA (composition in g/L: 15.0 tryptone, 5.0 soya peptone, 5.0 sodium chloride, 15.0 agar), Nutrient Agar (composition in g/L: peptone 5.0, meat extract 3.0, agar 15.0), Columbia Blood (catalogue number: CM0331B, ThermoFisher Scientific Inc., Massachusetts, USA), R2A (composition in g/L: 1 peptone, 0.5 yeast extract, 0.5 dextrose, 0.5 soluble starch, 0.3 dipotassium phosphate, 0.05 magnesium phosphate, 0.3 sodium pyruvate, 15.0 agar) and Yeast Mold (composition in g/L: malt extract 3.0, yeast extract 3.0, dextrose/glucose 10.0, peptone soybean 5.0, agar 15.0). Samples were incubated at 25 and 37 \u0026deg;C for one week. Colonies were then selected according to morphological traits, such as colour or shape, and isolated independently by re-streaking on fresh media. When pure cultures were obtained, strains were cryopreserved as glycerol stocks (12 % glycerol in their isolation media) at -80 \u0026deg;C until required.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eColony identification (16S rRNA/ITS gene sequencing)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMicrobial biomass from grown plates of pure cultures was suspended in 100 \u0026micro;L of Milli-Q sterile water. Cells were lysed by heat shock in two cycles of boiling-freezing steps. PCR was carried out for the taxonomic identification through 16S rRNA gene sequencing. Colony PCR and amplicon precipitation were carried out following the procedures previously described by Molina-Menor et al. (2021) [2]. Sequencing was performed with Sanger by Eurofins Genomics (Ebersberg, Germany). Trev tool (Staden Package, 2002) was used to manually edit 16S rRNA sequences in order to eliminate low-quality base calls. Sequences where then compared by EzBioCloud 16S rRNA BLAST tool to nucleotide databases. The sequences have been deposited under the GenBank/EMBL/DDBJ accession numbers OQ221901-OQ222055 (bacterial sequences) and OQ208835-OQ208843 (fungal sequences). Redundancy of the isolates was checked among the ones with the same identification that had been isolated from the same sample and media by Blast to Blast (https://blast.ncbi.nlm.nih.gov/Blast.cgi). The identifications are listed in Table S1.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eHigh-throughput 16S rRNA gene sequencing (metataxonomics)\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eTotal DNA extraction was carried out with the DNease PowerSoil kit (MO BIO laboratories, Carlsbad, CA, USA). In order to consider potential microbial contamination of the reagents used, two negative controls consisting of pure water, instead of samples, and processed with the same kit were included. Given that very low DNA concentrations were obtained, the amplification of the 16S rRNA gene through PCR was carried out following the protocol described by Molina-Menor et al. (2021) [2]. For those samples failing to be amplified with 16S rRNA gene primers, a PCR with ITS region primers ITS3 and ITS4 [92] was carried out under the following conditions: initial step at 95\u0026nbsp;\u0026deg;C for 5 min, followed by 30 cycles of 30 s at 94\u0026nbsp;\u0026deg;C for denaturation, 30 s at 53\u0026nbsp;\u0026deg;C for annealing and 30 s at 72\u0026nbsp;\u0026deg;C for elongation, and a final step of elongation of 5 min at 72\u0026nbsp;\u0026deg;C. Samples with a clear amplification band in the electrophoresis gel were selected for sequencing, ensuring the representation of all four cabins and sampling points (inside and outside). The samples selected consisted of: three samples from inside and two from outside cabin one, two samples from inside and two from outside cabin two, one sample from inside and one sample from outside cabin three, and one sample from inside and one sample from outside cabin four. Both sequencing (Illumina) and the bioinformatic analysis were carried out by Darwin Bioprospecting Excellence SL (Paterna, Spain). Rarefaction curves were plotted to check the sequencing depth (Figure S2).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eUV-radiation resistance assay\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eBased on the microbial identifications, a subset of isolates was selected from the collection to further perform UV irradiation and antibiotic resistance assays (from now on, sub-collection). Isolates from the most represented taxa were selected considering to have (1) a wide diversity of genera tested for each surface and (2) species that were isolated both from the inside and outside of the cabins (Table S2).\u003c/p\u003e\n\u003cp\u003eLiquid cell cultures of selected isolates were serially diluted in PBS to an OD\u003csub\u003e600\u003c/sub\u003e of 10\u003csup\u003e-4\u003c/sup\u003e/10\u003csup\u003e-5\u003c/sup\u003e in order to obtain isolated colonies after inoculation on R2A agar plates. Aliquots of 100 \u0026micro;l of the cultures were plated in triplicate. Two replicates were then exposed to UVC light for 15 s or 30 s, while the other replicate was the non-irradiated control. UVC irradiation was performed with a VILBER LOURMAT UV lamp emitting 354 nm light with an intensity of 340\u0026nbsp;mW/cm\u003csup\u003e2\u003c/sup\u003e at 15 cm of distance. Plates were incubated at 30\u0026nbsp;\u0026deg;C and colonies were counted 24 to 72 h post inoculation depending on each strain. Number of colonies in the irradiated plates were compared to the number of colonies in the control non-irradiated plates.