Frequency of blaCTX-M, blaTEM, and blaSHV Genes in Escherichia Coli Isolated from Urine Samples of Children in Kermanshah City, Iran

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.
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%).
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.