Drug Resistance and Serotyping of Uropathogenic Escherichia coli Among Patients With Urinary Tract Infection in Rasht, Iran

Background: Urinary Tract Infection (UTI) is one of the most common reasons for human to seek medical advice and is also one of the most frequently occurring nosocomial infections. Nosocomial UTIs are almost exclusively complicated with a broad spectrum of etiological pathogens. Escherichia coli remains the predominant uropathogen (80%) isolated in community-acquired infections. Objectives: The aim of this study was to determine the local incidence of UTIs, identification of Uropathogenic E. coli (UPEC), serotyping and strains antimicrobial resistance of E. coli isolated from these patients. Patients and Methods: In this prospective cross-sectional study, in order to isolate and identify bacterial agent (UPEC) causing UTI and to identify it’s sex and age distribution, a total 150 urine samples through simple random sampling method were analyzed for identification of bacterial isolates. Lactose fermenting colonies on MacConkey’s agar were processed and identified as E. coli by standard biochemical tests. Antibiotic susceptibility tests were performed with disk diffusion tests using Kirby-Bauer method on E. coli isolated from 110 cases with UTI aged from 1 year to 85 years and serotyping achieved by slide agglutination method. All data analyzed using SPSS-21 software. Results: Majority of UPEC belonged to serotype O1, O2, O4, O20, O25, O44, O64 and O78. Majority of the isolates were resistant to routinely used antibiotics amoxicillin, cotrimoxazole, tetracycline and gentamicin. Most of the isolates were sensitive to nalidixic acid, ciprofloxacin, nitrofurantoin and ceftazidime. Conclusions: The present study revealed that serotype O25 was isolated with maximum frequency followed by O2, O6, O1, O78, O44, O20 and O64 respectively.