TAXONOMY OF THE ORAL STREPTOCOCCUS-MUTANS BASED ON COLONIAL CHARACTERISTICS AND SEROLOGICAL, BIOCHEMICAL AND GENETIC FEATURES

Strains of Streptococcus mutans representing 6 different serotypes were cultured in pour plates containing a glucose agar medium under an atmosphere of 95 per cent nitrogen-5 per cent carbon dioxide. After growth, a sucrose solution was added to these plates. Three colonial types were obtained: type 1 colonies were rough spheroid shaped, with no white haze around any colony; type 2 were rough spheroid shaped with a white haze around each colony; type 3 were smooth lens shaped with white haze. On the other hand, all strains tested grew as rough spheroid shaped colonies in a sucrose agar medium pour plates. When these groupings were compared with groupings based on serological, genetic and biotype characterization demonstrated that strains belonging to the colonial type 1 were of serotype c or e, genetic group I and biotype I or V. Strains belonging to the colonial type 3 were of serotype a, d, or g, genetic group III or IV. © 1979.