Tabari Biomedical Student Research Journal

Background & Objectives: Urinary tract infection is a common disease, especially among women. Beta-lactam group of antibiotics are the commonly prescribed antibiotics for this disorder. The emergence of antibiotic resistance among gramnegative bacilli limited applicability and usefulness of the antibiotics. In this study, we assessed the prevalence of extended spectrum beta-lactamases (ESBL) produced in E. coli, extracted from urine samples in Taleghani Hospital of Tehran. Material and Methods: This descriptive study was performed on patients with urinary tract infection, who referred to Taleghani Hospital, from April to July 2014. A total of 1896 patients with urinary tract infection were investigated. After gram staining, morphology, growth characteristics and biochemical tests of 225 strains of E. coli were extracted from the samples. Following instructions of clinical laboratory standards institute (CLSI), diffusion disk method, sulfamethoxazoletrimethoprim disks, nitrofurantoin, tobramaysn, cefixime, cefpodoxime, piperacillin-tazobactam, ampicillin, cefazolin, ceftriaxone, amikacin, meropenem, colistin, ceftazidime, ciprofloxacin and gentamicin were used in Müller-Hinton agar medium to determine antibiotic sensitivity. Results: In this study, from the 225 separated E. coli samples, belonged to males (39.2%) and 137 were from females (60.8%). The mean age of the patients was 41±21 years. After determining ESBL-producing isolates through combined disk method, it was found that 97 out of 225 isolates were ESBL-producing. Conclusion: The rate of urinary tract infections caused by E. coli is still high. The investigations of resistance pattern demonstrate high level of E. coli resistance against various antibiotics, and it seems that this resistance is continuously increasing