A Latex Agglutination Test for Measuring Antibodies to Streptococcal Mucopeptides

The preparation and application of mucopeptide (MP)-coated latex particles for determining antibody to streptococcal group A MP is described. Anti-MP hyperimmune sera, normal animal and human sera, and commercial antisera to various antigens were tested. MP-latex agglutination proved to be both specific and highly sensitive, permitting the detection of low antibody levels in 20 to 40% of normal sera; these antibodies were not demonstrable by means of other serologic techniques. Data confirming the specificity of the reaction are presented. No cross-agglutinations were observed with the exception of commercial anti-C reactive protein (CRP) serum. This latter phenomenon may be due to traces of MP present in the preparations used to produce anti-CRP serum. Latex agglutination should prove useful for establishing the occurrence of anti-MP antibody and for elucidating the role of anti-MP antibody in the various toxic or inflammatory reactions induced by MP in vitro and in vivo.