The prevalence of Enterotoxigenic Isolates of Staphylococcus aureus in Bovine and Sheep Bulk Tank Milk Samples of Maku

Food-borne diseases are one of the major concerns of food and drug administration (FDA) and world health organization (WHO). Up to the present day، more than 250 types of food-borne diseases have been described and bacteria are responsible for two-third of them. Bacterial food poisoning is one of the most common food-associated diseases that are usually related to the consumption of contaminated foods with toxigenic bacteria. Among the bacterial agents responsible for food poisoning، staphylococcus aureus is the most common food poisoning agent worldwide. Milk and dairy products are the most common foods associated to staphylococcal food poisonings. Therefore، this study was considered to investigate the prevalence of enterotoxigenic isolates of Staphylococcus aureus in bovine and sheep bulk tank milk samples of Maku city. In this study، a total of 178 milk samples including bovine (n=92) and sheep (n=86) milk samples were collected. A total of 76 isolates from milk samples was examined for the production of staphylococcal enterotoxins and associated genes using Reverse Passive Latex Agglutination (RPLA) and Multiplex PCR (Polymerase Chain Reaction) respectively. Out of 44 and 32 isolaes from bovine and sheep bulk tank milk samples 19 (43. 1%) and 13 (40. 6%) were enterotoxin producers respectively. SEA، SED and SEC were the most common toxins detected in all isolates. The prevalence of classical enterotoxins and related genes are shown by SET-RPLA and m-PCR corresponded in 91. 1% of all S. aureus isolates، analyzed by both methods. Non-correspondence was observed in two sea positive isolates that were SEA negative، and in one isolates that were SEA and SEC positive only genes for sec were detected. This study indicated a high incidence of enterotoxigenic isolates of staphylococcus aureus in bovine and sheep bulk tank milk samples in Maku city.