Detection of Classical Enterotoxins of Staphylococcus aureus Strains Isolated From Raw Meat in Esfahan, Iran


Background: Staphylococcus aureus is an important pathogen of humans in both community acquired as well as nosocomial infections. It is also among the four most common causes of food-borne illnesses.

Objectives: This study was conducted to determine the prevalence of enterotoxin producing S. aureus strains in different raw meat and hamburgers in Isfahan.

Materials and Methods: From August to December 2012, 370 samples of raw beef (n = 160; minced and carcass), lamb (n = 80), goat (n = 80), and camel (n = 50) meat were purchased from randomly selected butcheries in Isfahan, Iran, and analyzed for the presence of S. aureus. Isolates were also tested for their ability to produce staphylococcal enterotoxins A, B, C, D, and E by enzyme linked immunosorbent assay (ELISA) test.

Results: Totally, 223 (60.3%) S. aureus were isolated. Among the 223S. aureus isolates 30 (13.5%) were found to be enterotoxigenic. Twenty-six (86.7%) were positive only for one type of SEs (14 SEA, 1 SEB, 6 SEC and 5 SED) while the remaining (13.3%) were positive for more than one SEs. None of the isolates were positive for SEE.

Conclusions: Only 8.3% of the total meat samples examined in the current study showed this count or above. This low degree of contamination by S. aureus is tolerated in most food stuffs and they are not considered a risk for public health. However, we need more epidemiological investigations about enterotoxigenic S. aureus isolates and their toxins for better management of food products and to decrease human diseases. The results of this study showed that most S. aureus strains isolated from samples produced SEA and SED compared to other SEs.