THE USE OF PRECIPITIN ANALYSIS IN AGAR FOR THE STUDY OF HUMAN STREPTOCOCCAL INFECTIONS

Abstract

It has been shown by agar precipitin tests (Ouchterlony and Oakley) that human sera may contain from 0 to 5 antibodies against antigens present in a partially purified streptolysin O preparation, and from 0 to 7 antibodies against antigens in a crude ammonium sulfate concentrate of the streptococcal culture supernate used. These antigens were prepared from a Group A hemolytic streptococcus (strain C203S). Strong evidence was presented suggesting that some of the bands seen with streptolysin O concentrate represented antibody reponses to streptococcal antigens heretofore undescribed. Tests were also carried out with other streptococcal antigens, including streptokinase-desoxyribonuclease mixture from Group C streptococci (varidase-Lederle), crystalline proteinase, proteinase precursor, C carbohydrate, and sonic vibrated streptococcal cell extracts (group A, C203S). Fewer bands were seen with these preparations, and with some they were quite uncommon. The observations indicated that the predominating antibody responses in human streptococcal infections were to extracellular products of the micro-organisms, and only very slightly and infrequently to intracellular antigens. The human sera studied included sera from patients with active or convalescent rheumatic fever, and non-rheumatic subjects suffering from a variety of illnesses. As was expected, the rheumatic subjects showed antibody responses to many more of the antigens present in these preparations than did the nonrheumatic group. Pooled normal human gamma globulin was found to contain many of the antibodies found in potent human sera. This finding confirmed the antigen-antibody nature of the bands seen with individual sera. The epidemiological significance of these findings with gamma, globulin was briefly discussed. It was found that rabbit, guinea pig, and human antibody precipitin bands join quite readily in the Ouchterlony tests. This finding adds another tool for the identification of the precipitin bands found with human sera. Evidence was obtained which indicated differing immunological specificities of two samples of streptococcal desoxyribonuclease, one from Group A, the other from a Group C streptococcus. The value of these technics as representing a new approach to the study of human infectious disease was discussed.