Agglutination of bacteria by a sialic acid-specific lectin of the snail Cepaea hortensis.

Aqueous extracts from lyophilized albumen glands of the garden snail (Cepaea hortensis) exhibit, after separation from a second lectin, a specificity against sialic acid-containing polymers. In agglutination studies with bacteria, the lectin interacts with all strains of group B streptococci (Streptococcus agalactiae) containing type-specific polysaccharides. In contrast, group B streptococci containing only protein type antigens as well as all strains of other Lancefield streptococcal groups and several other bacterial strains did not react.