Effect of Neuraminidase on the Adherence to Salivary Pellicle of Streptococcus sanguis and Streptococcus mitis

Abstract

Neuraminidase-sensitive adherence to experimental salivary pellicles was studied using eight strains of Streptococcus sanguis and five strains of Streptococcus mitis. Approximately 60% of the strains of each species showed significantly lower adherence to neuraminidase-treated versus untreated saliva-coated hydroxyapatite. In addition, the adherence of several of these streptococcal strains to saliva-coated hydroxyapatite and neuraminidase-treated saliva-coated hydroxyapatite was inhibited using galactose and N-acetyl-D-galactosamine. Results from these studies suggested that several salivary receptors mediate adherence of these species.

Saliva-Bacterium Interactions in Oral Microbial Ecology

“…This interaction is exquisitely stereospecific; the hemagglutination of red blood cells by streptococci is best inhibited by the trisaccharide Neuct2,3Gal11,3GalNAc (Murray et al, 1986;Murray etal., 1982). These data are consistent with the finding that the adhesion of these streptococci to sHA appears to involve sialic acid (Cowan et al, 1987b;Gibbons et al, 1985a;Liljemark et al, 1989). It should also be pointed out that other oral bacterial lectins that would be expected to interact with salivary glycoproteins have been identified, including galactose-specific lectins from E. corrodens (Yamazaki et al, 1988) and F. nucleatumn (Murray et al, 1988), and a Capnocvtophaga och racea rhamnose-and fucosespecific lectin (Weiss et al, 1987).…”

“…Several observations can be cited in support of this concept. Neuraminidase-treated salivary pellicles bind fewer S. sanguis cells but have more exposed galactose residues to serve as receptors for the adhesion of bacteria having galactose-specific adhesins, such as Actinomyces (Cowan et al, 1987b;Gibbons et al, 1985a;Liljemark et al, 1989). Other bacteria such as S. sanguis produce a protease that specifically cleaves IgA at the hinge region (Kilian et al, 1983;Mulks and Plaut, 1978;Plaut et al, 1974;Reinholdt and Kilian, 1987), which may inactivate the immunoglobulins.…”

“…In the case of the viridans ("S. sanguis") group, the evidence to date suggests several bacterial surface components, or "adhesins", are involved in this process. A highaffinity sialic acid lectin (Cowan et al, 1987b;Gibbons etal., 1985a;Gibbons etal., 1985b;Liljemark et al, 1989) and a low-affinity adhesin that binds hydrophobic or pH-sensitive pellicle receptors (Morris and McBride, 1984) have been described. Kinetic analysis of the binding of S. sanguis to sHA suggests a mechanism whereby bacteria are initially reversibly found to the pellicle but with time become more firmly bound (Cowan et al, 1986).…”

“…The adhesion of S. mutans and certain strains of S. sanguis to pellicle appears to involve fucoseor galactose-containing receptors (Gibbons and Etherden, 1982;Liljemark et al, 1989). Galactose, which is the penultimate sugar found on glycoprotein oligosaccharides , may be exposed following the removal of sialic acid by neuraminidase-producing organisms (Costello et al, 1979;Ellen et al, 1980;Murray et al, 1984).…”

“…For example, A. viscosus and S. sanguis both produce nuraminidase, an enzyme that removes terminal sialic acid from glycoproteins (Costello et al, 1979;Ellen et al, 1980;Murray et al, 1984). It is presumed that the removal of sialic acid from penultimate galactosyl residues of glycoproteins or glycolipids in saliva or on surface pellicles would expose galactose residues that may then serve as receptors for galactose binding bacteria Liljemark et al, 1989). Indeed, it has been shown that the sialic acid content of superficial epithelial cells is diminished in subjects with poor oral hygiene .…”