Biochemical Characterization and Enterotoxins Production by Staphylococcus aureus Strains Isolated from Raw Milk and Traditional Fresh Cheese in Dairy Farms of Zulia State

One hundred and fourteen strains of S Staphylococcus aureus were characterized based on its biochemical pattern and production of enterotoxins (SEs). The strains were isolated in nine farms in Zulia State where artisanal cheese was made. The isolates were made from 313 quarters milk samples with subclinical mastitis, nine churn milk samples, nine curd samples and nine fresh cheese samples. Nineteen different biochemical patterns were detected among isolates. The biochemical pattern A was predominant, being observed in 28.9% isolates. In all dairy farms there were more than two different biochemical patterns with a maximum of seven patterns in dairy farms I. In 27 isolates (24%) staphylococcal enterotoxins (SEs) were detected: 13(41.15%) isolates tested positive for SEB, 4 (14.81%) for SEC, 3 (11.11%) for SEA and 2 (7.40%) for SED. Furthermore, three isolates were positive for two different enterotoxins. According to the origin of the isolates enterotoxigenic, 70.4% were associated with subclinical mastitis, 14.8% were isolated from churn milk and 7.4% were isolated from curd and cheese, respectively. This study showed that most S. aureus strains isolated from bovine subclinical mastitis produced enterotoxins, and reveal that there is a direct risk to the health of consumers of artisanal fresh cheese.