Investigating the zoonotic origins of ESBL-producing E. coli in community-acquired urinary tract infections in Ecuador

Authors

• Yashan Wang, Department of Environmental and Occupational Health, Antibiotic Resistance Action Center, The George Washington University, Washington, DC, USA.
• Daniel E. Park, Department of Environmental and Occupational Health, Antibiotic Resistance Action Center, The George Washington University, Washington, DC, USA.
• Maliha Aziz, Department of Environmental and Occupational Health, Antibiotic Resistance Action Center, The George Washington University, Washington, DC, USA.
• Liseth Salinas, Colegio de Ciencias Biológicas y Ambientales, Instituto de Microbiología, Universidad San Francisco de Quito, Quito, Ecuador.
• Edward Sung, Department of Environmental and Occupational Health, Antibiotic Resistance Action Center, The George Washington University, Washington, DC, USA.
• Søren Hallstrøm, Department for Sequencing and Bioinformatics, Statens Serum Institut, Copenhagen, Denmark.
• Cindy M. Liu, Department of Environmental and Occupational Health, Antibiotic Resistance Action Center, The George Washington University, Washington, DC, USA.
• Marc Stegger, Department for Sequencing and Bioinformatics, Statens Serum Institut, Copenhagen, Denmark.
• Zhenke Wu, Department of Biostatistics, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA.
• Gabriel Trueba, Colegio de Ciencias Biológicas y Ambientales, Instituto de Microbiología, Universidad San Francisco de Quito, Quito, Ecuador.
• Joseph N. Eisenberg, Department of Epidemiology, School of Public Health, University of Michigan, Ann Arbor, Michigan, USA.
• Jay P. Graham, Division of Environmental Health Sciences, School of Public Health, University of California, Berkeley, California, USA.
• Lance B. Price, Department of Environmental and Occupational Health, Antibiotic Resistance Action Center, The George Washington University, Washington, DC, USA.

Document Type

Journal Article

Publication Date

4-8-2026

Journal

Microbiology spectrum

DOI

10.1128/spectrum.03325-25

Keywords

ESBL-producing E. coli; Ecuador; Escherichia coli; backyard animals; domestic animals; foodborne; poultry; urinary tract infection

Abstract

Extended-spectrum β-lactamase-producing Escherichia coli (ESBL-producing E. coli) pose a growing global health threat. Although Latin America has been identified as a global hotspot of antimicrobial resistance, the zoonotic contribution to drug-resistant infections in the region remains poorly defined. We analyzed 137 clinical ESBL-producing E. coli isolates from urinary tract infections (UTIs) in Quito, Ecuador, applying a Bayesian latent class model informed by host-associated mobile genetic elements to estimate the fraction of infections attributable to food-animal sources. We estimated that 25.5% (35/137) of UTI isolates were putative zoonotic cases. This proportion rose to 42.5% after excluding ST131-H30, a human-associated pandemic lineage. Putative zoonotic isolates were enriched for animal-associated β-lactamase genes (e.g., bla, bla), lacked human-associated markers such as bla, and exhibited diverse antimicrobial resistance gene profiles resembling those observed among food-animal isolates. These isolates were also enriched for ColV-associated virulence genes typically linked to avian pathogenic E. coli. Putative zoonotic strains contributed substantially to third-generation cephalosporin-resistant UTIs in Quito, Ecuador, challenging assumptions derived from high-income settings that such infections are driven predominantly by human-to-human transmission. These findings highlight the importance of integrated One Health surveillance and mitigation, particularly in low- and middle-income countries where gaps in water, sanitation, and hygiene (WASH) may interact with antimicrobial use in food production to amplify antimicrobial resistance transmission.IMPORTANCEESBL-producing E. coli have rapidly emerged as a major global antimicrobial resistance threat. In Latin America, cephalosporins are commonly used in food-animal production, fueling the emergence of ESBL-producing E. coli. In low- and middle-income countries, excessive antimicrobial use driven by poorly regulated over-the-counter sales, combined with inadequate water, sanitation, and hygiene (WASH) infrastructure, can facilitate antimicrobial-resistant pathogen transmission from food animals to humans. Using a novel statistical-genomic approach, we found that over one in four cephalosporin-resistant UTIs in Quito, Ecuador, may be caused by E. coli strains originating from food animals. Our findings highlight the public health risks associated with antimicrobial use in food-animal production and the role of environmental and infrastructure-related vulnerabilities. As global demand for animal protein continues rising in middle-income countries, controlling zoonotic antimicrobial resistance transmission becomes increasingly urgent for protecting human health through integrated One Health strategies.

APA Citation

Wang, Yashan; Park, Daniel E.; Aziz, Maliha; Salinas, Liseth; Sung, Edward; Hallstrøm, Søren; Liu, Cindy M.; Stegger, Marc; Wu, Zhenke; Trueba, Gabriel; Eisenberg, Joseph N.; Graham, Jay P.; and Price, Lance B., "Investigating the zoonotic origins of ESBL-producing E. coli in community-acquired urinary tract infections in Ecuador" (2026). GW Authored Works. Paper 9097.
https://hsrc.himmelfarb.gwu.edu/gwhpubs/9097

Department

Environmental and Occupational Health