Linking Ecology, Physiology and Human Land Use: The Impact of Environmental Stress on Disease Susceptibility in Larval Amphibians

将生态学、生理学和人类土地利用联系起来：环境压力对两栖动物幼虫疾病易感性的影响

• 批准号: 0431370
• 负责人: Lisa Belden
• 金额: $ 10.51万
• 依托单位: Virginia Polytechnic Institute and State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2004
• 资助国家: 美国
• 起止时间: 2004-05-15 至 2006-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0431370&HistoricalAwards=false
• 关键词: Linking; Ecology; Physiology; Human; Land

Understanding the role that infectious diseases play in natural communities is a key question in community ecology. Host-pathogen interactions, perhaps more so than other types of interactions (e.g. predator-prey & competition), are largely determined by the physiological condition of the host. To gain a predictive understanding of the impact that infection may have on host population dynamics requires a detailed understanding of host physiology and immunology. Freshwater wetlands are primary habitat for snails serving as intermediate hosts for a variety of helminthic parasites including digenetic trematodes. Trematodes are responsible for hundreds of thousands of cases of human disease each year (e.g., schistosomiasis) and have been linked with developmental abnormalities in amphibians. Amphibian deformities, in particular those related to limb development, have now been reported throughout North America. The widespread nature and apparent increase in the prevalence of deformities has lead to substantial interest from scientists and the general public. While preliminary laboratory experiments suggest that infection by trematodes can cause some deformities, researchers have pointed out that there is a need for more fieldwork to evaluate the association in nature. In addition, some research has suggested that land use changes in wetlands, such as increased eutrophication and altered hydrology, may precipitate outbreaks of deformities by increasing abundance of intermediate hosts (snails). We propose to examine the role of the host's hormonal response to land use changes (environmental stress) in terms of how it can regulate disease susceptibility. The proposed project will complement an ongoing study examining how land use changes affect snail (intermediate host) abundance and therefore influence amphibian infection rates. This proposal will add significantly to our knowledge of how free-living animals respond physiologically to anthropogenic land use changes, and the data generated on host susceptibility will add significantly to the development of a predictive model for disease outbreak in this host/parasite system.

了解传染病在自然群落中的作用是群落生态学中的一个关键问题。宿主-病原体相互作用，也许比其他类型的相互作用（例如捕食者-猎物竞争）更重要，在很大程度上取决于宿主的生理条件。 为了获得对感染可能对宿主种群动态产生的影响的预测性理解，需要对宿主生理学和免疫学进行详细的了解。 淡水湿地是蜗牛的主要栖息地，蜗牛是包括复殖吸虫在内的多种蠕虫寄生虫的中间宿主。吸虫每年造成数十万例人类疾病（例如，血吸虫病），并与两栖动物的发育异常有关。两栖动物畸形，特别是那些与肢体发育有关的畸形，现在已经在整个北美报道。 畸形的普遍性和明显增加的流行率引起了科学家和公众的极大兴趣。虽然初步的实验室实验表明，吸虫感染可能会导致一些畸形，但研究人员指出，需要进行更多的实地调查，以评估自然界中的相关性。 此外，一些研究表明，湿地土地利用的变化，如富营养化程度的增加和水文变化，可能会通过增加中间宿主（蜗牛）的丰度而加速畸形的爆发。 我们建议检查主机的激素反应的作用，土地利用的变化（环境压力）方面，它可以调节疾病的易感性。 拟议的项目将补充一项正在进行的研究，该研究探讨土地利用变化如何影响蜗牛（中间宿主）丰度，从而影响两栖动物感染率。这一建议将大大增加我们的知识，自由生活的动物如何生理响应人为土地利用的变化，和主机易感性产生的数据将大大增加在这个主机/寄生虫系统疾病爆发的预测模型的发展。