Immunologic cross-reactivity between Streptococcus mutans and mammalian tissues

The presence of cross-reacting antigens shared by oral streptococci and human and monkey tissue was investigated by indirect immunofluorescence. Rabbit antisera prepared against two strains of each of the seven serotypes of Streptococcus mutans were incubated on sections of cardiac muscle, skeletal muscle, kidney, brain, liver, and skin. Antisera to S. mutans, serotype g, strain OMZ-65 reacted with cardiac muscle components. This reactivity could be reduced by absorption with bacterial cell membranes. Antisera to S. mutans serotype g, strain K-1 reacted with both cardiac and skeletal muscle but could not be reduced by absorption with bacterial cells, cell walls, or cell membranes. Antisera to S. mutans serotype g, strain OMZ-65 reacted with kidney glomeruli and could be completely absorbed by a cell wall preparation. S. mutans, serotype e, strain MT703 also reacted with kidney glomeruli but could not be reduced by absorption with bacterial antigens.