IRFP: Rainfall and herbivory: characterizing the transmission route for anthrax in grazing wildlife

IRFP：降雨和食草：描述放牧野生动物中炭疽病的传播途径

• 批准号: 1103054
• 负责人: Wendy Turner
• 金额: $ 20.46万
• 依托单位: Turner Wendy C
• 依托单位国家: 美国
• 项目类别: Fellowship Award
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-12-01 至 2015-01-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1103054&HistoricalAwards=false
• 关键词: IRFP; Rainfall; herbivory; characterizing; transmission

1103054TurnerThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad. This award is co-funded with the ANESA Program in the Office of International Science and Engineering.This award will support a twenty-four-month research fellowship by Dr. Wendy C. Turner to work with Professor Nils Chr. Stenseth and Professor Anne-Brit Kolstø at the University of Oslo in Oslo, Norway and Professor Isaac Mapaure at the University of Namibia in Windhoek, Namibia.Many mysteries remain in understanding how herbivorous hosts acquire Bacillus anthracis, the bacterium causing anthrax infections. Like many other disease agents, transmission of B. anthracis between hosts involves passage through the external environment. Changes in environmental conditions, particularly rainfall, strongly correlate with increases in the incidence of many diseases, but the mechanistic relationships between rainfall and disease transmission are often unknown. Using anthrax in herbivorous wildlife as a model system, this project characterizes the determinants of a seasonally occurring infectious disease using consumer-resource interaction theory coupled with field studies and statistical modeling. It is hypothesized that grazing animals are exposed to B. anthracis spores when foraging at previous anthrax carcass sites and that the level of exposure at these sites is rainfall dependent. The PI is testing these hypotheses with two field studies based in Etosha National Park, Namibia. The first is a longitudinal observational study at anthrax carcass sites to determine the abundance of B. anthracis spores on grass leaves and how spore quantity varies in response to rainfall. The second is a natural experiment using motion sensing camera traps to determine if hosts selectively forage at carcass sites and over what time scale. Hierarchical models are used to determine if the observed correlation between rainfall and anthrax incidence can be explained mechanistically through variation in rainfall, spore abundance and host foraging behavior, with a focus on plains zebra (Equus quagga). Results of this research will provide an understanding of the mechanisms behind transmission of a widely distributed, seasonally occurring infectious disease of importance to farming, wildlife management and public health. Only once we understand the relationships between rainfall and exposure of grazers to B. anthracis, can we predict how animal exposure and anthrax dynamics may change with anticipated changes in rainfall patterns under various models of climate change. Understanding the mechanisms behind anthrax outbreaks in grazing systems will further provide information on where, when and how control measures need to be directed in order to lessen animal exposure. Education and training are essential components of the proposed research. In addition to broadening the PI's training, scientific expertise and international collaborations, this project will further develop her skills as a mentor and educator.

1103054特纳国际研究奖学金计划使美国科学家和工程师能够在国外进行9到24个月的研究。该计划的奖励为联合研究提供了机会，并利用独特或互补的设施、专业知识和国外的实验条件。该奖项由国际科学与工程办公室的ANESA项目共同资助。该奖项将支持Wendy C. Turner博士与Nils Chr教授进行为期24个月的研究。Stenseth和挪威奥斯陆大学的Anne-Brit Kolstø教授，以及纳米比亚温得和克纳米比亚大学的Isaac Mapaure教授。在了解草食性宿主如何获得炭疽芽孢杆菌（引起炭疽感染的细菌）方面仍有许多谜团。像许多其他疾病病原体一样，炭疽芽胞杆菌在宿主之间的传播涉及通过外部环境。环境条件的变化，特别是降雨，与许多疾病发病率的增加密切相关，但降雨与疾病传播之间的机制关系往往是未知的。利用草食野生动物中的炭疽作为模型系统，本项目利用消费者-资源相互作用理论，结合实地研究和统计建模，描述了季节性发生的传染病的决定因素。据推测，放牧动物在以前的炭疽尸体地点觅食时暴露于炭疽芽孢杆菌孢子，并且这些地点的暴露水平取决于降雨量。PI正在纳米比亚埃托沙国家公园进行两项实地研究，以验证这些假设。第一个是在炭疽尸体地点进行纵向观察研究，以确定草叶上炭疽芽孢杆菌孢子的丰度以及孢子数量如何随降雨量变化。第二个是一个自然实验，使用运动感应相机陷阱来确定宿主是否有选择性地在尸体地点觅食以及在什么时间尺度上觅食。本文以平原斑马（Equus quagga）为研究对象，采用层次模型来确定观测到的降雨量与炭疽发病率之间的相关性是否可以通过降雨量、孢子丰度和宿主觅食行为的变化来解释。这项研究的结果将使人们了解一种广泛分布、季节性发生的传染病的传播机制，这种传染病对农业、野生动物管理和公共卫生具有重要意义。只有了解降雨与食草动物暴露于炭疽芽胞杆菌之间的关系，我们才能预测在各种气候变化模型下，动物暴露和炭疽芽胞杆菌动力学如何随着预期的降雨模式变化而变化。了解放牧系统中炭疽疫情背后的机制将进一步提供信息，说明需要在何处、何时以及如何采取控制措施，以减少动物接触。教育和培训是拟议研究的重要组成部分。除了扩大PI的培训，科学专业知识和国际合作之外，该项目还将进一步发展她作为导师和教育者的技能。

项目成果

Coalescence modeling of intrainfection Bacillus anthracis populations allows estimation of infection parameters in wild populations

• DOI: 10.1073/pnas.1920790117
• 发表时间: 2020-02-25
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Easterday, W. Ryan;Ponciano, Jose Miguel;Turner, Wendy C.
• 通讯作者: Turner, Wendy C.