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAntibiotic resistance assay\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eMinimum Inhibitory Concentration (MIC) tests were carried out with the commercial MIC Test Strip (MTS) by Liofilchem SRL (Roseto degli Abruzzi (TE), Italy). Amoxicillin*-clavulanic acid (2/1) (ref: 920240, 0.016-256 mg/L), azithromycin (ref: 920300, 0.016-256 mg/L), clindamycin (ref: 920720, 0.016-256 mg/L), doxycycline (ref: 921560, 0.016-256 mg/L), gentamicin (ref: 920090, 0.016-256 mg/L) and mupirocin (ref: 920380, 0.064-1024 mg/L) were selected among the antibiotics that are commonly used in the Dermatology Service of the Hospital General of Valencia (AMC: amoxicillin-clavulanic acid; AZM: azithromycin; CD: clindamycin; DXT: doxycycline; GEN: gentamycin; MUP: mupirocin). Growth on Mueller Hinton-agar media was tested prior to the assay in order to ensure that all the strains were able to grow on it. The experiment was carried out following the manufacturer\u0026rsquo;s instructions, using OD\u003csub\u003e600\u003c/sub\u003e instead of McFarland turbidity standards to assess cell concentration. For this, PBS cell-resuspensions for each strain were diluted to OD\u003csub\u003e600\u003c/sub\u003e 0.1, 0.5 and 1, and 100\u0026nbsp;ml were plated on Mueller Hinton agar plates. We selected the dilution for inoculation for each strain based on confluent cell-growth after 24, 48 and 72 h incubation at 30\u0026nbsp;\u0026deg;C. MIC was registered 24 h, 48 h and 72 h for each sample. The quality check strains were \u003cem\u003eStaphylococcus aureus\u003c/em\u003e (ATCC 29213 \u0026ndash; WDCM 00131) for AZM, MUP and CD; and \u003cem\u003eEscherichia coli (\u003c/em\u003eATCC25922 \u0026ndash; WDCM 00013) for DXT, AMC and GEN. The strains were purchased from DSMZ (German Collection of Microorganisms and Cell Cultures, Leibniz Institute, Braunschweig, Germany). The MICs for control strains showed minor changes throughout the three days that lasted each replicate, but they were always inside the expected range as referred by the manufacturer. The results were interpreted following the manufacturer\u0026rsquo;s instructions, according to the European Committee on Antimicrobial Susceptibility testing (EUCAST) (EUCAST Clinical Breakpoint Tables v.12.0).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003ePhylogenetic tree\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe 16S rRNA gene sequences of the type strains of the subcollection (Table S2) were retrieved from EzBioCloud (www.ezbiocloud.net). Phylogenetic analysis was carried out with MEGA11 software (v.11.0.13). Sequences were aligned with MUSCLE algorithm and the phylogenetic tree was constructed using the Neighbour Joining method [93]. The branch pattern reliability was checked with bootstrap analysis based on 100 replicates with nucleotide p-distance substitution model including transitions and transversion.\u003c/p\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eACKNOWLEDGMENTS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe are thankful to Daniel Torrent and Adriel Latorre-P\u0026eacute;rez from Darwin Bioprospecting Excellence SL for their assistance and help with the bioinformatic analysis. We thank Lorena Mart\u0026iacute;nez and Cristina Calabuig for their help with the establishment and identification of the microbial collection.\u003cstrong\u003e\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAUTHOR CONTRIBUTIONS\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eE.M.M., A.P.F, G.P.P and M.P. conceived the work. E.M.M., N.C, \u0026Agrave;.V.V. carried out the experimental procedures. E.M.M., N.C, \u0026Agrave;.V.V, A.P.F, G.P. and M.P. analysed the results, wrote and approved the manuscript. All the authors agree to publish the manuscript.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eDATA AVAILABILITY STATEMENT\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe 16S rRNA gene sequences have been deposited under the GenBank/EMBL/DDBJ accession numbers OQ221901-OQ222055 (bacterial sequences) and OQ208835-OQ208843 (fungal sequences).\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eADDITIONAL INFORMATION\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eEMM and \u0026Agrave;VV are funded with a Formaci\u0026oacute;n del Profesorado Universitario (FPU) fellowship from the Spanish Ministry of Universities, with references FPU17/04184 and FPU18/02578, respectively. NC is funded with MICRO4BIOGAS project (reference ID101000470, funded by European Union\u0026apos;s Horizon 2020 research and innovation program). The authors declare no conflict of interest.\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n\u003cli\u003eShuryak I. (2019). Review of microbial resistance to chronic ionizing radiation exposure under environmental conditions. \u003cem\u003eJournal of environmental radioactivity\u003c/em\u003e, \u003cem\u003e196\u003c/em\u003e, 50\u0026ndash;63. https://doi.org/10.1016/j.jenvrad.2018.10.012\u003c/li\u003e\n\u003cli\u003eMolina-Menor, E., Gimeno-Valero, H., Pascual, J., Peret\u0026oacute;, J., \u0026amp; Porcar, M. (2021). High Culturable Bacterial Diversity From a European Desert: The Tabernas Desert. \u003cem\u003eFrontiers in microbiology\u003c/em\u003e, \u003cem\u003e11\u003c/em\u003e, 583120. https://doi.org/10.3389/fmicb.2020.583120\u003c/li\u003e\n\u003cli\u003eTanner, K., et al. (2020). Extremophilic microbial communities on photovoltaic panel surfaces: a two-year study. \u003cem\u003eMicrob. Biotechnol. \u003c/em\u003e13, 1819\u0026ndash;1830. doi: 10.1111/1751-7915.13620\u003c/li\u003e\n\u003cli\u003eRagon, M., Restoux, G., Moreira, D., M\u0026oslash;ller, A. P., \u0026amp; L\u0026oacute;pez-Garc\u0026iacute;a, P. (2011). Sunlight-exposed biofilm microbial communities are naturally resistant to chernobyl ionizing-radiation levels. \u003cem\u003ePloS one\u003c/em\u003e, \u003cem\u003e6\u003c/em\u003e(7), e21764. https://doi.org/10.1371/journal.pone.0021764\u003c/li\u003e\n\u003cli\u003eYu, L. Z., Luo, X. S., Liu, M., \u0026amp; Huang, Q. (2015). Diversity