Role of glucose side chains with serotype-specific polysaccharide in the cariogenicity of Streptococcus mutans.
Previously, we isolated and characterized a new Streptococcus mutans strain (serotype k) from human blood and oral cavity samples, and found that the serological properties of serotype k strains were similar to those of a gluA-inactivated mutant strain of MT8148 (MT8148GD). MT8148GD showed significantly lower sucrose-dependent adhesion to glass surfaces, sucrose-independent adhesion to saliva-coated hydroxyapatite, dextran-binding activity, and cell-associated glucosyltransferase (GTF) activity than the parent strain. Further, Western blot analysis revealed reduced GTFB and GTFC expression in serotype k strains as compared to MT8148, though the caries-inducing activities of MT8148GD and a serotype k oral isolate in rats were similar to that of MT8148. We conclude that a glucose side-chain defect in the serotype-specific polysaccharide of S. mutans may be associated with its cariogenicity, though to a lesser extent than its other major surface proteins.
Nakano
K
K
Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, Osaka, Japan.
Nomura
R
R
Nakagawa
I
I
Hamada
S
S
Ooshima
T
T
D000818:Animals; D001422:Bacterial Adhesion; D002352:Carrier Proteins / Q000235:genetics; D003731:Dental Caries / Q000382:microbiology*; D003911:Dextrans / Q000378:metabolism; D017886:Durapatite / Q000737:chemistry; D005856:Germ-Free Life; D005898:Glass / Q000737:chemistry; D005947:Glucose / Q000737:chemistry*; D005964:Glucosyltransferases / Q000378:metabolism; D006801:Humans; D006863:Hydrogen-Ion Concentration; D037102:Lectins; D008297:Male; D009154:Mutation / Q000235:genetics; D011135:Polysaccharides, Bacterial / Q000737:chemistry*; D051381:Rats; D017207:Rats, Sprague-Dawley; D012463:Saliva / Q000502:physiology; D012703:Serotyping; D013290:Streptococcal Infections / Q000382:microbiology*; D013295:Streptococcus mutans / Q000145:classification / Q000235:genetics / Q000472:pathogenicity*; D013395:Sucrose / Q000378:metabolism
D002352:Carrier Proteins; D003911:Dextrans; D037102:Lectins; D011135:Polysaccharides, Bacterial; C037937:glucan-binding proteins; D013395:Sucrose; D017886:Durapatite; C036655:1,3-alpha-D-glucan synthase; D005964:Glucosyltransferases; C110463:glucosyltransferase C; D005947:Glucose