MOLECULAR MECHANISM OF VIRULENT FACTOR PRODUCTION IN GRAM POSITIVE BACTERIA

1.研究革兰氏阳性菌产生毒素和其他毒力因子的分子机制，为革兰氏阳性菌产生多种致病毒力因子的感染控制提供新的手段。毒素和酶的产生受环境因素的调节，毒素(α，β，γ，ε，θ等，产气荚膜梭菌中的α，β，γ，ε，θ等，艰难梭菌中的A和B毒素，金黄色葡萄球菌中的可溶性和表面毒力因子)的产生受生长阶段、细菌密度/种群(Quoram传感)、碳源和营养底物、细胞间因子(如信息素)的调节。在高温、极端pH条件下，在重金属、抗生素的存在下，细菌诱导了包括毒力基因在内的应激反应基因。感知环境因子的特定受体。每种细菌都有特定的环境因子受体，即I…更重要的是，最常见的是双组分系统的传感器组件。在产气荚膜梭菌中，已经确定了几个系统，其中一个用于激活，另一个用于抑制毒素的产生。在金黄色葡萄球菌中，锌、碱性、β-内酰胺类药物的受体主要被鉴定出来。细菌中的信息传递网络。随着对产气荚膜梭菌和葡萄球菌的基因组分析，细菌中信息传递系统从受体到效应产物的分子基础已经被阐明，它是一个与全球调控系统相联系的序列“分子网络”。这一信息对今后抗生素的设计有一定的参考价值。在转录、翻译、翻译后和细胞分泌水平上的调控。在这些结果的基础上，毒力因子产生的分子网络得到了更清楚的证实，这一结果将有助于那些正在寻找更具体有效的抗感染药物和预防措施的人。较少

Molecular mechanism of production of toxins and the other virulence factors in Gram positive bacteria has been investigated to develop novel infection control measures for Gram positive bacteria which produce variety of virulence factors to cause desease in human.1. The production of toxins and enzymes was regulated by the environmental factors.The production of toxins (α, β, γ, ε, θ, etc, in Clostridium perfringens, toxin A and B in C. difficile, soluble and surface virulent factors in Staphylococcus aureus) was regulated by the growth phase, density/population of bacteria (quoram sensing), carbon source and nutritional substrate, inter-cellular factors (like pheromon). Under the stressful condition for bacteria, ie ; heat, extream pH, in the presence of heavy metals, antibiotics, the bacteria induced the stress responsible genes including virulent genes.2. Specific receptors for sensing environmental factors.Each bacterium has a certain specific receptors for environmental factors, i … More .e., the most common one is the sensor component of two-component system. In C. perfringens, several systems have been identified, among which one for activation and the other for inhibition of production of toxin. In S. aureus, the receptors for zinc, alkaline, β-lactams were mostly identified.3. Information transmitting network in bacteria.Along with genomic analysis of C. perfringens, and that of Staphylococci, molecular basis of information transmitting system in bacteria has been made clear from receptor to effecter production as an sequential "molecular net work" with global regulatory system. This information is useful for the design of antibiotics in future.4. Regulation at the level of transcription, translation, post translation and secretion from cell.On basing upon those results, molecular net work of virulent factor production has been more clearly confirmed and the results will contribute to those who are looking for more specific effective anti-infection drugs and preventive measures. Less