Likelihood of Antimicrobial Resistance in Urinary E. coli Isolates Among US Female Patients with Recurrent Versus Non-Recurrent uUTI

Objectives To assess the relative likelihood of antimicrobial resistance (AMR) and multi-drug resistance (MDR) among E. coli isolates from outpatients with recurrent versus non-recurrent uncomplicated urinary tract infection (uUTI). Methods In this retrospective observational US cohort study, female outpatients (≥12 years) with uUTI, positive E. coli culture, and treated with ≥1 oral antibiotic within ±5 days of diagnosis were grouped into recurrent and non-recurrent uUTI cohorts per their UTI history (past 12 months). AMR to specific drug classes was evaluated at index. Univariable and multivariable logistic regression models estimated the likelihood of not-susceptible E. coli isolates (AMR/MDR) among patients with recurrent uUTI versus non-recurrent uUTI. Results Recurrent (N=12,234) and non-recurrent (N=68,033) uUTI cohorts had similar distributions (race, ethnicity, region). Patients with recurrent uUTI had a higher prevalence of E. coli resistance to trimethoprim-sulfamethoxazole (21.8% vs 18.7%) and fluoroquinolones (14.2% vs 8.6%), and more isolates were extended-spectrum β-lactamase-producing (5.9% vs 4.1%) compared to non-recurrent uUTI patients. Patients with recurrent uUTI had a higher likelihood (odds ratio [95% confidence interval]) of any AMR (1.28 [1.22–1.34]), single drug-class resistance (1.18 [1.12–1.24]), and resistance to 2 (1.53 [1.41–1.67]) or ≥ 3 drug classes (1.70 [1.48–1.96]) (all P<0.001). Conclusions This study delineated the likelihood of AMR and MDR among E. coli isolates from patients with recurrent versus non-recurrent uUTI. While some treatment guidelines support empiric therapy in recurrent uUTI, the increased likelihood of resistance among these patients suggests that culture and susceptibility testing should be undertaken to inform recurrent uUTI treatment.