Antimicrobial susceptibility among urinary Escherichia coli isolates from female outpatients: age-related differences.

OBJECTIVES Urinary tract infections (UTIs) are common problems in women, and important reason for visiting primary care physicians, resulting in substantial financial burden to community. The aim of this study was to determine the resistance rates of E. coli to commonly prescribed antimicrobial drugs for community-acquired UTIs in women and to establish the association between age and resistance to antibiotics among isolates of E. coli from urine. METHODS The study was designed as a retrospective cross-sectional study during the 5-years period. It was conducted on a sample of urinary tract isolates of E. coli taken from women with community-acquired UTIs. After prevalence of E. coli resistance to antibiotics was established, the analysis of risk factors for emergence of resistance was conducted. RESULTS There were 10,734 isolates of E. coli, comprising 70.62% of all samples analyzed. E. coli was the most frequently resistant to ampicillin (54.68%), followed by trimethoprim-sulphamethoxazole (37.46%), first and second generation cephalosporins (cephalexin and cefaclor) (29.53% both), and ciprofloxacin (23.80%). Less than 50% of E. coli isolates was sensitive to all three tested antibiotics, and nearly 13% acquired triple-resistance. Prevalence of isolates resistant to two or three agents was higher in the subgroup of women older than 65 years. CONCLUSIONS Empirical choice of antimicrobial agent for community-acquired non-complicated UTIs in women should be individualized on the basis of the patient's age, prevalence of resistance in the local community, and compliance history of the patient.