Studies on proteases and biofilm formation: two potential critical factors in the pathogenesis of Streptococcus suis

猪链球菌是世界范围内一种主要的猪病原体，通过呼吸道传播，并在猪的腭扁桃体上定植。这种病原体引起的主要感染包括败血症、脑膜炎和心内膜炎。这些细菌感染给加拿大养猪业造成了重大的经济损失。猪链球菌入侵和感染宿主的机制尚不清楚，尽管在过去的十年中已经对潜在的毒力因素进行了大量的研究。我实验室的研究计划是基于我们的中心假设，即宿主-细菌相互作用在猪链球菌感染的发病机制中起关键作用，并侧重于蛋白酶活性和生物膜形成。我们实验室是第一个在猪链球菌感染中研究这两个相关方面的实验室。在本研究中，我们建议进一步研究猪链球菌的这些特性，并为其在感染过程中的作用提供证据。我们的研究计划有两个互补的目标：(i)增加我们对猪链球菌毒力决定因素的基本知识，（ii）利用这些知识来确定新的候选疫苗或治疗靶点来控制猪链球菌感染。

Streptococcus suis, a major swine pathogen worldwide, is transmitted via the respiratory route and colonizes the palatine tonsils of pigs. Major infections caused by this pathogen include septicemiae, meningitis and endocarditis. These bacterial infections generate important economic losses to the Canadian swine industry. The mechanisms by which S. suis invades and infects the host are still unclear even though numerous studies on potential virulence factors have been carried out over the past decade. The research program of my laboratory is based on our central hypothesis that host-bacteria interactions play a critical role in the pathogenesis of S. suis infections and focuses on protease activities and biofilm formation. Our laboratory is the first to study these two relevant aspects in S. suis infections. In this application, we propose to further investigate these properties of S. suis and to provide evidences for their contribution to the infectious process. Our research program has two complementary objectives: (i) increase our basic knowledge of the virulence determinants of the swine pathogen S. suis, and (ii) use this knowledge to identify new candidate vaccines or therapeutic targets to control S. suis infections.