[Extended-spectrum β-lactamase (ESBL)-producing Escherichia coli is frequently detected as a pathogen of urinary tract infection in nursing home residents].

AIM

To assess the prevalence of the fecal carriage of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli among nursing home residents and to demonstrate the relationship between fecal carriage and urinary tract infections (UTIs) in elderly patients.

METHODS

Data were collected for 12 months on aerobic bacteria obtained from the urine of elderly patients with UTI. Feces were analyzed for the bla(CTX-M) gene at the Department of Bioinformatics, Osaka University Graduate School of Medicine.

RESULTS

Among 56 strains of aerobic bacteria obtained from 40 patients with UTIs, there were 24 strains of Escherichia coli, 14 (58.3%) of which were ESBL-producing. All of these ESBL strains were also resistant to levofloxacin (LVFX). Fecal ESBL-carriage was detected in 21.5% of the residents, with similar ratios in men and women. Statistical analysis of the backgrounds of residents showed that the carriage rate was markedly high in those elderly patients who came from hospitals after the treatment of infectious/purulent diseases. Among the 145 residents, whose feces were analyzed for ESBL, UTIs developed in 10 patients, only 1 of whom was a man; urinary examination did not detect ESBL-producing Escherichia coli as a pathogen in this patient. In 9 female patients, ESBL-producing Escherichia coli was isolated from the urine of 8 women. While the combination of fosfomycin and minomycin was useful in the treatment of the UTIs in these cases, it did not completely remove the ESBL-producing bacteria from feces.

CONCLUSIONS

Fecal carriage of ESBL-producing Escherichia coli is prevalent in our facilities and is related to a high incidence of UTIs in elderly women, presenting treatment challenges.