title: Dissemination of multidrug-resistant, class 1 integron-carrying Acinetobacter baumannii isolates in Taiwan.
abstract: In this study, 283 multidrug-resistant Acinetobacter baumannii (MDR-AB) bloodstream isolates were collected between 1996 and 2004, from three teaching hospitals located in different regions of Taiwan. Susceptibility data showed that strains carrying class 1 integrons were significantly more resistant (p <0.01) to all tested antibiotics (except aztreonam and chloramphenicol) than strains lacking integrons, Seven types of gene cassette were identified among these strains, including two that have not been previously reported. The vast majority of the cassettes encoded aminoglycoside resistance genes, including aacA4, aacC1, aac(6')-II, aadA1, aadA2, aadA4 and aadDA1. Sixteen distinct ribotypes were identified in MDR-AB isolates carrying class 1 integrons. Only one strain was found to produce an extended-spectrum beta-lactamase, i.e. VEB-3. In the 18 imipenem-resistant strains, two carbapenenmase genes, bla(VIM-11) and bla(OXA-58), were found concomitantly in one isolate. An island-wide epidemic clone and an endemic clone from a hospital located in the northern region were identified by ribotyping. On the basis of the susceptibility data among the different ribogroups, the epidemic clone was associated more significantly with resistance to cefepime and ampicillin-sulbactam than was the endemic clone. In conclusion, the presence of class 1 integrons was significantly associated with resistance in MDR-AB, and the epidemic, class 1 integron-carrying MDR-AB clone was found to be widespread in Taiwan.
authors.affiliation: Graduate Institute of Medical Sciences, National Defence Medical Centre [corrected] Taipei, Taiwan.
authors.forename: L-Y
authors.initials: LY
authors.lastname: Huang
authors.forename: T-L
authors.initials: TL
authors.lastname: Chen
authors.forename: P-L
authors.initials: PL
authors.lastname: Lu
authors.forename: C-A
authors.initials: CA
authors.lastname: Tsai
authors.forename: W-L
authors.initials: WL
authors.lastname: Cho
authors.forename: F-Y
authors.initials: FY
authors.lastname: Chang
authors.forename: C-P
authors.initials: CP
authors.lastname: Fung
authors.forename: L K
authors.initials: LK
authors.lastname: Siu
mesh_terms: D000151:Acinetobacter Infections / Q000453:epidemiology* / Q000382:microbiology; D040981:Acinetobacter baumannii / Q000145:classification / Q000187:drug effects* / Q000235:genetics / Q000302:isolation & purification*; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D016470:Bacteremia / Q000453:epidemiology* / Q000382:microbiology; D015373:Bacterial Typing Techniques; D016172:DNA Fingerprinting; D004269:DNA, Bacterial / Q000235:genetics; D024901:Drug Resistance, Multiple, Bacterial; D005798:Genes, Bacterial; D005838:Genotype; D006784:Hospitals, Teaching; D006801:Humans; D032023:Integrons; D008826:Microbial Sensitivity Tests; D017720:Molecular Epidemiology; D021521:Ribotyping; D013624:Taiwan / Q000453:epidemiology; D001618:beta-Lactamases / Q000096:biosynthesis
chemical_list: D000900:Anti-Bacterial Agents; D004269:DNA, Bacterial; D001618:beta-Lactamases