Presence and Transfer of Antimicrobial Resistance Determinants inEscherichia coliin Pigs, Pork, and Humans in Thailand and Lao PDR Border Provinces

This study aimed to investigate antimicrobial resistance (AMR) characteristics ofEscherichia coliisolates from pig origin (including pigs, pig carcass, and pork) and humans in Thailand and Lao People's Democratic Republic (PDR) border provinces. The majority of theE. coliisolates from Thailand (69.7%) and Lao PDR (63.3%) exhibited multidrug resistance. Class 1 integrons with resistance gene cassettes were common (n = 43), of which the most predominant resistance gene cassette wasaadA1. The percentage of extended-spectrum beta-lactamase (ESBL) producers was 3.4 in Thailand and 3.2 in Lao PDR. The ESBL genes found werebla(CTX-M14),bla(CTX-M27), andbla(CTX-M55), of whichbla(CTX-M55)was the most common (58.6%). Ser-83-Leu and Asp-87-Asn were the predominant amino acid changes in GyrA of ciprofloxacin-resistant isolates. Twenty-two percent of all isolates were positive forqnrS. Class 1 integrons carryingaadA1from pigs (n = 1) and ESBL genes (bla(CTX-M55)andbla(CTX-M14)) from pigs (n = 2), pork (n = 1), and humans (n = 7) were located on conjugative plasmids. Most plasmids (29.3%) were typed in the IncFrepB group. In conclusion, AMRE. coliare common in pig origin and humans in these areas. The findings confirm AMR as One Health issue, and highlight the need for comprehensive and unified collaborations within and between sectors on research and policy.

Automated summary

The study revealed common antimicrobial resistance in pig-origin Escherichia coli and humans in border provinces of Thailand and Lao PDR, with a high prevalence of multidrug resistance. Resistance genes like aadA1 and ESBL genes like bla(CTX-M55) were frequently found. Collaboration in research and policy between sectors is essential to address the issue of AMR effectively.