Identification of staphylococci from bovine milk in Argentina.

Two hundred and thirty three strains of staphylococci isolated from bovine milk from 17 dairies in Argentina were classified into 16 species. Most of the strains (78%) belonged to 4 species; S. aureus, S. haemolyticus, S. hominis, and S. warneri (38.5, 20.5, 9.4 and 9.0%, respectively). The remaining 12 species appeared with low frequencies. Twenty-one of the strains were isolated from mammary quarters with signs of clinical mastitis. The majority of the milk samples infected with S. aureus or S. haemolyticus showed very high somatic cell counts.