Extended-spectrum β-lactamase-producing Escherichia coli strains in the feces of carriers contribute substantially to urinary tract infections in these patients.

Introduction: The current increase in the incidence of urinary tract infections (UTIs) worldwide caused by extended-spectrum β-lactamase (ESBL)-producing Escherichia coli may be due to the high number of ESBL-producing Enterobacteriaceae carriers in the community. However, whether ESBL-producing bacteria can cause UTIs in carriers remains uncertain.
Materials and Methods: In this study, 21 fecal carriers of ESBL-producing Enterobacteriaceae were assessed for UTIs caused by ESBL-producing E. coli. Bacterial isolates obtained from patients' urine and stool specimens were phenotypically and genotypically examined. Clonal similarities of isolates were assessed by multilocus sequence typing (MLST) and random amplified polymorphic DNA (RAPD) fingerprinting.
Results: The study revealed that 9 of 21 carriers developed UTIs, and genetic analysis showed that 44% of the UTIs developed were caused by the same ESBL-producing E. coli as that found in the feces of the patients.
Conclusions: The ESBL-producing E. coli in carriers can cause UTIs.