Cross-Reactions of the Group-Specific Polysaccharides of Streptococcal Groups B and G in Anti-Pneumococcal Sera with Especial Reference to Type XXIII and its Determinants

Abstract

Quantitative data are given on the extensive cross-reactivity of the group polysaccharides of streptococcal groups B and G in antipneumococcal type XXIII horse serum and on inhibition-reactions in this antiserum. L-Rhamnose, known to be a principal determinant of the two streptococcal substances, is even more easily split off from the specific polysaccharide of pneumococcal type XXIII. This, and the ready inhibition of both the S XXIII anti-XXIII and group B anti-XXIII reactions by L-rhamnose, show that this sugar, probably in the form of non-reducing end-groups, is also a major determinant of S XXIII. D-Galactose is also involved in the specificity of S XXIII and may reinforce the cross-reaction.