Comparison of antibiotic resistance in Escherichia coli isolated from urine of adult patients with regard to gender, age and kind of admission

Background and Objective: Urinary tract infection (UTI) is one of the most prevalent bacterial infections and Escherichia coli is the most common cause of it. The aim of this study was determination of the antibiotic resistance of E. coli isolated from urine of adult patients (≥15 years old) harboring UTI symptoms at Pars General Hospital in Tehran, Iran, for evaluating the most effective drug for the empirical treatment of this infection.

Materials and Methods: The results of antimicrobial susceptibility test, obtained by the disk diffusion method, were investigated for E. coli isolated from urine during three months from April to July 2013.

Results: The frequency of antibiotic resistance in E. coli isolates (562 isolate) was as follows: ampicillin 80.3%, cotrimoxazole 61.4%, ciprofloxacin 48.7%, cefazolin 46.1%, cefepime 45.8%, ceftriaxone 42.5%, tobramycin 28.7%, ceftazidime 27.3%, gentamicin 24.1%, nitrofurantoin 2.2%, piperacillin/tazobactam 1.4%, amikacin 0.5% and colistin 0.4%. Resistance to meropenem was not seen and 42.1% of E. coli isolates contained extended spectrum β-lactamases (ESBL). A higher resistance to most antibiotics was seen in E. coli isolated from men as compared to women, inpatient as compared to outpatients and elder patients as compared to younger patients, which these differences were statistically significant for some antibiotics (p