{"paper_id":"0edd2a76-e7a0-4319-ae9d-2ec1ddd8047c","body_text":"We conducted a multicenter, retrospective study in a hospital network in Hong Kong, China, including a 1,700-bed university-affiliated teaching hospital (Queen Mary Hospital) and 3 extended care hospitals ranging in size from 270 to 530 beds. We included all respiratory specimens, including sputum and bronchoalveolar lavage fluid (BALF) samples, collected during January 19–May 19, 2024, and sent to the microbiology laboratory at Queen Mary Hospital for routine bacterial culture. This study was approved by the Institutional Review Board of the University of Hong Kong Special Administrative Region, People’s Republic of China/Hospital Authority Hong Kong Special Administrative Region, People’s Republic of China West Cluster (UW 25-135).\nAs part of routine screening, we performed Gram stains on all lower respiratory specimens to semiquantify the number of leukocytes and assess specimen quality. We observed Gram stains under light microscopy at ×100 magnification and graded stains on the basis of the number of leukocytes as trace (<25 cells), 2+ (25–75 cells), or 3+ (>75 cells) and epithelial cells as 1+ (<10 cells), 2+ (10–25 cells), or 3+ (>25 cells) in an average of 10 fields. We inoculated all samples on blood and chocolate agar plates for routine bacterial culture and also inoculated BALF samples on MacConkey agar plates. Plates routinely are incubated at 35°C at 5% CO 2  and examined every 24 hours for 2 days. For this study, we also inoculated all respiratory tract samples on separate blood agar plates, incubated at 50°C, and examined plates every 24 hours for 5 days. We defined any colonies that grew from the blood agar plates at 50°C as thermotolerant bacteria, and subjected those to MALDI-TOF spectrometry and 16S rRNA PCR ( 3 ), when necessary, for bacterial identification. If the MALDI-TOF In Vitro Diagnostic database (Bruker,  https://www.bruker.com ) failed to identify bacteria, we performed subsequent Sanger sequencing.\nWhen MALDI-TOF spectrometry failed to identify bacterial isolates, we performed 16S rRNA sequencing. We used universal bacterial primers 16S-1F and 16S-2R and the QIAmp DNA Minikit (QIAGEN,  https://www.qiagen.com ) to extract DNA and sequenced on the 3500 Genetic Analyzer system (Thermo Fisher Scientific,  https://www.thermofisher.com ) ( Appendix ).\nWe considered bacteria that had suboptimal similarity percentages with existing bacteria in the BLAST ( https://blast.ncbi.nlm.nih.gov ) as possible novel species ( 4 ). We subjected those bacteria to whole-genome sequencing by using a dual platform of short- and long-read sequencing. For short-read sequencing, we performed DNA preparation by using the Nextera DNA Prep Kit, then sequenced on the iSeq100 (Illumina,  https://www.illumina.com ). For long-read sequencing, we used the Ligation Sequencing Kit for DNA preparation and MinION for sequencing (both Oxford Nanopore Technologies,  https://nanoporetech.com ) ( Appendix ).\nWe retrieved data on patients who had thermotolerant bacterial species identified from electronic health records. Patient information included demographic data, underlying medical conditions, signs and symptoms, time from hospital admission to sample collection, hematologic parameters, inflammatory markers, and radiologic findings.\nWe reported descriptive statistics as median and range and categorical variables as frequency and percentage. We used Fisher exact or χ 2  tests for 2-group comparisons. We performed statistical analyses in SPSS Statistics 24.0 (IBM,  https://www.ibm.com ) and considered p<0.05 statistically significant.\n\nDuring January 19–May 19, 2024, the microbiology laboratory collected 7,257 respiratory specimens, of which 6,766 were lower respiratory tract specimens: 5,922 expectorated sputum, 388 tracheal aspirates, and 456 bronchial specimens, including BALF and endobronchial biopsy specimens. The other 491 respiratory specimens were upper respiratory tract specimens: 113 nasal or nasopharyngeal swab samples, 283 oral or throat swab samples, and 95 gastric aspirates.\nAmong collected specimens, 66 (64 sputum and 2 throat swab) specimens from 65 patients grew thermotolerant bacteria that could not be identified by MALDI-TOF spectrometry ( Table 1 ). Among the 66 thermotolerant bacterial specimens, we identified  Tepidimonas  spp. in 42 (63.6%, 0.6% of all respiratory specimens, 41 sputum and 1 throat swab) specimens from 41 patients by 16S rRNA sequencing; 37 were  T. aquatica , 3 were undetermined  Tepidimonas  spp., 1 was  T. taiwanensis , and 1 was  T. fonticaldi.