Relatedness and Classification of Streptococcus mutans and "Mutans-like" Streptococci

The "mutans-like" streptococci can be separated into five species (Streptococcus mutans, S. rattus, S. sobrinus, S. cricetus, and S. ferus ) that belong to the same rRNA homology cluster. New valuable chemical characters for differentiation of the five species - such as peptidoglycan type, presence of cell wall teichoic acid, and cell wall sugar composition - are described. The peptidoglycan type and the cell wall sugar composition can be determined by rapid procedures.