Species and antimicrobial resistance of uropathogens isolated from patients with urinary catheter

Abstract

A large number of hospitalized patients have an indwelling urinary tract catheter (IUC) placed at some time during their hospital stay and may suffer from catheter-associated urinary tract infections, the leading cause of nosocomial infections. Here we investigated the prevalence of uropathogens associated with catheter-associated urinary tract infections and assessed the resistances of these pathogens to commonly prescribed antibiotics. In total, 2,997 urine samples were examined at a regional hospital in Taipei, Taiwan in 2004: 1,948 (65%) samples from hospitalized patients and 1,049 (35%) samples from outpatients. Patients with IUCs accounted for 1,381 samples (46%). Stratified analyses were used to calculate the age- and gender-adjusted odds ratio (OR) of antimicrobial resistance associated with the use of IUCs. Compared to the urine specimens of the patients without IUCs, those isolated from catheterized patients had a lower prevalence rate of Escherichia (E.) coli (23.4% vs 36.8%) and higher rates of resistant strains including Pseudomonas species (16.4% vs 8.6%) and rare gram-negative bacilli (5.8% vs 4.5%). Additionally, IUCs significantly increased the antimicrobial resistance of E. coli (OR 2.41-3.07), other species of Enterobacteriaceae (OR 1.57-2.38), and rare gram-negative bacilli (OR 2.41-5.21) to nearly all antibiotics tested, such as trimethoprim/sulfamethoxazole. Thus, IUCs increased the prevalence of urinary tract infections caused by some highly resistant pathogens. Moreover, IUCs were associated with the increased risk of concurrent resistance of Enterobacteriaceae. Clinicians are advised to exercise better management of urinary catheter in order to further reduce and control catheter-associated urinary tract infections in hospitals.