The Chemical Composition and Serological Reactions of Lipopolysaccharides from Serogroups A, B, X, and Y Neisseria meningitidis

Abstract

Analyses of the cell wall lipopolysaccharides prepared from Neisseria meningitidis serogroups A, B, X, and Y, indicated that they all contained glucose, galactose, glucosamine, heptose, lipid A, ethanolamine, fatty acids, phosphate, and protein. Some minor compositional differences in the sugar components did occur in that sialic acid (6–7%) was found only in serogroups B and Y, and galactosamine (2–3%) in serogroups B and X. The individual fatty acid and amino acid components in the four serogroups were also qualitatively similar. The Neisseria lipopolysaccharides studied have the same components as the core structure of the Enterobacterioceae but appear to lack the characteristic components of their O-antigen side chains. Serological studies indicated that the lipopolysaccharides were homogeneous and were for the main part group specific in nature, despite their compositional similarity. On the basis of compositional differences alone it is not possible to account for the group specificity that they exhibit.