Prevalence and mechanism of antimicrobial resistance and pathogenicity of Salmonella isolated from foodborne animal in China

Abstract

Antimicrobial resistance (AMR) in livestock-derived and poultry-derived Salmonella is a considerable public health risk in China. However, limited information is available on the prevalence of AMR and virulence genes in Salmonella among food-producing animals in Central China. The objective of this study was to assess the prevalence of AMR, virulence genes, mobile genetic elements, and multilocus sequence typing (MLST) distribution in Salmonella isolated from swine, chicken, and cattle in Central China. Furthermore, the molecular mechanism of AMR and pathogenicity of the bacteria were explored. PCR was used to assess 187 epidemiologically independent AMR isolates from three provinces for AMR and virulence genes.A total of 82 AMR genes were detected, with ramA, acrB, acrE, acrF, emrA, ydhE, mdtB, mdtC, ompC, ompF and tetB being present in all strains. The study detected 23 virulence factors (88.46%), with stn, hilA, prgH, sopB, bcfC, fimA and rpoS being the most prevalent (100%). MLST analysis of 187 isolates identified 5 distinct sequence types (STs), with ST1 (36.90%), ST4 (13.90%), and ST6 (28.88%) being the most prevalent. Bioinformatics analysis identified cbiA, cbiB, cbiC, cbiD, cbiE, cbiF, cbiG, cbiH, cbiK and cbiT as hub genes associated with AMR and virulence. The study reveals an elevated prevalence of AMR and virulence genes in Salmonella isolates from food-producing animals in Central China. The results offer valuable insights into the molecular mechanisms of AMR and pathogenicity of Salmonella.