S. mutans: Its mutacin Antibiotic

变形链球菌是导致龋齿的主要病原体， 疾病在发达国家和发展中国家。大多数临床分离的S.变形菌产生 称为突变素的抗菌肽。突变素对广谱革兰氏阳性 细菌，包括病原体和口腔病原体。因此，S.变异人可能扮演一个 双重作用：它为生产菌株提供了竞争优势，在牙科领域占据主导地位。 牙菌斑，导致龋齿。另一方面，它可以保护人类宿主免受革兰氏阳性 细菌感染拟议的研究旨在研究遗传，生化和生物 本发明涉及突变蛋白生物发生和调节的多个方面，其方法如下：目的1，表征突变蛋白的生物发生和调节。 突变蛋白基因调控的反式作用因子。目的2，表征调节细胞凋亡的顺式作用因子， mutacin基因表达目的3，确定变蛋白分子的结构/功能， 通过基因工程改善变蛋白的性质。目的4，提高变霉素的生物合成， 改善发酵条件。拟议的研究将在两个方面产生重大影响。 首先是对现有抗生素的耐药性激增， 病原体，以及利用基因工程病原体进行生物恐怖袭击的威胁日益增加 对现有的所有抗生素都有抗药性这些威胁凸显了寻找 非常规抗生素，尚未产生耐药性。第二条战线是 了解S.变异人这些知识 将有助于设计有效的控制措施，以遏制S.牙齿变形菌 _laque。

Streptococcus mutans is the major etiologic agent responsible for dental caries, the most prevalent disease in the developed as well as developing countries. Most clinical isolates of S. mutans produce antimicrobial peptides called mutacins. Mutacins are active against a wide spectrum of gram-positive bacteria including pathogens and oral commensals. Thus, mutacin production by S. mutans may play a double role: it provides the producing strain with a competitive edge in gaining dominance in the dental plaque, leading to dental caries. On the other hand, it may protect the human host from gram-positive bacterial infections. The proposed research aims to study the genetic, biochemical and biological aspects of mutacin biogenesis and regulation with the following approaches: Aim 1, to characterize the trans-acting factors for mutacin gene regulation. Aim2, to characterize the cis-acting factors that regulate mutacin gene expression. Aim 3, to determine the structure/function of the mutacin molecule and improve mutacin's properties by genetic engineering. Aim 4, to enhance mutacin biosynthesis and improve fermentation conditions. The proposed research will have a significant impact on two fronts. The first is the alarming surge in resistance to the existing battery of antibiotics by emerging and existing pathogens, and the increasing threat of bioterrorist attack using genetically engineered pathogens resistant to all existing antibiotics. These threats underpin the importance and urgency of finding unconventional antibiotics, to which resistance has not been developed. The second front is understanding the mechanism of gene regulation for mutacin production in S. mutans. This knowledge will help design effective control measures to curb the growth and virulence of S. mutans in the dental _laque.