Virulence Factors of Streptococcus mutans Related to Dental Caries

Abstract

Streptococcus mutans (S. mutans) has important virulence factors related to theetiology and pathogenesis of dental caries. Through mechanism of adhesion to asolid surface, S. mutans is able to colonize the oral cavity and form dental biofilm,which is composed of a matrix of exopolysaccharides that affect the physical andbiochemical structure of the biofilm. The additional properties that allow S. mutansto colonize the oral cavity include the generation of acid (acidogenicity), theinteraction with other bacterial species colonizing this ecosystem and the ability tosurvive in an acidic environment. In addition, these microorganisms can tolerate theacidic environment (aciduricity) due, at least in part, to the ATPases located in theplasma membrane responsible for the extrusion of the cytoplasmic proton. Changesin environmental pH can modify the fatty acid and proteins composition of theplasma membrane of S. mutans, inducing the alteration of its permeability. Thedifferent dental surfaces or biofilms can affect the lipid composition of the bacterialmembrane by altering the virulence factors of S. mutans, such as acid survival andATPase activity.