Specificity of salivary-bacterial interactions: role of terminal sialic acid residues in the interaction of salivary glycoproteins with Streptococcus sanguis and Streptococcus mutans

Abstract

Four highly purified salivary glycoproteins were used to study salivary-bacterial interactions. One pair of glycoproteins was mucin-like in composition, whereas the second pair was not. By an agglutination assay, it was found that only the mucin-glycoproteins agglutinated Streptococcus sanguis and S. mutans. Removal of sialic acid from these molecules resulted in a loss of agglutination of S. sanguis but not of S. mutans. The agglutination phenomenon was shown to require a salivary macromolecule of at least 150,000 daltons.

Glycosylation Pattern and Cell Attachment‐Inhibiting Property of Human Salivary Mucins

“…Involvement of sialic acid in specific receptor-ligand-like bacterial-mucin interactions during microbial colonization of oral surfaces is well known. 33,34 Present observations call for further more detailed studies of the role of sialic acid and sulphate residues in the mechanisms of inhibition of eukaryotic cell attachment by high molecular weight salivary mucin. While there is a possibility that heterotypic complexing of other low molecular weight proteins with Muc might be involved in the effects observed above, this appears very unlikely because of the use of highly dissociative conditions in the preparation of Muc in the present investigation.…”

Actinomyces viscosus and Actinomyces naeslundii agglutinins in human saliva

“…Non-imtnunoglobulin streptococcal agglutinins are known to be salivary glycoproteins, often of high molecular weight. Some of their agglutinating activities have been proposed to be mediated via the interaction of sugar end groups with lectin-like ligands on the bacterial cells (26)(27)(28). Both A. viscosus and A. naeslundii contain surface ligands with lectin-like affmity for P-Gal (4,5,29).…”

Purification and characterization of Eikenella corrodens aggregating factor from submandibularsublingual saliva

“…Saliva-mediated aggregation may function in vivo by causing adherence of the bacteria to oral tissues or to dissimilar bacteria (1,29,(31)(32)(33). Alternatively, this activity may function in vivo by aggregating bacteria into masses, thereby allowing easier removal from the oral cavity by swallowing or flushing actions (32,34).…”

“…The salivary molecules responsible for bacterial aggregation have been described by several groups (27,28,(33)(34)(35)(36)(37). It is not clear at the present time whether there is a single molecular species, a group of closely related molecules, or a large group of diverse substances that are responsible for salivamediated bacterial aggregation.…”