IDENTIFICATION & REGULATION OF STRESS RESPONSE GENES IN PATHOGENIC STREPTOCOCCI

这个子项目是许多研究子项目中的一个 由NIH/NCRR资助的中心赠款提供的资源。子项目和 研究者（PI）可能从另一个NIH来源获得了主要资金， 因此可以在其他CRISP条目中表示。所列机构为 研究中心，而研究中心不一定是研究者所在的机构。 变形链球菌被认为是龋病的主要病原体。S.变形杆菌也是感染性心内膜炎的重要病原体。这种微生物通过在牙齿表面形成多种多样的多物种生物膜（称为牙菌斑）来定居口腔。 这种病原体已经发展了多种机制来适应口腔的恶劣环境并在其中蓬勃发展。S.变形杆菌具有快速有效地响应各种环境通量的能力，包括严重的营养限制、pH和温度的波动以及氧化和渗透张力的变化。将细菌暴露于这些不利的环境中可以通过表达各种各样的基因来诱导应激耐受性反应，这些基因提供针对不同环境挑战的交叉保护。 胁迫耐受性基因受独特的转录调节因子群调节，包括交替的σ因子。 然而，与其他病原体不同，S.变形链球菌和其它链球菌不编码任何交替的σ因子。另一方面，在其他细菌中，一些在应激反应中起作用的基因也存在于S。变形链球菌基因组中，但其在胁迫和毒力中的作用尚未在变形链球菌中研究。变种人的详细信息 在这个项目中，我们计划确定生物体在口腔的恶劣环境中生存所必需的基因，以引起蛀牙。成功完成我们的研究可能会导致开发新的治疗方法来预防蛀牙。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. Streptococcus mutans is considered as the major etiological agent in dental caries. S. mutans is also an important agent of infective endocarditis. The organism colonizes the oral cavity by forming diverse, multispecies biofilms on the tooth surface, known as dental plaque. This pathogen has developed multiple mechanisms to adapt and to flourish in the hostile environment of the oral cavity. S. mutans has the ability to respond rapidly and efficiently to various environmental fluxes, including severe nutrient limitation, fluctuations in pH and temperature, and changes in oxidative and osmotic tensions. Exposure of bacteria to these adverse environments can induce a stress tolerance response through expression of a wide variety of genes that provides cross-protection against diverse environmental challenges. Stress tolerance genes are regulated by unique groups of transcriptional regulators, including alternate sigma factors. However, unlike other pathogens, S. mutans and other streptococci do not encode any alternate sigma factors. On the other hand, some genes that putatively function in stress responses in other bacteria are present in the S. mutans genome, but their role in stress and virulence has not been investigated in S. mutans in great detail. In this project, we plan to identify genes that are necessary for the organism to survive in the hostile environment of the oral cavity to cause tooth decay. Successful completion of our studies may lead to the development of novel therapeutic treatments for the prevention of tooth decay.