Enterotoxigenic Staphylococcus aureus in brined cheese from weekly street markets in Ankara, Turkey

A total of 63 brined cheeses (30 white pickled cheeses, 33 Tulum cheeses) were randomly collected from informal market places such as weekly street markets in the province Ankara during a seven-month period, and quantitatively analysed for Staphylococcus (S.) aureus. S. aureus isolates obtained from these samples were analysed for staphylococcal enterotoxin (SE) genes by PCR, selected isolates were tested for SEA-SEE production by enzyme immunoassay. S. aureus was found in eleven (17.0 %) of cheese samples at levels between 9.5 x 10(2) and 5.0 x 10(6) cfu/g. All 22 S. aureus isolates were positive by PCR for one or more toxin genes (sea, sed, seg, sei, selj, sem, sen, seo, sep, ser and selu), forming three distinct toxin profiles. SEA or SED production was found for isolates from five samples, by enzyme immunoassay. Further characterization of isolates by macrorestriction analysis yielded three different pulsed-field gel electrophoresis (PFGE) profiles which corresponded well with SE gene profiles. Identical PFGE profiles were obtained for isolates from several alleged unique cheeses, purchased from different vendors in different markets, indicating a common source of production and disproving the claimed originality. These findings highlight the existence of health hazards related to consumption of traditional cheeses originating from such underregulated markets and the need to implement more intensive hygiene control measures.