CAREER: Dual Effects Of Intraspecific Competition On Pathogen Dynamics In A Songbird: From Endocrinology to Epidemiology

所有生物体都必须不断地抵抗有害病原体的感染。然而，生物体抵抗病原体感染的能力不是恒定的，而是随其物理环境和社会环境动态变化的。了解疾病易感性的关键环境介质至关重要，因为它们最终决定大规模疾病暴发的可能性和程度。该项目的目标是调查自然和社会环境如何与鸣禽的生理相互作用，以影响疾病易感性和种群水平疾病暴发的程度。该项目研究了与几乎所有生物相关的环境因素-争夺有限的食物资源-如何影响家雀（Carpodacus mexicanus）对其衰弱性细菌病原体（鸡毒支原体，导致鸣鸟可见的眼睛肿胀）的敏感性。将在不同的物理和社会环境下对细菌感染过程进行实验研究，并利用圈养传播研究、基于网络的模型和对自由生活的家雀的实地研究，将实验结果扩大到种群水平的疾病结果。这项工作的结果将大大提高我们对环境在宿主对病原体易感性和疾病动态方面的作用的理解，并将允许更有针对性地管理人畜共患和非人畜共患疾病暴发。研究结果将由弗吉尼亚理工大学的研究生通过为初高中学生制作永久性的“疾病生态学”教育工具包广泛传播。由于感染鸡毒杆菌的鸣禽在整个学年都可以在鸟类喂食处看到，因此该项目的结果可以很容易地作为互动教育课程的基础。工具包课程将在教师暑期研讨会上进行试点，并分发给弗吉尼亚理工大学的所有五个区域中心，在弗吉尼亚的初中和高中教室中广泛而长期地使用。

All organisms must continually fight off infection with harmful pathogens. However, an organism's ability to resist pathogen infection is not constant, but varies dynamically with its physical and social environment. It is critical to understand key environmental mediators of disease susceptibility because they ultimately determine the likelihood and extent of large-scale disease outbreaks. The goal of this project is to investigate how the physical and social environment interacts with the physiology of songbirds to influence disease susceptibility and the extent of population-level disease outbreaks. The project examines how an environmental factor relevant to almost all organisms-- competition for limited food resources-- influences susceptibility of the house finch (Carpodacus mexicanus) to its debilitating bacterial pathogen (Mycoplasma gallisepticum, which causes visible eye swelling in songbirds). The course of bacterial infection will be examined experimentally under varying physical and social environments, and experimental results will be scaled up to population-level disease outcomes using captive transmission studies, network-based models, and field studies of free-living house finches. The results of this work will significantly improve our understanding of the role of the environment on host susceptibility to pathogens and disease dynamics, and will allow for more targeted management of zoonotic and non-zoonotic disease outbreaks. Results will be broadly disseminated by Virginia Tech graduate students through the creation of permanent "Disease ecology" education kits for middle and high-school students. Because songbirds infected with M. gallisepticum are readily visible at bird feeders throughout the school year, the project's results can readily serve as the basis for interactive educational curricula. Kit curricula will be piloted at teacher summer workshops and distributed to all five Virginia Tech regional centers for broad and long-term use in Virginia's middle and high school classrooms.