Lima broiler survey finds multidrug-resistant ESBL E. coli

A survey of apparently healthy broiler chickens at two poultry collection centers in Lima, Peru, found that 26.3% of the samples carried extended-spectrum beta-lactamase-producing Escherichia coli. The study recovered 79 such isolates from 300 cloacal swabs, with a 95% confidence interval of 21.4%–31.6% for the observed prevalence. All recovered isolates showed multidrug-resistant phenotypes.

Researchers collected the cloacal swabs and screened them on CHROMagar ESBL medium, followed by conventional biochemical identification of E. coli. Antimicrobial susceptibility was tested using disk diffusion according to Clinical and Laboratory Standards Institute guidelines, and ESBL production was confirmed phenotypically. The supplied study report does not specify the individual antimicrobial agents, resistance breakpoints, or susceptibility results for each isolate, so the full resistance profiles cannot be reconstructed from these findings.

Molecular analysis by quantitative PCR detected CTX-M group 1 in 87.3% of the isolates and CTX-M group 9 in 12.7%. Whole-genome sequencing of selected isolates identified the resistance genes bla_{CTX-M-55, blaCTX-M-65, and blaCTX-M-3 across multiple sequence types. Phylogenetic analysis showed both closely related clonal clusters and genetically diverse isolates, documenting several distinct patterns among the sequenced bacteria rather than a single uniformly distributed resistance genotype.}

The authors describe poultry production systems as potential reservoirs of multidrug-resistant ESBL-producing E. coli in Peru and place the observations within a One Health framework linking antimicrobial resistance across animals, humans, and the environment. The results demonstrate carriage in apparently healthy broilers at the two sampled Lima collection centers, but they do not establish transmission to people or environmental spread. Because the survey was geographically limited and only selected isolates underwent genomic sequencing, the authors characterize the findings as preliminary and call for expanded surveillance before the prevalence and genetic patterns can be generalized across Peru.

Subject of Research: Prevalence and genomic diversity of CTX-M-producing ESBL E. coli in Lima broiler chickens

Article Title: Antimicrobial resistance and molecular characterization of bla CTX-M -producing Escherichia coli isolated from broiler chickens in Peru

Article References: Gonzales-Escalante, E., & Gonzales-Rodriguez, A. (2026). Antimicrobial resistance and molecular characterization of blaCTX-M-producing Escherichia coli isolated from broiler chickens in Peru. PLOS One, 21(10), e0360681. https://doi.org/10.1371/journal.pone.0360681

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DOI: 10.1371/journal.pone.0360681

Keywords: antimicrobial resistance, Escherichia coli, ESBL, broiler chickens, Lima, Peru, CTX-M, whole-genome sequencing, poultry surveillance, One Health, Antimicrobial, resistance