title: Newly recognized distinctive M protein associated with certain M type 1 group A streptococci.
abstract: Immunological and epidemiological characteristics of M1T1 and M1T8 (T8, 25, Imp.19) group A streptococci isolated in Egypt have been described. Both strains possess a common M1 antigen. The M1T8 strains possess a second antigen which has the immunological and biological characteristics of M protein. The M1T1 strains do not possess this second M antigen. Absorbed rabbit antisera which are specific for this second antigen do not react with extracts of any of the known M protein serotypes. This second antigen is therefore a newly recognized M protein. The M1T1 and M1T8 strains had mutually exclusive geographical and temporal distributions. This finding may have been a consequence of the immunity which occurred after the initial occurrence of the M1T8 strain.
mesh_terms: D000042:Absorption; D000372:Agglutination Tests; D000818:Animals; D000918:Antibody Specificity; D000942:Antigens, Bacterial / Q000032:analysis*; D001426:Bacterial Proteins; D001433:Bacteriolysis; D002473:Cell Wall / Q000276:immunology; D002648:Child; D003720:Densitometry; D004534:Egypt; D006801:Humans; D007106:Immune Sera; D005779:Immunodiffusion; D010614:Pharynx / Q000382:microbiology; D011817:Rabbits / Q000276:immunology; D013291:Streptococcus / Q000145:classification / Q000276:immunology* / Q000302:isolation & purification; D014357:Trypsin
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D007106:Immune Sera; D014357:Trypsin