مجله دانشکده پزشکی اصفهان (Jul 2017)
Frequency of blaCTX-M, blaTEM, and blaSHV Genes in Escherichia Coli Isolated from Urine Samples of Children in Kermanshah City, Iran
Abstract
Background: Escherichia coli (E. coli), as the main cause of urinary tract infections among most of the age groups including children, due to extended-spectrum beta-lactamases (ESBL) producing has high ability to acquire antibiotic resistance. The purpose of this study was to determine the frequency of ESBL-producing genes in E. coli extracted from urine samples of children in Kermanshah City, Iran. Methods: In this cross-sectional study, 95 E. coli isolates were identified via specific biochemical methods. After determination of antibiotic susceptibility using disk diffusion, ESBL-producing isolates were determined by using phenotypic combined disk (double-disk synergy) methods. The frequency of blaTEM, blaCTX-M, and blaSHV genes were determined via using specific primers and polymerase chain reaction (PCR) method. Findings: Of 95 E. coli isolates, 24 samples (25.3%) were ESBL-positive and 71 (74.7%) were ESBL-negative samples. The frequency of blaCTX-M, blaTEM, and blaSHV genes was 47.5%, 37.5%, and 4.17%, respectively. The highest antibiotic resistance among isolates was to ampicillin (83.2%), cefixime (69.5%), and trimethoprim/sulfamethoxazole (co-trimoxazole) (67.4%), and the most antibiotic sensitivity was to imipenem (90.5%), norfloxacin (86.3%), and nitrofurantoin (83.2%). Conclusion: The results showed that prevalence of ESBL-producing E. coli in children was 25.3% and blaCTX-M gene was the most common. According to these findings and relatively high level of resistance to third-generation cephalosporins, the need for more medical care in the correct and appropriate use of antibiotics is concluded; further studies on this subject are recommended, too.
