JOURNAL OF FOOD SAFETY, vol.30, no.1, pp.196-212, 2010 (SCI-Expanded)
A total of 413 samples of milk, dairy products, meat and meat products were analyzed for the presence of Staphylococcus aureus in a 2-year survey (2004-2006). One hundred thirty-eight samples were (33.4%) contaminated with S. aureus. A total of 138 S. aureus strains were isolated and identified. Enterotoksin profiles were determined by Staphylococcal Enterotoxin Test Reversed Passive Latex Agglutination. Their resistance to nine antibiotics were tested. The contamination rate of the meat product samples (48.7%) was significantly higher than milk and dairy products (23.2%). Most of the strains (60.1%) produced staphylococcal enterotoxins. Four strains produced staphylococcal enterotoxin C and staphylococcal enterotoxin D. All of the strains tested were resistant to many of the nine antibiotics. One strain isolated from feta cheese was resistant to all of the antibiotics tested. Penicillin G resistance was the highest (92.7%) among the antibiotics. Seventy-one strains choosen randomly were compared by the DNA macrorestriction patterns obtained from pulsed field gel electrophoresis following Sma I digestion and 33 pulsotypes were determined. Seventy-three strains were characterized by automated ribotyping using Eco RI and 8 ribotypes were determined. The same, as well as different pulsotypes, were identified among strains with the identical ribotyping profile. The presence of enterotoxigenic and antimicrobial resistant strains of S. aureus has become remarkably wide spread in the foods examined and poor sanitary conditions during processing may create a health risk for the consumers. The results of genotyping showed high diversity among the strains.