Risk Factors for Amoxicillin-Clavulanate Resistance in Community-Onset Urinary Tract Infections Caused by or : The Role of Prior Exposure to Fluoroquinolones.

Background: High rates of amoxicillin-clavulanate (AMC) resistance among Enterobacterales isolated from urinary tract infections (UTIs) were observed in our area. The aim of this study was to identify risk factors associated with AMC resistance in patients with community-onset UTI in emergency departments (EDs).

Methods: A retrospective study was performed of all ED patients with positive urine cultures for or in a Spanish tertiary-care hospital.

Results: 330 urine cultures in all were included: 261 (79.1%) for and 69 (20.90%) for Rates of AMC resistance were 14.94% and 34.78%, respectively. UTI was clinically confirmed in 212 (64.24%) cases. Previous antimicrobial exposure was independently associated with AMC resistance development in and urinary isolates (OR = 2.94, 95% CI = 1.55-5.58). Analyses of infected patients revealed that previous exposure to fluoroquinolones (OR = 3.33, 95% CI = 1.10-10.12, = 0.034) and to AMC (OR = 5.68, 95% CI = 1.97-16.44, = 0.001) was significantly associated with isolation of AMC-resistant strains.

Conclusions: Prior antibiotic exposure, particularly to AMC or fluoroquinolones, was the only independent risk factor associated with development of AMC resistance in and urinary isolates from patients attending the ED.