Staphylococcus aureus is regarded as the most important causal agent of bovine mastitis. Some eleven antigenically-distinct capsular polysaccharides are recognized as being produced by S. aureus. Preliminary studies indicated that two capsular types, type 5 and type 8, are predominant among the isolates. Using the colony immunoblot method in this study, we investigated which capsular serotype predominates in S. aureus isolates from bovine mastitis in Shimane prefecture, Japan. Our investigation involved the capsular serotyping of 69 bovine mastitis isolates of S. aureus from 27 farms in Shimane prefecture. Serotypes 5 and 8 accounted for 69.6% and 2.9% of the isolates, respectively. Type 5 was therefore predominant in Shimane prefecture.Our investigation attempted to detect the whey antibody from 101 bovine mastitis cases infected with type 5 S. aureus, CNS, Streptococcus and E. coli. Whey which had infected with type 5 S. aureus had a more positive-agglutination and higher antibody titer than the others.
(Shimane Prefecture Animal Health Institute, TEL +81-853-43-2455)
