Detection of a New blaOXA-51-Like Variant (blaOXA-1328) and a Novel Sequence Type (ST3457/2790) in Acinetobacter baumannii Isolated from Community Sewage and an Incinerator Surface in Nigeria

Detection of a New blaOXA-51-Like Variant (blaOXA-1328) and a Novel Sequence Type (ST3457/2790) in Acinetobacter baumannii Isolated from Community Sewage and an Incinerator Surface in Nigeria | 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 Short Report Detection of a New blaOXA-51-Like Variant (blaOXA-1328) and a Novel Sequence Type (ST3457/2790) in Acinetobacter baumannii Isolated from Community Sewage and an Incinerator Surface in Nigeria Khalifa Jamil Saleh, Muhammad Yushau, Abdullahi Hassan Kawo, Evelyn Skiebe, and 2 more This is a preprint; it has not been peer reviewed by a journal. https://doi.org/ 10.21203/rs.3.rs-6332131/v1 This work is licensed under a CC BY 4.0 License Status: Published Journal Publication published 06 Aug, 2025 Read the published version in BMC Research Notes → Version 1 posted 13 You are reading this latest preprint version Abstract Objective: Acinetobacter baumannii is an opportunistic pathogen with a high capacity to acquire antimicrobial resistance (AMR) determinants, including OXA-type β-lactamases, which confer carbapenem resistance. Environmental reservoirs play a crucial role in the persistence and spread of the bacteria, yet limited data exist on A. baumannii from non-hospital environments (which is critical in epidemiological studies) in Nigeria. This study aimed to study the genetic diversities of A. baumannii strains from different non-hospital environments in Nigeria, determine their sequence types (STs), and characterize their resistance genes. Results: While studying the prevalence of A. baumannii from 404 environmental samples (soil, sewage, water, and air) collected from three non-hospital communities in Nigeria, 2 isolates with novel features were discovered. Following culture-based and molecular identification, 33 isolates (7.5%) were confirmed as A. baumannii . Whole-genome sequencing (WGS) revealed the presence of one novel bla OXA-51 -like variant ( bla OXA1283 ) (that was diverged from bla OXA-180 variants that were previously isolated from different environments in Nigeria) and one sequence type (ST3457/2790). A variant (bla OXA-707 ) isolated from semi-pristine soil, is closely related to only one strain isolated from a stork bird in Poland. Another strain from an incinerator surface, clustered with strains from human oral sources in China, suggesting a potential link to clinical strains. The three isolates were susceptible to carbapenems (imipenem, meropenem), ceftazidime, tetracycline, gentamicin, sulfamethoxazole, and ciprofloxacin, suggesting minimal clinical exposure. However, a related strain carrying bla OXA-120 from Egypt has been reported with additional bla NDM-1 , a gene that mediates carbapenem resistance. Acinetobacter baumannii blaOXA-51 like genes variants sewage molecular diversity Acinetobacter baumannii phylogeny Figures Figure 1 Introduction Acinetobacter baumannii is a significant opportunistic pathogen known for its remarkable ability to acquire and disseminate antimicrobial resistance (AMR) determinants, particularly carbapenemases, which confer resistance to last-resort antibiotics [ 1 , 2 ]. Among these carbapenemases, OXA-type β-lactamases (oxacillinases) play a crucial role in carbapenem resistance, with bla OXA-51 - like genes being intrinsic to A. baumannii [ 3 ]. However, novel variants of bla OXA-51 -like genes continue to emerge [ 4 – 6 ], contributing to the increasing complexity of AMR phenotypes in this pathogen. Environmental media, such as waste disposal sites, soil, and water, have been identified as hotspots for the dissemination of antimicrobial-resistant bacteria, including A. baumannii , due to the selective pressure exerted by antimicrobial-like chemicals or residues and other pollutants present in the sources [ 7 – 9 ]. In addition, they also serve as a critical surveillance point for detecting emerging resistance genes before they become widespread in clinical settings [ 7 ]. Despite the concerns about the environment's role in AMR propagation, data on the molecular epidemiology of A. baumannii from environmental sources in Nigeria—particularly from unconventional sites such as air, unexplored surfaces, semi-pristine soil and water, and community sewage—remain scarce. These environments, often overlooked in routine surveillance, could serve as hidden reservoirs for emerging resistant pathogens. In this study, we report the detection of a novel bla OXA-51-like variant, bla OXA-1328 , in A. baumannii obtained from community sewage in Nigeria, and a novel sequence type (ST3457 oxf /2790 pas ) from an incinerator surface as part of a study aimed at exploring non-hospital sources of A. baumannii in Nigerian environments. To our knowledge, this is the first report of these variants, which further highlights the importance of environmental AMR surveillance in identifying emerging resistance mechanisms in A. baumannii . The findings suggest the need for continuous genomic monitoring of A. baumannii in both clinical and environmental settings to understand its evolutionary dynamics and mitigate the spread of resistance. Methods We collected 404 samples of 101 each of soil, sewage, water, and air from 3 non-hospital environments in Kano metropolitan communities as A. baumannii was isolated on MacConkey and CHROMAgar Acinetobacter as previously described [ 2 , 7 ]. Thirty-three (33) isolates were biochemically confirmed as presumptive A. baumannii and later confirmed using polymerase chain reaction (PCR) by amplifying bla OXA−51 −like gene using specific forward and reverse primers [ 2 , 10 ]. The coding region of bla OXA−51−like was amplified and sequenced using Sanger technology to determine the bla OXA−51−like variants. Whole-genome sequencing (WGS) of selected strains (isolated from unusual sites) was performed to explore their genetic composition, sequence type, and resistance mechanisms using Illumina technology [ 11 ]. To understand the genetic relatedness of the new variant and other environmental A. baumannii strains isolated in this study with other clinical and non-clinical sources across the globe, the BV-BRC workspace was used to generate a phylogenetic tree [ 12 ]. Results and Discussion Phenotypic and Molecular identification A 7.5% recovery rate of A. baumannii was reported (33 out of 440). Of the 33 isolates, 3 bla OXA−51 variants isolated from community sewage, incinerator surface, and semi pristine soil near migratory birds’ stop-over tree revealed an interesting result. Of the 3 strains, S6 which was isolated from a community sewage did not yield 100% similarity with other bla OXA−51 variants in the NCBI data (Blastp), to reveal a new variant. The sequence of the new variant was deposited in NCBI; it was designated as bla OXA−1328 and was given accession number PQ659032. However, strain from semi pristine soil (S4) and the one from incinerator surface (S5) harbour variants bla OXA−707 and bla OXA−120, respectively. In contrast to S4, previous isolates harbouring bla OXA−707 are predominantly isolated from healthcare devices, patient belongings as well as wounds of burn patients in ICUs [ 13 , 14 ]. In addition, bla OXA−120 carried by strain S5 which was isolated from the incinerator surface, has been reported from clinical settings in intensive care unit (ICU), environmental sources from hospital