The group studies on the structural and functional roles of the bacterial surfaces in the infections.

该项目成员的工作可分为三个不同的实验小组，即关于定植因子的小组、关于细胞表面物质的生物活性的小组和关于侵袭机制的小组。这三年的实验结果总结如下：定殖因子群：从几种细菌中分离、纯化菌毛定殖因子，并对其化学成分进行分析。在大肠杆菌中分离到一种新的菌毛，命名为CFA III，并对其进行了鉴定。在粘质链霉菌中克隆了mr菌毛基因，并在大肠杆菌中进行了表达。DNA序列分析表明，该菌毛亚基N-末端的氨基酸序列与其他形态难以区分的菌毛几乎相同。作为霍乱弧菌的定植因子，血凝集作用被证明在人的肠粘膜上的粘附物上。Biolo…群表面活性：作为细胞壁成分的生物效应之一，MDP是一种胞壁二肽，具有对抗内毒素的毒性作用。经MDP处理的小鼠在血管内注射少量脂多糖时出现过敏反应。这一现象的发生机制尚待阐明。利用凝固酶和蛋白A这两种细胞壁成分的缺失突变体，研究了凝固酶和蛋白A在金黄色葡萄球菌感染中的作用。凝固酶与该菌的毒力关系更为密切。侵袭性群：用于分析志贺氏菌的侵袭性。抗Sh.细胞表面单抗。松内被生产出来了。其中一些克隆只与该细菌的I期菌株反应。这些抗体可能有助于分析该细菌的侵袭因素。对梭状芽孢杆菌(Clostridium spp.)细胞表面的保护性屏障--规则表面排列进行了形态和生物学研究。较少

The works of the member in this project can be categorized into three different experimental groups, the group on the colonization factor, on the biological activity of cell surface materiales and on the invasing mechanisms. The experimental results of these groups in these three years are summerized as follow.The group of the colonization factors: From several species of bacteria fimbrial colonization factors were isolated, purified and the chemical compositions were analysed. In E. coli a new fimbriae called CFA III was isolated and ch aracterized. In S.marcescens a gene for MR fimbria was cloned and expressed in E. coli. Its DNA sequence analysis showed that the sequence of amino acids at the N-terminal portion of the fimbrial subunit was almost the same as those of the other morphologically indistinguishable fimbria of E. coli. As a colonization factor for Vibrio cholerae the roles of hemagglution on the adherece on the intestinal mucosa of human was demonstrated.The group of biolo … More gical activity of suface materiales: As one of the biological effects of the cell wall components, MDP,a muramyl dipeptide, exserted a stimulating effect against the toxic effect of the endotoxin. Mice pretreated with MDP showed an anaphylactic reaction when a small amount of LPS was administered intravacularly. The mechanisms of this phenomenon is remained to be elucidated. The role of coagulase and protein A on the infection of Staphylococcus aureus are investigate using the deficient mutant of these cell wall components. Coagulase is more closely related to the virulence of this bacteria.The group of the invasiveness: For the analysis of the invasivenes of Shigella spp. the monoclonal antibodies for the cell surface of Sh. sonnei was produced. Some of the clones were reacted only with phase I strains of this bacteria. These antibodies might be usefull for the anlysis of invasive factors of this bacteria. The morphological and biological studies of the regular surface array ,an protective barrier on the cell surface, were carried out on Clostridium spp.. Less