Staphylococcus aureus is an important contagious bacteria of bovine mastitis. S. aureus from bovine mastitic milk are shown to comprise two dominant genotypes, A and B by pulsed-field gel electrophoresis (PFGE). Most of the isolates belonging to A are coagulase serotype VI and capsule serotype 8, do not produce egg-yolk factor, and possess the toxin genes, staphylococcal enterotoxin and toxic shock syndrome toxin-1. On the other hand most of isolates belonging to B are coagulase serotype VI and capsule serotype 5, produce egg-yolk factor, and do not possess toxin genes. Moreover, we investigated the distribution of S. aureus in cow barns by PFGE. S. aureus, which shows the same genotype as milk isolates, is isolated from mammary, teats, and milking equipment. Isolates from environmental samples in cow barns show different genotypes from milk isolates. These results support the belief that movements of cows plays an important role of the spread of S. aureus between cow barns. Moreover, elucidating the occurrence of bovine mastitis by S. aureus will help in focusing on the virulence of isolates belonging to dominant genotypes.
(Research Team for Bacterial/Parasitic Diseases, TEL +81-11-851-5226)
Reference:
Hata et al. (2006) J. Vet. Med. Sci. 68 : 165-170.