\n*Identified by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry.\n†Unable to identify species-level by 16S rRNA sequencing.\nPatients with  Tepidimonas  spp. bacterial isolates were from all age groups; 56.1% of patients were female and 43.9% were male ( Table 2 ). The most common underlying conditions in the cohort were solid organ malignancy (41.5%), hypertension (36.6%), chronic lung disease (24.4%), and hyperlipidemia (24.4%). Among  Tepidimonas  spp. isolates, 58.5% were from sputum saved in the outpatient setting or collected  < 48 hours of hospital admission, suggesting a possible community source. Common clinical signs and symptoms included cough, fever, and shortness of breath. Some of the patients had abnormal chest radiograph findings, including consolidation or pulmonary infiltrates (26.8%), pleural effusion (19.5%), and chronic lung changes (24.4%). However, 34.1% of patients with  Tepidimonas  spp. isolated had unremarkable findings on chest radiographs, representing possible bacterial colonization of the respiratory tract.\n*Values are no. (%) except as indicated.\nAmong laboratory characteristics of the 41 sputum specimens, 51.2% had trace leukocytes, and 46.3% had <10 epithelial cells per field ( Table 3 ). In addition, 36.6% had growth of other pathogenic organisms, the most common of which were  Haemophilus influenzae  and  Flavobacterium  species.\nOur study identified 3 clinical isolates of a novel  Tepidimonas  sp. bacterium. Here, we report phenotypic characteristics and genomic features of those bacteria, including detection of virulence, antimicrobial resistance (AMR), and stress-related genes. To investigate potential sources of this bacterium, we also performed environmental sampling in the hospital.\nThe 3 undetermined sequences detected by 16S rRNA sequencing displayed 96.68%–97.59% sequence identity to known  Tepidimonas  spp. available in the BLAST database, suggesting that the taxonomic position of those isolates remained uncertain. The sequences were from 3 isolates (HKU77, HKU78, and HKU79) from 3 patients: 1 with pulmonary metastasis, 1 with community-acquired pneumonia, and 1 with underlying Graves’ disease and schizophrenia who had fever during hospitalization.\nGram stain of isolates HKU77, HKU78, and HKU79 revealed gram-negative, non–spore-forming, motile rods with occasional spherical enlargement ( Appendix  Figure, panel A). We observed small translucent and nonpigmented colonies with no hemolysis on blood agar after 24 hours of incubation. The size of colonies gradually increased with prolonged incubation. We noted no pigment production at 35°C or 42°C, but colonies displayed a slight brown pigmentation after prolonged incubation at 50°C. Optimal growth of those bacteria occurred at 50°C, and we noted no visible growth at 25°C ( Appendix  Figure, panels B–D). The 3 isolates did not grow in anaerobic conditions. Growth on chocolate agar and  Haemophilus  test medium at 50°C was similar to that for blood agar; we observed slower growth on  Brucella  agar. However, we noted no growth on buffered charcoal yeast extract agar or brain heart infusion agar supplemented with X and V factor. We observed no fluorescence under ultraviolet light ( Table 4 ).\n*Strains of novel  T. hongkongensis . BCYE, buffered charcoal yeast extract; ONPG, ortho-Nitrophenyl-β-galactoside; UV, ultraviolet.\n†bioMérieux,  https://www.biomerieux.com .\nBiochemically, all 3 isolates were oxidase-positive and weakly catalase-positive (with 15% hydrogen peroxide) and tested negative for lipase, lecithinase, DNAase, and gelatinase at 50°C. The isolates were positive for nitrate reductase, glutamyl arylamidase, and tyrosine arylamidase and weakly positive for urease. Sugar fermentation (glucose, lactose, sucrose, citrate), indole, H 2 S production, and ortho-nitrophenyl-β-galactoside were all negative after incubation at 50°C. We evaluated enzymatic activity by using the VITEK AutoMicrobic GNI+ card (bioMérieux,  https://www.biomerieux.com ), which was positive for glutamyl arylamidase and tyrosine arylamidase, and 1 strain (HKU78) showed additional enzymatic activity of L-proline arylamidase and a positive Ellman’s test result.