PURIFIED GROUP A STREPTOCOCCAL M-PROTEIN IN LATEX AGGLUTINATION FOR DETECTION OF TYPE-SPECIFIC M-ANTIBODIES.

Abstract

M-protcins from several M-typcs of group A streptococci were extracted with hot acid and precipitated with 30% and 60% saturated ammonium sulphate giving two main fractions designated P60 and S60. After purification and serological testing the S60 fraction was found to be more specific and absorption of homologous sera with it emoved their bactericidal activity. It was also used in latex agglutination tests to detect type-specific M antibodies in patients suffering from streptococcal sore throat, rheumatic fever, rheumatic heart disease and in normal individuals of comparable age groups and sex. The S60 latex agglutination test could also detect rise in antibody litre to the infecting streptococcal M-type.