HUMAN IMMUNITY TO THE MENINGOCOCCUS

TLDR

A novel Cetavlon‑based precipitation method isolates high‑molecular‑weight group A, C, and B meningococcal polysaccharides, and a passive hemagglutination assay confirms their serogroup‑specific antibody reactivity. The isolated polysaccharides are high‑molecular‑weight, with group A composed of N‑acetyl, O‑acetyl mannosamine phosphate and group C of N‑acetyl, O‑acetyl neuraminic acid, and hemagglutination inhibition confirms their group‑specificity, enabling serogrouping of isolates.

Abstract

The group-specific polysaccharides of group A and group C meningococci have been isolated by a new procedure which employs the cationic detergent Cetavlon to precipitate these polysaccharides from the whole culture. The A and C polysaccharide prepared by this method are noteworthy because they are of high molecular weight. The main constituent of the A polysaccharide is N-acetyl, O-acetyl mannosamine phosphate; of the C polysaccharide N-acetyl, O-acetyl neuraminic acid. This purification procedure, when applied to cultures of group B organisms, yields a polysaccharide consisting primarily of N-acetyl neuraminic acid. A passive hemagglutination test developed to measure antibodies to the polysaccharides demonstrated the specificity of these antigens. Using a hemagglutination inhibition test, these antigens were again found to be group-specific, and this test could be used for serogrouping meningococcal isolates.