Antibiotic resistance genes in Acinetobacter baumanii isolates from nosocomial infection

Background and Aim : Bla-oxa enzymes are belonged to the beta-lactamase enzymes with strong penicillinase activity. Most of these enzymes can hydrolyze the carbapenems which cause resistance increasing to the carbapenems. bla-oxas, like betalactamases are exist on the naive chromosome in A.bumannii.Methods : Presence of following bla-oxa related genes were assessed by polymerase chain reaction (PCR), for ۱۰۰ clinical isolated A.baumannii samples: bla-oxa bla-oxa like, bla-oxaz like and bla-oxa۴ like. Agar disk diffusion antibiotic susceptibility testing was performed for at least ۱۰ different antibiotics. And finally using E.test. MIC measuring was evaluated for these three antibiotics ampicillin-sulbactam, gentamicin and meropenem.Results : Present study showed that ۱۰۰% of the clinical isolated A.baumannii samples have bla-oxas like gene, ۳۸% were positive for bla-oxazı gene, ۳۲% for bla- oxazlike and the presence of bla-oxa۵۸ like gene was only ۱%. Gentamicin and Meropenem were most effective antibiotics against A.baumannii in this study with ۵۷% and ۴۶% sensitivity respectively.Conclusion : Due to the presence of bla-oxa related genes A.baumannii isolated clinical samples are highly resistance to the carbapenem in this study. Identifying of bla-oxas like gene can be a potentially reliable marker for specific diagnosis of A.baumannii

کلیدواژه ها:

Acinetobacter baumannii ، Beta-lactamases enzymes ، Bla-oxa genes