Prevalence of Enterotoxin Genes in Poultry Staphylococcus aureus Isolates

Staphylococcus aureus is an important opportunist that can cause superficial to life-threatening illnesses in humans and a variety of animal species. Staphylococcal enterotoxin has an important role in food poisoning in human. Staphylococcal enterotoxin A is the most commonly reported enterotoxin in staphylococcal food poisoning. This study revealed the presence of enterotoxin (like) genes (sea, seb, sec, sed, see, seg, seh, sei, selj, selk, sell, selm, seln, selo, selp, selq and selu) in 100 poultry S. aureus isolates that were collected from 165 healthy flocks immediately before slaughtered in slaughter houses from Iran and Belgium. All the isolates were confirmed as Staphylococcus aureus by standard biochemical and molecular test. Ten out of 100 isolates were confirmed as MRSA belonging to the animal-associated clone ST398. 25 of the isolates carried sea. Fifty seven percent of the isolates were positive for the five staphylococcal enterotoxin genes, seg, sei, selm, seln and selo (egc cluster). All isolates were negative for other genes that we have screened in this study. All MRSA isolates were negative for all the genes. Our data indicated that poultry S. aureus isolates can possess superantigen genes and consumption of the contaminated carcasses with these bacteria may be induce food poisoning in humans. In comparison, no relevant significant differences between the frequency of the genes encoding entrotoxins in the groups of S. aureus isolates from Iran and Belgium could be found.