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Viridans streptococcal carbohydrates and their salivary receptor proteins
Author(s) -
Khagi Simon,
Quinn Tim,
Herndon Betty
Publication year - 2008
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.22.1_supplement.860.11
Subject(s) - microbiology and biotechnology , virulence , saliva , titer , streptococcus , agglutination (biology) , bacterial adhesin , infective endocarditis , fetuin , streptococcus mutans , biology , glycoprotein , immunology , bacteria , medicine , antigen , antibody , biochemistry , genetics , gene
Streptococcal colonization of damaged heart surfaces in infective endocarditis depends on the recognition of host lectin‐receptors by bacterial glycoprotein. Our group has studied the viridans streptococcal glycoproteins of 30 bacteremic patient isolates both by carbo‐HPLC and by endocarditis production in the rat model. Two strains, endocarditis virulent Streptococcus#15 (Strep 15)and endocarditis negative #4 (Strep 4) were used to measure salivary receptor protein titer for the bacterial sugars. Tests were run on 16 samples (96 tests). Mixed saliva was stimulated by chewing sterile paraffin, collected on ice, sterile filtered and stored at −70C until serially diluted for in vitro agglutination with washed, killed streps 4 and 15, suspended at 0.6 absorbance. Triplicate twofold dilutions of each saliva sample were incubated 24 hr with each fixed streptococcus, and aggregation was scored both visually and microscopically. Individual patients showed an agglutination titer representing the subject's salivary mucins and platelet surface sialic acids, and ranged from 1:8 for strep 4 to 1:2048 for strep15 with young, healthy subjects and 1:2 and 1:4 in other subjects. Although salivary titer differed significantly between subjects, the ratio of virulent to non‐virulent titer was constant between individuals. These experiments suggest that host recognition of bacterial sugars relates more to the bacterial sugar (and its virulence?) than to individual differences in salivary target lectins. This concept, if shown in a larger population, may provide important insights into the pathogenesis of infective endocarditis induced by oral streptococci.