Background and Aims: Urinary Tract Infection (UTI) is one of the most common bacterial infections, and several studies have reported the prevalence of UTI caused by ESBLproducing E.coli strains in different cities of Iran. The aim of this study was to evaluate antibiotic resistant UTI factors in outpatients and determine the prevalence of ctx-m gene in ESBL-producing E. coli strains of Bonab (East Azerbaijan, Iran). Materials and Methods: In 2015, 266 clinical isolates of E. coli were collected from clinical laboratories in Bonab. Phenotypic screening and confirmation tests for extendedspectrum beta-lactamases (ESBLs) were carried out using disk diffusion (Kirby Bauer) method. All of the ESBL producing isolates were tested by PCR using specific primers. A total of 10 PCR products were randomly selected and purified and subsequently sent for sequencing. Results & Conclusion: The maximum resistance was seen regarding ampicillin (67.3 %) and the maximum sensitivity was seen regarding imipenem (92.5%). In this study, 45 % of isolates were multidrug resistance, which showed at least resistance for three antibiotics. Out of 154 isolates, 58 (37.7%) isolates were ESBL producers which 94.8% of isolates contained ctx-m gene. The prevalence of the ctx-m gene, as in other parts of Iran and the world, is high in Bonab. For the treatment of infections suspected to be an ESBL producer, appropriate antibiotics should be selected, and strains that have decreased their sensitivity to ceftazidime, cefotaxime, and cefetoxin should be considered for ESBL genes.
