Molecular Determinants of Virulence and Antimicrobial Resistance among Enterococcus Species Isolated from Chickens

Enterococci cause meat and environmental contamination during slaughter time. In this study, virulence and antimicrobial resistance (AMR) characteristics of enterococci isolated from chickens were determined. A total of ۱۰۷ cloacal swabs of chickens were inoculated onto Slanetz and Bartley agar and incubated at ۳۷ºC for ۲۴-۴۸ h. Gram staining, catalase, and hemolytic tests were done. AMR was determined using the disc diffusion technique against twelve antimicrobials. Molecular detection of AMR genes: blaZ, aphA, aacA-aphD, ermB, tetL, tetM, and vanC, and virulence factors: agrBEfs, efaAEfs, esp, gelE, and hyl were done on selected isolates using PCR. Ninety-five isolates were Enterococcus species. The isolates showed resistance to tetracycline, cefoxitin, amoxicillin, and imipenem and possessed tetL, tetM, ermB, aphA, vanC, aaca-aphD resistance and gelE, agrBef, efaAfs, espfs and hyl virulence genes. This is the first detection of AMR and virulence genes in multi-drug resistant enterococci among chickens in the locality. These enterococci could constitute a reservoir of virulence and resistance properties which are of animal and public health concern.

Keywords:

Chicken , Virulence gene , Enterococcus species , Multi-drug resistance , Antimicrobial resistance gene