February 9, 2022
By Daniel Mendoza, MD
Uncomplicated urinary tract infection (UTI) is predominantly caused by Escherichia coli. There is a lack of information about the prevalence of antimicrobial resistance (AMR) at the community level in the U.S.
Kaye et al. performed a retrospective multicenter study of AMR using the Becton, Dickinson and Company Insights Research Database from 2011 to 2019. The study included 30-day, nonduplicate E. coli urine isolates from U.S. female outpatients (aged ≥ 12 years). Isolates were evaluated for susceptibility to antibiotics and assessed for extended-spectrum β-lactamase production (ESBL+) and for ≥ 2 or ≥ 3 drug-resistance phenotypes.
Among 1,513,882 E. coli isolates, the overall prevalence of isolates nonsusceptible to trimethoprim-sulfamethoxazole, fluoroquinolones, and nitrofurantoin was 25.4%, 21.1%, and 3.8%, respectively. Among the isolates, 6.4% were ESBL+, 14.4% had ≥ 2 drug-resistance phenotypes, and 3.8% had ≥ 3. There was a relative average yearly increase of 7.7% (95% confidence interval [CI], 7.2%-8.2%) for ESBL+ isolates and 2.7% (95% CI, 2.2%-3.2%) for ≥ 3 drug-phenotypes (both P < .0001). The prevalence of ESBL+ was higher in states bordering Mexico (e.g., California, Arizona, Texas).
The prevalence of AMR among outpatient E. coli isolates is increasing, and there is significant variation between U.S. regions. Knowledge of regional AMR rates can help determine empiric treatment of UTI.