WASHINGTON — Antibiotic resistance did not increase the number of nosocomial urinary tract infections among elderly patients in a long-term care facility, Dr. Walter Zingg reported in a poster presented at the Interscience Conference on Antimicrobial Agents and Chemotherapy.
Dr. Zingg, of the University Children's Hospital, and his colleagues at University Hospital, Zürich, tested urine samples for Escherichia coli to determine the impact of resistant E. coli on the development and outcome of UTIs in long-term care facility residents.
Prevalence studies were conducted from June 2002 to May 2004. The 80 patients with E. coli (mean age 86 years) and 91 controls (mean age 85 years) were observed for an average of 278 days and 365 days, respectively. Overall, 96% of the E. coli cases showed reduced susceptibility against combination amoxicillin/clavulanic acid, 55% showed reduced susceptibility against trimethoprim/sulfamethoxazole, 41% showed reduced susceptibility against norfloxacin, and 10% showed reduced susceptibility against ciprofloxacin.
Surprisingly, the level of resistance did not result in more frequent nosocomial infections, the investigators found. The incidence density (the estimated rate of occurrence of infection) was 3.3 per 1,000 days among patients with E. coli, compared with 3.2 per 1,000 days among controls.
The meeting was sponsored by the American Society for Microbiology.