[Serologic cross reactions of group B streptococci]

Group B streptococci contain sialic acid in their capsular polysaccharides thus resembling human and vertebrate glycoconjugates which are especially increased in human tumors. Sterical and conformational reasons are responsible for the fact, that certain streptococcal antigens do not react with antibodies, including monoclonal antibodies, against these carbohydrate structures. The usefulness of lectins in detecting streptococcal antigens is demonstrated with antigalactans. In summary, the relationships between the biochemical structure of streptococcal antigens on one side and the serological reactivity on the other side are not evident a priori, because there are many cross-reactions which, although being expected, serologically do not take place.