ADHESIVE PROPERTIES OF VIRIDANS STREPTOCCOCAL SPECIES

Seventy-one strains of viridans streptococci, classified as Streptococ cus sanguis, S. gordonii, S. oralis, S. mitis or S. anginosus by a rev ised taxonomic scheme, were characterized and compared by their specif ic adhesive properties. The frequency of bacterial adhesion to saliva- coated hydroxyapatite (SHA) was greater among strains of S. sanguis, S . gordonii and S. oralis than among those of S. mitis and S. anginosus . Similarly, the expression of sialic acid reactive adhesins, detected by neuraminidase sensitive bacterial haemagglutination, was noted mor e frequently with strains of S. sanguis (19 of 21), S. gordonii (14 of 16) and S. oralis (8 of 11) than those of S. mitis (2 of 12) and S. a nginosus (0 of 11). Most strains of S. gordonii (14 of 16) and S. oral is (7 of 11) also aggregated acidic proline rich protein-coated latex beads, but this activity was observed rarely with strains of S. sangui s (2 of 21), & mitis (1 of 12) and & anginosus (0 of 11). Strains of S . anginosus (6 of 11) participated in lactose resistant coaggregations with actinomyces in coaggregation groups A (e.g. Actinomyces viscosus T14V-J1) and B (e.g. A. naeslundii WVU45). Lactose resistant coaggreg ations were also observed between strains of & gordonii (9 of 16) and actinomyces in coaggregation group A. Lactose sensitive coaggregations occurred between actinomyces and each of 11 S. oralis strains but les s frequently with strains of S. sanguis (6 of 21), & gordonii (3 of 16 ), S. mitis (3 of 12) and S. anginosus (1 of 11). Certain streptococca l strains with receptors for the lactose sensitive lectins of actinomy ces, including 9 of 11 S. oralis, also coaggregated frequently with st rains of either S. sanguis (10 of 21) or S. gordonii (9 of 16). Furthe r studies with representatives of these latter three streptococcal spe cies suggested that the streptococci with receptors for the GalNAc sen sitive lectins of S. sanguis and S. gordonii were those with GalNAcbet a1 --> 3Gal- rather than Galbeta1 --> 3GalNAc-containing cell wall pol ysaccharides.