Distribution of blaTEM, blaSHV and blaCTX-M Genes Among Escherichia coli Isolates Causing Urinary Tract Infection in Children

Background: Emerging antibacterial resistance rates and extended-spectrum-B-lactamase producing Escherichia coli recovered from urinary tract infections (UTI) is an increasing problem in different regions, limiting therapeutic options. Objectives: The aim of this study was the detection of blaTEM, blaSHV and blaCTX-M genes among Escherichia coli strains causing Urinary Tract Infection in children from Iran. Materials and Methods: A total of 100 Escherichia coli isolates were collected from urine specimens of patients with UTI who had referred to the Children Medical Center, Tehran, Iran between November 2012 and July 2013. Antibiotic susceptibility test was performed by Kirby- Bauer disc diffusion method according to CLSI guidelines. The blaCTX-M, blaTEM and blaSHV genes were detected by PCR and sequencing methods. Results: The resistance rate of isolates to cefotaxime, ceftazidime, imipenem, gentamicin, amikacin, cefepime, piperacillin/tazobactam, co-trimoxazole, nitrofurantoin, cefixime and cephalothin, were 51 (51%), 24 (24%), 0 (0%), 25 (25%), 2 (2%), 6 (6%), 2 (2%), 79 (79%), 7 (7%), 36 (36%) and 43 (43%), respectively. In this study, imipenem was more active than other antibiotics. The existence of blaTEM-1 and blaCTX-M-15 was detected in 69 (69%) and 74 (74%) isolates respectively, while blaSHV gene was not detected. Conclusions: The prevalence of B-lactamase-producing genes in E. coli detected by this study is of great concern and highlights the need of infection control measures including antibacterial management and prompt identification of isolates with beta-lactamase-producing genes.