The analysis of streptococcal infections. VI. Immunoelectrophoretic observations on extracellular antigens detectable with human antibodies.

It has been found by immunoelectrophoresis, that Group A streptococci release at least 20 distinct extracellular antigens in human tissues, as judged by naturally occurring antibodies present in normal pooled human gamma globulin. Several of these precipitin arcs have been identified with streptococcal antigens previously purified by electrophoresis and chromatography. Human gamma globulin, as well as several rheumatic fever sera, were shown to be remarkably potent in antistreptococcal antibodies, when compared to four horse antibody concentrates obtained by hyperimmunization with several streptococcal filtrates. A Group C streptococcal culture concentrate revealed 8 or 9 antigens for which corresponding antibodies were present in human gamma globulin.