Elham Zarifi1, Gilda Eslami2,3, Azad Khaledi4, Mahmood Vakili5, Hossein Vazini6 and Hengameh Zandi1,2*

1Department of Microbiology, Faculty of Medicine,Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
2Research Center for Food Hygiene and Safety, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
3Department of Parasitology and Mycology, Faculty of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
4Department of Microbiology and Immunology, School of Medicine, Kashan University of Medical Sciences, Kashan, Iran.
5Department of Community Medicine, School of Medicine, Shahid Sadoughi University of Medical Sciences, Yazd, Iran.
6Nursing Department Basic Sciences Faculty, Hamedan Branch, Islamic Azad University, Hamedan, Iran.

Abstract

Acinetobacterbaumanniiis an important opportunistic pathogen that mainly infects critically patients in intensive care units (ICU). The production of plasmid-mediated extended-spectrum β-lactamases (ESBLs) is one of the most important mechanisms of resistance against β-lactam antibiotics. This study aimedtoevaluate the prevalence of ESBLs in A. baumannii isolated from ICU of Ghaem hospital, Mashhad, Iran A total of 140 A. baumannii isolates recovered from hospitalized patients in ICU of Ghaem hospital in Mashhad city from December 2014to March 2015. Identification of A. baumannii isolates carried out using biochemical laboratory methods and then confirmed by OXA-51 PCR screening. Susceptibility testing performed using disk diffusion (Kirby-Bauer) methodas recommended byCLSI guidelines. A. baumannii isolates screened for production of ESBLs using combination disk test.blaPER, blaGES, blaTEM, blaSHV, blaCTX, blaVEBand blaOXA-10 beta-lactamase genesdetected using conventional PCR. The mostantibacterial resistance was against cefuroxime (­99.3%) andcolistin was the most effective antibiotic. None of the isolates were ESBL producer by combination disk test. However, results of PCR revealed that the prevalence ofblaPER, blaGES andblaTEM genes were7.1%, 4.3% and 27.1%, respectively. blaCTX, blaVEB, and blaOXA-10 were not found in any of isolates.According to the results, the high resistance was seen against selected antibiotics and the phenotypic tests are not sufficient alone for determination of ESBLs producer ofA. baumanniiisolates. So, molecular tests are also necessary for detection of these enzymes.

Keywords: A. baumannii, ESBLs, ICU, Iran.