PR000280 (Project)

Description:Streptococcus mutans is capable of withstanding a variety of stressors encountered in the oral cavity. The ability to efficiently and rapidly adjust to the changing environment is essential for its pathogenic lifestyle. Oxidative stress is one of the most important environmental variables affecting the pathogenic potential of S. mutans, as high oxygen concentrations disfavor growth of S. mutans and other oral bacteria. In order to fulfill its role as a major constituent of cariogenic oral biofilms and sustain virulence, S. mutans must overcome oxidative stress. Oxidation sensing and response is a complex yet highly-regulated process, particularly because it is cross-regulated with other metabolic pathways, stress responses and virulence physiology. In addition, we previously showed that exposure of S. mutans to oxygen strongly inhibits biofilm formation and alters cell surface biogenesis, possibly through AtlA, a major autolysin of the organism. More recently, we have also shown that S. mutans Cid/Lrg system, potentially mediating cell lysis/death in a programmed fashion, uniquely leads a global readjustment in central metabolism and virulence processes, particularly in coping with oxidative stress. To this end, a targeted metabolomics approach will be employed to understand how these autolytic systems influence the metabolism of S. mutans, ultimately leading to a more complete appreciation of how S. mutans survives and persists in hostile host microenvironment.