Distribution of cross-reactive antigens A and B in Streptococcus mutans and other oral streptococci.

A collection of strains representing the various common species of oral streptococci was examined for the presence of antigens cross-reacting with A and B from Streptococcus mutans serotype c. Antigens cross-reacting with A were found only in S. mutans serotype b. Antigens cross-reacting with B were found in S. mutans serotypes a, c, d, e, f and g and also in strains of S. sanguis. All antigens cross-reacting with B were precipitated by antiserum to human heart tissue.