sewage and urban wastewater sources, and food samples [ 15 ]. This shows it's wide spread and the possibility of establishing itself in different environments including non-healthcare settings. The 3 isolates are phenotypically susceptible to imipenem, meropenem, tetracycline, ceftazidime, gentamicin, sulfamethoxazole, and ciprofloxacin, which may be due to their lesser exposure to clinical settings. However, a related strain harbouring bla OXA−120 variant isolated from an Egyptian hospital setting has been reported to have acquired bla NDM−1 which mediates carbapenem resistance [ 16 ]. In addition, other carbapenemase resistance genes such as bla OXA−23 , and bla OXA−58, which are frequently associated with transposons and often integrated into A. baumannii chromosome with upstream insertion sequences regulating their expression are reported in another bla OXA−707 harbouring strain [ 17 ] and being related to isolate S4. In contrast, WGS analysis using ResFinder revealed the presence of some clinically relevant bla OXA and bla ADC beta-lactamase genes among the isolates. Notably, S6 ( bla OXA−1328 ), harbored bla ADC−25 (96.89%) and bla OXA−51 (100%), with resistance phenotypes including amoxicillin, ampicillin, and imipenem. IS Aba1 which plays an important role in the expression of carbapenem resistance was only detected in S6 (truncated), but IS Aba12 (known for conferring impressive genetic plasticity and colistin dependence) and IS Aba13 (known for capsule, virulence, and antibiotic resistance) were found in S4 and S5respectively. MLST analysis assigned 2 of the isolates (S4 and S6) to diverse sequence types (STs), revealing both local and international genetic links to environmental and clinical strains. However, isolate S5 which did not yield exact match with any ST. it exhibited a single locus mismatch with ST1589 (Pasteur), previously identified in an environmental sample from Germany, suggesting a non distant evolutionary relationship. Additionally, S5 showed two mismatches (71.4% loci similarity) with ST615 (Oxford) from China, as well as ST1479 and ST1496, recovered from urine and blood samples in China and South Korea, respectively. These findings indicate that S5 represents a novel sequence type, which has been submitted to MLST and was assigned new ST number (ST3457 oxf and ST2790 pas ). ST3457 (S5) shares identical alleles with A. baumannii ST615, ST1479, and ST1496 in most genes analyzed ( tonB, rpoB, phoE, infB , and fusA ), except for recA and gpI . The divergence in recA observed may affect DNA repair, which can influence the strain’s ability to adapt to environmental stress, antimicrobial exposure, or acquire foreign genes through horizontal transfer. Meanwhile, variation in gpI , involved in lipopolysaccharide biosynthesis and membrane integrity, could impact virulence, immune evasion, or antimicrobial susceptibility. In contrast, S6 matched exactly with ST2132 pas , previously isolated from a sputum sample of a patient in India, suggesting its global distribution and potential clinical relevance. S6 also exhibited a single mismatch (85.7% loci similarity) with ST3122 oxf , a strain previously identified in a stork from Poland. The genetic proximity of S6 to both human and avian sources raises important questions about potential transmission pathways, including airborne dispersal or indirect environmental contamination. Isolate S4 was an exact match to ST2111 pas , first identified in Israel in 2004 from an unknown source. Under the Oxford scheme, S4 exhibited four mismatches with ST2963 and ST3122—both previously isolated from A. baumannii strains recovered from storks in Poland. Their genetic resemblance to avian-associated strains suggests a possible ecological link between environmental isolates and wildlife reservoirs[ 11 ]. These findings support the hypothesis that environmental persistence and indirect transmission play significant roles in the epidemiology of A. baumannii . Phylogenetic analysis of these strains revealed a divergence of S6 from cluster of bla OXA−180 variants previously isolated from different Nigerian environment (Fig. 1 ). Additionally, it also revealed a close relationship between S4 and another A. baumannii isolated from a stork bird from Poland. Isolate S5 which was recovered from the incinerator surface clustered with two A. baumannii strains from human oral source in China further indicating its closeness to clinical strains. Table 1 sequence and OXA-type features of the three isolates Isolate Source WGS predicted phenotypes AMR genes (% gene hit) MLST oxf MLST pas S4 Semi pristine soil Unknown beta-lactam blaADC-25 (96.96%), blaOXA-242 (98.91%), blaOXA-341 (98.91%) ST3122* ST2132 S5 Incinerator surface Unknown beta-lactam blaADC-25 (96.25%), blaOXA-120 (100%) ST615** ST1496** ST1496** ST3457 n ST132* ST1589* ST2790 n S6 Community sewage Amoxicillin, ampicillin, imipenem, unknown beta-lactam blaADC-25 (96.89%),bla-OXA-51 (100%) ST2122 * indicate single locus mismatch, ** two locus mismatch, n indicate new ST number Table 2 Multilocus sequence type Oxford/Pasteur schemes analysis of S5 (ST3457 oxf ) and closely related isolates from database (PubMLST) Oxford scheme ST gltA gyrB gdhB recA Cpn60 gpi rpoD Isolation source 3457 (S5) 33 31 2 11 1 140 5 Incinerator surface 615 33 31 2 26 1 83 5 Unknown 1479 33 31 2 28 1 145 5 Urine sample 1496 33 31 2 28 1 143 5 Blood sample Pasteur scheme ST Cpn60 fusA gltA pyrG recA rplB rpoB Isolation source 2790 (S5) 3 5 5 1 13 1 4 Incinerator surface 1589 3 5 5 1 247 1 4 Environment (medical) 132 3 5 5 1 7 1 7 Waste water Key: ST=Sequence type, gltA = citrate synthase, gyrB = DNA gyrase, gdhB = Glucose dehydrogenase, recA = Recombinase A, Cpn60 = Chaperonin, gpi = Glucose−6−phoshate isomerase, rpoD = RNA polymerase sigma factor, pyrG = CTP synthase, Cpn60 = Chaperonin, rplB = Ribosomal protein L2, rpoB = RNA polymerase beta subunit. Conclusions In conclusion, this study reports for the first time the detection of a new bla OXA−51−like variant encoding OXA-1328from community sewage from a densely populated community indicating a recent divergence from established bla OXA−180 variants in the environment. In addition, a new ST was also identified from the dust on the surface of an incinerator. This calls for continuous surveillance studies to detect other emerging strains of clinical and environmental relevance. Abbreviations AMR Antimicrobial resistance Blastp Blast protein ICU Intensive care unit LCMI Low and Middle Income countries MLST Multilocus sequence type Oxf Oxford Pas Pasteur S4 Soil sample isolate S5 Incinerator surface isolate S6 Community sewage isolate ST Sequence type WGS Whole-genome sequencing. Declarations Author’s details 1 Department of Microbiology, Faculty of Life Sciences, Bayero University Kano, Nigeria. 2 Project group P2, Robert Koch Institute, Burgstr. 37, D-38855 Wernigerode, Germany. 