This invention provides isolated nucleic acids encoding polypeptides comprising amino acid sequences of streptococcal matrix adhesion (Ema) polypeptides. The invention provides nucleic acids encoding Group B streptococcal Ema polypeptides EmaA, EmaB, EmaC, EmaD and EmaE. The present invention provides isolated polypeptides comprising amino acid sequences of Group B streptococcal polypeptides EmaA, EmaB, EmaC, EmaD and EmaE, including analogs, variants, mutants, derivatives and fragments thereof. Ema homologous polypeptides from additional bacterial species, including S. pneumoniae, S. pyogenes, E. faecalis and C. diptheriae are also provided. Antibodies to the Ema polypeptides and immunogenic fragments thereof are also provided. The present invention relates to the identification and prevention of infections by virulent forms of streptococci. This invention provides pharmaceutical compositions, immunogenic compositions, vaccines, and diagnostic and therapeutic methods of use of the isolated polypeptides, antibodies thereto, and nucleic acids. Assays for compounds which modulate the polypeptides of the present invention for use in therapy are also provided.