\nThe 3 isolates were susceptible to piperacillin, piperacillin/tazobactam, ceftazidime, amikacin, ciprofloxacin, tobramycin, and cefepime, according to the Clinical Laboratory Standards Institute  Pseudomonas  breakpoints ( 5 ). The MICs of penicillin for the 3 isolates were  < 0.016 μg/mL, and MICs of vancomycin were 48–64 μg/mL. Comparison with phenotypic characteristics of  T. aquatica  and  T. taiwanensis  showed that the  Tepidimonas  species from our 3 strains did not grow on buffered charcoal yeast extract agar, but both  T. aquatica  and  T. taiwanensis  did. Furthermore,  T. taiwanensis  is gelatinase- and nitrate-positive, but  T. aquatica  and the novel  Tepidimonas  species from our study are not ( Table 4 ).\nThe de novo assembly, using Illumina and Oxford Nanopore Technology reads, yielded complete genomes for the strains HKU77, HKU78, and HKU79 ( Figure 1 ). The genome sizes of the 3 strains ranged from 2,842,968 to 2,891,522 bp, and GC content spanned 67.1%–67.2% ( Table 5 ). We submitted the assembled genome sequences to PROKKA ( https://github.com/tseemann/prokka ) for annotation, which resulted in 2,695–2,786 protein-coding sequences, 3 rRNA operons, and 50–52 tRNA-coding genes ( Table 5 ). Annotation via the RAST pipeline (Rapid Annotations using Subsystems Technology; Argonne National Laboratory,  https://www.anl.gov/mcs/rast-rapid-annotation-using-subsystem-technology ) indicated that the 3 strains possess a similar number of genes and subsystems, except for strain HKU78, which harbored a phage genome containing an additional integron integrase  IntI1  gene related to the phages, prophages, transposable elements, and plasmids subsystem in RAST ( Figure 2 ).\nCircular genome map of novel thermotolerant  Tepidimonas  spp. bacteria detected in human respiratory specimens, Hong Kong, China, 2024. Using patient strain HKU77 T  as the reference genome forming the backbone, the ring compares genome matches from patient strains HKU78 and HKU79 and the 2 closest  Tepidimonas  species,  T. fonticoaldi  AT-A2 T  and  T. taiwanensis  I1–1 T  genomes. The genome features include GC content and plus (+) or minus (–) GC skew.\n*Genome statistics obtained from PROKKA ( https://github.com/tseemann/prokka ) annotation and seqkit ( https://github.com/shenwei356/seqkit/releases ) results.\nComparison of feature counts of functional annotations from detection of novel thermotolerant  Tepidimonas  spp. bacteria in human respiratory specimens, Hong Kong, China, 2024. Annotations were determined by using Rapid Annotations using Subsystems Technology (Argonne National Laboratory,  https://www.anl.gov/mcs/rast-rapid-annotation-using-subsystem-technology ). Each functional category is represented by bars corresponding to the 3 patient strains of  T. hongkongensis  identified in this study.\nTo determine the phylogenetic positions of the 3 strains within the genus  Tepidimonas , we used Type (Strain) Gene Server (Leibniz Institute,  https://tygs.dsmz.de ) results to construct a phylogenetic tree incorporating genome data from the 3 strains and complete genomes of other  Tepidimonas  spp. type strains. That analysis revealed that HKU77, HKU78, and HKU79 cluster together, forming a distinct and well-supported phylogenetic clade, separate from other  Tepidimonas  species, and are most closely related to  T. fonticaldi  ( Figure 3 , panel A). Similarly, the phylogenetic tree constructed from core-genome sequences displayed a consistent topology ( Figure 3 , panel B). In silico genome-to-genome comparison demonstrated that the 3 strains from our study shared pairwise digital DNA-DNA hybridization (dDDH) values ranging from 95.3% to 97.8% among each other. Those 3 strains were most closely related to  T. fonticaldi  AT-A2 (dDDH value 26.1%–26.2%), followed by  T. taiwanensis  I1–1 (dDDH value 24.7%–24.8%), and  T. charontis  SPSP-6T (dDDH value 24.0%–24.3%), but the dDDH values were below the 70.0% threshold, indicating the 3 strains from our study are a different species ( Table 6 ). On the basis of those results, we propose that strains HKU77, HKU78, and HKU79 represent a newly identified  Tepidimonas  species. We suggest the name  Tepidimonas hongkongensis  sp. nov. for the location of isolation and that strain HKU77 T  (GenBank accession no.  CP187300 ) be designated as the type strain.\nPhylogeny of novel thermotolerant  Tepidimonas  spp. bacteria isolated from human respiratory specimens, Hong Kong, China, 2024. Phylogenetic trees show the relationship between 3 patient strains identified in this study (bold font) and global representative  Tepidimonas  spp. strains. A) Tree was inferred using whole-genome data with Type (Strain) Gene Server (Leibniz Institute,  https://tygs.dsmz.de ). B) Tree inferred from the species-specific core genes and compared with existing  Tepidimonas  spp. in GenBank. Scale bar indicates nucleotide substitutions per site.