title: Protein antigen in serotype k Streptococcus mutans clinical isolates.
abstract: Streptococcus mutans, a major pathogen of dental caries and infective endocarditis, is classified into serotypes c, e, f, and k, with serotype k strains recently reported to be frequently detected in persons with infective endocarditis. Thus, we hypothesized that common properties associated with infective endocarditis are present in those strains. Fifty-six oral S. mutans strains, including 11 serotype k strains, were analyzed. Western blotting analysis revealed expression of the 3 types of glucosyltransferases in all strains, while expression of the approximately 190-kDa cell-surface protein (PA) was absent in 12 strains, among which the prevalence of serotype k (7/12) was significantly high. Furthermore, cellular hydrophobicity and phagocytosis susceptibility were lower in the group of serotype k strains. These results indicate that the absence of PA expression, low cellular hydrophobicity, and phagocytosis susceptibility are common bacterial properties associated with serotype k strains, which may be associated with virulence for infective endocarditis.
authors.affiliation: Department of Pediatric Dentistry, Osaka University Graduate School of Dentistry, 1-8 Yamada-oka, Suita, Osaka 565-0871, Japan.
authors.forename: K
authors.initials: K
authors.lastname: Nakano
authors.forename: R
authors.initials: R
authors.lastname: Nomura
authors.forename: H
authors.initials: H
authors.lastname: Nemoto
authors.forename: J
authors.initials: J
authors.lastname: Lapirattanakul
authors.forename: N
authors.initials: N
authors.lastname: Taniguchi
authors.forename: L
authors.initials: L
authors.lastname: Grönroos
authors.forename: S
authors.initials: S
authors.lastname: Alaluusua
authors.forename: T
authors.initials: T
authors.lastname: Ooshima
mesh_terms: D000595:Amino Acid Sequence; D000942:Antigens, Bacterial / Q000737:chemistry*; D001426:Bacterial Proteins / Q000737:chemistry; D004697:Endocarditis, Bacterial / Q000276:immunology / Q000382:microbiology*; D005964:Glucosyltransferases / Q000737:chemistry; D057927:Hydrophobic and Hydrophilic Interactions; D008565:Membrane Proteins / Q000737:chemistry*; D008970:Molecular Weight; D010587:Phagocytosis; D012703:Serotyping; D013045:Species Specificity; D013295:Streptococcus mutans / Q000145:classification* / Q000276:immunology / Q000472:pathogenicity*; D014774:Virulence
chemical_list: D000942:Antigens, Bacterial; D001426:Bacterial Proteins; D008565:Membrane Proteins; D005964:Glucosyltransferases