title: Streptococcus mutans out-competes Streptococcus gordonii in vivo.
abstract: Streptococcus gordonii and Streptococcus mutans avidly colonize teeth. S. gordonii glucosyltransferase (GtfG) and amylase-binding proteins (AbpA/AbpB), and S. mutans glucosyltransferase (GtfB), affect their respective oral colonization abilities. We investigated their interrelationships and caries association in a rat model of human caries, examining the sequence of colonization and non- vs. high-sucrose diets, the latter being associated with aggressive decay in humans and rats. Virulence-characterized wild-types of both species and well-defined mutants of S. gordonii with interrupted abpA and gtfG genes were studied. While both S. gordonii and S. mutans were abundant colonizers of rat's teeth in the presence of either diet, if inoculated singly, S. mutans always out-competed S. gordonii on the teeth, independent of diet, strain of S. mutans, simultaneous or sequential inoculation, or presence/absence of mutations of S. gordonii's abpA and gtfG genes known to negatively or positively affect its colonization and to interact in vitro with S. mutans GtfB. S. mutans out-competed S. gordonii in in vivo plaque biofilm. Caries induction reflected S. mutans or S. gordonii colonization abundance: the former highly cariogenic, the latter not. S. gordonii does not appear to be a good candidate for replacement therapy. These results are consistent with human data.
authors.affiliation: Schools of Dental Medicine and Medicine, University of Connecticut Health Center, Farmington, CT 06030-1605, USA. tanzer@nso.uchc.edu
authors.forename: J M
authors.initials: JM
authors.lastname: Tanzer
authors.forename: A
authors.initials: A
authors.lastname: Thompson
authors.forename: K
authors.initials: K
authors.lastname: Sharma
authors.forename: M M
authors.initials: MM
authors.lastname: Vickerman
authors.forename: E M
authors.initials: EM
authors.lastname: Haase
authors.forename: F A
authors.initials: FA
authors.lastname: Scannapieco
mesh_terms: D000818:Animals; D001425:Bacterial Outer Membrane Proteins / Q000235:genetics; D001426:Bacterial Proteins / Q000235:genetics; D003731:Dental Caries / Q000382:microbiology*; D003773:Dental Plaque / Q000382:microbiology*; D019422:Dietary Sucrose / Q000378:metabolism; D004195:Disease Models, Animal; D005964:Glucosyltransferases / Q000235:genetics; D056265:Microbial Interactions / Q000235:genetics; D051381:Rats; D054773:Streptococcus gordonii / Q000502:physiology*; D013295:Streptococcus mutans / Q000502:physiology*; D037521:Virulence Factors / Q000235:genetics
chemical_list: C112818:AbpA protein, Streptococcus gordonii; D001425:Bacterial Outer Membrane Proteins; D001426:Bacterial Proteins; D019422:Dietary Sucrose; D037521:Virulence Factors; C036655:1,3-alpha-D-glucan synthase; D005964:Glucosyltransferases; C101905:GtfG protein, Streptococcus gordonii