Role of Two-component System of Streptococcus mutans in the Adaptive Response to the Oral Environment

Biofilm is a colony-like aggregate consisting of microorganisms and polysaccharide (glycocalyx) that are produced by microorganisms and adhere to solid surfaces. In the oral cavity, biofilm, called dental plaque, is known as a virulence factor for dental caries. Biofilm is formed and adapts to various environmental factors in the oral cavity. Streptococcus mutans, a cariogenic bacteria, plays an important role in biofilm formation. In this study, we focused on a bacterial two-component system (TCS) as an environmental adaptation factor in S. mutans. We comprehensively evaluated the involvement of TCS in response to various factors associated with the oral cavity using 14 TCS deletion mutants of S. mutans. Furthermore, we evaluated the expression of each TCS in sucrose-dependent biofilm cells of S. mutans. Our findings suggested that multiple TCS play important roles promoting in resistance to environmental stresses and the formation of biofilm.