of ionizing radiation-resistant bacteria obtained from the Taklimakan Desert. \u003cem\u003eJournal of basic microbiology\u003c/em\u003e, \u003cem\u003e55\u003c/em\u003e(1), 135\u0026ndash;140. https://doi.org/10.1002/jobm.201300390\u003c/li\u003e\n\u003cli\u003eArrigoni, E., Antonielli, L., Pindo, M., Pertot, I., \u0026amp; Perazzolli, M. (2018). Tissue age and plant genotype affect the microbiota of apple and pear bark. \u003cem\u003eMicrobiological research\u003c/em\u003e, \u003cem\u003e211\u003c/em\u003e, 57\u0026ndash;68. https://doi.org/10.1016/j.micres.2018.04.002\u003c/li\u003e\n\u003cli\u003eJaiaue, P., et al (2022). Mathematical Modeling for Evaluating Inherent Parameters Affecting UVC Decontamination of Indicator Bacteria. \u003cem\u003eApplied and environmental microbiology\u003c/em\u003e, \u003cem\u003e88\u003c/em\u003e(7), e0214821. https://doi.org/10.1128/aem.02148-21\u003c/li\u003e\n\u003cli\u003eMoore, G., et al. (2012). Use of UV-C radiation to disinfect non-critical patient care items: a laboratory assessment of the Nanoclave Cabin. \u003cem\u003eBMC infectious diseases\u003c/em\u003e, \u003cem\u003e12\u003c/em\u003e, 174. https://doi.org/10.1186/1471-2334-12-174\u003c/li\u003e\n\u003cli\u003eCieplik, F., et al. (2018). Antimicrobial photodynamic therapy - what we know and what we don\u0026apos;t. \u003cem\u003eCritical reviews in microbiology\u003c/em\u003e, \u003cem\u003e44\u003c/em\u003e(5), 571\u0026ndash;589. https://doi.org/10.1080/1040841X.2018.1467876\u003c/li\u003e\n\u003cli\u003eRezaie, A., et al. (2020). Ultraviolet A light effectively reduces bacteria and viruses including coronavirus. \u003cem\u003ePloS one\u003c/em\u003e, \u003cem\u003e15\u003c/em\u003e(7), e0236199. https://doi.org/10.1371/journal.pone.0236199\u003c/li\u003e\n\u003cli\u003eWang, M., Ateia, M., Awfa, D., \u0026amp; Yoshimura, C. (2021). Regrowth of bacteria after light-based disinfection - What we know and where we go from here. \u003cem\u003eChemosphere\u003c/em\u003e, \u003cem\u003e268\u003c/em\u003e, 128850. https://doi.org/10.1016/j.chemosphere.2020.128850\u003c/li\u003e\n\u003cli\u003eWorld Health Organization, WHO (9\u003csup\u003eth\u003c/sup\u003e March 2016). Radiation: Ultraviolet (UV) radiation. https://www.who.int/news-room/questions-and-answers/item/radiation-ultraviolet-(uv)\u003c/li\u003e\n\u003cli\u003eHargreaves, A., Taiwo, F. A., Duggan, O., Kirk, S. H., \u0026amp; Ahmad, S. I. (2007). Near-ultraviolet photolysis of \u0026beta;-phenylpyruvic acid generates free radicals and results in DNA damage. \u003cem\u003eJournal of Photochemistry and Photobiology B: Biology\u003c/em\u003e, \u003cem\u003e89\u003c/em\u003e(2-3), 110-116\u003c/li\u003e\n\u003cli\u003eMadronich, S., Bj\u0026ouml;rn, L. O., and McKenzie, R. L. (2018). Solar UV radiation and microbial life in the athmosphere. \u003cem\u003ePhotochem. Photobiol. Sci\u003c/em\u003e., 17, 1918.\u003c/li\u003e\n\u003cli\u003eBattie, C., et al. (2014). New insights in photoaging, UVA induced damage and skin types. \u003cem\u003eExperimental dermatology\u003c/em\u003e, \u003cem\u003e23 Suppl 1\u003c/em\u003e, 7\u0026ndash;12. https://doi.org/10.1111/exd.12388\u003c/li\u003e\n\u003cli\u003eRicha, Sinha, R. P., \u0026amp; H\u0026auml;der, D. P. (2015). Physiological aspects of UV-excitation of DNA. \u003cem\u003eTopics in current chemistry\u003c/em\u003e, \u003cem\u003e356\u003c/em\u003e, 203\u0026ndash;248. https://doi.org/10.1007/128_2014_531\u003c/li\u003e\n\u003cli\u003eJohann To Berens, P., \u0026amp; Molinier, J. (2020). Formation and Recognition of UV-Induced DNA Damage within Genome Complexity. \u003cem\u003eInternational journal of molecular sciences\u003c/em\u003e, \u003cem\u003e21\u003c/em\u003e(18), 6689. https://doi.org/10.3390/ijms21186689\u003c/li\u003e\n\u003cli\u003eLlabr\u0026eacute;s, M., Agust\u0026iacute;, S., Alonso-Laita, P., \u0026amp; Herndl, G. J. (2010). \u003cem\u003eSynechococcus\u003c/em\u003e and \u003cem\u003eProchlorococcus\u003c/em\u003e cell death induced by UV radiation and the penetration of lethal UVR in the Mediterranean Sea. \u003cem\u003eMarine Ecology Progress Series\u003c/em\u003e, \u003cem\u003e399\u003c/em\u003e, 27-37.\u003c/li\u003e\n\u003cli\u003eRathod DG, Muneer H, Masood S. Phototherapy. [Updated 2022 Oct 3]. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 Jan-. Available from: https://www.ncbi.nlm.nih.gov/books/NBK563140/\u003c/li\u003e\n\u003cli\u003eWoodgate, P., \u0026amp; Jardine, L. A. (2015). Neonatal jaundice: phototherapy. BMJ clinical evidence, 2015, 0319.\u003c/li\u003e\n\u003cli\u003eBae, J. M., et al. (2017). Phototherapy for Vitiligo: A Systematic Review and Meta-analysis. \u003cem\u003eJAMA dermatology\u003c/em\u003e, \u003cem\u003e153\u003c/em\u003e(7), 666\u0026ndash;674. https://doi.org/10.1001/jamadermatol.2017.0002\u003c/li\u003e\n\u003cli\u003eTorres, A. E., Lyons, A. B., Hamzavi, I. H., \u0026amp; Lim, H. W. (2021). Role of phototherapy in the era of biologics. \u003cem\u003eJournal of the American Academy of Dermatology\u003c/em\u003e, \u003cem\u003e84\u003c/em\u003e(2), 479\u0026ndash;485. https://doi.org/10.1016/j.jaad.2020.04.095\u003c/li\u003e\n\u003cli\u003eMancuso, G., Midiri, A., Gerace, E., \u0026amp; Biondo, C. (2021). Bacterial Antibiotic Resistance: The Most Critical Pathogens. \u003cem\u003ePathogens (Basel, Switzerland)\u003c/em\u003e, \u003cem\u003e10\u003c/em\u003e(10), 1310. https://doi.org/10.3390/pathogens10101310\u003c/li\u003e\n\u003cli\u003eCoculescu, B.I. (2009). Antimicrobial resistance induced by genetic changes. \u003cem\u003eJ. Med. Life\u003c/em\u003e, \u003cem\u003e2\u003c/em\u003e, 114\u0026ndash;123.