3 Department of Microbiology, Federal University Dutsin-Ma, Kilometer 60, Along Katsina-Kankara Road, PMB 5001 Dutsin-ma, Katsina State, Nigeria. Acknowledgement We acknowledge Robert Koch Institute (RKI) sequencing core facility for providing Whole Genome Sequencing services for the isolates in this study. Limitations This study is limited to exploring environmental reservoirs of Acinetobacter baumannii as clinical samples were not included. Funding Availability of data and materials The genome sequence for the new variant reported I this study is available on the NCBI Genome Database under the accession number PQ659032. The new ST of S5 is available publicly in PubMLST database (BIGSdb_20250217150044_2933080_32507, isolate ID: 19412) Authors’ contributions Conceptualization: [Ibrahim Yusuf, Khalifa Jamil Saleh], Methodology: [Khalifa Jamil Saleh, Evelyn Skiebe], Formal analysis and investigation: [Ibrahim Yusuf, Gottfried Wilharm], Writing - original draft preparation: [Khalifa Jamil Saleh]; Writing - review and editing: [Ibrahim Yusuf Gottfried Wilharm], Supervision: [Ibrahim Yusuf, Gottfried Wilharm]. Ethics approval No formal ethics approval was required for this study. Consent for publication Not applicable Competing Interest There are no competing interests References Liu C, Chang Y, Xu Y, Luo Y, Wu L, Mei Z, et al. Distribution of virulence-associated genes and antimicrobial susceptibility in clinical Acinetobacter baumannii isolates. Oncotarget. 2018;9:21663. doi:10.18632/ONCOTARGET.24651. Yusuf I, Skiebe E, Wilharm G. Evaluation of CHROMagar Acinetobacter and MacConkey media for the recovery of Acinetobacter baumannii from soil samples. Lett Appl Microbiol. 2023;76:1–7. Héritier C, Poirel L, Fournier PE, Claverie JM, Raoult D, Nordmann P. Characterization of the naturally occurring oxacillinase of Acinetobacter baumannii. Antimicrob Agents Chemother. 2005;49:4174–9. doi:10.1128/AAC.49.10.4174-4179.2005/ASSET/FDB057BE-A86F-49CE-A4C5-FA795B7D2D46/ASSETS/GRAPHIC/ZAC0100553150001.JPEG. Chan KW, Liu CY, Wong HY, Chan WC, Wong KY, Chen S. Specific Amino Acid Substitutions in OXA-51-Type β-Lactamase Enhance Catalytic Activity to a Level Comparable to Carbapenemase OXA-23 and OXA-24/40. Int J Mol Sci. 2022;23. Carascal MB, Destura R V., Rivera WL. Molecular genotyping reveals multiple carbapenemase genes and unique blaOXA-51-like (oxaAb) alleles among clinically isolated Acinetobacter baumannii from a Philippine tertiary hospital. Trop Med Health. 2024;52. doi:10.1186/s41182-024-00629-w. Lee YT, Kuo SC, Chiang MC, Yang SP, Chen CP, Chen TL, et al. Emergence of carbapenem-resistant non-baumannii species of Acinetobacter harboring a blaOXA-51-like gene that is intrinsic to A. baumannii. Antimicrob Agents Chemother. 2012;56:1124–7. Yusuf I, Muhammad ZD, Muhammad Amin B, Shuaibu MD, Hamza N, Isah HD, et al. Detection of clinically relevant antibiotic-resistant bacteria in shared fomites, waste water and municipal solid wastes disposed near residential areas of a Nigerian city. Access Microbiol. 2023;5. Hrenovic J, Goic-Barisic I, Kazazic S, Kovacic A, Ganjto M, Tonkic M. Carbapenem-resistant isolates of Acinetobacter baumannii in a municipal wastewater treatment plant, Croatia, 2014. Eurosurveillance. 2016;21:30195. doi:10.2807/1560-7917.ES.2016.21.15.30195/CITE/PLAINTEXT. Wareth G, Linde J, Hammer P, Nguyen NH, Nguyen TNM, Splettstoesser WD, et al. Phenotypic and WGS-derived antimicrobial resistance profiles of clinical and non-clinical Acinetobacter baumannii isolates from Germany and Vietnam. Int J Antimicrob Agents. 2020;56. Wilharm G, Skiebe E, Łopińska A, Higgins PG, Weber K, Neugebauer C, et al. On the ecology of Acinetobacter baumannii – jet stream rider and opportunist by nature R UNNING T ITLE : Acinetobacter baumannii ecology. bioRxiv. 2024. Wilharm G, Skiebe E, Higgins PG, Poppel MT, Blaschke U, Leser S, et al. Relatedness of wildlife and livestock avian isolates of the nosocomial pathogen Acinetobacter baumannii to lineages spread in hospitals worldwide. Environ Microbiol. 2017;19:4349–64. doi:10.1111/1462-2920.13931. Olson RD, Assaf R, Brettin T, Conrad N, Cucinell C, Davis JJ, et al. Introducing the Bacterial and Viral Bioinformatics Resource Center (BV-BRC): a resource combining PATRIC, IRD and ViPR. Nucleic Acids Res. 2023;51:D678–89. Kilic A, Li H, Mellmann A, Basustaoglu AC, Kul M, Senses Z, et al. 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Infect Drug Resist. 2022;15:7631–50. Additional Declarations No competing interests reported. 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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-6332131","acceptedTermsAndConditions":true,"allowDirectSubmit":false,"archivedVersions":[],"articleType":"Short Report","associatedPublications":[],"authors":[{"id":442041851,"identity":"85a09d63-b1ce-4c93-90c5-d58d53c82600","order_by":0,"name":"Khalifa Jamil Saleh","email":"","orcid":"","institution":"Federal University Dutsin-Ma","correspondingAuthor":false,"prefix":"","firstName":"Khalifa","middleName":"Jamil","lastName":"Saleh","suffix":""},{"id":442041852,"identity":"ca253cfd-5827-4daa-88dd-0b9833c912cd","order_by":1,"name":"Muhammad Yushau","email":"","orcid":"","institution":"Bayero University Kano","correspondingAuthor":false,"prefix":"","firstName":"Muhammad","middleName":"","lastName":"Yushau","suffix":""},{"id":442041855,"identity":"ffc37970-6afe-451e-a017-908d4098dcbc","order_by":2,"name":"Abdullahi Hassan Kawo","email":"","orcid":"","institution":"Bayero University Kano","correspondingAuthor":false,"prefix":"","firstName":"Abdullahi","middleName":"Hassan","lastName":"Kawo","suffix":""},{"id":442041856,"identity":"fb8086ed-b473-4a58-a5cf-7b7a9257b54e","order_by":3,"name":"Evelyn Skiebe","email":"","orcid":"","institution":"Robert Koch Institute","correspondingAuthor":false,"prefix":"","firstName":"Evelyn","middleName":"","lastName":"Skiebe","suffix":""},{"id":442041857,"identity":"861a417d-88e8-4f83-9872-887ac38940fd","order_by":4,"name":"Gottfried Wilharm","email":"","orcid":"","institution":"Robert Koch Institute","correspondingAuthor":false,"prefix":"","firstName":"Gottfried","middleName":"","lastName":"Wilharm","suffix":""},{"id":442041858,"identity":"8ac984a2-be41-4794-b514-a74b6e525930","order_by":5,"name":"Ibrahim Yusuf","email":"data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAZAAAAAyAQMAAABI0h/eAAAABlBMVEX///8AAABVwtN+AAAACXBIWXMAAA7EAAAOxAGVKw4bAAAA60lEQVRIiWNgGAWjYBACNjBpw5DAxsB8jIHhAAMEE9aSBtLClkacFgaYFgYGHjPitPBJ5Bh/5klgyONj7/n2mOcMgxzfjQS2h1/wOUwix0waqKWYjefsdmOeGwzGkjcS2I1lCGhh5v3BkNgmkbtNmucDQ+IGoC3SEvi1gB0G1JLzDKSlnhgtBtJQLWzSQIclGAC1SH7Ap4XnWZnknAQJoF+OmRvOOSNhOPPMwzZpPDoY5NuTN394k2CTJ9/e/OzBm2M28nzHk49J/sCnRyABRMLdDmIwNjDz4NPCfwCLICNeW0bBKBgFo2CkAQANb0ZWuWniCQAAAABJRU5ErkJggg==","orcid":"","institution":"Bayero University Kano","correspondingAuthor":true,"prefix":"","firstName":"Ibrahim","middleName":"","lastName":"Yusuf","suffix":""}],"badges":[],"createdAt":"2025-03-29 05:53:14","currentVersionCode":1,"declarations":"","doi":"10.21203/rs.3.rs-6332131/v1","doiUrl":"https://doi.org/10.21203/rs.3.rs-6332131/v1","draftVersion":[],"editorialEvents":[{"content":"https://doi.org/10.1186/s13104-025-07384-z","type":"published","date":"2025-08-06T15:57:18+00:00"}],"editorialNote":"","failedWorkflow":false,"files":[{"id":81181256,"identity":"22636a6e-2b87-4c8d-9f71-88fd021a4ef8","added_by":"auto","created_at":"2025-04-23 07:24:02","extension":"png","order_by":1,"title":"Figure 1","display":"","copyAsset":false,"role":"figure","size":1682626,"visible":true,"origin":"","legend":"\u003cp\u003eMaximum likelihood phylogenetic tree based on whole-genome sequencing of \u003cem\u003eAcinetobacter baumannii\u003c/em\u003e strains isolated from environmental sources in Nigeria (S4, S5, and S6 harbouring \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA1283\u003c/sub\u003e), alongside other strains from Nigeria, Poland, and China.