Drug-Resistance Phenotypes of Uropathogenic Escherichia coli Isolates: A Retrospective Study

BACKGROUND AND OBJECTIVESUrinary tract infections caused by Escherichia coli are common causes of patients' referral to health centers and it is a common nosocomial infection that has recently become difficult to treat because of the increased emergence of drug-resistant strains. The present study aimed to determine frequency of multidrug-resistant (MDR) and extensively drug-resistant (XDR) E.coli isolates originated from hospitalized patients.MATERIALS AND METHODSUrine samples were obtained from ۶۲۴ patients (age range۳۵ years) in hospitals of Golestan province, northeast of Iran during ۲۰۱۸-۲۰۲۳. After identification of bacterial strains and isolation of E. coli, the Kirby-Bauer disk diffusion test was performed to evaluate the antibiotic susceptibility pattern to ten categories of antibacterial agents according to the Clinical and Laboratory Standards Institute M۱۰۰ guidelines (۲۰۲۱). Minimum inhibitory concentrations (MICs) of drug-resistant isolates to gemifloxacin were determined using the microdilution broth method over a concentration range of ۰.۰۳-۸ μg/mL.RESULTS AND DISCUSSIONThe frequency of isolates were Escherichia coli (۴۹.۵۰%), Klebsiella pneumonia (۲۲%), Citrobacter freundii (۱۵.۴۵%) and Proteus mirabilis (۱۳.۰۵%). Among E. coli isolates, the majority were from patients with urinary catheters (۶۵.۱۴%), most of which originated from ICU patients. The highest resistance and susceptibility among the E,coli isolates belonged to tetracycline (۷۵.۳۰%) and gemifloxacin (۹۳.۵۰%). Among E.coli isolates, ۷۸.۲۱% and ۱۳.۹۰% were MDR and XDR respectively. Moreover, Gemifloxacin (MIC=۲ μg/mL) inhibited the growth of ۷۸% of XDR and ۸۶% of MDR isolates (P=۰.۰۱).CONCLUSIONIn this study, the high frequency of MDR/XDR phenotypes in the isolates may suggest an increasing trend of antibiotic resistance in E.coli strains. Our results indicated a high bactericidal activity of gemifloxacin against uropathogenic E. coli isolates. considering the great inhibitory properties of gemifloxacin against MDR E. coli strains, it is suggested to investigate the efficacy of this agent for the treatment of urethritis particularly in patients with urinary catheters.

کلیدواژه ها:

Escherichia coli ، Drug resistance ، urethritis