The role of fructans on dental biofilm formation by Streptococcus sobrinus, Streptococcus mutans, Streptococcus gordonii and Actinomyces viscosus

Dental plaque biofilm plays a pivotal role in the progression of dental dis eases. Polysaccharides are of great importance in the ecology of the dental biofilm. We studied the effect of fructans, glucans and a mixture of both fructans and glucans, synthesized in situ by immobilized fructosyltransfera se or glucosyltransferase, on the adhesion of Streptococcus sobrinus. Strep tococcus mutans, Streptococcus gordonii and Actinomyces viscosus to hydroxy apatite beads coated with human saliva (sHA). The adhesion of A. viscosus t o sHA was found to be fructan-dependent. Adhesion of both S. sobrinus and S . mutans was found to be mediated mainly by glucans. while the adhesion of S. gordonii was found to be both glucan- and fructan-dependent. Treatment w ith fructanase prior to A. viscosus; adhesion resulted in a significant red uction in adhesion to sHA. while adhesion of S. sobrinus, S. mutans and S. gordonii was slightly influenced by fructanase treatment. Treatment with fr uctanase after adhesion of S. gordonii to sHA resulted in a significant red uction in their adhesion to sHA. Our results show that fructans may play a role in the adhesion and colonization of several cariogenic bacteria to sHA , thus contributing to the formation of dental plaque biofilm. (C) 2001 Fed eration of European Microbiological Societies. Published by Elsevier Scienc e B.V. All rights reserved.