Climate change and marine pathogens: Environmentally-driven changes in Vibrio vulnificus and Vibrio parahaemolyticus gene expression and pathogenicity

项目总结 全球气候变化和海平面上升将影响海洋病原体的丰度和分布 在沿海水域和海鲜中。这将导致重大的公共健康风险，这可能导致 暴露人群中的疾病。由海洋弧菌引起的人类感染发病率上升 革兰氏阴性条件致病菌，发生于1996-2010年。弧菌的年发病率 2010年的患病人数比2006-2008年间增加了43%，与发病率相比增加了115% 1996-1998年间。接触创伤弧菌每年导致超过22人死亡，是世界上最大的 美国每年因食用海鲜死亡的人数约占所有死亡人数的95% 独自一人。副溶血性弧菌感染虽然很少致命，但每年超过8000例。尽管风险越来越大 在这些感染中，人们对环境参数如何影响复杂的毒力知之甚少。 与致病性有关的机制。随着弧菌感染率的不断上升，预计有 迫切需要填补有关气候变化如何通过以下方式影响弧菌毒力的知识空白 适应性进化和基因表达的改变。这项研究的长期目标是了解气候如何 变化会影响弧菌的毒力。要做到这一点，实验将确定遗传机制是如何 创伤弧菌和副溶血性弧菌的毒力和耐药性受变化的影响 环境参数。中心假设(H1)是弧菌的毒力和抗生素耐药性将 在模拟气候变化的条件下增加。通过机械数据与弧菌的耦合 在丰度和分布方面，预测模型可能会得到加强，从而更准确地预测公共卫生风险。 将涉及三个具体目标：(目标1)确定环境的不同组合如何 参数(温度、盐度、金属、营养物质)影响创伤弧菌和副溶血性弧菌的生长和 生存能力。(目的2)评估改变的生长条件如何影响创伤弧菌和副溶血性弧菌的毒力 使用秀丽隐杆线虫致病模型。(目标3)确定改变生长的影响 创伤弧菌和副溶血性弧菌基因表达条件的研究我们的工作假设是改变了 生长条件将导致弧菌应激反应基因上调，导致下游变化 毒力基因表达。这项研究的结果可以纳入弧菌预测模型，以更好地 预测致病弧菌分布的时空格局。然后可以使用增强的模型 指导更好的公共卫生暴露控制和法规。

PROJECT SUMMARY Global climate change and sea-level rise will influence the abundances and distributions of marine pathogens in coastal waters and seafood. This will result in a significant public health risk, which may lead to enhanced illness in exposed populations. Increasing incidences of human infections due to species of Vibrio, a marine Gram-negative opportunistic pathogen, have occurred from 1996-2010. The annual incidence rate of Vibrio illnesses in 2010 increased by 43% from those found during 2006-2008 and by 115% when compared to rates during 1996-1998. Exposures to Vibrio vulnificus causes more than 22 deaths annually and is the leading cause of death from seafood consumption accounting for approximately 95% of all deaths each year in the US alone. V. parahaemolyticus infections, while rarely fatal, exceed 8,000 cases annually. Despite the growing risk of these infections, little is known about how environmental parameters affect the complex virulence mechanisms involved in pathogenicity. With increasing rates of Vibrio infection expected to continue, there is an urgent need to fill this gap in knowledge related to how climate change may affect Vibrio virulence through adaptive evolution and altered gene expression. A long-term goal of this study is to understand how climate change influences Vibrio virulence. To accomplish this, experiments will determine how genetic mechanisms of V. vulnificus and V. parahaemolyticus virulence and antibiotic resistance are affected by changing environmental parameters. The central hypothesis (H1) is that Vibrio virulence and antibiotic resistance will increase under conditions simulating climate change. Through the coupling of mechanistic data to Vibrio abundance and distribution, forecast models may be enhanced and more accurately predict public health risk. Three specific aims will be addressed: (Aim 1) Determine how different combinations of environmental parameters (temperature, salinity, metals, nutrients) affect V. vulnificus and V. parahaemolyticus growth and viability. (Aim 2) Assess how altered growth conditions affect V. vulnificus and V. parahaemolyticus virulence using a Caenorhabditis elegans model of pathogenicity. (Aim 3) Determine the effect of altered growth conditions on V. vulnificus and V. parahaemolyticus gene expression. Our working hypothesis is that altered growth conditions will lead to upregulation of Vibrio stress response genes causing downstream changes in virulence gene expression. The results of this study can be incorporated into Vibrio forecast models to better predict spatial and temporal patterns of pathogenic Vibrio distribution. The enhanced model can then be used to guide better public health exposure controls and regulations.