{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T10:00:12Z","timestamp":1785319212467,"version":"3.55.0"},"reference-count":38,"publisher":"Frontiers Media SA","license":[{"start":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T00:00:00Z","timestamp":1785283200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":["frontiersin.org"],"crossmark-restriction":true},"short-container-title":["Front. Antibiot."],"abstract":"<jats:sec>\n                    <jats:title>Introduction<\/jats:title>\n                    <jats:p>\n                      <jats:italic>Acinetobacter baumannii<\/jats:italic>\n                      , a World Health Organization (WHO) critical-priority pathogen, causes difficult-to-treat nosocomial infections. The link between resistance genes, biofilm, and virulence carriage remains poorly understood in clinical isolates of high\u2212burden South Asian settings. This study intended to thoroughly describe and explain linkages among clinical isolates collected in Haryana, India.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Methods<\/jats:title>\n                    <jats:p>\n                      A total of 200 non-duplicate\n                      <jats:italic>A. baumannii<\/jats:italic>\n                      isolates underwent antimicrobial susceptibility testing by broth microdilution against 17 antibiotics, interpreted according to CLSI M100 guidelines (32nd edition). Biofilm forming capacity was quantified using the standardized microtiter plate crystal violet assay. Polymerase chain reaction (PCR) was used to detect six carbapenemase genes (blaOXA-23, blaOXA-24, blaOXA-58, blaNDM-1, blaVIM, and blaIMP), beta-lactamase genes (blaPER-1, AmpC, and blaTEM), and virulence genes (bap, ompA, and csuE). Concordance was assessed by Cohen\u2019s \u03ba; gene-resistance and gene-biofilm links were tested using regression and non\u2212parametric analyses. A total of 200 pure, non\u2212duplicate\n                      <jats:italic>A. baumannii<\/jats:italic>\n                      isolates were included and contaminated cultures were excluded. Sample size adequacy was assessed using Buderer\u2019s formula based on expected sensitivity, specificity, carbapenem-resistance prevalence, 95% confidence level, and desired precision.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Results<\/jats:title>\n                    <jats:p>\n                      Among 200 isolates, 54% were MDR, 34% XDR, and 61% carbapenem-resistant. The blaOXA-23 gene, present in 61%, showed near-perfect concordance with carbapenem resistance (\u03ba = 0.81). Composite carbapenemase carriage improved concordance (\u03ba = 0.88). Biofilm capacity was unrelated to overall resistance, but strong biofilm formers had higher colistin MICs (p = 0.001). Virulence genes (\n                      <jats:italic>bap<\/jats:italic>\n                      ,\n                      <jats:italic>ompA<\/jats:italic>\n                      , and\n                      <jats:italic>csuE<\/jats:italic>\n                      ) were linked to strong biofilm formation (p &amp;lt; 0.001) without resistance escalation.\n                    <\/jats:p>\n                  <\/jats:sec>\n                  <jats:sec>\n                    <jats:title>Conclusions<\/jats:title>\n                    <jats:p>blaOXA\u221223 emerged as the dominant genetic driver of carbapenem resistance, underscoring its value in rapid diagnostics. Colistin tolerance was linked to biofilm\u2212associated phenotypes rather than cumulative resistance.<\/jats:p>\n                  <\/jats:sec>","DOI":"10.3389\/frabi.2026.1888133","type":"journal-article","created":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T09:12:17Z","timestamp":1785316337000},"update-policy":"https:\/\/doi.org\/10.3389\/crossmark-policy","source":"Crossref","is-referenced-by-count":0,"title":["Carbapenem resistance genes and biofilm\u2212virulence uncoupling in Acinetobacter baumannii"],"prefix":"10.3389","volume":"5","author":[{"given":"Shyam","family":"Tripathi","sequence":"first","affiliation":[{"name":"Department of Biotechnology and Microbiology, School of Science and Humanities, SRM University","place":["Sonepat, Haryana, India"]},{"name":"Centre for Drug Design Discovery and Development (C4D), SRM University","place":["Sonepat, Haryana, India"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Kusum","family":"Rani","sequence":"additional","affiliation":[{"name":"Centre for Drug Design Discovery and Development (C4D), SRM University","place":["Sonepat, Haryana, India"]},{"name":"Department of Infection Prevention and Epidemiology, Amrita