【作者】 郭会田；

【导师】 郭定宗；

【作者基本信息】 华中农业大学 ， 临床兽医学， 2008， 硕士

【摘要】 猪链球菌(Streptococcus suis)是一种引起猪败血症、脑膜炎症、心内膜炎和关节炎的主要病原,也是一种重要的人畜共患病病原。以前我国发现的病原主要是马链球菌兽疫亚种。20世纪90年代以来,其他种类的猪链球菌病被不断报道,其中尤以猪链球菌2型感染的发生较多,曾在局部地区引起流行。细菌对宿主组织的黏附是细菌定殖和发展成感染性疾病的第一步,可最终导致宿主菌血症、败血症甚至脑膜炎。研究证明,猪链球菌能黏附很多种宿主细胞,如上皮细胞、吞噬细胞、脑微血管内皮细胞。血清白蛋白可与人的C群和G群链球菌黏附,并可以增强细菌毒力、增加细菌的生长速度。有研究表明血清白蛋白与细菌黏附后可以为其提供营养。本试验中,我们研究了马链球菌兽疫亚种和猪链球菌2型基本生物学特性的差异;制备了两种链球菌的多克隆抗体,并检测其抗体滴度皆为1:512;采用ELISA的方法研究了两种链球菌与血清白蛋白的黏附差异。结果表明:两种链球菌生物学特性存在很大差异;两种链球菌与血清白蛋白的黏附力受各种因素的影响;不同动物的血清白蛋白与细菌的黏附力不同;两种链球菌黏附血清白蛋白的配基很可能都是蛋白质性质的;马链球菌兽疫亚种与猪链球菌2型相比,前者同血清白蛋白的黏附力更强。为以后进一步研究两种链球菌的致病机理奠定基础,并提供理论依据。本试验对两种链球菌进行了多方面的比较分析,为以后鉴别两种链球菌提供了理论和技术支持;用间接ELISA法检测两种链球菌与血清白蛋白的黏附,是本试验的主要创新点,可为以后类似研究提供简便、快捷的试验技术。更多还原

【Abstract】 Streptococcus suis is an important zoonotic pathogen causing mainly septicaemia, meningitis, endocarditis and endocarditis. In china, Streptococcus equi subsp.zooepidemicus had been identified as a major cause of contagious disease in pigs several decades ago. This situation has been changing from 1990, more and more other serotypes of Streptococcus suis have been isolated from diseased animals, serotype 2 has been considered as the most frequently isolated serotype and caused prevalence in some areas.Bacteria adhering to the tissular of host is the first step of colonization and developing infectious diseases. Sooner or later, it will develop bacteremia, sometimes septicemia, and finally meningitis. A recent study suggested that S. suis proteins have a role as adhesins to host cell surfaces, such as epithelial cells, phagocytes and brain microvascular endothelial cells.As one of the more common plasma proteins, serum albumin is bound to the surface of human group C and G streptococci, presumably in support of bacterial virulence. In vitro studies have shown that albumin-binding bacterial strains exhibit increased growth rates in the presence of human serum albumin compared to those which were grown in the absence the ligand—possibly benefiting from access to nutrients bound by the albumin.The differences of essential biology characteristic between Streptococcus suis type 2 and Streptococcus equi subsp. zooepidemicus were compared. The results showed that they are very different. The polyclonal antibodies of Streptococcus suis type 2 and Streptococcus equi subsp. zooepidemicus were prepared, and their titres were both 1:512. The bindings of serum albumin to Streptococcus suis type 2 and Streptococcus equi subsp. zooepidemicus were identified by enzyme-labeled immunosorbent assay. The results suggested that there are many agents can impact the bindings of serum albumin to Streptococcus suis type 2 and Streptococcus equi subsp. zooepidemicus, the bindings of serum albumin from different animals to Streptococcus suis type 2 and Streptococcus equi subsp. zooepidemicus are different, the adhesins of Streptococcus suis type 2 and Streptococcus equi subsp. zooepidemicus are both proteinaceous, and there are more adhesions binding to serum albumin on Streptococcus equi subsp. zooepidemicus surface than that on Streptococcus suis type 2 surface.The differences between Streptococcus suis type 2 and Streptococcus equi subsp. zooepidemicus can be used to distinguish them. Identifying the bindings of serum albumin to Streptococcus suis type 2 and Streptococcus equi subsp.zooepidemicus by enzyme-labeled immunosorbent assay is considered to be the point of innovation of this experiment.更多还原