Characterization of virulence gene distribution and antibiotic susceptibility profiles of diarrheagenic Escherichia coli from chicken faeces

The inappropriate use of antibiotics in the poultry industry for prophylaxis and growth promotion has contributed to the development and spread of antibiotic resistance in zoonotic pathogens. This study aimed to understand the prevalence of pathogenic Escherichia coli (E. coli) in chicken faeces and their antibiotic susceptibility profiles. Forty-five E. coli isolated from the chicken faeces were further tested for virulence genes associated with diarrheagenic E. coli and extended-spectrum β-lactamase (ESBL) genes blaCTX, blaTEM, blaSHV and Metallo-beta-lactamase gene blaNDM. Results showed that eaeA and astA genes were detected in 60% of the isolates, followed by bfpA in 57.8%, lt in 26.7% and st gene in 2.2% of the isolates. Further, 15.5% of the isolates produced ESBL phenotypically whereas genotypically, one isolate was positive for blaCTX, one for blaTEM, and one for the blaSHV gene. Twelve isolates (26.7%) harbored gene blaNDM. High levels of resistance were observed against cefepime (93.3%), ertapenem (78.9%), meropenem (73.6%), tetracycline (88.9%), and cotrimoxazole (75.6%). This study highlights the importance of poultry as a source of human pathogenic multidrug-resistant (MDR) E. coli and their environmental dissemination.