\u003c/p\u003e","description":"","filename":"1.png","url":"https://assets-eu.researchsquare.com/files/rs-6332131/v1/b07042c30bc5d8408f0a1d1c.png"},{"id":88814115,"identity":"bd6f08f5-88f5-4e55-8450-7215d357416d","added_by":"auto","created_at":"2025-08-11 16:07:08","extension":"pdf","order_by":0,"title":"","display":"","copyAsset":false,"role":"manuscript-pdf","size":2199529,"visible":true,"origin":"","legend":"","description":"","filename":"manuscript.pdf","url":"https://assets-eu.researchsquare.com/files/rs-6332131/v1/ae1a71c1-bfbd-4cc0-be7f-13822c9baecd.pdf"}],"financialInterests":"No competing interests reported.","formattedTitle":"Detection of a New blaOXA-51-Like Variant (blaOXA-1328) and a Novel Sequence Type (ST3457/2790) in Acinetobacter baumannii Isolated from Community Sewage and an Incinerator Surface in Nigeria","fulltext":[{"header":"Introduction","content":"\u003cp\u003e \u003cem\u003eAcinetobacter baumannii\u003c/em\u003e is a significant opportunistic pathogen known for its remarkable ability to acquire and disseminate antimicrobial resistance (AMR) determinants, particularly carbapenemases, which confer resistance to last-resort antibiotics [\u003cspan citationid=\"CR1\" class=\"CitationRef\"\u003e1\u003c/span\u003e, \u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e]. Among these carbapenemases, OXA-type β-lactamases (oxacillinases) play a crucial role in carbapenem resistance, with \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA-51\u003c/sub\u003e\u003cem\u003e-\u003c/em\u003elike genes being intrinsic to \u003cem\u003eA. baumannii\u003c/em\u003e [\u003cspan citationid=\"CR20\" class=\"CitationRef\"\u003e3\u003c/span\u003e]. However, novel variants of \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA-51\u003c/sub\u003e\u003cem\u003e-like\u003c/em\u003e genes continue to emerge [\u003cspan additionalcitationids=\"CR5\" citationid=\"CR21\" class=\"CitationRef\"\u003e4\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR6\" class=\"CitationRef\"\u003e6\u003c/span\u003e], contributing to the increasing complexity of AMR phenotypes in this pathogen.\u003c/p\u003e \u003cp\u003eEnvironmental media, such as waste disposal sites, soil, and water, have been identified as hotspots for the dissemination of antimicrobial-resistant bacteria, including \u003cem\u003eA. baumannii\u003c/em\u003e, due to the selective pressure exerted by antimicrobial-like chemicals or residues and other pollutants present in the sources [\u003cspan additionalcitationids=\"CR8\" citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e\u0026ndash;\u003cspan citationid=\"CR9\" class=\"CitationRef\"\u003e9\u003c/span\u003e]. In addition, they also serve as a critical surveillance point for detecting emerging resistance genes before they become widespread in clinical settings [\u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Despite the concerns about the environment's role in AMR propagation, data on the molecular epidemiology of \u003cem\u003eA. baumannii\u003c/em\u003e from environmental sources in Nigeria\u0026mdash;particularly from unconventional sites such as air, unexplored surfaces, semi-pristine soil and water, and community sewage\u0026mdash;remain scarce. These environments, often overlooked in routine surveillance, could serve as hidden reservoirs for emerging resistant pathogens.\u003c/p\u003e \u003cp\u003eIn this study, we report the detection of a novel \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA-51-like\u003c/sub\u003e variant, \u003cem\u003ebla\u003c/em\u003e\u003csub\u003e\u003cem\u003eOXA-1328\u003c/em\u003e\u003c/sub\u003e, in \u003cem\u003eA. baumannii\u003c/em\u003e obtained from community sewage in Nigeria, and a novel sequence type (ST3457\u003csup\u003eoxf\u003c/sup\u003e/2790\u003csup\u003epas\u003c/sup\u003e) from an incinerator surface as part of a study aimed at exploring non-hospital sources of \u003cem\u003eA. baumannii\u003c/em\u003e in Nigerian environments. To our knowledge, this is the first report of these variants, which further highlights the importance of environmental AMR surveillance in identifying emerging resistance mechanisms in \u003cem\u003eA. baumannii\u003c/em\u003e. The findings suggest the need for continuous genomic monitoring of \u003cem\u003eA. baumannii\u003c/em\u003e in both clinical and environmental settings to understand its evolutionary dynamics and mitigate the spread of resistance.\u003c/p\u003e"},{"header":"Methods","content":"\u003cp\u003eWe collected 404 samples of 101 each of soil, sewage, water, and air from 3 non-hospital environments in Kano metropolitan communities as \u003cem\u003eA. baumannii\u003c/em\u003e was isolated on MacConkey and CHROMAgar \u003cem\u003eAcinetobacter\u003c/em\u003e as previously described [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR7\" class=\"CitationRef\"\u003e7\u003c/span\u003e]. Thirty-three (33) isolates were biochemically confirmed as presumptive \u003cem\u003eA. baumannii\u003c/em\u003e and later confirmed using polymerase chain reaction (PCR) by amplifying \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;51\u003cem\u003e\u0026minus;like\u003c/em\u003e\u003c/sub\u003e gene using specific forward and reverse primers [\u003cspan citationid=\"CR2\" class=\"CitationRef\"\u003e2\u003c/span\u003e, \u003cspan citationid=\"CR10\" class=\"CitationRef\"\u003e10\u003c/span\u003e]. The coding region of \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;51\u0026minus;like\u003c/sub\u003e was amplified and sequenced using Sanger technology to determine the \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;51\u0026minus;like\u003c/sub\u003e variants. Whole-genome sequencing (WGS) of selected strains (isolated from unusual sites) was performed to explore their genetic composition, sequence type, and resistance mechanisms using Illumina technology [\u003cspan citationid=\"CR28\" class=\"CitationRef\"\u003e11\u003c/span\u003e]. To understand the genetic relatedness of the new variant and other environmental \u003cem\u003eA. baumannii\u003c/em\u003e strains isolated in this study with other clinical and non-clinical sources across the globe, the BV-BRC workspace was used to generate a phylogenetic tree [\u003cspan citationid=\"CR12\" class=\"CitationRef\"\u003e12\u003c/span\u003e].\u003c/p\u003e"},{"header":"Results and Discussion","content":"\u003cdiv id=\"Sec4\" class=\"Section2\"\u003e\n \u003ch2\u003ePhenotypic and Molecular identification\u003c/h2\u003e\n \u003cp\u003eA 7.5% recovery rate of \u003cem\u003eA. baumannii\u003c/em\u003e was reported (33 out of 440). Of the 33 isolates, 3 \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;51\u003c/sub\u003e variants isolated from community sewage, incinerator surface, and semi pristine soil near migratory birds\u0026rsquo; stop-over tree revealed an interesting result. Of the 3 strains, S6 which was isolated from a community sewage did not yield 100% similarity with other \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;51\u003c/sub\u003e variants in the NCBI data (Blastp), to reveal a new variant. The sequence of the new variant was deposited in NCBI; it was designated as \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;1328\u003c/sub\u003e and was given accession number PQ659032. However, strain from semi pristine soil (S4) and the one from incinerator surface (S5) harbour variants \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;707\u003c/sub\u003e and \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;120,\u003c/sub\u003e respectively. In contrast to S4, previous isolates harbouring \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;707\u003c/sub\u003e are predominantly isolated from healthcare devices, patient belongings as well as wounds of burn patients in ICUs [\u003cspan class=\"CitationRef\"\u003e13\u003c/span\u003e, \u003cspan class=\"CitationRef\"\u003e14\u003c/span\u003e]. In addition, \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;120\u003c/sub\u003e carried by strain S5 which was isolated from the incinerator surface, has been reported from clinical settings in intensive care unit (ICU), environmental sources from hospital sewage and urban wastewater sources, and food samples [\u003cspan class=\"CitationRef\"\u003e15\u003c/span\u003e]. This shows it\u0026apos;s wide spread and the possibility of establishing itself in different environments including non-healthcare settings.