Antimicrobial Resistance among Community-Acquired Uropathogens in Mashhad, Iran.

BACKGROUND

Antimicrobial resistance among community-acquired uropathogens is an emerging concern over the past decades that warrants a continuing reevaluation of the appropriateness of recommended empiric antimicrobial regimens for treatment of urinary tract infections (UTIs).

AIMS: To describe the microbial spectrum and resistance profile of community-acquired uropathogens and predictors of isolation of resistant strains.

METHODS

Between October 2017 and June 2019, individuals who visited the outpatient clinics for diagnosis of UTIs or screening of asymptomatic bacteriuria were included in the study if they were tested for urine culture in one of the three main medical diagnostic laboratories of Mashhad, Iran. The standard disk diffusion antimicrobial susceptibility testing was used, with the Clinical and Laboratory Standards Institute (CLSI) threshold cutoffs for susceptibility of isolated uropathogens.

RESULTS

Three hundred thirty cases were included with a median age of 47 years. Two hundred seventy-six (83.6%) were female. The most common isolated uropathogens were Escherichia coli in 201 (60.9%) cases and Klebsiella species in 46 (13.9%) cases. E. coli isolates showed the highest rates of susceptibility to nitrofurantoin (89.3%), cefixime (75%), and gentamicin (72.4%). Exposure to antibiotics in the past 3 months was a predictor of resistance to ciprofloxacin (OR: 2.8, 95% CI: 1.33-6.28), and older age was a predictor of resistance to TMP-SMX (OR: 2.1, 95% CI: 1.07-3.97) among E. coli isolates. Conclusion. E. coli and Klebsiella species accounted for about two-thirds of community-acquired uropathogens. In regard to the high susceptibility rates, nitrofurantoin was identified as the first-choice agent for empiric treatment of community-acquired cystitis, while cefixime and gentamicin might be the second-choice alternatives. Ciprofloxacin and TMP-SMX, on the other hand, cannot be considered appropriate agents for empiric therapy of community-acquired UTIs, particularly in those who had exposure to antibiotics in the past 3 months and the elderly.