\n*Comparison through digital DNA-DNA hybridization by using Type (Strain) Gene Server (Leibniz Institute,  https://tygs.dsmz.de ). ID, identification.\nWe characterized virulence factors of  T. hongkongensis  by using the Virulence Factors of Pathogenic Bacteria database ( https://www.mgc.ac.cn/VFs/main.htm ), on the basis of available sequences ( Appendix  Table 1). We identified several genes that contribute to the function of motility and adherence, some of which are similar to genes of type IV pili of  Pseudomonas  spp., including  pilB ,  pilC , and  pilT , contributing to the adhesion of  T. hongkongensis  to other cells. We also detected different genes related to immune evasion and several genes that contribute to counteracting phagocytosis in humans. Those genes included  uge , which is observed to generate the capsule in  Klebsiella  spp. Bacteria, and  algC ,  algU , and  algW , which are responsible for alginate regulation and biosynthesis in  Pseudomonas  spp. bacteria. In addition, we observed genes in  T. hongkongensis  that are associated with secretion systems in other bacteria, including  clpV  (type VI secretory system),  epsE , and  lspG  (type II secretory system).  T. hongkongensis  strains also contained  hemE  and  hemL  genes, which are observed in heme biosynthesis in  Haemophilus  spp. bacteria.\nAnother species,  T. taiwanensis , has previously been reported to produce alkaline protease and polyhydroxyalkanoates (PHA), renewable and biodegradable polymers that can replace conventional plastic ( 6 ). Comparison of  T. hongkongensis  and type strain  T. taiwanensis  LMG22826T (GenBank accession no.  CP083911 ) showed that  T. hongkongensis  contained alkaline proteases, except lysyl endopeptidase. Furthermore,  T. taiwanensis  possesses  phaC  and  phaR  genes that are necessary for PHA production, as well as  phaZ  coding PHA depolymerase. Similarly, all 3  T. hongkongensis  strains possessed the  phaC ,  phaR , and  phaZ , suggesting that  T. hongkongensis  is associated with PHA production. Oxidation of thiosulfate to sulfate has been reported in all  Tepidimonas  species through the  sox  pathway ( 7 ), and all 3  T. hongkongensis  strains contained the genes encoding the sulfur-oxidizing protein.\nUsing the National Center for Biotechnology Information AMRfinder ( https://www.ncbi.nlm.nih.gov/pathogens/antimicrobial-resistance/AMRFinder ), we found that all 3  T. hongkongensis  harbored aminoglycoside resistance genes ( aadA2 ) and a β-lactamase gene ( bla OXA-2 ). We also identified stress-related genes, including multiple heat-shock proteins and efflux pumps, including  qacL  ( Appendix  Table 2).\nThe isolate of strain HKU77 T  was from a patient with pulmonary metastases. The DNA GC content was 67.2% mol; we considered this the type strain. The isolate of the second strain, HKU78, was from a patient with community-acquired pneumonia and had DNA GC content of 67.1% mol. The isolate of the third strain, HKU79, was from a patient with underlying Graves’ disease and paranoid schizophrenia and had DNA GC content of 67.2% mol.\nWe collected 101 water samples from the faucets in various areas of the hospital, including wards, utility rooms, bathrooms, and the pantry, after the study period in April 2025. Among collected samples, 47 (46.5%) grew thermotolerant bacteria ( Table 7 ). From those 47 samples, we subsequently identified 43 (91.5%; 42.6% of all water samples collected) thermotolerant bacteria as  Schlegelella aquatica . We identified  T. hongkongensis  in 2 (2.0%) water samples and  Prophyrobacter cryptus  bacteria in 1 (1.0%) water sample. The percentages of water samples growing  S. aquatica  (42.6%) and  T. hongkongensis  (2.0%) were higher than the rates in respiratory specimens: 0.6%  S. aquatica  and 0.2%  T. hongkongensis  (p<0.05). Although we identified >20 times more  S. aquatica  isolates than  Tepidimonas  spp. isolates in the water samples, we isolated 3 times as many  Tepidimonas  spp. bacteria than  S. aquatica  in respiratory specimens. Furthermore, among the 17 patients with  Tepidimonas  spp. bacteria isolated from sputum 48 hours after hospitalization ( Table 2 ), none were hospitalized in the 2 wards from which we isolated  T. hongkongensis  in the water samples.\n*Water samples were collected from faucets in various areas of the hospital, including wards, utility rooms, bathrooms, and the pantry.