Roles of Oral Bacteria in Cardiovascular Diseases — From Molecular Mechanisms to Clinical Cases: Cell-Surface Structures of Novel Serotype k Streptococcus mutans Strains and Their Correlation to Virulence

Kazuhiko Nakano, Ryota Nomura, Michiyo Matsumoto, Takashi Ooshima
2010 Journal of Pharmacological Sciences  
Streptococcus mutans is generally known as a pathogen of dental caries, and it is also considered to cause bacteremia and infective endocarditis (IE). S. mutans was previously classified into 3 serotypes, c, e, and f , due to the different chemical compositions of the serotype-specific polysaccharides, which are composed of a rhamnose backbone and glucose side chains. We recently designated non-c / e / f serotype S. mutans strains as novel serotype k , which is characterized by a drastic
more » ... on in the amount of the glucose side chain. A common biological feature of novel serotype-k strains is a lower level of cariogenicity due to alterations of several major cell surface protein antigens. As for virulence in blood, these strains survive in blood for a longer duration due to lower antigenicity, while the detection rate of all strains carrying the gene encoding collagen-binding adhesin has been shown to be high. Furthermore, molecular biological analyses of infected heart valve specimens obtained from IE patients revealed a high detection rate of serotype-k S. mutans . Together, these findings suggest that serotype-k S. mutans strains show low cariogenicity but high virulence in blood as compared to the other serotypes, due to alterations of several cell surface structures.
doi:10.1254/jphs.09r24fm pmid:20501965 fatcat:i6qmuinbijhftf6wipagraao64