The impact of co-infection on host and parasite population dynamics

该项目将提高预测引起疾病的寄生虫如何影响其宿主（动物）种群的能力，以及当不同种类的寄生虫在同一个体宿主内出现时，疾病传播是否会改变，这一过程被称为共同感染。根据定义，寄生虫利用被感染宿主的能量进行繁殖并传播给新的宿主。虽然以前的研究在了解单一寄生虫物种的特征如何影响疾病传播方面取得了很大进展，但预测共感染寄生虫之间的相互作用仍然是一个研究前沿。当两种寄生虫占据同一宿主时，由于寄生虫之间的相互作用，感染的结果可能与每种寄生虫单独发生时不同。该项目将利用一种影响储存谷物食品安全的模式生物，评估共同感染对宿主健康、疾病传播和宿主种群生物学的影响。此外，该项目将为高中生、本科生和研究生提供科学培训和指导；确定影响害虫和传粉媒介农业控制的因素；并实施一项外展项目，从代表性不足的少数族裔招募女性进入STEM领域。研究人员将使用数学模型和实验室实验来评估寄生虫共同感染对面粉甲虫（Tribolium castaneum）模型宿主系统的影响。第一个目标是确定共感染寄生虫相互作用的机制，以评估共感染对寄生虫生长速度和宿主感染结果的影响。研究人员将操纵宿主营养获取，改变寄生虫感染途径，并使用下一代mRNA测序量化共同感染对宿主免疫反应的影响。这一目标将阐明自上而下（免疫介导）与自下而上（资源介导）的生态相互作用对构建宿主内寄生虫群落的重要性。第二个目标是量化感染顺序和宿主内相互作用强度对每一种共感染寄生虫向面粉甲虫新宿主传播的影响，并将宿主内与流行病学过程联系起来。最终目标是根据实验数据建立Tribolium种群生物学的数学模型，预测共同感染的寄生虫如何影响宿主种群动态和寄生虫持久性。该项目将为共同感染的更广泛的生态背景和跨尺度动态反馈的影响提供新颖和可推广的见解。该奖项反映了美国国家科学基金会的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

This project will improve the ability to predict how disease causing parasites affect their host (animal) populations and whether disease transmission is altered when different species of parasite occur within the same individual host, a process known as co-infection. Parasites, by definition, use energy from the hosts they infect in order to reproduce and spread to new hosts. While previous research has made great strides in understanding how traits of single parasite species affect disease transmission, predicting interactions among co-infecting parasites remains a research frontier. When two parasite species occupy the same host, the outcome of infection may not be the same as when each parasite occurs separately, due to interactions between the parasites. This project will evaluate the consequences of co-infection for host health, the spread of disease, and host population biology, using a model organism that impacts food safety in stored grains. Additionally, this project will provide scientific training and mentoring to high school, undergraduate, and graduate students; identify factors that affect the agricultural control of pests and pollinators; and implement an outreach project to recruit women from under-represented minorities to fields in STEM.The researchers will use mathematical models and laboratory experiments to evaluate the effects of parasite co-infection on a flour beetle (Tribolium castaneum) model host system. The first objective is to determine the mechanisms through which co-infecting parasites interact in order to evaluate the impact of co-infection on parasite growth rates and host infection outcomes. The researchers will manipulate host nutrient acquisition, alter parasite infection routes, and quantify the impact of co-infection on host immune response using next-generation mRNA sequencing. This objective will elucidate the importance of top-down (immune-mediated) versus bottom-up (resource-mediated) ecological interactions for structuring parasite communities within the host. The second objective is to quantify the impact of infection order and the strength of within-host interactions on the transmission of each co-infecting parasite to new flour beetle hosts, connecting within-host to epidemiological processes. The final objective is to develop mathematical models of Tribolium population biology that predict how co-infecting parasites influence host population dynamics and parasite persistence, based on the experimental data. This project will provide novel and generalizable insight into the wider ecological context of co-infection and the impact of dynamical feedback across scales.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.