Identification of sea and seb frequency in Staphylococcus aureus isolated from cow, sheep and goat mastitic milk samples in Sanandaj city

Staphylococcus aureus is one of the most important causes of food poisoning in human. The main etiological agent, staphylococcal enterotoxins (SEs) are in different types. Based on the plausible role of contaminated milk with enterotoxigenic strains of this bacterium in human food poisoning and the important role of SEA and SEB in bacterial intestinal pathogenesis, plus with the multiple role of SEB as a biological weapon on one hand, and the lack of any data on the role of milk and the two mentioned enterotoxins in public health threatening in Sanandaj on the other hand, this study was aimed to determine the prevalence of sea and seb genes, as the most clinically important enterotoxines in mastitic milk samples.
120 cow, 60 sheep, and 60 goat mastitic milk samples were collected under sterile conditions and analyzed for the presence of S. aureus by routine bacteriological methods. The isolates were confirmed by thermonuclease (nuc)-based PCR and were evaluated for detection of sea and seb genes using molecular technique.
Totally, 23.33% (28 numbers) of cow milk, 31.66% (19 numbers) of sheep milk, and 21.66% (13 numbers) of goat milk samples were contaminated with S. aureus. Among the bovine originated S. aureus, 100% were found to harbor sea with no seb. sea was detected in 78.94% (15 numbers) and 23.07% (3 numbers) of S. aureus isolates with ovine and caprine origins, respectively, and seb was detected in 10.52% (2 numbers) and 30.78% of S. aureus with ovine and caprine origins, respectively.
The high percentage of SE genes in S. aureus isolated from milk samples constitutes a potential risk for consumers′ health. Therefore, improving the hygienic quality of milk is essential in the mentioned area.