\u003c/p\u003e\n \u003cp\u003eThe 3 isolates are phenotypically susceptible to imipenem, meropenem, tetracycline, ceftazidime, gentamicin, sulfamethoxazole, and ciprofloxacin, which may be due to their lesser exposure to clinical settings. However, a related strain harbouring \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;120\u003c/sub\u003e variant isolated from an Egyptian hospital setting has been reported to have acquired \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eNDM\u0026minus;1\u003c/sub\u003e which mediates carbapenem resistance [\u003cspan class=\"CitationRef\"\u003e16\u003c/span\u003e]. In addition, other carbapenemase resistance genes such as \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;23\u003c/sub\u003e, and \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;58,\u003c/sub\u003e which are frequently associated with transposons and often integrated into \u003cem\u003eA. baumannii\u003c/em\u003e chromosome with upstream insertion sequences regulating their expression are reported in another \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;707\u003c/sub\u003e harbouring strain [\u003cspan class=\"CitationRef\"\u003e17\u003c/span\u003e] and being related to isolate S4. In contrast, WGS analysis using ResFinder revealed the presence of some clinically relevant \u003cem\u003ebla\u003c/em\u003eOXA and \u003cem\u003ebla\u003c/em\u003eADC beta-lactamase genes among the isolates. Notably, S6 (\u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;1328\u003c/sub\u003e), harbored \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eADC\u0026minus;25\u003c/sub\u003e (96.89%) and \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;51\u003c/sub\u003e (100%), with resistance phenotypes including amoxicillin, ampicillin, and imipenem. IS\u003cem\u003eAba1\u003c/em\u003e which plays an important role in the expression of carbapenem resistance was only detected in S6 (truncated), but IS\u003cem\u003eAba12\u003c/em\u003e (known for conferring impressive genetic plasticity and colistin dependence) and IS\u003cem\u003eAba13\u003c/em\u003e (known for capsule, virulence, and antibiotic resistance) were found in S4 and S5respectively.\u003c/p\u003e\n \u003cp\u003eMLST analysis assigned 2 of the isolates (S4 and S6) to diverse sequence types (STs), revealing both local and international genetic links to environmental and clinical strains. However, isolate S5 which did not yield exact match with any ST. it exhibited a single locus mismatch with ST1589 (Pasteur), previously identified in an environmental sample from Germany, suggesting a non distant evolutionary relationship. Additionally, S5 showed two mismatches (71.4% loci similarity) with ST615 (Oxford) from China, as well as ST1479 and ST1496, recovered from urine and blood samples in China and South Korea, respectively. These findings indicate that S5 represents a novel sequence type, which has been submitted to MLST and was assigned new ST number (ST3457\u003csup\u003eoxf\u003c/sup\u003e and ST2790\u003csup\u003epas\u003c/sup\u003e). ST3457 (S5) shares identical alleles with \u003cem\u003eA. baumannii\u003c/em\u003e ST615, ST1479, and ST1496 in most genes analyzed (\u003cem\u003etonB, rpoB, phoE, infB\u003c/em\u003e, and \u003cem\u003efusA\u003c/em\u003e), except for \u003cem\u003erecA\u003c/em\u003e and \u003cem\u003egpI\u003c/em\u003e. The divergence in \u003cem\u003erecA\u003c/em\u003e observed may affect DNA repair, which can influence the strain\u0026rsquo;s ability to adapt to environmental stress, antimicrobial exposure, or acquire foreign genes through horizontal transfer. Meanwhile, variation in \u003cem\u003egpI\u003c/em\u003e, involved in lipopolysaccharide biosynthesis and membrane integrity, could impact virulence, immune evasion, or antimicrobial susceptibility. In contrast, S6 matched exactly with ST2132\u003csup\u003epas\u003c/sup\u003e, previously isolated from a sputum sample of a patient in India, suggesting its global distribution and potential clinical relevance. S6 also exhibited a single mismatch (85.7% loci similarity) with ST3122\u003csup\u003eoxf\u003c/sup\u003e, a strain previously identified in a stork from Poland. The genetic proximity of S6 to both human and avian sources raises important questions about potential transmission pathways, including airborne dispersal or indirect environmental contamination. Isolate S4 was an exact match to ST2111\u003csup\u003epas\u003c/sup\u003e, first identified in Israel in 2004 from an unknown source. Under the Oxford scheme, S4 exhibited four mismatches with ST2963 and ST3122\u0026mdash;both previously isolated from \u003cem\u003eA. baumannii\u003c/em\u003e strains recovered from storks in Poland. Their genetic resemblance to avian-associated strains suggests a possible ecological link between environmental isolates and wildlife reservoirs[\u003cspan class=\"CitationRef\"\u003e11\u003c/span\u003e]. These findings support the hypothesis that environmental persistence and indirect transmission play significant roles in the epidemiology of \u003cem\u003eA. baumannii\u003c/em\u003e.\u003c/p\u003e\n \u003cp\u003ePhylogenetic analysis of these strains revealed a divergence of S6 from cluster of \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;180\u003c/sub\u003e variants previously isolated from different Nigerian environment (Fig. \u003cspan class=\"InternalRef\"\u003e1\u003c/span\u003e). Additionally, it also revealed a close relationship between S4 and another \u003cem\u003eA. baumannii\u003c/em\u003e isolated from a stork bird from Poland. Isolate S5 which was recovered from the incinerator surface clustered with two \u003cem\u003eA. baumannii\u003c/em\u003e strains from human oral source in China further indicating its closeness to clinical strains.