\n\nThermotolerant bacteria can thrive under elevated temperatures, typically 45°C–60°C. Examples of thermotolerant bacteria causing human infection include  Campylobacter fetus  ( 8 ) and  Mycobacterium xenopi  ( 2 ). Various thermotolerant bacteria, such as  Tepidimonas  spp., have been isolated or detected in environmental hot water samples, including hot springs ( 9 – 11 ). However, the clinical consequences of most thermotolerant bacteria are uncertain.\nIn addition to  Tepidimonas  spp., our study identified different thermotolerant bacteria in clinical specimens, including  S. aquatica , which belongs to the Comamonadaceae family and was first isolated from a hot spring in Taiwan ( 9 ) but was not known to cause human infection. In addition, we identified  Vulcaniibacterium thermophilum  in 4 patient samples; it was first isolated from a geothermal soil sample in Tengchong, Yunnan Province, in southwest China in 2012 ( 10 ) and was the reported cause of prosthetic joint infection in 1 case ( 13 ). In addition,  Thermomonas  spp. bacteria, which we detected in 2 specimens, frequently have been isolated from hot water ( 11 , 14 ), marine sediment ( 15 ), and soil ( 16 – 18 ). One study reported its detection in the naso-oropharyngeal microbiome from breast cancer patients with severe COVID-19 ( 19 ).  Lactobacillus delbrueckii  bacteria, which we detected in 1 specimen, commonly are used for probiotics and food fermentation ( 20 ); however, that bacterium has been reported to cause urinary tract infection and bacteremia ( 21 – 24 ). Finally, we detected 3  Bacillus  spp. bacteria, which are known to form heat-resistant spores; although non– B. \n anthracis Bacillus  are usually considered environmental bacteria, they can cause infection in patients with prostheses and central catheters ( 25 , 26 ).\nThe genus  Tepidimonas  was established in 2000 ( 27 ), and its members are gram-negative bacilli with positive catalase and oxidase activity that are motile due to a single polar flagellum.  Tepidimonas  spp. bacteria typically exhibit optimal growth at temperatures >45°C; therefore, most have been isolated from relatively high-temperature environments, such as hot springs and spas worldwide ( 9 – 11 ). As of January 25, 2026, only 8  Tepidimonas  species have been validly published in the List of Prokaryotic names with Standing in Nomenclature:  T. ignava ,  T. aquatica ,  T. taiwanensis ,  T. thermarum ,  T. fonticaldi ,  T. sediminis ,  T. alkaliphila , and  T. charontis  ( https://lpsn.dsmz.de/genus/tepidimonas ). Within the genus,  T. taiwanensis  is the only strain that uses glucose and fructose for growth, due to the presence of putative ABC glucose/mannose ( gtsABCD ) and fructose ( frcABC ) transporters ( 7 ), whereas other species are frequently referred to as asaccharolytic. Similar to a previous report ( 7 ), the novel  T. hongkongensis  bacterium does not use glucose and fructose for growth. Of note,  T. taiwanensis  produces alkaline protease and PHA, renewable and biodegradable polymers that can replace conventional plastic ( 6 ). Genome analysis revealed that  T. hongkongensis  contains most of the alkaline protease genes found in  T. taiwanensis , as well as genes associated with PHA production ( 12 ). Analysis of stress-related genes in  T. hongkongensis  revealed the presence of heat-resistant protein and ATPase genes, which explain its thermotolerant characteristic.\nIn our study, 0.6% of respiratory specimens grew  Tepidimonas  spp. bacteria after prolonged incubation at 50°C, and most patients from whom specimens were collected had solid organ malignancy and chronic lung disease, although ages were wide ranging. Other  Tepidimonas  spp. bacteria have been detected in clinical samples. For instance, a proposed new  Tepidimonas  species,  T. arfidensis , was cultured from a bone marrow aspirate sample from a patient with leukemia with neutropenic fever ( 28 ). Other  Tepidimonas  spp. bacteria have been implicated in different human microbiome studies, including the urine microbiome for urinary incontinence ( 29 , 30 ), the endometrial microbiome for endometriosis ( 31 ), the gut microbiome in primary sclerosing cholangitis ( 32 ), and the sinus microbiome in chronic rhinosinusitis ( 33 ). In our study, only 36.6% of the patients had growth of other pathogenic bacteria in the sputum ( Table 3 ), suggesting that  Tepidimonas  spp. are pathogenic and can cause lower respiratory tract infection.