Production of bla oxa-23 type genes carrying by Acinetobacter baumannii isolated from hospitalized patients in Tehran, Iran

Abstract

ISSN Carbapenems are potent b-lactam antibiotics, including imipenem and meropenem that is used to treat serious infections caused by Acinetobacter baumannii. The aim of this study was to determine the resistance rate of A. baumannii to imipenem and meropenem by producing OXA-23 gene. Sixty A. baumannii isolates were collected from four hospitals. Susceptibility testing of all A. baumannii isolates was determined by disk diffusion method. After bacterial DNA extraction, PCR was used for detection of blaoxa-51 and blaoxa-23 beta-lactamase genes. According to the result, 98% of A. baumannii isolates were resistant to amikacin, ceftazidime and ceftriaxone. Resistance rates to imipenem and meropenem was 72%. All isolates were resistant to cefixime; however, were susceptible to colistin. PCR method determined the presence of resistance-encoding class D carbapenemase including blaoxa-51 like and blaoxa-23 like in 60 (100%) and 51 (85%) isolates, respectively, which was in agreement with disk diffusion method. Our study revealed a high rate of drug resistance among A. baumannii isolates with presence of blaoxa-51 and blaoxa-23 b-lactamase gens. However, colistin were the effective antimicrobial agents, in vitro. Therefore, the rate of carbapenemresistant A. baumannii susceptibility profiling highlights the need for a comprehensive Iranian national antimicrobial drug resistance survey to monitor A. baumannii isolates from all parts of the country. Copyright 2020 Wolters Kluwer Health, Inc. All rights reserved.