\u003c/p\u003e\n \u003cdiv class=\"gridtable\"\u003e\u0026nbsp;\u003ctable id=\"Tab1\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 1\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003esequence and OXA-type features of the three isolates\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eIsolate\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eSource\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eWGS predicted phenotypes\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eAMR genes (% gene hit)\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMLST\u003csup\u003eoxf\u003c/sup\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eMLST\u003csup\u003epas\u003c/sup\u003e\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eS4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eSemi pristine soil\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUnknown beta-lactam\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eblaADC-25 (96.96%), blaOXA-242 (98.91%), blaOXA-341 (98.91%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eST3122*\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eST2132\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eS5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eIncinerator surface\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUnknown beta-lactam\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eblaADC-25 (96.25%), blaOXA-120 (100%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eST615** ST1496** ST1496**\u003c/p\u003e\n \u003cp\u003eST3457\u003csup\u003en\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eST132* ST1589*\u003c/p\u003e\n \u003cp\u003eST2790\u003csup\u003en\u003c/sup\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eS6\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eCommunity sewage\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eAmoxicillin, ampicillin, imipenem, unknown beta-lactam\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eblaADC-25 (96.89%),bla-OXA-51 (100%)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\u0026nbsp;\u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eST2122\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003ctfoot\u003e\n \u003ctr\u003e\n \u003ctd colspan=\"6\"\u003e* indicate single locus mismatch, ** two locus mismatch, n indicate new ST number\u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tfoot\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cdiv class=\"gridtable\"\u003e\n \u003cdiv align=\"left\" class=\"colspec\"\u003e\u003cbr\u003e\u003c/div\u003e\u0026nbsp;\u003ctable id=\"Tab2\" border=\"1\"\u003e\n \u003ccaption language=\"En\"\u003e\n \u003cdiv class=\"CaptionNumber\"\u003eTable 2\u003c/div\u003e\n \u003cdiv class=\"CaptionContent\"\u003e\n \u003cp\u003eMultilocus sequence type Oxford/Pasteur schemes analysis of S5 (ST3457\u003csup\u003eoxf\u003c/sup\u003e) and closely related isolates from database (PubMLST)\u003c/p\u003e\n \u003c/div\u003e\n \u003c/caption\u003e\n \u003cthead\u003e\n \u003ctr\u003e\n \u003cth align=\"left\" colspan=\"9\"\u003e\n \u003cp\u003eOxford scheme\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eST\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003egltA\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003egyrB\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003egdhB\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003erecA\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eCpn60\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003egpi\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003erpoD\u003c/p\u003e\n \u003c/th\u003e\n \u003cth align=\"left\"\u003e\n \u003cp\u003eIsolation source\u003c/p\u003e\n \u003c/th\u003e\n \u003c/tr\u003e\n \u003c/thead\u003e\n \u003ctbody\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3457 (S5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e11\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e140\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eIncinerator surface\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e615\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e26\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e83\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUnknown\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1479\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e145\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eUrine sample\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1496\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e33\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e31\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e28\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e143\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eBlood sample\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\" colspan=\"9\"\u003e\n \u003cp\u003e\u003cstrong\u003ePasteur scheme\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eST\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eCpn60\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003efusA\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003egltA\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003epyrG\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003erecA\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003erplB\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003erpoB\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e\u003cstrong\u003eIsolation source\u003c/strong\u003e\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e2790 (S5)\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e13\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eIncinerator surface\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1589\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e247\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e4\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eEnvironment (medical)\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003ctr\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e132\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e3\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e5\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e1\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003e7\u003c/p\u003e\n \u003c/td\u003e\n \u003ctd align=\"left\"\u003e\n \u003cp\u003eWaste water\u003c/p\u003e\n \u003c/td\u003e\n \u003c/tr\u003e\n \u003c/tbody\u003e\n \u003c/table\u003e\n \u003c/div\u003e\n \u003cp\u003eKey: ST=Sequence type, gltA = citrate synthase, gyrB = DNA gyrase, gdhB = Glucose dehydrogenase, recA = Recombinase A, Cpn60 = Chaperonin, gpi = Glucose\u0026minus;6\u0026minus;phoshate isomerase, rpoD = RNA polymerase sigma factor, pyrG = CTP synthase, Cpn60 = Chaperonin, rplB = Ribosomal protein L2, rpoB = RNA polymerase beta subunit.\u003c/p\u003e\n\u003c/div\u003e"},{"header":"Conclusions","content":"\u003cp\u003eIn conclusion, this study reports for the first time the detection of a new \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;51\u0026minus;like\u003c/sub\u003e variant encoding OXA-1328from community sewage from a densely populated community indicating a recent divergence from established \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA\u0026minus;180\u003c/sub\u003e variants in the environment. In addition, a new ST was also identified from the dust on the surface of an incinerator. This calls for continuous surveillance studies to detect other emerging strains of clinical and environmental relevance.\u003c/p\u003e \u003cp\u003e \u003c/p\u003e"},{"header":"Abbreviations","content":"\u003cdiv class=\"DefinitionList\"\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eAMR\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eAntimicrobial resistance\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eBlastp\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eBlast protein\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eICU\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eIntensive care unit\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eLCMI\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eLow and Middle Income countries\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eMLST\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eMultilocus sequence type\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eOxf\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eOxford\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003ePas\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003ePasteur\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eS4\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSoil sample isolate\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eS5\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eIncinerator surface isolate\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eS6\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eCommunity sewage isolate\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eST\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eSequence type\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003cdiv class=\"DefinitionListEntry\"\u003e \u003cdiv class=\"Term\"\u003eWGS\u003c/div\u003e \u003cdiv class=\"Description\"\u003e \u003cp\u003eWhole-genome sequencing.