title: Investigations on the genomic diversity of OXA from isolated Acinetobacter baumannii.
abstract: We distinguished the four OXA-type carbapenemase subgroup alleles present in 120 strains of Acinetobacter baumannii by using polymerase chain reaction (PCR) and investigated the distributions of the OXA subgroups in clinically isolated samples. Amplification of the OXA genes blaOXA-23, blaOXA-24, blaOXA-51, and blaOXA-58 was performed by multiplex PCR. Antibiotics susceptibility test was conducted for determine the sensitivity of the A. baumannii to clinical common used antibiotics by Kirby-Bauer method. Results revealed that 46 (51.69%) of the samples were positive for only the blaOXA51 gene and 41 (46.07%) were positive for both the blaOXA51 and blaOXA58 genes in the 89 isolates of A. baumannii. Among these, 45 were carbapenem-resistant and 44 carbapenem-sensitive. Strains containing either blaOXA51 or blaOXA58 showed resistance or sensitivity to carbapenems, respectively. A. baumannii isolated from intensive care units showed significantly higher resistance rate to Cefepime, Piperacillin-tazobactam, Amikacin, Ceftazidime, Cefotaxime, Sulfamethoxazole-trimethoprim, and Gentamicin than those isolated from other departments (P < 0.05). In conclusion, we found that the presence of blaOXA-51 and blaOXA-58 appears to convey a mechanism of resistance or sensitivity to carbapenems, respectively, in A. baumannii clinical isolates.
authors.affiliation: Department of Medical Imaging Center, The First Affiliated Hospital of Jinan University, Guangzhou, China.
authors.forename: Z
authors.initials: Z
authors.lastname: Ma
authors.affiliation: Department of Neurosurgery, Shenzhen Longgang Central Hospital, Shenzhen, China.
authors.forename: L Q
authors.initials: LQ
authors.lastname: Zhou
authors.affiliation: Microbiology laboratory, Shenzhen Longgang Central Hospital, Shenzhen, China.
authors.forename: H
authors.initials: H
authors.lastname: Wang
authors.affiliation: Department of Medical Imaging Center, The First Affiliated Hospital of Jinan University, Guangzhou, China tluolp_jnu@163.com.
authors.forename: L P
authors.initials: LP
authors.lastname: Luo
mesh_terms: D040981:Acinetobacter baumannii / Q000187:drug effects / Q000235:genetics / Q000472:pathogenicity; D000900:Anti-Bacterial Agents / Q000494:pharmacology; D001426:Bacterial Proteins / Q000235:genetics* / Q000302:isolation & purification; D024901:Drug Resistance, Multiple, Bacterial / Q000235:genetics; D014644:Genetic Variation; D006801:Humans; D008826:Microbial Sensitivity Tests; D060885:Multiplex Polymerase Chain Reaction / Q000379:methods; D001618:beta-Lactamases / Q000235:genetics* / Q000302:isolation & purification
chemical_list: D000900:Anti-Bacterial Agents; D001426:Bacterial Proteins; D001618:beta-Lactamases; C000599728:beta-lactamase OXA-23, Acinetobacter baumannii; C410345:beta-lactamase OXA-24; C063912:carbapenemase