\u003c/li\u003e\n\u003cli\u003eCollignon, P., \u0026amp; Beggs, J. J. (2019). Socioeconomic Enablers for Contagion: Factors Impelling the Antimicrobial Resistance Epidemic. \u003cem\u003eAntibiotics (Basel, Switzerland)\u003c/em\u003e, \u003cem\u003e8\u003c/em\u003e(3), 86. https://doi.org/10.3390/antibiotics8030086\u003c/li\u003e\n\u003cli\u003eStrich, J. R., \u0026amp; Palmore, T. N. (2017). Preventing Transmission of Multidrug-Resistant Pathogens in the Intensive Care Unit. \u003cem\u003eInfectious disease clinics of North America\u003c/em\u003e, \u003cem\u003e31\u003c/em\u003e(3), 535\u0026ndash;550. https://doi.org/10.1016/j.idc.2017.05.010\u003c/li\u003e\n\u003cli\u003eElRakaiby, M. T., Gamal-Eldin, S., Amin, M. A., \u0026amp; Aziz, R. K. (2019). Hospital Microbiome Variations As Analyzed by High-Throughput Sequencing. \u003cem\u003eOmics: a journal of integrative biology\u003c/em\u003e, \u003cem\u003e23\u003c/em\u003e(9), 426\u0026ndash;438. https://doi.org/10.1089/omi.2019.0111\u003c/li\u003e\n\u003cli\u003eChu, L., et al. (2020). Degradation of antibiotics and inactivation of antibiotic resistance genes (ARGs) in Cephalosporin C fermentation residues using ionizing radiation, ozonation and thermal treatment. \u003cem\u003eJournal of hazardous materials\u003c/em\u003e, \u003cem\u003e382\u003c/em\u003e, 121058. https://doi.org/10.1016/j.jhazmat.2019.121058\u003c/li\u003e\n\u003cli\u003evan Dijk, B., et al. (2020). Treating infections with ionizing radiation: a historical perspective and emerging techniques. \u003cem\u003eAntimicrobial resistance and infection control\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(1), 121. https://doi.org/10.1186/s13756-020-00775-w\u003c/li\u003e\n\u003cli\u003e\u0026Aacute;lvarez-Molina, A., et al. (2020). Selection for Antimicrobial Resistance in Foodborne Pathogens through Exposure to UV Light and Nonthermal Atmospheric Plasma Decontamination Techniques. \u003cem\u003eApplied and environmental microbiology\u003c/em\u003e, \u003cem\u003e86\u003c/em\u003e(9), e00102-20. https://doi.org/10.1128/AEM.00102-20\u003c/li\u003e\n\u003cli\u003eDancer S. J. (2014). Controlling hospital-acquired infection: focus on the role of the environment and new technologies for decontamination. \u003cem\u003eClinical microbiology reviews\u003c/em\u003e, \u003cem\u003e27\u003c/em\u003e(4), 665\u0026ndash;690. https://doi.org/10.1128/CMR.00020-14\u003c/li\u003e\n\u003cli\u003eOren, A., \u0026amp; Garrity, G. M. (2021). Valid publication of the names of forty-two phyla of prokaryotes. \u003cem\u003eInternational journal of systematic and evolutionary microbiology\u003c/em\u003e, \u003cem\u003e71\u003c/em\u003e(10), 10.1099/ijsem.0.005056. https://doi.org/10.1099/ijsem.0.005056\u003c/li\u003e\n\u003cli\u003eByrd, A. L., Belkaid, Y., and Segre, J. A. (2018). The human skin microbiome. \u003cem\u003eNature reviews. Microbiology\u003c/em\u003e, \u003cem\u003e16\u003c/em\u003e(3), 143\u0026ndash;155.\u003c/li\u003e\n\u003cli\u003eTang, V. H., et al. (2013). Skin-associated Bacillus, staphylococcal and micrococcal species from the house dust mite, Dermatophagoides pteronyssinus and bacteriolytic enzymes. \u003cem\u003eExperimental \u0026amp; applied acarology\u003c/em\u003e, \u003cem\u003e61\u003c/em\u003e(4), 431\u0026ndash;447. https://doi.org/10.1007/s10493-013-9712-8\u003c/li\u003e\n\u003cli\u003eLi, S. Y., et al. (2021). \u003cem\u003eArthrobacter woluwensis\u003c/em\u003e Bacteremia: A Clinical and Genomic Report. \u003cem\u003ePathogens (Basel, Switzerland)\u003c/em\u003e, \u003cem\u003e10\u003c/em\u003e(4), 443. https://doi.org/10.3390/pathogens10040443\u003c/li\u003e\n\u003cli\u003eNabal-D\u0026iacute;az, S., Garc\u0026iacute;a-Lechuz Moya, J. M., Mormeneo Bayo, S., \u0026amp; Mill\u0026aacute;n Lou, M. I. (2020). Arthrobacter creatinolyticus: An emerging human pathogen causing urinary tract infection. \u003cem\u003eEnfermedades infecciosas y microbiologia clinica (English ed.)\u003c/em\u003e, \u003cem\u003e38\u003c/em\u003e(2), 88\u0026ndash;89. https://doi.org/10.1016/j.eimc.2019.02.003\u003c/li\u003e\n\u003cli\u003eMages, I. S., Frodl, R., Bernard, K. A., \u0026amp; Funke, G. (2008). Identities of \u003cem\u003eArthrobacter\u003c/em\u003e spp. and \u003cem\u003eArthrobacter\u003c/em\u003e-like bacteria encountered in human clinical specimens. \u003cem\u003eJournal of clinical microbiology\u003c/em\u003e, \u003cem\u003e46\u003c/em\u003e(9), 2980\u0026ndash;2986. https://doi.org/10.1128/JCM.00658-08\u003c/li\u003e\n\u003cli\u003eStehlikova, Z., et al. (2019). Dysbiosis of Skin Microbiota in Psoriatic Patients: Co-occurrence of Fungal and Bacterial Communities. \u003cem\u003eFrontiers in microbiology\u003c/em\u003e, \u003cem\u003e10\u003c/em\u003e, 438.\u003c/li\u003e\n\u003cli\u003eEhling-Schulz, M., Lereclus, D., \u0026amp; Koehler, T. M. (2019). The \u003cem\u003eBacillus cereus\u003c/em\u003e Group: \u003cem\u003eBacillus\u003c/em\u003eSpecies with Pathogenic Potential. \u003cem\u003eMicrobiology spectrum\u003c/em\u003e, \u003cem\u003e7\u003c/em\u003e(3), 10.1128/microbiolspec.GPP3-0032-2018. https://doi.org/10.1128/microbiolspec.GPP3-0032-2018\u003c/li\u003e\n\u003cli\u003eRen, W., et al. (2022). Cross-habitat distribution pattern of Bacillus communities and their capacities of producing industrial hydrolytic enzymes in Paracel Islands: Habitat-dependent differential contributions of the environment. \u003cem\u003eJournal of environmental management\u003c/em\u003e, \u003cem\u003e323\u003c/em\u003e, 116252. https://doi.org/10.1016/j.jenvman.2022.116252\u003c/li\u003e\n\u003cli\u003eAsgarani, E., Soudi, M. R., Borzooee, F., \u0026amp; Dabbagh, R. (2012). Radio-resistance in psychrotrophic \u003cem\u003eKocuria\u003c/em\u003e sp. ASB 107 isolated from Ab-e-Siah radioactive spring. \u003cem\u003eJournal of environmental