Diminished virulence of glucan synthesis-defective mutants of Streptococcus mutans.
The virulence of cell surface-associated, glucan synthesis-defective mutants of Streptococcus mutans strain 6715-13 was studied. Representatives from three groups of such mutants were tested for their pathogenicity in conventionalized, specific pathogen-free rats and gnotobiotic rats. The mutants differ from the wild-type strain in that each failed to form plaque on the smooth surfaces of the teeth and to cause smooth surface caries. Although the ability to form cell surface-associated glucans was not a strict requirement for the expression of virulence in the sulci of the teeth, it augmented virulence at such sites. However, the ability to form cell surface-associated glucans and to adhere to the teeth was clearly not the sole determinant of virulence.
D000818:Animals; D003731:Dental Caries / Q000382:microbiology; D003773:Dental Plaque / Q000382:microbiology; D004037:Diet, Cariogenic; D004352:Drug Resistance, Microbial; D005243:Feces / Q000382:microbiology; D005856:Germ-Free Life; D006003:Glycogen / Q000096:biosynthesis*; D008963:Molar / Q000382:microbiology; D009154:Mutation; D051381:Rats; D013291:Streptococcus / Q000302:isolation & purification / Q000472:pathogenicity*; D013307:Streptomycin; D014774:Virulence
D006003:Glycogen; D013307:Streptomycin