\u003c/p\u003e \u003c/div\u003e \u003c/div\u003e \u003c/div\u003e"},{"header":"Declarations","content":"\u003cp\u003e\u003cstrong\u003eAuthor\u0026rsquo;s details\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e1\u003c/sup\u003eDepartment of Microbiology, Faculty of Life Sciences, Bayero University Kano, Nigeria.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003csup\u003e2\u003c/sup\u003eProject group P2, Robert Koch Institute, Burgstr. 37, D-38855 Wernigerode, Germany. \u003csup\u003e3\u003c/sup\u003eDepartment of Microbiology, Federal University Dutsin-Ma, Kilometer 60, Along Katsina-Kankara Road, PMB 5001 Dutsin-ma, Katsina State, Nigeria.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAcknowledgement\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eWe acknowledge Robert Koch Institute (RKI) sequencing core facility for providing Whole Genome Sequencing services for the isolates in this study. \u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eLimitations\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThis study is limited to exploring environmental reservoirs of \u003cem\u003eAcinetobacter baumannii\u0026nbsp;\u003c/em\u003eas clinical samples were not included.\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eFunding\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAvailability of data and materials\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThe genome sequence for the new variant reported I this study is available on the NCBI Genome Database under the accession number PQ659032. The new ST of S5 is available publicly in PubMLST database (BIGSdb_20250217150044_2933080_32507, isolate ID: 19412)\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eAuthors\u0026rsquo; contributions\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eConceptualization: [Ibrahim Yusuf, Khalifa Jamil Saleh], Methodology: [Khalifa Jamil Saleh, Evelyn Skiebe], Formal analysis and investigation: [Ibrahim Yusuf, Gottfried Wilharm], Writing - original draft preparation: [Khalifa Jamil Saleh]; Writing - review and editing: [Ibrahim Yusuf Gottfried Wilharm], Supervision: [Ibrahim Yusuf, Gottfried Wilharm].\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eEthics approval\u0026nbsp;\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNo formal ethics approval was required for this study.\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eConsent for publication\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eNot applicable\u0026nbsp;\u003c/p\u003e\n\u003cp\u003e\u003cstrong\u003eCompeting Interest\u003c/strong\u003e\u003c/p\u003e\n\u003cp\u003eThere are no competing interests\u003c/p\u003e"},{"header":"References","content":"\u003col\u003e\n \u003cli\u003eLiu C, Chang Y, Xu Y, Luo Y, Wu L, Mei Z, et al. Distribution of virulence-associated genes and antimicrobial susceptibility in clinical Acinetobacter baumannii isolates. Oncotarget. 2018;9:21663. doi:10.18632/ONCOTARGET.24651.\u003c/li\u003e\n \u003cli\u003eYusuf I, Skiebe E, Wilharm G. Evaluation of CHROMagar Acinetobacter and MacConkey media for the recovery of Acinetobacter baumannii from soil samples. Lett Appl Microbiol. 2023;76:1\u0026ndash;7.\u003c/li\u003e\n \u003cli\u003eH\u0026eacute;ritier C, Poirel L, Fournier PE, Claverie JM, Raoult D, Nordmann P. Characterization of the naturally occurring oxacillinase of Acinetobacter baumannii. Antimicrob Agents Chemother. 2005;49:4174\u0026ndash;9. doi:10.1128/AAC.49.10.4174-4179.2005/ASSET/FDB057BE-A86F-49CE-A4C5-FA795B7D2D46/ASSETS/GRAPHIC/ZAC0100553150001.JPEG.\u003c/li\u003e\n \u003cli\u003eChan KW, Liu CY, Wong HY, Chan WC, Wong KY, Chen S. Specific Amino Acid Substitutions in OXA-51-Type \u0026beta;-Lactamase Enhance Catalytic Activity to a Level Comparable to Carbapenemase OXA-23 and OXA-24/40. Int J Mol Sci. 2022;23.\u003c/li\u003e\n \u003cli\u003eCarascal MB, Destura R V., Rivera WL. Molecular genotyping reveals multiple carbapenemase genes and unique blaOXA-51-like (oxaAb) alleles among clinically isolated Acinetobacter baumannii from a Philippine tertiary hospital. Trop Med Health. 2024;52. doi:10.1186/s41182-024-00629-w.\u003c/li\u003e\n \u003cli\u003eLee YT, Kuo SC, Chiang MC, Yang SP, Chen CP, Chen TL, et al. Emergence of carbapenem-resistant non-baumannii species of Acinetobacter harboring a blaOXA-51-like gene that is intrinsic to A. baumannii. Antimicrob Agents Chemother. 2012;56:1124\u0026ndash;7.\u003c/li\u003e\n \u003cli\u003eYusuf I, Muhammad ZD, Muhammad Amin B, Shuaibu MD, Hamza N, Isah HD, et al. Detection of clinically relevant antibiotic-resistant bacteria in shared fomites, waste water and municipal solid wastes disposed near residential areas of a Nigerian city. Access Microbiol. 2023;5.\u003c/li\u003e\n \u003cli\u003eHrenovic J, Goic-Barisic I, Kazazic S, Kovacic A, Ganjto M, Tonkic M. Carbapenem-resistant isolates of Acinetobacter baumannii in a municipal wastewater treatment plant, Croatia, 2014. Eurosurveillance. 2016;21:30195. doi:10.2807/1560-7917.ES.2016.21.15.30195/CITE/PLAINTEXT.\u003c/li\u003e\n \u003cli\u003eWareth G, Linde J, Hammer P, Nguyen NH, Nguyen TNM, Splettstoesser WD, et al. Phenotypic and WGS-derived antimicrobial resistance profiles of clinical and non-clinical Acinetobacter baumannii isolates from Germany and Vietnam. Int J Antimicrob Agents. 2020;56.\u003c/li\u003e\n \u003cli\u003eWilharm G, Skiebe E, Łopińska A, Higgins PG, Weber K, Neugebauer C, et al. On the ecology of Acinetobacter baumannii \u0026ndash; jet stream rider and opportunist by nature R UNNING T ITLE : Acinetobacter baumannii ecology. bioRxiv. 2024.\u003c/li\u003e\n \u003cli\u003eWilharm G, Skiebe E, Higgins PG, Poppel MT, Blaschke U, Leser S, et al. Relatedness of wildlife and livestock avian isolates of the nosocomial pathogen Acinetobacter baumannii to lineages spread in hospitals worldwide. Environ Microbiol. 2017;19:4349\u0026ndash;64. doi:10.1111/1462-2920.13931.\u003c/li\u003e\n \u003cli\u003eOlson RD, Assaf R, Brettin T, Conrad N, Cucinell C, Davis JJ, et al. Introducing the Bacterial and Viral Bioinformatics Resource Center (BV-BRC): a resource combining PATRIC, IRD and ViPR. Nucleic Acids Res. 2023;51:D678\u0026ndash;89.\u003c/li\u003e\n \u003cli\u003eKilic A, Li H, Mellmann A, Basustaoglu AC, Kul M, Senses Z, et al. Acinetobacter septicus sp. nov. association with a nosocomial outbreak of bacteremia in a neonatal intensive care unit. J Clin Microbiol. 2008;46:902\u0026ndash;8.\u003c/li\u003e\n \u003cli\u003eCustovic A, Smajlovic J, Tihic N, Hadzic S, Ahmetagic S, Hadzagic H. Epidemiological monitoring of nosocomial infections caused by acinetobacter baumannii. Med Arch (Sarajevo, Bosnia Herzegovina). 2014;68:402\u0026ndash;6.