Identification of coagulase-positive staphylococci isolated from bovine milk

A total of 414 coagulase-positive staphylococcal strains obtained at the ma stitis laboratory, National Veterinary Institute, Uppsala, Sweden, were stu died. One hundred and seventy seven strains were used for a frequency study . Ninety-seven per cent were identified as Staphylococcus aureus, 2% as Sta phylococcus intermedius and 1% as Staphylococcus hyicus. Two hundred and th irty seven strains with atypical hemolysis reactions on bovine blood agar w ere randomly selected with the aim to increase the number of S. intermedius and S. hyicus strains available for testing. Eight different characteristi cs, including physiological, enzymatical and biochemical properties, were u sed to identify the coagulase-positive Staphylococcus species. The results of this study suggest that the following tests should be included for corre ct identification of the 3 different species of coagulase-positive staphylo cocci: P agar supplemented with acriflavin, beta-galactosidase and hemolyti c reaction on chocolate agar. These 3 tests are simple and quick to perform and enable accurate for easy differentiation of the 3 coagulase-positive S taphylococcus species.