Detection of Genes Encoding Metallo-beta-lactamases in Carbapenem Resistant Acinetobacter baumannii

Abstract

Background: Drug resistant Acinetobacter baumannii have emerged as a major problem in many hospitals and intensive care units. The aim of this study was to determine the antibiotic resistance pattern and the prevalence of metallo-beta-lactamase genes among nosocomial A. baumannii isolates from Qom/ Iran.Methods: For this study, a total of 108 A. baumannii isolates were collected from hospitalized patients in four teaching hospitals of Qom/ Iran. Antibiotic susceptibility profile of isolates was tested by Kirby-Bauer disc diffusion method and distribution of MBL genes among carbapenem-resistant isolates was determined by polymerase chain reaction (PCR) method.Results: According to the results, 97 (89.81%) isolates of 108 A. baumannii isolates were resistant to carbapenem. All isolates carried bla oxa-51like gene. Among carbapenem resistant isolates, 79.38% carried bla VIM and 1.03% had bla IMP genes. Among the MBL- producing isolates, 7 isolates were MDR, 73 ones were XDR and 5 isolates were PDR.Conclusion: This study also revealed that suceptibility to carbapenems in the population of A. baumannii isolates reduced and the bla VIM gene was the most prevalent metallo-beta-lactamase genotype among carbapenem resistant A. baumannii isolates in this area. MBL-producing A. baumannii in recent years has become a serious concern. Rapid identification and good infection control are requiered to reduce their impact.

Keywords

• acinetobacter baumannii
• metallo-beta-lactamases
• carbapenem resistance
• polymerase chain reaction