\u003c/li\u003e\n \u003cli\u003eEvans BA, Hamouda A, Towner KJ, Amyes SGB. OXA-51-like \u0026beta;-lactamases and their association with particular epidemic lineages of Acinetobacter baumannii. Clin Microbiol Infect. 2008;14:268\u0026ndash;75.\u003c/li\u003e\n \u003cli\u003eS\u0026aacute;nchez-Urtaza S, Ocampo-Sosa A, Molins-Bengoetxea A, El-Kholy MA, Hernandez M, Abad D, et al. Molecular characterization of multidrug resistant Acinetobacter baumannii clinical isolates from Alexandria, Egypt. Front Cell Infect Microbiol. 2023;13:1208046.\u003c/li\u003e\n \u003cli\u003eGupta N, Angadi K, Jadhav S. Molecular Characterization of Carbapenem-Resistant Acinetobacter baumannii with Special Reference to Carbapenemases: A Systematic Review. Infect Drug Resist. 2022;15:7631\u0026ndash;50.\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":"bmc-research-notes","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"resn","sideBox":"Learn more about [BMC Research Notes](http://bmcresnotes.biomedcentral.com)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/resn/default.aspx","title":"BMC Research Notes","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true},"keywords":"Acinetobacter baumannii, blaOXA-51 like genes, variants, sewage, molecular diversity, Acinetobacter baumannii phylogeny","lastPublishedDoi":"10.21203/rs.3.rs-6332131/v1","lastPublishedDoiUrl":"https://doi.org/10.21203/rs.3.rs-6332131/v1","license":{"name":"CC BY 4.0","url":"https://creativecommons.org/licenses/by/4.0/"},"manuscriptAbstract":"\u003cp\u003e\u003cem\u003e\u003cstrong\u003eObjective:\u003c/strong\u003e\u003c/em\u003e\u003c/p\u003e\n\u003cp\u003e\u003cem\u003eAcinetobacter baumannii\u003c/em\u003e is an opportunistic pathogen with a high capacity to acquire antimicrobial resistance (AMR) determinants, including OXA-type β-lactamases, which confer carbapenem resistance. Environmental reservoirs play a crucial role in the persistence and spread of the bacteria, yet limited data exist on \u003cem\u003eA. baumannii\u003c/em\u003e from non-hospital environments (which is critical in epidemiological studies) in Nigeria. This study aimed to study the genetic diversities of \u003cem\u003eA. baumannii\u003c/em\u003e strains from different non-hospital environments in Nigeria, determine their sequence types (STs), and characterize their resistance genes.\u003c/p\u003e\n\u003cp\u003e\u003cem\u003e\u003cstrong\u003eResults: \u003c/strong\u003e\u003c/em\u003eWhile studying the prevalence of \u003cem\u003eA. baumannii\u003c/em\u003e from 404 environmental samples (soil, sewage, water, and air) collected from three non-hospital communities in Nigeria, 2 isolates with novel features were discovered. Following culture-based and molecular identification, 33 isolates (7.5%) were confirmed as \u003cem\u003eA. baumannii\u003c/em\u003e. Whole-genome sequencing (WGS) revealed the presence of one novel \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA-51\u003c/sub\u003e-like variant (\u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA1283\u003c/sub\u003e) (that was diverged from \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA-180\u003c/sub\u003e variants that were previously isolated from different environments in Nigeria) and one sequence type (ST3457/2790). A variant (bla\u003csub\u003eOXA-707\u003c/sub\u003e) isolated from semi-pristine soil, is closely related to only one strain isolated from a stork bird in Poland. Another strain from an incinerator surface, clustered with strains from human oral sources in China, suggesting a potential link to clinical strains. The three isolates were susceptible to carbapenems (imipenem, meropenem), ceftazidime, tetracycline, gentamicin, sulfamethoxazole, and ciprofloxacin, suggesting minimal clinical exposure. However, a related strain carrying \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eOXA-120\u003c/sub\u003efrom Egypt has been reported with additional \u003cem\u003ebla\u003c/em\u003e\u003csub\u003eNDM-1\u003c/sub\u003e, a gene that mediates carbapenem resistance.\u003c/p\u003e","manuscriptTitle":"Detection of a New blaOXA-51-Like Variant (blaOXA-1328) and a Novel Sequence Type (ST3457/2790) in Acinetobacter baumannii Isolated from Community Sewage and an Incinerator Surface in Nigeria","msid":"","msnumber":"","nonDraftVersions":[{"code":1,"date":"2025-04-23 07:23:19","doi":"10.21203/rs.3.rs-6332131/v1","editorialEvents":[{"type":"communityComments","content":0},{"type":"decision","content":"Revision requested","date":"2025-06-02T13:32:25+00:00","index":"","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-23T18:29:35+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-12T09:03:36+00:00","index":"hide","fulltext":""},{"type":"editorInvitedReview","content":"","date":"2025-04-11T18:15:42+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"157149551823058296522199685900797083927","date":"2025-04-07T00:21:45+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"41498467639514943440201804413888946744","date":"2025-04-04T17:27:58+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"74712319642573655320285681323262596588","date":"2025-04-03T06:34:12+00:00","index":"hide","fulltext":""},{"type":"reviewerAgreed","content":"303682748841505858436100531960110357810","date":"2025-04-02T12:55:35+00:00","index":"hide","fulltext":""},{"type":"reviewersInvited","content":"","date":"2025-04-02T12:24:11+00:00","index":"","fulltext":""},{"type":"editorInvited","content":"","date":"2025-04-02T11:53:34+00:00","index":"","fulltext":""},{"type":"editorAssigned","content":"","date":"2025-04-01T09:39:09+00:00","index":"","fulltext":""},{"type":"checksComplete","content":"","date":"2025-04-01T09:36:02+00:00","index":"","fulltext":""},{"type":"submitted","content":"BMC Research Notes","date":"2025-03-29T05:47:58+00:00","index":"","fulltext":""}],"status":"published","journal":{"display":true,"email":"[email protected]","identity":"bmc-research-notes","isNatureJournal":false,"hasQc":true,"allowDirectSubmit":false,"externalIdentity":"resn","sideBox":"Learn more about [BMC Research Notes](http://bmcresnotes.biomedcentral.com)","snPcode":"","submissionUrl":"https://www.editorialmanager.com/resn/default.aspx","title":"BMC Research Notes","twitterHandle":"@BMC_series","acdcEnabled":true,"dfaEnabled":false,"editorialSystem":"em","reportingPortfolio":"BMC Series","inReviewEnabled":true,"inReviewRevisionsEnabled":true}}],"origin":"","ownerIdentity":"7a9d5871-41b1-423f-b93c-6eb62a2a269c","owner":[],"postedDate":"April 23rd, 2025","published":true,"recentEditorialEvents":[],"rejectedJournal":[],"revision":"","amendment":"","status":"published-in-journal","subjectAreas":[],"tags":[],"updatedAt":"2025-08-11T16:00:17+00:00","versionOfRecord":{"articleIdentity":"rs-6332131","link":"https://doi.org/10.1186/s13104-025-07384-z","journal":{"identity":"bmc-research-notes","isVorOnly":false,"title":"BMC Research Notes"},"publishedOn":"2025-08-06 15:57:18","publishedOnDateReadable":"August 6th, 2025"},"versionCreatedAt":"2025-04-23 07:23:19","video":"","vorDoi":"10.1186/s13104-025-07384-z","vorDoiUrl":"https://doi.org/10.1186/s13104-025-07384-z","workflowStages":[]},"version":"v1","identity":"rs-6332131","journalConfig":"researchsquare"},"__N_SSP":true},"page":"/article/[identity]/[[...version]]","query":{"redirect":"/article/rs-6332131","identity":"rs-6332131","version":["v1"]},"buildId":"8U1c8b4HqxoKbykW_rLl7","isFallback":false,"isExperimentalCompile":false,"dynamicIds":[84888],"gssp":true,"scriptLoader":[]}