Characterisation of ESBL/AmpC-Producing Enterobacteriaceae isolated from poultry farms in Peninsular Malaysia

Extended-spectrum beta-lactamases (ESBLs) and AmpC beta-lactamases (AmpCs)-producing Enterobacteriaceae have been increasingly reported and imposing significant threat to public. Livestock production industry might be the important source for clinically important ESBL-producing Enterobacteriaceae. This study aims to investigate the resistance profile, phenotypic ESBL production, beta-lactamase genes, virulence factors, and plasmid replicon types among 59 Enterobacteriaceae strains isolated from poultry faecal samples in Malaysia's commercial poultry farm. There were 38.7% and 32.3% of Escherichia coli resistant to cefotaxime and cefoxitin, respectively, while Klebsiellaspp. demonstrated resistance rate of 52.6% to both mentioned antimicrobials. Majority of the E. coli isolates carried bla(TEM) and bla(CMY-2 group). bla(SHV) was the most prevalent gene detected in Klebsiellaspp., followed by bla(DHA) and bla(TEM). Resistance to extended spectrum cephalosporin in our isolates was primarily mediated by plasmid mediated AmpC beta-lactamase such as CMY-2 group and DHA enzyme. The CTX-M genes were found in two ESBL-producing E. coli. IncF, IncI1, and IncN plasmids were most frequently detected in E. coli and Klebsiellaspp. The virulence factor, including EAST1 and pAA were identified at low frequency. This study highlights the poultry as a reservoir of resistance and virulence determinants and prevalence of plasmids in Enterobacteriaceae might drive their dissemination.

Automated summary

This study investigated 59 Enterobacteriaceae strains isolated from poultry fecal samples in Malaysia's commercial poultry farm, focusing on their resistance profile, phenotypic ESBL production, beta-lactamase genes, virulence factors, and plasmid replicon types. The study found that bla(TEM) and bla(CMY-2 group) were the most prevalent genes in Escherichia coli isolates, while bla(SHV), bla(DHA), and bla(TEM) were most commonly detected in Klebsiella spp. Resistance to extended spectrum cephalosporin was primarily mediated by plasmid-mediated AmpC beta-lactamase. The presence of plasmids in Enterobacteriaceae highlights their potential dissemination and the poultry as a reservoir of resistance and virulence determinants.