title: Antimicrobial Resistance Mechanisms and Genetic Diversity of Multidrug-Resistant Acinetobacter baumannii Isolated from a Teaching Hospital in Malaysia.
abstract: Multidrug-resistant (MDR) Acinetobacter baumannii has increasingly emerged as an important nosocomial pathogen. The aim of this study was to determine the resistance profiles and genetic diversity in A. baumannii clinical isolates in a tertiary medical center in Malaysia. The minimum inhibitory concentrations of carbapenems (imipenem and meropenem), cephalosporins (ceftazidime and cefepime), and ciprofloxacin were determined by E-test. PCR and sequencing were carried out for the detection of antibiotic resistance genes and mutations. Clonal relatedness among A. baumannii isolates was determined by REP-PCR. Sequence-based typing of OXA-51 and multilocus sequence typing were performed. One hundred twenty-five of 162 (77.2%) A. baumannii isolates had MDR phenotype. From the 162 A. baumannii isolates, 20 strain types were identified and majority of A. baumannii isolates (66%, n = 107) were classified as strain type 1 and were positive for ISAba1-blaOXA-23and ISAba1-blaADCand had mutations in both gyrA and parC genes at positions, 83 and 80, resulting in serine-to-leucine conversion. REP-PCR analysis showed 129 REP types that generated 31 clones with a 90% similarity cutoff value. OXA-66 variant of the blaOXA-51-likegenes was predominantly detected among our A. baumannii clinical isolates belonging to ST195 (found in six clones: 1, 8, 9, 19, 27, and 30) and ST208 (found in clone 21). The study helps us in understanding the genetic diversity of A. baumannii isolates in our setting and confirms that international clone II is the most widely distributed clone in Universiti Kebangsaan Malaysia Medical Centre, Malaysia.
authors.affiliation: 1 Department of Medical Microbiology and Immunology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre , Kuala Lumpur, Malaysia .
authors.forename: Shirin
authors.initials: S
authors.lastname: Biglari
authors.affiliation: 1 Department of Medical Microbiology and Immunology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre , Kuala Lumpur, Malaysia .
authors.forename: Alfizah
authors.initials: A
authors.lastname: Hanafiah
authors.affiliation: 1 Department of Medical Microbiology and Immunology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre , Kuala Lumpur, Malaysia .
authors.forename: Shaliawani
authors.initials: S
authors.lastname: Mohd Puzi
authors.affiliation: 1 Department of Medical Microbiology and Immunology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre , Kuala Lumpur, Malaysia .
authors.forename: Ramliza
authors.initials: R
authors.lastname: Ramli
authors.affiliation: 1 Department of Medical Microbiology and Immunology, Faculty of Medicine, Universiti Kebangsaan Malaysia Medical Centre , Kuala Lumpur, Malaysia .
authors.forename: Mostafizur
authors.initials: M
authors.lastname: Rahman
authors.affiliation: 2 Department of Medical Microbiology, School of Medicine, Medical Sciences and Nutrition, University of Aberdeen , Aberdeen, United Kingdom .
authors.forename: Bruno Silvester
authors.initials: BS
authors.lastname: Lopes
mesh_terms: D000151:Acinetobacter Infections / Q000188:drug therapy / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000187:drug effects / Q000201:enzymology / Q000235:genetics* / Q000302:isolation & purification; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D015780:Carbapenems / Q000494:pharmacology; D002511:Cephalosporins / Q000494:pharmacology; D002939:Ciprofloxacin / Q000494:pharmacology; D002999:Clone Cells; D003428:Cross Infection / Q000188:drug therapy / Q000382:microbiology; D027081:DNA Gyrase / Q000235:genetics / Q000378:metabolism; D027101:DNA Topoisomerase IV / Q000235:genetics / Q000378:metabolism; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics*; D015870:Gene Expression; D006784:Hospitals, Teaching; D006801:Humans; D007527:Isoenzymes / Q000235:genetics / Q000378:metabolism; D008296:Malaysia; D008826:Microbial Sensitivity Tests; D058885:Multilocus Sequence Typing; D009154:Mutation; D010957:Plasmids / Q000737:chemistry / Q000378:metabolism; D017422:Sequence Analysis, DNA; D001618:beta-Lactamases / Q000235:genetics* / Q000378:metabolism
chemical_list: D000900:Anti-Bacterial Agents; D015780:Carbapenems; D002511:Cephalosporins; D007527:Isoenzymes; D002939:Ciprofloxacin; D001618:beta-Lactamases; C577373:beta-lactamase OXA-51, Acinetobacter baumannii; D027101:DNA Topoisomerase IV; D027081:DNA Gyrase
keywords: Acinetobacter baumannii; MLST; OXA-51 sequence typing; multidrug resistance