Interactions of Streptococcus mutans Fimbria-Associated Surface Proteins with Salivary Components

Abstract

Streptococcus mutans has been implicated as the major causative agent of human dental caries. S. mutans binds to saliva-coated tooth surfaces, and previous studies suggested that fimbriae may play a role in the initial bacterial adherence to salivary components. The objectives of this study were to establish the ability of an S. mutans fimbria preparation to bind to saliva-coated surfaces and determine the specific salivary components that facilitate binding with fimbriae. Enzyme-linked immunosorbent assay (ELISA) established that the S. mutans fimbria preparation bound to components of whole saliva. Sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and Western blot techniques were used to separate components of whole saliva and determine fimbria binding. SDS-PAGE separated 15 major protein bands from saliva samples, and Western blot analysis indicated significant binding of the S. mutans fimbria preparation to a 52-kDa salivary protein. The major fimbria-binding salivary protein was isolated by preparative electrophoresis. The ability of the S. mutans fimbria preparation to bind to the purified salivary protein was confirmed by Western blot analysis and ELISA. Incubation of the purified salivary protein with the S. mutans fimbria preparation significantly neutralized binding of the salivary protein-fimbria complex to saliva-coated surfaces. The salivary protein, whole saliva, and commercial amylase reacted similarly with antiamylase antibody in immunoblots. A purified 65-kDa fimbrial protein was demonstrated to bind to both saliva and amylase. These data indicated that the S. mutans fimbria preparation and a purified fimbrial protein bound to whole-saliva-coated surfaces and that amylase is the major salivary component involved in the binding.

Effect of a propolis extract on Streptococcus mutans counts in vivo

“…Thus, a single bacterial species such as S. mutans can be present in the mouth in three different serotypes, i.e., serotypes C, E and F (Beihton, et al 2 , 1991, Dasanayake, et al 4 1995, Sarni, et al 21 , 1998, Zárate 24 , 1999, Shibata, et al 22 , 2003). Ray, et al 20 (1999) also demonstrated that host binding characteristics are as important as the characteristics of bacterial adhesion in the process of colonization. The authors suggested that salivary amylase may show the best binding to S. mutans .…”

Intranasal Immunization against Dental Caries with aStreptococcus mutans-Enriched Fimbrial Preparation

“…Our laboratory has been extensively involved in establishing the role S. mutans fimbriae play in adherence to and coloni-zation of the tooth surface by this bacterium and testing if antibodies against S. mutans fimbria components reduce the adherence of S. mutans to the tooth surface, thereby inhibiting the development of primary dental caries (6,23,24). Cariesfree (CF) adult individuals have higher levels of salivary IgA antibodies to fimbria-enriched preparation of S. mutans than do caries-active (CA) individuals (7).…”

“…These results suggest that the differences between the composition of S. mutans fimbriae in isolates from CA and CF subjects may play an important role in the virulence of this microorganism in dental caries. Our laboratory has also reported that a 52-kDa salivary protein, identified as amylase, is the major protein in human saliva which binds S. mutans fimbria-enriched preparations (24). In addition, results obtained with an in vitro bacterial model demonstrated the efficacy of antibodies against S. mutans fimbria-enriched surface components in decreasing caries development (6).…”

Enhanced adhesion of Streptococcus mutans to hydroxyapatite after exposure to saliva

“…Most studies focus on the adhesion of oral bacteria to salivary agglutinin (SAG) that is adsorbed to the oral pellicle on tooth surfaces . Additionally, it has been shown that the characteristics of biofilm formation by S. mutans depend on many parameters like for example oxygen content or the presence of specific enzymes in the bacterial cell .…”

“…Next to other constituents, the salivary sucrose content increases adhesion to surfaces significantly and is also a key factor in the production of biofilms . Furthermore, by using genetically modified S. mutans cells, the function of many proteins in adhesion processes and biofilm formation on SAG was identified …”