School of Medicine, Amrita Vishwa Vidyapeetham","place":["Faridabad, Haryana, India"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rivan","family":"Berlia","sequence":"additional","affiliation":[{"name":"Centre for Drug Design Discovery and Development (C4D), SRM University","place":["Sonepat, Haryana, India"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Amit","family":"Sharma","sequence":"additional","affiliation":[{"name":"Department of Biotechnology and Microbiology, School of Science and Humanities, SRM University","place":["Sonepat, Haryana, India"]},{"name":"Centre for Drug Design Discovery and Development (C4D), SRM University","place":["Sonepat, Haryana, India"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Anandu","family":"Hari","sequence":"additional","affiliation":[{"name":"Department of Infection Prevention and Epidemiology, Amrita School of Medicine, Amrita Vishwa Vidyapeetham","place":["Faridabad, Haryana, India"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Pratibha","family":"Gaur","sequence":"additional","affiliation":[{"name":"Department of Biotechnology and Microbiology, School of Science and Humanities, SRM University","place":["Sonepat, Haryana, India"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Poornima Sheba Samuel","family":"Raj","sequence":"additional","affiliation":[{"name":"PRIMSR Hospital, SRM University","place":["Sonipat, Haryana, India"]}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"V. Samuel","family":"Raj","sequence":"additional","affiliation":[{"name":"Department of Biotechnology and Microbiology, School of Science and Humanities, SRM University","place":["Sonepat, Haryana, India"]},{"name":"Centre for Drug Design Discovery and Development (C4D), SRM University","place":["Sonepat, Haryana, India"]}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1965","published-online":{"date-parts":[[2026,7,29]]},"reference":[{"key":"B1","doi-asserted-by":"publisher","first-page":"629","DOI":"10.1016\/S0140-6736(21)02724-0","article-title":"Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis","volume":"399","year":"2022","journal-title":"Lancet"},{"key":"B2","doi-asserted-by":"publisher","first-page":"3370","DOI":"10.1128\/AAC.00079-11","article-title":"Phosphoethanolamine modification of lipid A in colistin-resistant variants of Acinetobacter baumannii mediated by the pmrAB two-component regulatory system","volume":"55","author":"Beceiro","year":"2011","journal-title":"Antimicrob. Agents Chemother."},{"key":"B3","doi-asserted-by":"publisher","first-page":"1","DOI":"10.1016\/j.jgar.2024.07.012","article-title":"Increased biofilm-associated carbapenem-resistant Acinetobacter calcoaceticus-baumannii complex infections among hospitalised patients in Kathmandu Model Hospital, Nepal","volume":"39","author":"Bhandari","year":"2024","journal-title":"J. Global Antimicrob. Resist."},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1093\/jacamr\/dlaf134","article-title":"The global epidemiology of carbapenem-resistant Acinetobacter baumannii","volume":"7","author":"Boutsoukas","year":"2025","journal-title":"JAC-antimicrobial Resist."},{"key":"B5","doi-asserted-by":"publisher","first-page":"228","DOI":"10.1128\/IAI.05913-11","article-title":"The Acinetobacter baumannii biofilm-associated protein plays a role in adherence to human epithelial cells","volume":"80","author":"Brossard","year":"2012","journal-title":"Infect. Immun."},{"key":"B6","doi-asserted-by":"publisher","first-page":"10.1128\/aac.01110","DOI":"10.1128\/aac.01110-18","article-title":"New treatment options against carbapenem-resistant Acinetobacter baumannii infections","volume":"63","author":"Burcu","year":"2018","journal-title":"Antimicrob. Agents Chemother."},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.3389\/fmicb.2017.00163","article-title":"Spread of the bla(OXA-23)-containing Tn2008 in carbapenem-resistant Acinetobacter baumannii isolates grouped in CC92 from China","volume":"8","author":"Chen","year":"2017","journal-title":"Front. Microbiol."},{"key":"B8","doi-asserted-by":"publisher","first-page":"33892","DOI":"10.1038\/s41598-025-09530-w","article-title":"Characterization of carbapenem-resistant biofilm forming Acinetobacter baumannii isolates from clinical and surveillance samples","volume":"15","author":"Choudhary","year":"2025","journal-title":"Sci. Rep."},{"key":"B9","first-page":"18","article-title":"Methods for dilution antimicrobial susceptibility tests for bacteria that grow aerobically; approved standard \u2014 ninth edition. CLSI document M07-A9","volume":"32","author":"CLSI","year":"2015","journal-title":"Clin. Lab. Standars Inst."