radioactivity\u003c/em\u003e, \u003cem\u003e113\u003c/em\u003e, 171\u0026ndash;176. https://doi.org/10.1016/j.jenvrad.2012.04.009\u003c/li\u003e\n\u003cli\u003eDeng, W., et al. (2016). Radiation-Resistant Micrococcus luteus SC1204 and Its Proteomics Change Upon Gamma Irradiation. \u003cem\u003eCurrent microbiology\u003c/em\u003e, \u003cem\u003e72\u003c/em\u003e(6), 767\u0026ndash;775. https://doi.org/10.1007/s00284-016-1015-y\u003c/li\u003e\n\u003cli\u003eLiu, H., Xu, Y., Ma, Y., \u0026amp; Zhou, P. (2000). Characterization of Micrococcus antarcticus sp. nov., a psychrophilic bacterium from Antarctica. \u003cem\u003eInternational journal of systematic and evolutionary microbiology\u003c/em\u003e, \u003cem\u003e50 Pt 2\u003c/em\u003e, 715\u0026ndash;719. https://doi.org/10.1099/00207713-50-2-715\u003c/li\u003e\n\u003cli\u003eReddy, G. S. N., et al. (2003). Kocuria polaris sp. nov., an orange-pigmented psychrophilic bacterium isolated from an Antarctic cyanobacterial mat sample. \u003cem\u003eInternational journal of systematic and evolutionary microbiology\u003c/em\u003e, \u003cem\u003e53\u003c/em\u003e(Pt 1), 183\u0026ndash;187. https://doi.org/10.1099/ijs.0.02336-0\u003c/li\u003e\n\u003cli\u003eHu, Q. W., et al. (2016). Arthrobacter deserti sp. nov., isolated from a desert soil sample. \u003cem\u003eInternational journal of systematic and evolutionary microbiology\u003c/em\u003e, \u003cem\u003e66\u003c/em\u003e(5), 2035\u0026ndash;2040. https://doi.org/10.1099/ijsem.0.000986\u003c/li\u003e\n\u003cli\u003eYe, J. J., et al. (2020). \u003cem\u003eArthrobacter mobilis\u003c/em\u003e sp. nov., a novel actinobacterium isolated from Cholistan desert soil. \u003cem\u003eInternational journal of systematic and evolutionary microbiology\u003c/em\u003e, \u003cem\u003e70\u003c/em\u003e(10), 5445\u0026ndash;5452. https://doi.org/10.1099/ijsem.0.004431\u003c/li\u003e\n\u003cli\u003eSaxena, A. K., Kumar, M., Chakdar, H., Anuroopa, N., \u0026amp; Bagyaraj, D. J. (2020). Bacillus species in soil as a natural resource for plant health and nutrition. \u003cem\u003eJournal of applied microbiology\u003c/em\u003e, \u003cem\u003e128\u003c/em\u003e(6), 1583\u0026ndash;1594. https://doi.org/10.1111/jam.14506\u003c/li\u003e\n\u003cli\u003eMaslova, O., Mindlin, S., Beletsky, A., Mardanov, A., \u0026amp; Petrova, M. (2022). Plasmids as Key Players in \u003cem\u003eAcinetobacter\u003c/em\u003e Adaptation. \u003cem\u003eInternational journal of molecular sciences\u003c/em\u003e, \u003cem\u003e23\u003c/em\u003e(18), 10893. https://doi.org/10.3390/ijms231810893\u003c/li\u003e\n\u003cli\u003eSilby, M. W., Winstanley, C., Godfrey, S. A., Levy, S. B., \u0026amp; Jackson, R. W. (2011). Pseudomonas genomes: diverse and adaptable. \u003cem\u003eFEMS microbiology reviews\u003c/em\u003e, \u003cem\u003e35\u003c/em\u003e(4), 652\u0026ndash;680. https://doi.org/10.1111/j.1574-6976.2011.00269.x\u003c/li\u003e\n\u003cli\u003eZhao, W. H., \u0026amp; Hu, Z. Q. (2012). Acinetobacter: a potential reservoir and dispenser for \u0026beta;-lactamases. \u003cem\u003eCritical reviews in microbiology\u003c/em\u003e, \u003cem\u003e38\u003c/em\u003e(1), 30\u0026ndash;51. https://doi.org/10.3109/1040841X.2011.621064\u003c/li\u003e\n\u003cli\u003eDe Oliveira, D. M. P., et al. (2020). Antimicrobial Resistance in ESKAPE Pathogens. \u003cem\u003eClinical microbiology reviews\u003c/em\u003e, \u003cem\u003e33\u003c/em\u003e(3), e00181-19. https://doi.org/10.1128/CMR.00181-19\u003c/li\u003e\n\u003cli\u003eLee, K., Yong, D., Jeong, S. H., \u0026amp; Chong, Y. (2011). Multidrug-resistant Acinetobacter spp.: increasingly problematic nosocomial pathogens. \u003cem\u003eYonsei medical journal\u003c/em\u003e, \u003cem\u003e52\u003c/em\u003e(6), 879\u0026ndash;891. https://doi.org/10.3349/ymj.2011.52.6.879\u003c/li\u003e\n\u003cli\u003eBrooke J. S. (2012). \u003cem\u003eStenotrophomonas maltophilia\u003c/em\u003e: an emerging global opportunistic pathogen. \u003cem\u003eClinical microbiology reviews\u003c/em\u003e, \u003cem\u003e25\u003c/em\u003e(1), 2\u0026ndash;41. https://doi.org/10.1128/CMR.00019-11\u003c/li\u003e\n\u003cli\u003eIoannou, P., Mavrikaki, V., \u0026amp; Kofteridis, D. P. (2020). \u003cem\u003eRoseomonas\u003c/em\u003e species infections in humans: a systematic review. \u003cem\u003eJournal of chemotherapy (Florence, Italy)\u003c/em\u003e, \u003cem\u003e32\u003c/em\u003e(5), 226\u0026ndash;236. https://doi.org/10.1080/1120009X.2020.1785742\u003c/li\u003e\n\u003cli\u003eMajidzadeh, M., \u0026amp; Fatahi-Bafghi, M. (2018). Current taxonomy of Rhodococcus species and their role in infections. \u003cem\u003eEuropean journal of clinical microbiology \u0026amp; infectious diseases: official publication of the European Society of Clinical Microbiology\u003c/em\u003e, \u003cem\u003e37\u003c/em\u003e(11), 2045\u0026ndash;2062. https://doi.org/10.1007/s10096-018-3364-x\u003c/li\u003e\n\u003cli\u003eMay, R. C., Stone, N. R., Wiesner, D. L., Bicanic, T., \u0026amp; Nielsen, K. (2016). Cryptococcus: from environmental saprophyte to global pathogen. \u003cem\u003eNature reviews. Microbiology\u003c/em\u003e, \u003cem\u003e14\u003c/em\u003e(2), 106\u0026ndash;117. https://doi.org/10.1038/nrmicro.2015.6\u003c/li\u003e\n\u003cli\u003eDorado-Morales, P., et al. (2016). A highly diverse, desert-like microbial biocenosis on solar panels in a Mediterranean city. \u003cem\u003eScientific reports\u003c/em\u003e, \u003cem\u003e6\u003c/em\u003e, 29235. https://doi.org/10.1038/srep29235\u003c/li\u003e\n\u003cli\u003eLee, J. H., Jung, J. H., Kim, M. K., \u0026amp; Lim, S. (2022). Deinococcus taeanensis sp. nov., a Radiation-Resistant Bacterium Isolated from a Coastal Dune. \u003cem\u003eCurrent microbiology\u003c/em\u003e, \u003cem\u003e79\u003c/em\u003e(11), 