Vet World   Vol.18   November-2025  Article - 26 

Prevalence, antimicrobial resistance, and extended-spectrum β-lactamase gene profiles of Escherichia coli isolated from poultry eggshells in Can Tho City, Vietnam

Background and Aim: The emergence of extended-spectrum β-lactamase (ESBL)-producing Escherichia coli in food sources poses a growing threat to public health. Poultry eggs may act as vehicles for these resistant bacteria, facilitating their transmission through the food chain. This study aimed to determine the prevalence, antimicrobial resistance (AMR) patterns, and ESBL-encoding genes among E. coli isolates recovered from chicken, duck, and quail eggs sold in Can Tho City, Vietnam.

Materials and Methods: A total of 900 eggs (300 each from chicken, duck, and quail) were collected from local markets, retail stores, and supermarkets between June and December 2024. E. coli isolates were identified through biochemical tests and polymerase chain reaction (PCR) targeting the uidA gene. ESBL production was determined using the disk diffusion method, and the presence of blaCTX-M, blaTEM, blaNDM, and blaSHV genes was confirmed by PCR. Antimicrobial susceptibility was tested against 10 antibiotics representing eight classes following Clinical and Laboratory Standards Institute (2021) guidelines.

Results: Out of 179 pooled samples positive for E. coli, 52 isolates (29.1%) were confirmed as ESBL producers. The highest prevalence was observed in chicken (32.4%) and duck (32.8%) eggs, while quail eggs showed a prevalence of 20%. ESBL-producing isolates most frequently carried blaCTX-M (65.4%) and blaTEM (44.2%) genes, whereas blaNDM was detected in 1.9% of isolates and blaSHV was absent. All isolates were multidrug-resistant, exhibiting resistance to 4–9 antibiotic classes. High resistance was observed to amoxicillin-clavulanate (69.2%), ceftriaxone (69.2%), tetracycline (75%), and trimethoprim-sulfamethoxazole (61.5%). No E. coli was detected in supermarket eggs, suggesting improved hygiene practices reduce contamination.

Conclusion: The detection of ESBL-producing and multidrug-resistant E. coli on poultry eggshells underscores a significant public health concern. The predominance of blaCTX-M and blaTEM genes highlights the risk of resistance gene dissemination through the egg supply chain. Enhanced surveillance, responsible antibiotic use, and strict hygiene control in small-scale poultry production systems are urgently needed to mitigate the spread of AMR under the One Health framework.

Keywords: blaCTX-M, Eggshell contamination, Escherichia coli, extended-spectrum β-lactamase, multidrug resistance, One Health, Vietnam.

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How to cite this article: Lien NT, Huyen TTS, Anh QNT, Dat TM, Duy NK, Phu NT, and Khuong TTT (2025) Prevalence, antimicrobial resistance, and extended-spectrum β-lactamase gene profiles of Escherichia coli isolated from poultry eggshells in Can Tho City, Vietnam, Veterinary World, 18(11): 3640-3650.

Received: 23-06-2025   Accepted: 29-10-2025   Published online: 29-11-2025

Corresponding author: Nguyen Thi Lien    E-mail: ntlien@ctu.edu.vn

DOI: 10.14202/vetworld.2025.3640-3650

Copyright: Lien, et al. This article is an open access article distributed under the terms of the Creative Commons Attribution 4.0 International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made. The Creative Commons Public Domain Dedication waiver (http:// creativecommons.org/publicdomain/zero/1.0/) applies to the data made available in this article, unless otherwise stated.