Occurrence of enterotoxigenic staphylococci in raw milk

The aim of this study was to determine the occurrence of enterotoxigenic staphylococci among staphylococci isolated from raw milk. There is a chance of transmitting into milk enterotoxigenic strains from cows, which have no symptoms of mastitis. The investigations were carried out on 150 samples of cow's milk from two different dairy farms and 100 samples of swabs from dairy equipment after washing and-disinfection. From the examined samples, 40 strains of stapylococci were isolated; 36: strains' taken front milk samples and 4 from the swabs. Nearly half of the isolated strains were coagulase-positive: In the group of coagulase-positive staphylococci, 18 strains were determined as Staphylococcus aureus and 1 as Stapylococcus intermedius. The ability to produce enterotoxins was found in 66% of the strains of S. aureus. Generally enterotoxigenic strains were determined in 5% of the examined samples. None of the strains of coagulase-negative staphylococci or S. intermedius have any ability to produce enterotoxin. The examination of enterotoxigenicity of staphylococci occurring in food products seems to be more reliable for the evaluation of hazards caused by these bacteria.