Antimicrobial Resistance and Genomic Characteristics of Escherichia coli Strains Isolated from the Poultry Industry in Henan Province, China.

Escherichia coli ( E. coli ) is an important foodborne pathogen and a biomarker for monitoring antimicrobial resistance. Investigating the prevalence of E. coli in the poultry industry holds great importance, particularly in Henan province, a major poultry-producing region in China. Here, we investigated the antimicrobial resistance (AMR) phenotypes of E. coli strains obtained from the poultry industry in Henan, China. A total of 344 E. coli strains were isolated from 638 samples collected from seven farms, three slaughterhouses, and ten terminal markets. Approximately 96.4%, 81.7%, and 52.5% of the isolates from the farms, slaughterhouses, and terminal markets exhibited multidrug resistance. Whole-genome sequencing was performed on 169 strains to reveal their genomic characteristics. The sequence type (ST) analysis revealed that ST10 and ST156 were the most frequent types within the poultry supply chain, whereas ST10 and ST162 were commonly found across the farms, slaughterhouses, and terminal markets. Fourteen ST10 E. coli strains belonged to phylogenetic group A, while fifteen ST165 and six ST162 E. coli strains belonged to phylogenetic group B1. In addition, several antimicrobial resistance genes and virulence factor genes were identified. The bla NDM-5 gene mediated carbapenem resistance in two E. coli strains, while mcr-1 -mediated colistin resistance was detected in nine E. coli strains. Phylogenetic group A exhibited fewer virulence genes compared to other groups of E. coli . Plasmid replicons, such as IncFIB (AP001918), IncX1, IncFIC (FII), and IncFII (pHN7A8), were frequently observed. These findings provide valuable insights into the current AMR profiles of E. coli strains isolated from the poultry industry in Central China and highlight the need to implement good manufacturing practices and reduce antibiotic usage to mitigate potential risks associated with E. coli .