Molecular Genetic Analysis of S. mutans Cariogenicity

本申请将集中于表征变形链球菌中参与菌斑形成和生长的必需基因。 利用体外模型系统，将在S.变异株GS5。 此外，两个基因最近在我们的实验室确定为重要的这个过程中，comB和sgp，将进一步分析其各自的作用，在生物膜形成。 涉及这两个基因的潜在信号转导机制将使用基因表达技术进行研究。此外，将评估玉米系统在相对于基因转移和生物膜形成的种内群体感应中的作用。本实验室开发的一种新的方法，以确定在任何可转化的微生物中的必需基因将被用来确定在S。这种基于反义RNA诱导的方法具有鉴定靶位点以开发特异性防龋剂的潜力。此外，这种方法可以很容易地用于鉴定普遍存在的细菌中的必需基因，用于开发广谱抗菌剂。本研究的目的是提供关于沙门氏菌主要毒力因子的新信息。这些变异体可以用来设计新的防龋策略。

This application will focus on characterizing essential genes in Streptococcus mutans involved in plaque formation and growth. Utilizing model in vitro systems, genes essential for biofilm formation will be identified and characterized following insertion duplication mutagenisis of S. mutans GS5. In addition, two genes recently identified in our laboratory as important for this process, comB and sgp, will be further analyzed as to their respective roles in biofilm formation. Potential signal transduction mechanisms involving both genes will be investigated using gene expression techniques in addition, the role of the com system in inraspecies quorum sensing relative to gene transfer and biofilm formation will be assessed. A novel approach developed in this laboratory to identify essential genes in any transformable microorganism will be utilized to identify such genes in S. mutans this approach, based upon antisense RNA induction, has the potential of identifying target sites for the development of specificanticaries agents. In addition, this approach can be readily used to identify essential genes in ubiquitous bacteria for development of broad- spectrum antibacterial agents. The specific aims of this proposal are designed to provide new information regarding essential virulence factors of S. mutans which could be exploited to design novel anticaries strategies.