Agglutination by human sera of erythrocytes incubated with streptococcal culture concentrates.

It was demonstrated by Keogh et al. (1947) and Warburton et al. (1949) that several products of bacterial cultures could be adsorbed to erythrocytes, which then could be agglutinated by sera containing antibodies to those bacterial antigens. This approach was developed in the case of a constituent of tuberculin by Middlebrook and Dubos (1948) and Rothbard et al. (1950). The work of the latter groups served to emphasize the point that a single constituent might be adsorbed to the erythrocyte from a mixture of antigens by a selective adsorption. Recently this technique has been applied to work with the plague bacillus (Amies, 1951), the hemolytic streptococcus (EKirby, 1951), and the colon bacillus (Neter et al., 1952). The present study arose in the course of an exploration of antigens of the hemolytic streptococcus in terms of a possible agent in the pathogenesis of rheumatic fever. The current emphasis in this work is on the extracellular antigens of the hemolytic streptococcus, as found in concentrates of streptococcal culture supernates. Since there are presumably a number of streptococcal products in such concentrates, it was decided to undertake the present study to see whether erythrocytes would adsorb any constituent of the culture supernate concentrates to which antibodies might be present in human sera. Concurrent studies on the entire culture supernate concentrates are in progress.