Clinical and Healthcare Related Factors Associated with ESBL and AmpC-Producing Uropathogenic Escherichia coli in Inpatient and Outpatient Settings

Abstract

Background: Extended-spectrum β-lactamase (ESBL)- and AmpC-producing uropathogenic Escherichia coli (UPEC) complicate treatment of urinary tract infections. This study evaluated clinical and healthcare-related factors associated with these resistance phenotypes in inpatient and outpatient settings. Methods: A prospective observational study was conducted at a tertiary-care teaching hospital in southern Haryana from February 2020 to January 2021. Seventy-one resistant UPEC isolates with complete clinical and microbiological data were analysed. Associations with ESBL and AmpC production were assessed using univariable and multivariable logistic regression. Results: ESBL production was identified in 45.1% and AmpC production in 62.0% of isolates. ESBL-producing isolates were more frequent among outpatients (61.1% vs 28.6%), whereas AmpC-producing isolates predominated among inpatients (74.3% vs 50.0%). Outpatient status (aOR 3.72; 95% CI 1.07–12.92) and prior antibiotic exposure (aOR 4.47; 95% CI 1.41–14.17) independently predicted ESBL production. Prior antibiotic exposure was associated with lower odds of AmpC production (aOR 0.29; 95% CI 0.09–0.94). Conclusion: ESBL and AmpC production showed distinct epidemiological patterns, supporting phenotype-specific surveillance and consideration of recent antibiotic and healthcare exposure in UTI management.

Keywords: Uropathogenic Escherichia coli; ESBL; AmpC β-lactamase; urinary tract infection; antimicrobial resistance