Belongs to a phenotypic group called the mutans streptococci which include S. sobrinus, S. ferus, S. cricetus, S. rattus and serotype "h" [4].  Phylogenetically distinct from other species of Streptococcus. 

Colonies are whitish about 0.5 to 1 mm that stick to the agar.  When media is supplemented with sucrose, puddles of liquid (e.g., soluble extracellular polysaccharide) surround the colonies. 

Facultatively anaerobic, Gram positive cocci (0.5 to 0.75 um in diameter), which occurs in pairs, or short chains [4] 

Produces extracellular polysaccharides from sucrose by glucosyltransferase (e.g., glucans) and fructoosyltransferases (e.g. fructans).  These polysaccharides promotes binding to cell surfaces.

Glucose is fermented to L-lactic acid with no gas.  Final pH in glucose broth cultures is 4.0 to 4.3.  Growth is not inhibited by lower pH. 

Strains of S. mutans can be distinguished serologically.  Peptidoglycan contains glutamic acid, alanine, lysine, glucosamine adn muranmic acid [4]

Commonly detected o­n human teeth in supragingival plaque, and usually associated with caries.  Has been isolated from human feces.

Strong association with human dental caries, considered the primary cause of caries, although caries can occur in the absence of S. mutans.    Also associated with endodontic lesions, odontogenic infections, infectious endocarditis and cardiovascular disease [2]

Is carogenic in experimental animals (rats, hamsters, gerbils, mice and monkey.

Vaccines which target S. mutans are being developed to prevent caries formation [1].