Zoonotic Escherichia coli and urinary tract infections in Southern California

Authors

Maliha Aziz, Department of Environmental and Occupational Health, George Washington University, Washington, DC, USA.
Daniel E. Park, Department of Environmental and Occupational Health, George Washington University, Washington, DC, USA.
Vanessa Quinlivan, Department of Environmental and Occupational Health, George Washington University, Washington, DC, USA.
Evangelos A. Dimopoulos, Centre for Genomic Pathogen Surveillance Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom.
Yashan Wang, Department of Environmental and Occupational Health, George Washington University, Washington, DC, USA.
Edward H. Sung, Department of Environmental and Occupational Health, George Washington University, Washington, DC, USA.
Annie L. Roberts, Department of Environmental and Occupational Health, George Washington University, Washington, DC, USA.
Ann Nyaboe, Department of Environmental and Occupational Health, George Washington University, Washington, DC, USA.
Meghan F. Davis, Department of Environmental Health and Engineering, Johns Hopkins School of Public Health, Baltimore, Maryland, USA.
Joan A. Casey, Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, California, USA.
Julio Diaz Caballero, Centre for Genomic Pathogen Surveillance Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom.
Keeve E. Nachman, Department of Environmental Health and Engineering, Johns Hopkins School of Public Health, Baltimore, Maryland, USA.
Harpreet S. Takhar, Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, California, USA.
David M. Aanensen, Centre for Genomic Pathogen Surveillance Big Data Institute, Li Ka Shing Centre for Health Information and Discovery, University of Oxford, Oxford, United Kingdom.
Julian Parkhill, Department of Veterinary Medicine, University of Cambridge, Cambridge, United Kingdom.
Sara Y. Tartof, Department of Research & Evaluation, Kaiser Permanente Southern California, Pasadena, California, USA.
Cindy M. Liu, Department of Environmental and Occupational Health, George Washington University, Washington, DC, USA.
Lance B. Price, Department of Environmental and Occupational Health, George Washington University, Washington, DC, USA.

Document Type

Journal Article

Publication Date

11-12-2025

Journal

mBio

Volume

16

Issue

11

DOI

10.1128/mbio.01428-25

Keywords

Bayesian latent class model; Escherichia coli; antimicrobial resistance; extraintestinal pathogenic E. coli; genomic attribution model; urinary tract infection; zoonotic infections

Abstract

Extraintestinal pathogenic Escherichia coli (ExPEC) is the leading cause of urinary tract infections (UTIs) worldwide and may be transmitted from food animals to humans via contaminated meat. However, the contribution of zoonotic ExPEC strains to UTIs in metropolitan areas remains unclear. We estimated the proportion of UTIs attributable to zoonotic ExPEC across eight Southern California counties. Between 2017 and 2021, we collected 12,616 E. coli isolates from retail meat and 23,483 from UTI patients, sequencing a representative subset of 5,728 isolates. Using a Bayesian latent class model trained with 17 host-associated genetic markers, we inferred the host origin of each isolate. Demographic, clinical, and antimicrobial resistance profiles were compared between meat isolates and clinical isolates inferred to be of human or food-animal origin. Most UTI patients were female (88%), with a median age of 50 years; 37% were Hispanic and 31% non-Hispanic white. Zoonotic ExPEC strains accounted for 18% of UTIs overall, rising to 21.5% in high-poverty neighborhoods. Women had a higher zoonotic proportion than men (19.7% vs 8.5%, P < 0.001). Among men, those with zoonotic infections were older than those with non-zoonotic infections (median 73.0 vs 65.0 years, P = 0.028). These findings underscore the contribution of zoonotic ExPEC to the UTI burden in Southern California and the need for targeted interventions to reduce risk in vulnerable communities.IMPORTANCEUrinary tract infections (UTIs) are among the most common bacterial infections worldwide and are primarily caused by Escherichia coli. While E. coli is known to colonize both humans and food-producing animals, the extent to which zoonotic strains impact human disease remains poorly understood. Emerging evidence suggests that food animals may serve as an underrecognized reservoir for extraintestinal pathogenic E. coli (ExPEC). In this study, we used a genomic attribution model to quantify the contribution of zoonotic strains to UTIs in Southern California. We found that approximately 18% of E. coli UTIs were likely attributable to food animals. Individuals living in high-poverty neighborhoods had a 1.6-fold increased risk of zoonotic UTIs compared to those in low-poverty areas. These findings highlight zoonotic transmission as an important driver of UTIs and suggest that reducing ExPEC in food-animal reservoirs could help lower disease burden and address health disparities.

APA Citation

Aziz, Maliha; Park, Daniel E.; Quinlivan, Vanessa; Dimopoulos, Evangelos A.; Wang, Yashan; Sung, Edward H.; Roberts, Annie L.; Nyaboe, Ann; Davis, Meghan F.; Casey, Joan A.; Caballero, Julio Diaz; Nachman, Keeve E.; Takhar, Harpreet S.; Aanensen, David M.; Parkhill, Julian; Tartof, Sara Y.; Liu, Cindy M.; and Price, Lance B., "Zoonotic Escherichia coli and urinary tract infections in Southern California" (2025). GW Authored Works. Paper 8103.
https://hsrc.himmelfarb.gwu.edu/gwhpubs/8103

Department

Environmental and Occupational Health