A comparison of antigenic structure and phage pattern with biochemical properties of Staphylococcus aureus strains isolated from sheep.

Of 84 Staphylococcus aureus strains isolated from the anterior nares of healthy sheep and from the udders of ewes suffering from purulent mastitis the 89 per cent belonging to the C biotype contained agglutinogen h2 as well as polysaccharide Abeta. Ninety-five per cent of the C biotype strains were lysed by the bovine phage 78, the human phage set giving only weak reactions at RTD X 100. Two pigment-negative deficit variants as well as three unclassified strains gave similar results while three A biotype strains and one E biotype strain were definitely different. The close correlation between biochemistry, serology and phage typing substantiates the practical usefulness of the subdivision of S. aureus into biotypes.