Identification of oxacillinase and metallobetalactamase genes inAcinetobacter baumannii strains isolated from several hospitals inIsfahan

Background and Aim : Increasing of multi-drug resistant strains of Acinetobacter baumanniiespecially carbapenem resistance strains is a challenge for the treatment of infections. The aim ofthe present study was to determine susceptible pattern and frequency of carbapenem resistancegenes (oxacillinase and metallobetalactamase) in Acinetobacter baumannii strains collected fromdifferent clinical samples of Isfahan hospitals.Methods : Antibiogram profiles of the isolates were determined using disc diffusion method.Frequency of OXA_۵۸, OXA_۵۱, OXA_۲۳, blaNDM, blaVIM and blaIMP genes wereinvestigated in carbapenem resistant isolates using PCR method and positive results weresequenced.Results : : total of ۱۰۰ samples were obtained from blood, urine, wound, and tracheal culturesfrom Isfahan hospitals. Out of ۱۰۰ bacteria identified as Acinetobacter baumannii, ۶۰ isolates(۶۰%) were resistant to carbapenems (meropenem and imipenem), and these bacteria were selectedfor antibiogram and detection of resistance genes. Result showed ۱۰۰% of selected isolates wereresistant to Cefotaxime, Ceftazidime, Cotrimoxazole, Gentamicin, Ampicilline-sulbactam,Ciprofloxacin and Piperacillin-Tazobactam. In addition, ۸.۳% and ۸۵% of the isolates weresensitive to Amikacin and colistin respectively. Among these isolates, ۱۰۰%, ۱۰۰%, ۴% and ۲۴%for OXA_۵۱, OXA_۲۳, NDM and VIM were positive respectively. IMP and OXA_۵۸ genes werenot detected.Conclusion : the result showed the best antibiotic against isolates was colistin. The OXA_۵۱ andOXA_۲۳ (oxacillinase genes) are predominant genes but IMP and OXA_۵۸ were not local genesof carbapenem resistant in Isfahan hospitals.

کلیدواژه ها:

Carbapenemase ، Oxaclinase ، Metallobetalactamase ، Acinetobacter baumannii