\nThe tap water samples collected from the hospital revealed the presence of  T. hongkongensis  sp. nov. and a high percentage of  S. aquatica . Those results align with previous findings that  Tepidimonas  spp. and  S. aquatica  bacteria are commonly found in the environment ( 9 , 34 ). Of note, we detected  Tepidimonas  spp. bacteria more frequently than  S. aquatica  in the water samples, but we detected more  Tepidimonas  spp. than  S. aquatica  in respiratory specimens ( Tables 1 ,  7 ), suggesting that  Tepidimonas  spp. bacteria could have a greater potential for colonizing the human respiratory tract than other environmental bacteria.\nComparative genomic analysis revealed that all 3  T. hongkongensis  strains contained various virulence genes spanning critical functional classes, including adherence, iron uptake, lipid metabolism, nutritional virulence, serum resistance, and stress adaptation, but those genes are absent in  S. aquatica  LMG 23380 ( Appendix  Table 1). Those genes support colonization of host tissue, nutrient scavenging, immune evasion, and persistence under stress, further underscoring the potential pathogenicity of  T. hongkongensis.  Although resistome profiling did not demonstrate substantial antimicrobial resistance in  T. hongkongensis  ( Appendix  Table 2), we did detect it in environmental samples, and its ability to acquire other resistance, such as colistin resistance, through horizontal gene transfer from other gram-negative bacteria, is not known ( 35 , 36 ). Therefore, further surveillance is warranted.\nWhether detection of  T. hongkongensis  in the hospital water systems warrants interventions requires further risk assessments and studies. First, the infectious threshold of  T. hongkongensis  should be established to assess the risk that patients could acquire it from the water system. Furthermore, whether usual water disinfection protocols, such as chlorine or ultraviolet light, are effective against this bacterium is unknown. Ongoing vigilance and documentation will help define the baseline incidence and clinical significance for this bacterium and guide future recommendations.\nThe first limitation of our study is that it was conducted in a hospital network in Hong Kong; whether similar observations occur in other hospitals and countries requires further investigation. Second, we only used 50°C for agar incubation to isolate thermotolerant bacteria, which might have failed to recover other clinically relevant pathogens that do not grow at such high temperatures. Third, although isolation of  Tepidimonas  spp. bacteria from the clinical specimens in our study might be related to a hot water source, other studies have isolated various  Tepidimonas  spp. bacteria in sterile clinical specimens, suggesting this genus might not solely be an environmental contaminant. Finally, isolation of  Tepidimonas  spp. and other thermotolerant bacteria in respiratory specimens could represent colonization instead of respiratory pathogens. However, many patients in our study had underlying solid organ malignancy, suggesting pathogenicity is still possible in severely immunocompromised patients, such as bone marrow transplant recipients. Further studies are required to investigate the pathogenic potential of  T. hongkongensis  and the range of illnesses the bacteria can cause.\nIn conclusion, we successfully isolated 42 thermotolerant  Tepidimonas  spp. bacterial strains from clinical specimens, including 3 novel strains confirmed by whole-genome sequencing. We propose the name  T. hongkongensis  sp. nov. to describe the 3 novel strains and designation of HKU77 T  as the type strain of this novel species. The combination of high incubation temperature for selection, prolonged incubation for growth, and MALDI-TOF mass spectrometery and 16S rRNA sequencing enabled discovery of this novel species. Analysis of water samples from the hospital further confirmed the presence of  T. hongkongensis  in the environment. Although clinical implications of  T. hongkongensis , especially in immunocompromised patients, are not yet known, its potential spread in water systems is concerning. Ongoing vigilance and documentation will help define the baseline incidence and clinical significance of  T. hongkongensis  and guide future recommendations.\n\nAdditional information on detection of novel thermotolerant  Tepidimonas  species bacteria in human respiratory specimens, Hong Kong, China, 2024.","source_license":"CC-BY-4.0","license_restricted":false}