334. https://doi.org/10.1007/s00284-022-03044-8\u003c/li\u003e\n\u003cli\u003eVerma, A., et al. (2017). Domibacillus mangrovi sp. nov. and Domibacillus epiphyticus sp. nov., isolated from marine habitats of the central west coast of India. \u003cem\u003eInternational journal of systematic and evolutionary microbiology\u003c/em\u003e, \u003cem\u003e67\u003c/em\u003e(8), 3063\u0026ndash;3070. https://doi.org/10.1099/ijsem.0.002085\u003c/li\u003e\n\u003cli\u003eWalterson, A. M., \u0026amp; Stavrinides, J. (2015). Pantoea: insights into a highly versatile and diverse genus within the Enterobacteriaceae. \u003cem\u003eFEMS microbiology reviews\u003c/em\u003e, \u003cem\u003e39\u003c/em\u003e(6), 968\u0026ndash;984. https://doi.org/10.1093/femsre/fuv027\u003c/li\u003e\n\u003cli\u003eAli, G. A., Ibrahim, E. B., Doiphode, S. H., \u0026amp; Goravey, W. (2022). \u003cem\u003eMassilia timonae\u003c/em\u003ebacteremia: An unusual pathogen of septic abortion. \u003cem\u003eIDCases\u003c/em\u003e, \u003cem\u003e29\u003c/em\u003e, e01592. https://doi.org/10.1016/j.idcr.2022.e01592\u003c/li\u003e\n\u003cli\u003eBhatti, M. D., et al. (2017). Identification and Whole Genome Sequencing of the First Case of \u003cem\u003eKosakonia radicincitans\u003c/em\u003e Causing a Human Bloodstream Infection. \u003cem\u003eFrontiers in microbiology\u003c/em\u003e, \u003cem\u003e8\u003c/em\u003e, 62. https://doi.org/10.3389/fmicb.2017.00062\u003c/li\u003e\n\u003cli\u003eMorioka, H., et al. (2022). Lysinibacillus fusiformis bacteremia: Case report and literature review. \u003cem\u003eJournal of infection and chemotherapy: official journal of the Japan Society of Chemotherapy\u003c/em\u003e, \u003cem\u003e28\u003c/em\u003e(2), 315\u0026ndash;318. https://doi.org/10.1016/j.jiac.2021.10.030\u003c/li\u003e\n\u003cli\u003eVerdecia, J., Jankowski, C. A., Reynolds, M. L., McCarter, Y., \u0026amp; Ravi, M. (2022). Fungemia due to \u003cem\u003eAureobasidium pullulans\u003c/em\u003e. \u003cem\u003eMedical mycology case reports\u003c/em\u003e, \u003cem\u003e37\u003c/em\u003e, 26\u0026ndash;28. https://doi.org/10.1016/j.mmcr.2022.06.004\u003c/li\u003e\n\u003cli\u003eBaek, J. H., et al. (2022). \u003cem\u003eMassilia soli\u003c/em\u003esp. nov., isolated from soil. \u003cem\u003eInternational journal of systematic and evolutionary microbiology\u003c/em\u003e, \u003cem\u003e72\u003c/em\u003e(2), 10.1099/ijsem.0.005227. https://doi.org/10.1099/ijsem.0.005227\u003c/li\u003e\n\u003cli\u003eLi, C., et al. (2021). \u003cem\u003eMassilia rhizosphaerae\u003c/em\u003e sp. nov., a rice-associated rhizobacterium with antibacterial activity against \u003cem\u003eRalstonia solanacearum\u003c/em\u003e. \u003cem\u003eInternational journal of systematic and evolutionary microbiology\u003c/em\u003e, \u003cem\u003e71\u003c/em\u003e(9), 10.1099/ijsem.0.005009. https://doi.org/10.1099/ijsem.0.005009\u003c/li\u003e\n\u003cli\u003eArroyo, M. G., et al. (2020). Broad Diversity of Fungi in Hospital Water. \u003cem\u003eTheScientificWorldJournal\u003c/em\u003e, \u003cem\u003e2020\u003c/em\u003e, 9358542. https://doi.org/10.1155/2020/9358542\u003c/li\u003e\n\u003cli\u003eOliveira W.F., et al. (2018). Staphylococcus aureus and Staphylococcus epidermidis infections on implants. J Hosp Infect. 98, 111-7\u003c/li\u003e\n\u003cli\u003eMiller, C. D., Mortensen, W. S., Braga, G. U., \u0026amp; Anderson, A. J. (2001). The rpoS gene in \u003cem\u003ePseudomonas syringae\u003c/em\u003e is important in surviving exposure to the near-UV in sunlight. \u003cem\u003eCurrent microbiology\u003c/em\u003e, \u003cem\u003e43\u003c/em\u003e(5), 374\u0026ndash;377. https://doi.org/10.1007/s002840010319\u003c/li\u003e\n\u003cli\u003eK\u0026auml;mpfer, P., et al. (2000). Frigoribacterium faeni gen. nov., sp. nov., a novel psychrophilic genus of the family Microbacteriaceae. \u003cem\u003eInternational journal of systematic and evolutionary microbiology\u003c/em\u003e, \u003cem\u003e50 Pt 1\u003c/em\u003e, 355\u0026ndash;363. https://doi.org/10.1099/00207713-50-1-355\u003c/li\u003e\n\u003cli\u003eRampelotto, P.H., Sereia, A.F.R., de Oliveira, L.F.V., Margis, R. (2019) Exploring the Hospital Microbiome by High-Resolution 16S rRNA Profiling. \u003cem\u003eInt. J. Mol. Sci\u003c/em\u003e, \u003cem\u003e20\u003c/em\u003e, 3099\u003c/li\u003e\n\u003cli\u003eChander, A. M., et al. (2017). Genome Sequence of \u003cem\u003eKocuria polaris\u003c/em\u003eStrain CD08_4, an Isolate from the Duodenal Mucosa of a Celiac Disease Patient. \u003cem\u003eGenome announcements\u003c/em\u003e, \u003cem\u003e5\u003c/em\u003e(43), e01158-17. https://doi.org/10.1128/genomeA.01158-17\u003c/li\u003e\n\u003cli\u003eMetwally, R. A., El-Sersy, N. A., El Sikaily, A., Sabry, S. A., \u0026amp; Ghozlan, H. A. (2022). Optimization and multiple in vitro activity potentials of carotenoids from marine Kocuria sp. RAM1. \u003cem\u003eScientific reports\u003c/em\u003e, \u003cem\u003e12\u003c/em\u003e(1), 18203. https://doi.org/10.1038/s41598-022-22897-4\u003c/li\u003e\n\u003cli\u003eTian, B., \u0026amp; Hua, Y. (2010). Carotenoid biosynthesis in extremophilic Deinococcus-Thermus bacteria. \u003cem\u003eTrends in microbiology\u003c/em\u003e, \u003cem\u003e18\u003c/em\u003e(11), 512\u0026ndash;520. https://doi.org/10.1016/j.tim.2010.07.007\u003c/li\u003e\n\u003cli\u003eLim, S., Jung, J. H., Blanchard, L., \u0026amp; de Groot, A. (2019). Conservation and diversity of radiation and oxidative stress resistance mechanisms in Deinococcus species. \u003cem\u003eFEMS microbiology reviews\u003c/em\u003e, \u003cem\u003e43\u003c/em\u003e(1), 19\u0026ndash;52. https://doi.org/10.1093/femsre/fuy037\u003c/li\u003e\n\u003cli\u003eHern\u0026aacute;ndez-Fern\u0026aacute;ndez, G., Gal\u0026aacute;n, B., Carmona, M., Castro, L., \u0026amp; Garc\u0026iacute;a, J. L. (2022). Transcriptional