Ciprofloxacin resistances rates in Escherichia coli across Canada (CREAC): a longitudinal analysis 2015-2019.

Clinical guidelines recommend empirical fluoroquinolone therapy for urinary tract infections (UTIs) only where local Escherichia coli resistance does not exceed 10%; however, access to local susceptibility data is not uniform across Canada and it is not known which regions meet this threshold. Our objective was to collect susceptibility data from across Canada to evaluate regional trends of E. coli resistance to fluoroquinolones. Antibiogram data were collected retrospectively for the years 2015-2019 from the most local level within each province, typically regional health authorities (RHAs) or local health zones. Antibiogram data were collected from publicly available sources or by directly contacting RHAs or health zones. Susceptibility data were aggregated into regional or population-level data. Antibiograms were collected from 72 regions across 10 provinces. These included 1 949 515 E. coli isolates. Only seven regions throughout Canada met the IDSA target of <10% resistance to consider empirical fluoroquinolone therapy at any point during the study period. The data consistently show that outpatient populations tend to have the highest susceptibility to fluoroquinolones, followed by inpatient populations, and finally long-term care patients. Rural populations also generally had higher susceptibility than urban. Nationally, the Atlantic provinces tended to show the highest susceptibility, especially towards the end of the study period. Fluoroquinolone resistance in E. coli appears to be plateauing within Canada after a rapid increase in the past 20 years. However, fluoroquinolones are rarely appropriate first-line treatment options for UTIs within Canada in the absence of factors eliminating other therapeutic options.