[Quantitative determination of protein A in strains of staphylococci isolated in the course of different clinical states and localization of the process].

The main properties of 370 staphylococcal strains isolated from the blood, pus, sputum and the throat washings of patients were studied, and the identification of these strains was carried out. The level of cell-bound protein A in the strains was determined in the hemagglutination test with erythrocytes sensitized with hemolytic serum. Out of 269 S. aureus strains 93.7% formed protein A, out of 90 strains of plasmocoagulasonegative staphylococci, including S. epidermidis, S. saprophyticus and strains with intermediate properties, 88 strains were protein A-negative, 2 S. epidermidis strains yielded unstable and faintly pronounced reaction to protein A. In the presence of correlation between the test for protein A and other pathogenicity tests no relationship between the quantitative content of protein A and the character of the pathological process was established.