Rapid Method for Detection of Staphylococcus aureus Enterotoxins in Food

Abstract

Food-borne bacteria have the most concern in public health and food safety. S. aureus food poisoning is one of the most economically important food-borne pathogen worldwide. In the present study a total of 250 food samples (milk samples n=50, white soft cheese samples n=50, yoghurt samples n=50, meat and meat products n=50 and chicken products n=50) were investigated bacteriologically to detect the occurrence of enterotoxigenic S. aureus among the examined food samples. Out of 250 examined food samples, 127 isolates were identified as Staphylococcus species (50.8 %). 32 S. aureus isolates were identified from the examined samples with an incidence of 12.8%. The highest isolation rate was observed in raw milk samples (56%) followed by yoghurt samples (22%), chicken products (6%), white soft cheese samples and pasteurized milk samples (4% each) then meat and meat products samples (2%). Using PCR, out of 32 S. aureus isolated from the examined food samples 10 isolates could produce enterotoxins. Protein profile analysis of 8 enterotoxigenic S. aureus strains were analyzed by Sodium Dodecyl Sulphate Poly Acrylamide Gel Electrophoresis (SDS-PAGE). All enterotoxigenic isolates had a band at 26 to 29 kDa. Direct detection of S. aureus enterotoxins were investigated among 6 samples (3 raw milk samples, 2 yoghurt samples and one chicken product sample) using mPCR. It could be concluded that S. aureus producing enterotoxins present in the food samples.