},{"key":"B10","article-title":"European Committee on Antimicrobial Susceptibility Testing Breakpoint tables for interpretation of MICs and zone diameters","year":"2026"},{"key":"B11","doi-asserted-by":"publisher","first-page":"241","DOI":"10.1128\/CMR.00117-13","article-title":"OXA \u03b2-lactamases","volume":"27","author":"Evans","year":"2014","journal-title":"Clin. Microbiol. Rev."},{"key":"B12","doi-asserted-by":"publisher","first-page":"3711","DOI":"10.2147\/IDR.S332051","article-title":"Acinetobacter baumannii biofilm formation and its role in disease pathogenesis: a review","volume":"14","author":"Gedefie","year":"2021","journal-title":"Infect. Drug Resist."},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.1155\/2024\/8842625","article-title":"Carbapenem resistance in Acinetobacter calcoaceticus-baumannii complex isolates from Kathmandu Model Hospital, Nepal, is attributed to the presence of blaOXA-23-like and blaNDM-1 genes","volume":"2024","author":"Gurung","year":"2024","journal-title":"BioMed. Res. Int."},{"key":"B14","doi-asserted-by":"publisher","first-page":"173","DOI":"10.2147\/BTT.S381237","article-title":"Phage therapy: a different approach to fight bacterial infections","volume":"16","author":"Hibstu","year":"2022","journal-title":"Biologics"},{"key":"B15","doi-asserted-by":"publisher","first-page":"2974","DOI":"10.1128\/jcm.01021-06","article-title":"Identification of Acinetobacter baumannii by detection of the blaOXA-51-like carbapenemase gene intrinsic to this species","volume":"44","author":"J. F.","year":"2006","journal-title":"J. Clin. Microbiol."},{"key":"B16","doi-asserted-by":"publisher","first-page":"4848","DOI":"10.1128\/AAC.00762-13","article-title":"Structures of the class D carbapenemases OXA-23 and OXA-146: mechanistic basis of activity against carbapenems, extended-spectrum cephalosporins, and aztreonam","volume":"57","author":"Kaitany","year":"2013","journal-title":"Antimicrob. Agents Chemother."},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1016\/j.bbrc.2025.152487","article-title":"Deciphering the twinning act of antimicrobial resistance and biofilm-associated virulence in multidrug-resistant Acinetobacterbaumannii","volume":"780","author":"Kannan","year":"2025","journal-title":"Biochem. Biophys. Res. Commun."},{"key":"B18","doi-asserted-by":"publisher","first-page":"1729","DOI":"10.3390\/antibiotics12121729","article-title":"Cefiderocol and sulbactam-durlobactam against carbapenem-resistant Acinetobacter baumannii","volume":"12","author":"Karruli","year":"2023","journal-title":"Antibiot (Basel Switzerland)"},{"key":"B19","doi-asserted-by":"publisher","first-page":"1","DOI":"10.3390\/pathogens10030373","article-title":"Acinetobacter baumannii antibiotic resistance mechanisms","volume":"10","author":"Kyriakidis","year":"2021","journal-title":"Pathogens"},{"key":"B20","doi-asserted-by":"publisher","first-page":"48","DOI":"10.1016\/j.ijid.2022.12.010","article-title":"Geographic patterns of Acinetobacter baumannii and carbapenem resistance in the Asia-Pacific region: results from the Antimicrobial Testing Leadership and Surveillance (ATLAS) program, 2012-2019","volume":"127","author":"Lee","year":"2023","journal-title":"Int. J. Infect. Dis. IJID Off. Publ Int. Soc Infect. Dis."},{"key":"B21","doi-asserted-by":"publisher","first-page":"268","DOI":"10.1111\/j.1469-0691.2011.03570.x","article-title":"Multidrug-resistant, extensively drug-resistant and pandrug-resistant bacteria: an international expert proposal for interim standard definitions for acquired resistance","volume":"18","author":"Magiorakos","year":"2012","journal-title":"Clin. Microbiol. Infect."},{"key":"B22","doi-asserted-by":"publisher","first-page":"328","DOI":"10.3390\/antibiotics12020328","article-title":"Horizontal gene transfer of antibiotic resistance genes in biofilms","volume":"12","author":"Michaelis","year":"2023","journal-title":"Antibiot (Basel Switzerland)"},{"key":"B23","doi-asserted-by":"publisher","first-page":"93","DOI":"10.1007\/s12038-021-00209-8","article-title":"Polymyxins, the last-resort antibiotics: mode of action, resistance emergence, and potential solutions","volume":"46","author":"Mohapatra","year":"2021","journal-title":"J. Biosci."},{"key":"B24","doi-asserted-by":"publisher","first-page":"629","DOI":"10.1016\/S0140-6736(21)02724-0","article-title":"Global burden of bacterial antimicrobial resistance in 2019: a systematic analysis","volume":"399","author":"Murray","year":"2022","journal-title":"Lancet"},{"key":"B25","doi-asserted-by":"publisher","first-page":"33","DOI":"10.4103\/jrpp.jrpp_50_24","article-title":"Carbapenem-resistant Acinetobacter baumannii and ventilator-associated pneumonia; epidemiology, risk factors, and current therapeutic approaches","volume":"13","author":"Najafabadi","year":"2024","journal-title":"J. Res. Pharm. Pract."