Multidrug-resistant Escherichia coli in the swine production chain: genomic evidence of abattoir-associated dissemination.

Authors

Adriana Alpízar-Boza, Laura Jiménez-Madrigal, Thorsten Thye, Isaac Sabillón-Zelaya, Joaquim Ruiz, Maria J Pons, Andrea Molina, Lohendy Muñoz-Vargas

Published in

Journal of food protection. Pages 100874. Jul 24, 2026. Epub Jul 24, 2026.

Abstract

Antimicrobial resistance (AMR) is a rising public health issue that compromises human, animal and environmental health. This study assessed AMR in the swine production chain in Costa Rica using commensal Escherichia coli as an indicator microorganism. Sampling of feces, carcass and lymphoid tissue at exporting swine abattoirs yielded 269 presumed E. coli isolates identified by lactose-positive growth on MacConkey agar and indole production. A subset of isolates (n=40) was confirmed as E. coli by VITEK® 2 GN testing. Antimicrobial susceptibility testing against 18 antibiotics was performed using the antibiotic disk agar diffusion method in 242 recovered isolates, and resistance to all antimicrobial classes evaluated was detected. The highest resistance levels were observed for ampicillin, cefazolin and chloramphenicol, and notable resistance to quinolones, trimethoprim-sulfamethoxazole and β-lactam combination agents. Resistance to clinically-important drugs including ceftazidime, cefepime, aztreonam and imipenem was observed, as well as selected β-lactamase genes. Overall, 50 distinct AMR profiles were identified, and more than half of the isolates displayed multidrug-resistance. A subset of isolates (n=30) underwent uidA PCR and ERIC-PCR analysis, revealing evidence of fecal and cross-contamination as plausible routes for dissemination of resistant bacteria during slaughter. Antimicrobial susceptibility testing by VITEK®2 automated system and whole genome sequencing (WGS) of 27 isolates further characterized phenotype-genotype concordance, AMR determinants, virulence factors, serotypes and sequence types of public health relevance. These findings provide insight into current AMR trends in the Costa Rican swine production system and highlight the role of abattoir-level contamination in AMR transmission, supporting targeted interventions to mitigate the emergence and dissemination of AMR along the pork production chain.

PMID:
42498208
Bibliographic data and abstract were imported from PubMed on 25 Jul 2026.

Read full publication at:
Please sign in to see all details.

Stats

1-terrible, 9-excellent. How would you rate this publication? Sign in in to submit your rating.

Post a comment

You need to be signed in to post comments. You can sign in here.

Comments

There are no comments yet.