Risk factors for enterococcal urinary tract infection and colonization in a rehabilitation facility.

BACKGROUND: We attempted to define the risk factors for urinary tract acquisition of enterococcus in a 155-bed rehabilitation facility in Southeastern Michigan by performing a prospective, case-controlled observational study. METHODS: All cases were identified from daily review of microbiologic records of urine culture results. All urinary isolates of enterococcus species, whether representing infection or colonization, were saved on agar plates for subsequent pulsed-field gel electrophoresis. Thirty-five percent of urinary tract isolates were due to enterococcal species compared with 5% to 15% in adjacent acute-care facilities. A control was defined as the next patient with a nonenterococcal urinary isolate. RESULTS: No differences were found between cases and controls with respect to age, sex, admitting diagnosis, voiding habits, symptoms, laboratory values, geographic location, caregivers, or urinary infection versus colonization. CONCLUSIONS: Prior antibiotic use was more frequent in the patients colonized or infected with enterococcal isolates (78% vs 41%). No evidence was found for a single clone of enterococcal isolates in our facility by DNA analysis, suggesting that the acquisition of enterococcus in the urinary tract was endogenous.

Nosocomial candidiasis: epidemiology and drug resistance.

The epidemiology of nosocomial Candida is complex. Molecular DNA analysis has provided useful information in the study of nosocomial infection. The most important inpatient hospital reservoir is colonized patients. Most patients are infected with strains they harbor. Findings from recent studies suggest that some nosocomial Candida colonization is the result of exogenous acquisition. Hospital personnel and the inanimate hospital environment may serve as reservoirs, reservoir and they may be sources of acquired strains. The mechanism by which patients acquire Candida remains unproven, but most authors agree that indirect contact transmission is the most likely route for exogenous nosocomial acquisition of strains. Environmental surfaces in contact with healthcare workers and/or patients should also be considered a source of some Candida organisms when infection control measures are designed. Antifungal drug resistance has not been responsible for the spread of isolates. Further prospective studies using DNA typing methods for analysis of cultures using control strains are needed to define more clearly the patient and hospital reservoirs of infection and the modes of transfer. With increasing knowledge of the epidemiology of nosocomial Candida, novel control strategies are needed.

Characterization of antimicrobial resistance in enterococci of animal origin.

Among 97 enterococci cultured from animals, gentamicin MICs were > or = 2,000 micrograms/ml for 9 isolates and between 250 and 1,024 micrograms/ml for 6 isolates. For two isolates tested (gentamicin MICs, 256 and 512 micrograms/ml, respectively), there was no in vitro synergy with penicillin plus gentamicin, resistance was transferable, and there was no hybridization with a probe specific for 6'-aminoglycoside acetyltransferase-2"-aminoglycoside phosphotransferase. The results of the study indicate the presence of a unique gentamicin resistance genotype in enterococci of animal origin.