response of the xerotolerant \u003cem\u003eArthrobacter\u003c/em\u003e sp. Helios strain to PEG-induced drought stress. \u003cem\u003eFrontiers in microbiology\u003c/em\u003e, \u003cem\u003e13\u003c/em\u003e, 1009068. https://doi.org/10.3389/fmicb.2022.1009068\u003c/li\u003e\n\u003cli\u003eRomaniuk, K., Golec, P., \u0026amp; Dziewit, L. (2018). Insight Into the Diversity and Possible Role of Plasmids in the Adaptation of Psychrotolerant and Metalotolerant \u003cem\u003eArthrobacter\u003c/em\u003e spp. to Extreme Antarctic Environments. \u003cem\u003eFrontiers in microbiology\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e, 3144. https://doi.org/10.3389/fmicb.2018.03144\u003c/li\u003e\n\u003cli\u003eFlegler, A., \u0026amp; Lipski, A. (2021). The C\u003csub\u003e50\u003c/sub\u003ecarotenoid bacterioruberin regulates membrane fluidity in pink-pigmented Arthrobacter species. \u003cem\u003eArchives of microbiology\u003c/em\u003e, \u003cem\u003e204\u003c/em\u003e(1), 70. https://doi.org/10.1007/s00203-021-02719-3\u003c/li\u003e\n\u003cli\u003eTao, K., Noda, A., \u0026amp; Yonei, S. (1987). The roles of different excision-repair mechanisms in the resistance of Micrococcus luteus to UV and chemical mutagens. \u003cem\u003eMutation research\u003c/em\u003e, \u003cem\u003e183\u003c/em\u003e(3), 231\u0026ndash;239. https://doi.org/10.1016/0167-8817(87)90005-8\u003c/li\u003e\n\u003cli\u003eZherebtsov, S. V., \u0026amp; Tomilin, N. V. (1982). The roles of different repair mechanisms in the ultraviolet resistance of \u003cem\u003eMicrococcus luteus\u003c/em\u003e. \u003cem\u003eBiochimica et biophysica acta\u003c/em\u003e, \u003cem\u003e698\u003c/em\u003e(3), 295\u0026ndash;302. https://doi.org/10.1016/0167-4781(82)90160-9\u003c/li\u003e\n\u003cli\u003eDi Capua, C., Bortolotti, A., Far\u0026iacute;as, M. E., \u0026amp; Cortez, N. (2011). UV-resistant Acinetobacter sp. isolates from Andean wetlands display high catalase activity. \u003cem\u003eFEMS microbiology letters\u003c/em\u003e, \u003cem\u003e317\u003c/em\u003e(2), 181\u0026ndash;189. https://doi.org/10.1111/j.1574-6968.2011.02231.x\u003c/li\u003e\n\u003cli\u003eGhosh, A., Goyal, A., \u0026amp; Jain, R. K. (2007). Study of methanol-induced phenotypic changes in a novel strain of Acinetobacter lwoffii. \u003cem\u003eArchives of microbiology\u003c/em\u003e, \u003cem\u003e188\u003c/em\u003e(5), 533\u0026ndash;539. https://doi.org/10.1007/s00203-007-0268-z\u003c/li\u003e\n\u003cli\u003eHan, S. R., Kim, K. H., Ahn, D. H., Park, H., \u0026amp; Oh, T. J. (2016). Complete genome sequence of carotenoid-producing Microbacterium sp. strain PAMC28756 isolated from an Antarctic lichen. \u003cem\u003eJournal of biotechnology\u003c/em\u003e, \u003cem\u003e226\u003c/em\u003e, 18\u0026ndash;19. https://doi.org/10.1016/j.jbiotec.2016.03.034\u003c/li\u003e\n\u003cli\u003eReis-Mansur, M. C. P. P., et al. (2019). Carotenoids from UV-resistant Antarctic Microbacterium sp. LEMMJ01. \u003cem\u003eScientific reports\u003c/em\u003e, \u003cem\u003e9\u003c/em\u003e(1), 9554. https://doi.org/10.1038/s41598-019-45840-6\u003c/li\u003e\n\u003cli\u003eZhang, W., et al. (2010). Microbacterium radiodurans sp. nov., a UV radiation-resistant bacterium isolated from soil. \u003cem\u003eInternational journal of systematic and evolutionary microbiology\u003c/em\u003e, \u003cem\u003e60\u003c/em\u003e(Pt 11), 2665\u0026ndash;2670. https://doi.org/10.1099/ijs.0.017400-0\u003c/li\u003e\n\u003cli\u003eEllington, A. J., Bryan, N. C., Christner, B. C., \u0026amp; Reisch, C. R. (2021). Draft Genome Sequences of Actinobacterial and Betaproteobacterial Strains Isolated from the Stratosphere. \u003cem\u003eMicrobiology resource announcements\u003c/em\u003e, \u003cem\u003e10\u003c/em\u003e(50), e0100921. https://doi.org/10.1128/MRA.01009-21\u003c/li\u003e\n\u003cli\u003eEltwisy, H. O., Twisy, H. O., Hafez, M. H., Sayed, I. M., \u0026amp; El-Mokhtar, M. A. (2022). Clinical Infections, Antibiotic Resistance, and Pathogenesis of \u003cem\u003eStaphylococcus haemolyticus\u003c/em\u003e. \u003cem\u003eMicroorganisms\u003c/em\u003e, \u003cem\u003e10\u003c/em\u003e(6), 1130. https://doi.org/10.3390/microorganisms10061130\u003c/li\u003e\n\u003cli\u003eKloos, W. E., et al. (1998). Staphylococcus hominis subsp. novobiosepticus subsp. nov., a novel trehalose- and N-acetyl-D-glucosamine-negative, novobiocin- and multiple-antibiotic-resistant subspecies isolated from human blood cultures. \u003cem\u003eInternational journal of systematic bacteriology\u003c/em\u003e, \u003cem\u003e48 Pt 3\u003c/em\u003e, 799\u0026ndash;812. https://doi.org/10.1099/00207713-48-3-799\u003c/li\u003e\n\u003cli\u003eLienen, T., et al. (2021). Multidrug-resistant Staphylococcus cohnii and Staphylococcus urealyticus isolates from German dairy farms exhibit resistance to beta-lactam antibiotics and divergent penicillin-binding proteins. \u003cem\u003eScientific reports\u003c/em\u003e, \u003cem\u003e11\u003c/em\u003e(1), 6075. https://doi.org/10.1038/s41598-021-85461-6\u003c/li\u003e\n\u003cli\u003eMendoza-Olazar\u0026aacute;n, S., et al. (2015). Antibiotic Susceptibility of Biofilm Cells and Molecular Characterisation of Staphylococcus hominis Isolates from Blood. PloS one, 10(12), e0144684. https://doi.org/10.1371/journal.pone.0144684\u003c/li\u003e\n\u003cli\u003eJałowiecki, Ł.,et al. (2017). Using phenotype microarrays in the assessment of the antibiotic susceptibility profile of bacteria isolated from wastewater in on-site treatment facilities. \u003cem\u003eFolia microbiologica\u003c/em\u003e, \u003cem\u003e62\u003c/em\u003e(6), 453\u0026ndash;461. https://doi.org/10.1007/s12223-017-0516-9\u003c/li\u003e\n\u003cli\u003eWhite, T., Bruns, T., Lee, S., Taylor, J. (1990). Amplification