Transmission pathways and immunological factors driving invasion potential of the recently discovered pathogen, Batrachochytrium salamandrivorans

最近发现的真菌病原体Batrachochytrium salamandra vorans（Bsal）被认为来自亚洲，并可能通过国际贸易引入欧洲，在那里它出现在火蝾螈（Salamandra salamandra）种群中。Bsal是一种食肉病原体，可导致坏死性皮肤溃疡，并可导致易感蝾螈在不到2周内死亡。这种病原体在美国的出现将对生物多样性产生破坏性影响。北美东部是100多种蝾螈物种的家园，这些物种为各种生态系统服务做出了贡献，包括控制致病昆虫，营养循环和为社会提供生物医学产品。该奖项将资助研究，将表征流行病学，宿主免疫反应和Bsal的发病机制在北美分布最广泛的蝾螈物种之一，东部蝾螈（Notophthalmus viridescens）。通过采取积极主动的方法来研究Bsal，该项目将产生旨在开发预测性疾病应对工具的基本信息，这些工具可供自然资源组织用于预防或阻止Bsal在北美的爆发。此外，该项目将为美国学术机构、机构和组织的学生和专业人员提供广泛的培训机会和能力建设。目前对Bsal流行病学的了解主要限于欧洲火蝾螈，它们的生活史策略与大多数北美蝾螈物种不同。该项目将利用东部蝾螈成年和幼年的对照实验来参数化Bsal流行病学模型，这些实验将：（1）包括在一系列环境温度下水生和陆地环境中的传播途径，（2）考虑两种独特形式的传染性Bsal游动孢子，（3）确定游动孢子在水和土壤中持久存在的作用，以及影响它的因素，（4）明确地模拟游动孢子脱落和宿主间传播随疾病进展的变化，以及（5）包括恢复阶段作为感染结果。该项目还将量化对Bsal的先天性和适应性免疫反应，确定Bsal发病机制，以及探索宿主抗性和感染耐受性对蝾螈-Bsal动力学影响的参数积分投影模型。该奖项将显著推进Bsal流行病学、免疫学和病理学的基础知识，并将为科学衍生的疾病干预策略提供基础，这些策略可在类似的风险物种中推广。该奖项反映了NSF的法定使命，并被认为值得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来支持。

The recently discovered fungal pathogen, Batrachochytrium salamandrivorans (Bsal) is believed to be from Asia and was likely introduced into Europe through international trade, where it is emerging in fire salamander (Salamandra salamandra) populations. Bsal is a flesh-eating pathogen that causes necrotic skin ulcerations and can lead to death in susceptible salamanders in less than 2 weeks. Emergence of this pathogen in the United States would have devastating effects on biodiversity. Eastern North America is home to more than 100 salamander species that contribute to various ecosystem services, including control of disease-causing insects, nutrient cycling, and biomedical products for society. This award will fund research that will characterize the epidemiology, host immune responses, and pathogenesis of Bsal in one of the most widely distributed salamander species in North America, the eastern newt (Notophthalmus viridescens). By taking a proactive approach to studying Bsal now, this project will generate essential information aimed at developing predictive disease response tools that can be used by natural resource organizations to prevent or thwart an outbreak of Bsal in North America. Additionally, this project will provide broad training opportunities and capacity building for students and professionals at US academic institutions, agencies and organizations. The current knowledge of Bsal epidemiology is restricted mostly to European fire salamanders, which have different life history strategies than most North American salamander species. This project will parameterize Bsal epidemiological models using controlled experiments with adult and juvenile eastern newts that will: (1) include transmission pathways in both the aquatic and terrestrial environments for a range of ambient temperatures, (2) consider two unique forms of infectious Bsal zoospores, (3) identify the role of zoospore persistence in water and soil, and factors that affect it, (4) explicitly model zoospore shedding and between-host transmission as disease progresses, and (5) include a recovery stage as an infection outcome. The project also will quantify innate and adaptive immune responses to Bsal, identify the mechanisms of Bsal pathogenesis, and parameterize integral projection models that explore the impacts of host resistance and infection tolerance on salamander-Bsal dynamics. This award will significantly advance the foundational knowledge of Bsal epidemiology, immunology, and pathology, and will provide the basis for science-derived disease intervention strategies that are generalizable across similar at-risk species.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.