Evaluation of virulence factors of isolated Echerichia coli from nosocomial urinary tract infections

Abstract

Urinary tract infections are the most common nosocomial infections in hospitalized patients. The most common microbial agent causing these infections is Escherichia coli. The aim of the present study was to investigate the drug resistance pattern of E. coli isolated from hospital urinary tract infections, the ability to form biofilm in them and to investigate the frequency of virulence genes in these isolates. Methods: One hundered E. coli isolates obtained from nosocomial unrinary tract infections in Sina and Imam Reza hospitals in Tabriz between April 2022 and January 2023. Antibiotic susceptibility pattern was determined using the disk diffusion method and the ability to produce broad-spectrum beta-lactam enzymes (ESBLs) and carbapenemase were investigated with phenotypic tests. The microtitreplate method was used to study the biofilm formation ability and the PCR method was used to detect the presence of virulence indicators. Results: The highest rate of resistance was observed to piperacillin (82%), followed by aztronam and ciprofloxacin (81%) and the lowest resistance was observed to piperacillin/tazobactam (12%) and meropenem (9%). The presence of ESBLs was observed by phenotypic method in 62% of the isolates. Among the studied isolates, 32% were strong biofilm-former, 33% had moderate biofilm-forming ability, and 24% were weak biofilm-former. In this study, the most common virulence gene was fimA with a frequency of 74%, followed by hlyF (68%), papA (44%), papC (32%), iroN (26%) and cnf (20%).