},{"key":"B26","doi-asserted-by":"publisher","first-page":"2119","DOI":"10.1128\/AAC.02522-13","article-title":"Class D \u03b2-lactamases: are they all carbapenemases","volume":"58","author":"NT","year":"2014","journal-title":"Antimicrob. Agents Chemother."},{"key":"B27","doi-asserted-by":"publisher","first-page":"24","DOI":"10.1128\/AAC.01512-08","article-title":"Diversity, epidemiology, and genetics of class D \u03b2-lactamases","volume":"54","author":"Poirel","year":"2010","journal-title":"Antimicrob. Agents Chemother."},{"key":"B28","doi-asserted-by":"publisher","first-page":"85","DOI":"10.3390\/antibiotics15010085","article-title":"An unexpected inverse relationship between biofilm formation and antibiotic resistance in Stenotrophomonas maltophilia","volume":"15","author":"Pompilio","year":"2026","journal-title":"Antibiot (Basel Switzerland)"},{"key":"B29","doi-asserted-by":"publisher","first-page":"540","DOI":"10.1007\/s12088-024-01188-8","article-title":"Solithromycin in combination with other antimicrobial agents against the carbapenem resistant Klebsiella pneumoniae (CRKP)","volume":"64","author":"Rani","year":"2024","journal-title":"Indian J. Microbiol"},{"key":"B30","doi-asserted-by":"publisher","first-page":"481","DOI":"10.1099\/jmm.0.000686","article-title":"High prevalence of fluoroquinolone resistance amongst commensal flora of antibiotic na\u00efve neonates: a study from India","volume":"67","author":"Saksena","year":"2018","journal-title":"J. Med. Microbiol."},{"key":"B31","doi-asserted-by":"publisher","first-page":"e00872","DOI":"10.1128\/spectrum.00872-24","article-title":"Genetic profiling of multidrug-resistant Acinetobacter baumannii from a tertiary care center in Malaysia","volume":"13","author":"Shahari","year":"2025","journal-title":"Microbiol. Spectr"},{"key":"B32","doi-asserted-by":"publisher","first-page":"28","DOI":"10.1007\/s44351-025-00028-4","article-title":"The antimicrobial spectrum to manage the co-infections of Pseudomonas aeruginosa and Staphylococcus aureus","volume":"3","author":"Sharma","year":"2025","journal-title":"Discov. Bact"},{"key":"B33","doi-asserted-by":"publisher","first-page":"83","DOI":"10.52403\/ijhsr.20251211","article-title":"Isolation and prevalence of multi-drug resistant Acinetobacter from various clinical samples in a tertiary care hospital","author":"Sultana","year":"2025"},{"key":"B34","doi-asserted-by":"publisher","first-page":"318","DOI":"10.1016\/S1473-3099(17)30753-3","article-title":"Discovery, research, and development of new antibiotics: the WHO priority list of antibiotic-resistant bacteria and tuberculosis","volume":"18","author":"Tacconelli","year":"2018","journal-title":"Lancet Infect. Dis."},{"key":"B35","doi-asserted-by":"publisher","DOI":"10.1016\/j.isci.2024.111367","article-title":"iScience review carbapenem-resistant Acinetobacter baumannii raises global alarm for new antibiotic regimens","volume":"27","author":"Thacharodi","year":"2024","journal-title":"ISCIENCE"},{"key":"B36","doi-asserted-by":"publisher","first-page":"3","DOI":"10.3390\/antibiotics10010003","article-title":"Biofilms as promoters of bacterial antibiotic resistance and tolerance","volume":"10","author":"Uru\u00e9n","year":"2020","journal-title":"Antibiot (Basel Switzerland)"},{"key":"B37","doi-asserted-by":"publisher","first-page":"1","DOI":"10.62347\/kbsb9946","article-title":"Analysis of carbapenem-resistant Acinetobacter baumannii carbapenemase gene distribution and biofilm formation","author":"Wang","year":"2024"},{"key":"B38","volume-title":"Global Antimicrobial Resistance and Use Surveillance System (GLASS)","year":"2024"}],"container-title":["Frontiers in Antibiotics"],"original-title":[],"link":[{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/frabi.2026.1888133\/full","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,7,29]],"date-time":"2026-07-29T09:12:18Z","timestamp":1785316338000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.frontiersin.org\/articles\/10.3389\/frabi.2026.1888133\/full"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,7,29]]},"references-count":38,"alternative-id":["10.3389\/frabi.2026.1888133"],"URL":"https:\/\/doi.org\/10.3389\/frabi.2026.1888133","relation":{},"ISSN":["2813-2467"],"issn-type":[{"value":"2813-2467","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,7,29]]},"article-number":"1888133"}}