Detection of Carbapenemase Genes among Clinical Isolates of Acinetobacter baumannii

Background and Objective: Acinetobacter baumannii is a non-motile Gram-negative bacterial pathogen with multiple resistance to antibiotics. The aim of this study was to determine the possibility of existence of carbapenemase genes among clinical isolates of A. baumannii resistant to metalobetalactams obtained from Tehran hospitals.Materials and Methods: Common biochemical and molecular tests were used to identify 101 isolates as A. baumannii. The susceptibility to different antibiotics was assessed with Kirby-Bauer disk diffusion method. Phenotypic Detection of MBLs was performed with CDT test and PCR assay was also performed for detection of blaOXA-23-like, blaOXA-24-like, blaOXA-40-like,blaOXA-51-like,blaOXA-58-like and blaOXA-143-like genes Results: High-level of resistance to all antibiotics, except Polymyxin B, were shown for all isolates of A. baumannii . The blaOXA-51 like genes was found in all of the isolates and the prevalence of blaOXA-143like, blaOXA-23like,blaOXA-40like and blaOXA-24like were 56%, 45.45%, 33% and 11.8%, respectively. Conclusion: The blaOXA-51-like was the predominant mechanism of resistance to imipenem in A. baumannii and, therefore, early recognition of carbapenem-resistant A. baumannii isolates is a useful tool to prevent their spread within the hospital environment.