Contribution of the vibrio parahaemolyticus chromosome I type III secretion system to colonization of the Pacific oyster, crassostrea gigas

副溶血性弧菌 I 型 III 型染色体分泌系统对太平洋牡蛎、巨牡蛎定殖的贡献

• 批准号: 261996-2008
• 负责人: DeVinney, Rebekah
• 金额: $ 2.4万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2010
• 资助国家: 加拿大
• 起止时间: 2010-01-01 至 2011-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=456206
• 关键词: Contribution; vibrio; parahaemolyticus; chromosome; type

Vibrio parahaemolyticus is a significant cause of gastroenteritis resulting from the consumption of raw or undercooked shellfish. V. parahaemolyticus accumulates in bivalve invertebrates, particularly oysters and mussels. There is a large amount of diversity within V. parahaemolyticus isolates, and the aresenal of factors required for virulence is not well understood. V. parahaemolytics does not cause disease in adult oysters, and is thought to be part of the oyster normal flora. The V. parahaemolyticus genome encodes two type III secretion systems. Type III secretion systems are mult-protein complexes used by Gram negative bacteria to inject proteins directly into the host cell. They are commonly found in animal and plant pathogens, and are considered important virulence factors. Surprisingly, data from our lab indicates that one of the type III secretion systems, the CI-T3SS, is found in both disease-associated and environmental isolates. This led us to hypothesize that the CI-T3SS is involved in colonization and survival within oysters. In this proposal, we examine the interaction between V. parahaemolyticus and the oyster immune system. Bacteria that live in close association with a host need to avoid recognition as foreign by the immune system. The oyster immune system is comprised of phagocytic cells called hemocytes. Our data suggests that V. parahaemolyticus evades phagocytosis, which could enable it to survive within the oyser. We will therefore examine whether the CI-T3SS plays a role in avoiding phagocytosis. A second aim is to determine whether the CI-T3SS is required for persistent colonization of the oyster. Collectively, these studies will allow us to better understand the marine lifestyle of V. parahaemolyticus. As virulence in V. parahaemolyticus is not well defined, methods for eliminating V. parahaemolyticus from oysters before they go to market is an important strategy to decrease the risk of disease. Understanding how V. parahaemolyticus persists in oysters will enhance our ability to develop these tools.

颤动溶血性是由于食用原始贝类或未煮熟的贝类引起的胃肠炎的重要原因。 V.副溶血症在双壳无脊椎动物，尤其是牡蛎和贻贝中积聚。 darahayticus分离株中有很大的多样性，毒力所需的因素的奇迹尚不清楚。 V.副溶血剂不会在成年牡蛎中引起疾病​​，并且被认为是牡蛎正常植物的一部分。 V. parahaeyticus基因组编码两个III型分泌系统。 III型分泌系统是革兰氏阴性细菌使用的多蛋白复合物，将蛋白直接注入宿主细胞。它们通常在动物和植物病原体中发现，被认为是重要的毒力因素。令人惊讶的是，我们实验室的数据表明，在与疾病相关和环境分离株中发现了III型分泌系统之一CI-T3SS。这使我们假设CI-T3SS参与了牡蛎中的定殖和生存。在此提案中，我们研究了副溶血杆菌与牡蛎免疫系统之间的相互作用。与宿主密切相关的细菌需要避免通过免疫系统识别为异物。牡蛎免疫系统由称为血细胞的吞噬细胞组成。我们的数据表明，副溶血杆菌逃避了吞噬作用，这可以使其能够在牡蛎中生存。因此，我们将检查CI-T3SS是否在避免吞噬作用中起作用。第二个目的是确定牡蛎持续定植是否需要CI-T3SS。总的来说，这些研究将使我们能够更好地理解V. parahayticus的海洋生活方式。由于darahayticus的毒力没有很好地定义，因此在牡蛎上市之前消除副溶血杆菌的方法是降低疾病风险的重要策略。了解V. parahayticus在牡蛎中如何持续存在将增强我们开发这些工具的能力。