Origin Herd A B C D Quarter milk sample 1 a 1 ab - - Skin of teats   1 b - 5 Human hands       1(F) Human nasal cavities 1 a (S), 2(F) 1 b (S) 5(S), 5(F) 3(S) Bulkmilk   2 a - - Cheese   1 a

Table7: Number and origin of S. aureus isolates possessing the sak gene. S=sampler; F= farmer. Identical letters in each column correspond to the existence of identical isolate profiles.