Staphylococci outside the hospital. Staphylococcus aureus in sheep.

Biochemical properties were studied in Staph. aureus strains obtained from the anterior nares of healthy sheep and from the udders of ewes suffering from purulent mastitis. Of the total number of 84 isolated staphylococcal strains 75 (89.3%) were classified as the C biotype. These undoubtedly sheep-adapted staphylococci produced pigment and beta hemolysin, they were growing on crystal violet agar as the negative type in violet colonies lacking both fibrinolysin and alpha hemolysin. All of them coagulated human plasma within one hour after inoculation. In bovine plasma 27 strains (36%) formed the coagulum within 3 hours, 16 (21.3%) within 24 hours, and the remaining 32 strains (42.7%) only within 72 hours. Mannitol was fermented after five days only by 33 cultures (44%). The staphylococci were sensitive to the applied antibiotics without exception. All these sheep-adapted staphylococci had analogous biochemical features to the earlier discussed staphylococcal strains obtained by the authors from the nasal cavities of cattle. Next two strains were denoted as deficit variants of the C biotype because of their lack of pigment. Of quite a different character were 3 strains (3.6%) of the A biotype and one strain identified as the E biotype. The former were presumably transferred to sheep from man while the latter from a dog. The remaining 3 strains could not be subdivided according to the classificatory criteria used here.