and direct sequencing of fungal ribosomal RNA genes for phylogenetics. PCR-protocols a guide to methods and applications. Edited by: Innis MA, Gelfand DH, Sninski JJ, White TJ. 1990, San Diego: Academic press, 315-322\u003c/li\u003e\n\u003cli\u003eSaitou N, Nei M. (1987). The neighbor-joining method: A new method for reconstructing phylogenetic trees. \u003cem\u003eMol Biol Evol, \u003c/em\u003e4, 406\u0026ndash;425\u003c/li\u003e\n\u003c/ol\u003e"}],"fulltextSource":"","fullText":"","funders":[],"hasAdminPriorityOnWorkflow":false,"hasManuscriptDocX":true,"hasOptedInToPreprint":true,"hasPassedJournalQc":"","hasAnyPriority":false,"hideJournal":false,"highlight":"","institution":"","isAcceptedByJournal":true,"isAuthorSuppliedPdf":false,"isDeskRejected":"","isHiddenFromSearch":false,"isInQc":false,"isInWorkflow":false,"isPdf":false,"isPdfUpToDate":true,"isWithdrawnOrRetracted":false,"journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"","lastPublishedDoi":"10.21203/rs.3.rs-2800931/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-2800931/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003eMicroorganisms colonize all possible ecological habitats, including those subjected to harsh stressors such as UV radiation. Hospitals, in particular the UV cabins used in phototherapy units, constitute an environment in which microbes are intermittently subjected to UV irradiation. This selective pressure, in addition to the frequent use of antibiotics by patients, may represent a threat in the context of the increasing problem of antimicrobial resistance. In this work, a collection of microorganisms has been established in order to study the microbiota associated to the inner and outer surfaces of UV cabins and to assess their resistance to UV light and the antibiotics frequently used in the Dermatology Service of a Spanish hospital. Our results show that UV cabins harbor a relatively diverse biocenosis dominated by typically UV-resistant microorganisms commonly found in sun-irradiated environments, such as \u003cem\u003eKocuria\u003c/em\u003e, \u003cem\u003eMicrococcus\u003c/em\u003eor \u003cem\u003eDeinococcus\u003c/em\u003e spp., but also clinically relevant taxa, such as \u003cem\u003eStaphylococcus\u003c/em\u003eor \u003cem\u003ePseudomonas\u003c/em\u003e spp. The UV-radiation assays revealed that, although some isolates displayed some resistance, UV is not a major factor shaping the biocenosis living on the cabins, since a similar pool of resistant microorganisms was identified on the external surface of the cabins. Interestingly, some \u003cem\u003eStaphylococcus\u003c/em\u003e spp. displayed resistance to one or more antibiotics, although the hospital reported no cases of antibiotic-resistance infections of the patients using the cabins. Finally, no association between UV and antibiotic resistances was found.\u003c/p\u003e","manuscriptTitle":"Microbial communities on UV cabins in the dermatology service of a Spanish hospital: ecology and resistance to UV light and antibiotics","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2023-04-17 21:18:08","doi":"10.21203/rs.3.rs-2800931/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Major revision","date":"2023-08-01T08:55:43+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2023-07-15T15:18:21+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"2a546860-8cfb-4faf-b4dd-2f3bb2f04147","date":"2023-04-24T07:15:03+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2023-04-22T14:04:51+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"4d856c07-2528-403a-9b61-20e05487bf49","date":"2023-04-19T10:15:29+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2023-04-19T09:53:33+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2023-04-19T09:51:19+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2023-04-15T06:06:21+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2023-04-15T06:00:32+00:00","index":"","fulltext":""},{"type":"submitted","content":"Scientific Reports","date":"2023-04-11T08:09:48+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"scientific-reports","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"scirep","sideBox":"Learn more about [Scientific Reports](http://www.nature.com/srep/)","snPcode":"","submissionUrl":"","title":"Scientific Reports","twitterHandle":"","acdcEnabled":true,"dfaEnabled":true,"editorialSystem":"stoa","reportingPortfolio":"Scientific Reports","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"bf26a9ad-c2c2-4feb-8ff8-35b9fd058a80","owner":[],"postedDate":"April 17th, 2023","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[{"id":20729575,"name":"Biological sciences/Microbiology/Communities"},{"id":20729576,"name":"Biological sciences/Microbiology/Communities/Metagenomics"},{"id":20729577,"name":"Biological sciences/Microbiology/Communities/Microbial ecology"},{"id":20729578,"name":"Biological sciences/Microbiology/Communities/Microbiome"},{"id":20729579,"name":"Biological sciences/Microbiology/Policy and public health in microbiology"}],"tags":[],"updatedAt":"2023-09-11T15:06:29+00:00","versionOfRecord":{"articleIdentity":"rs-2800931","link":"https://doi.org/10.1038/s41598-023-40996-8","journal":{"identity":"scientific-reports","isVorOnly":false,"title":"Scientific Reports"},"publishedOn":"2023-09-04 15:02:20","publishedOnDateReadable":"September 4th, 2023"},"versionCreatedAt":"2023-04-17 21:18:08","video":"","vorDoi":"10.1038/s41598-023-40996-8","vorDoiUrl":"https://doi.org/10.1038/s41598-023-40996-8","workflowStages":[]},"version":"v1","identity":"rs-2800931","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-2800931","identity":"rs-2800931","version":["v1"]},"buildId":"ApUGefWb6u5IBVtyqm6d5","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}