[Comparative studies of protein A from staphylococci isolated from sheep]

The passive hemagglutination test was employed to establish the presence of protein A in a total of 133 strains of coagulase-positive and coagulase-negative staphylococci isolated from sheep with mastitis. Defined were also the antigen structure, phage behaviour, and some biologic properties of these staphylococci. It was found that 91 per cent out of 110 strains of Staphylococcus aureus studied produced protein A. At the same time not one of the 23 strains of Staphylococcus epidermidis showed the presence of this surface antigen. This data showed the necessity of introducing the hemagglutination test in routine microbiologic work for the demonstration of protein A in staphylococci isolated in the cases of pathologic processes in animals.