Glycan-binding specificities of Streptococcus mutans and Streptococcus sobrinus lectin-like adhesins

Abstract

Since the adhesion of bacteria to the tooth surface is a prerequisite for dental plaque and subsequent caries development, a promising caries preventive strategy could be to block the lectin-glycan-mediated adherence of cariogenic bacteria. The aim of the study was to evaluate potential differences in glycan-binding specificities of two Streptococcus mutans strains (DSM 20523 and DSM 6178) and Streptococcus sobrinus (DSM 20381). A competitive enzyme-linked lectin-binding assay was used to identify the binding specificities of isolated bacterial surface lectins. Blotting of the microbial proteins on neoglycoprotein-coated PVP membranes enabled a qualitative protein analysis of all specific bacterial lectins. Different glycan-binding sites could be identified for the S. mutans strains in comparison to S. sobrinus. An earlier reported glycan-binding specificity for terminal galactose residues could be confirmed for the S. mutans strains. For the S. sobrinus strain, more than one glycan-binding specificity could be found (oligomannose and terminal sialyl residues). Each of the tested strains showed more than one surface lectin responsible for the specific lectin-binding with varying molecular weight (S. mutans, 90/155 kDa and S. sobrinus, 35/45 kDa). The established experimental setup could be used as future standard procedure for the identification of bacterial lectin-derived binding specificities. The findings from this study might serve as basis for the design of an individual 'glycan cocktail' for the competitive inhibition of lectin-mediated adhesion of mutans streptococci to oral surfaces.

Bacterial reduction in sealed caries lesions is strain- and material-specific

“…This observation may be due to the strain-specific differences in cell aggregation and cell adhesion, which among other factors depend on the composition of the extracellular matrix produced by the bacteria. The extracellular matrix of SS is formed by homo-exopolysaccharides, mainly mutan, which results in a strong binding to surfaces and between bacterial cells 23 – 25 . In contrast, LR uses hetero-exopolysaccharides in order to build up a matrix 23 , 24 .…”

Tea Polyphenols Synergistic Enhancement of Antibacterial Effects of NaF on the Cultured Streptococcus mutans

“…Streptococcus mutans is recognized as a cause of dental caries. It can degrade sugar into glucose which is polymerized into glucan [3,4]. Dental plaque containing 70 % of S. mutans and glucan was performed on the enamel surface.…”

Polymers for binding of the gram-positive oral pathogen Streptococcus mutans

“…A prerequisite for this process is the adherence of bacteria to the acquired pellicle and subsequent development of oral biofilm, which often occurs through interaction between bacterial lectins and host glycosylated (macro)molecules. [ 25 ] Host defence mechanisms include the production of soluble glycoconjugates in saliva, which can offer a first line of defence by competitively blocking bacterial adhesion proteins. Thus, biomimetic approaches which include analogous anti-adhesion glycosylated molecules could be potentially utilized to modulate the virulence of oral pathogens.…”

“…mutans to bind to glycans with galactosyl residues has been described in several studies. [ 25 – 28 ] Reduction of salivary galactosylated O –glycans has been associated with increased caries susceptibility in children,[ 29 ] whilst early work by Nagata et. al.…”