Keynote Address: Streptococcus: Pillar of the Community

Streptococci have been a focus in oral microbiology research for over 60 years, and their role in the etiology of dental caries is well-documented. It is also evident that several species of non-cariogenic oral streptococci act as pillars for microbial community development at different oral cavity sites. The streptococci orchestrate physical, chemical and metabolic associations with other microorganisms facilitating biofilm formation. Unique streptococcal adhesion factors recognize other microbial and host cell receptors, and diffusible signaling molecules modulate nearby cellular activities. The structures and functions of some important Streptococcus surface molecules have now been at least partly resolved. Each reveals novel features that begin to explain the extraordinary adaptability of streptococci to life in the human body. Streptococcal metabolites have also been identified that regulate architecture and composition of oral plaque communities. Multiple new oral microbial phylotypes have recently been identified, but their activities in the community are currently vague. Precisely how the streptococci might influence and interact with these microorganisms is an avenue for future research.