The virulence of Streptococcus mutans and the ability to form biofilms

Abstract

In some diseases, a very important role is played by the ability of bacteria to form multi-dimensional complex structure known as biofilm. The most common disease of the oral cavity, known as dental caries, is a top leader. Streptococcus mutans, one of the many etiological factors of dental caries, is a microorganism which is able to acquire new properties allowing for the expression of pathogenicity determinants determining its virulence in specific environmental conditions. Through the mechanism of adhesion to a solid surface, S. mutans is capable of colonizing the oral cavity and also of forming bacterial biofilm. Additional properties enabling S. mutans to colonize the oral cavity include the ability to survive in an acidic environment and specific interaction with other microorganisms colonizing this ecosystem. This review is an attempt to establish which characteristics associated with biofilm formation—virulence determinants of S. mutans—are responsible for the development of dental caries. In order to extend the knowledge of the nature of Streptococcus infections, an attempt to face the following problems will be made: Biofilm formation as a complex process of protein–bacterium interaction. To what extent do microorganisms of the cariogenic flora exemplified by S. mutans differ in virulence determinants “expression” from microorganisms of physiological flora? How does the environment of the oral cavity and its microorganisms affect the biofilm formation of dominant species? How do selected inhibitors affect the biofilm formation of cariogenic microorganisms?

Comparison of biofilm formation and migration of Streptococcus mutans on tooth roots and titanium miniscrews

“…mutans mainly create water‐insoluble glucan that will form a semisolid solid polysaccharide to cover the bacteria cell (Koo et al, 2010; Mattos‐Graner et al, 2000); which corresponds to the result from SEM images, in which bacteria cells can be hardly seen (Figure 3a–d). The extracellular polysaccharide forms the gelatinous bulk structure of the biofilm and protects the bacteria from harmful environmental conditions (Bowen & Koo, 2011; Krzyściak, Jurczak, Kościelniak, Bystrowska, & Skalniak, 2014; Welin‐Neilands & Svensäter, 2007). Nutrients are lacking below the gel interface with the media, and this starves S .…”

Effects of Arginine on Streptococcus mutans Growth, Virulence Gene Expression, and Stress Tolerance

“…Glucans are the key matrix components enabling S. mutans organisms to adhere to each other and to the tooth surfaces. Each of the three GTFs plays roles in the production of glucans from sucrose and in the virulence of dental plaque biofilm (7,42). The basis for the observed effects of arginine on biofilm architecture in these model systems is undoubtedly complex and may involve the physicochemical properties of arginine itself.…”

Two-component signal transduction systems in oral bacteria

“…Clinical, animal, biochemical, genetic, and molecular studies on S. mutans , the major species affecting host-biofilm homeostasis during caries development, revealed a panel of virulence genes for the synthesis of highly stable water-insoluble glucan from sucrose ( gtfB , gtfC ) and other exopolysaccharides ( ftf , gtfD , epsC ), for bacterial binding to these polymers ( gbpA , gbpB, gbpC ), and for production and tolerance to acids from fermentable sugars and other stresses (including multiple metabolic and stress response genes), as addressed in several reviews [8,9,92–94]. Some of these gene functions are also associated with the ability of S. mutans to avoid host immune functions in systemic infections [95].…”