Chemical Studies on Bacterial Agglutination Vi. the Agglutinin Content of ~tisera to Hemolytic Streptococci

In most of the bacterial agglutinating systems previously studied by the quantitative method (1-5) well defined capsular polysaccharide antigens and their corresponding antibodies were principally involved. The greater part of the antibody produced as a result of intravenous injections of microorganisms such as type-specific pneumococci or It. influenzae reacts with these capsular antigens, relatively little being directed toward minor antigens such as somatic polysaccharides and proteins. On the other hand, immunization with hemolytic streptococci results in the production of antibodies reactive with a number of different antigenic components, of which the type-specific M(6) and T(7) substances, the groupspecific somatic polysaccharide-C (6), and at least two group-specific protein antigens (6, 8-11) have been recognized as separate entities. Adaptation of the quantitative agglutinin method to hemolytic streptococcus systems therefore raises even more complicated questions and difficulties than in the case of R (Dawson S) pneumococci (4). Before consistent results could be obtained much preliminary work was necessary and details of this phase of the study will be omitted.