Does urinary tract infection caused by extended-spectrum β-lactamase-producing Escherichia coli show same antibiotic resistance when it recurs?

This study was performed to evaluate what percentage of urinary tract infections (UTIs)caused by extended spectrum β-lactamase (ESBL)-producing strains recurs with ESBL-producing strains during follow up and to assess the risk factors for recurrence with ESBL-producing Escherichia coli strains on subsequent first recurrence episode. We enrolled female patients with UTIs caused by ESBL-producing E. coli between May 2012 and December 2015, who were longitudinally followed up for at least 24 months. Among the 206 patients with ESBL positive UTI, 180 completed the study. 60 (60/180, 33.3%)of patient with first episode of UTI caused by ESBL-producing E. coli experienced recurrent UTIs during follow up. Of 60 patients, 43 (43/60, 71.7%)recurred with ESBL-producing E. coli on the first UTI recurrence episode. On multivariate analysis, the time to recurrence and history of cephalosporin usage in the last 6 months were identified as risk factors for recurrence with ESBL-producing E. coli per se (odds ratio [OR]= 0.9, 95% confidence interval [CI]0.8–1.0, p = 0.030 and OR = 27.0, 95% CI 2.4–299.8, p = 0.007, respectively). These findings show that high proportion of patient with UTI caused by ESBL-producing E. coli recurs with ESBL-producing E. coli on subsequent recurrence episode. While result of antibiotic susceptibility cannot be identified on the visit day empirical treatment should be referred to the antecedent antibiotic resistance profile in patients whose previous UTIs were due to ESBL-producing strains.