From specialist to generalist: biotic and abiotic reservoirs of fungal pathogens

项目摘要 许多真菌病原体具有广泛的寄主范围、长时间的环境阶段和 腐殖化生长的潜力。这种类型的病原体需要新的模型，以便 提高我们了解这一独特、多样和 病原菌种类丰富。这个项目的总体目标是扩大我们对 新出现的真菌病原体在宿主内部和外部的动态。实验室 并将进行田间试验和田间调查，以开发和拟合疾病模型， 利用两栖壶菌--树状巴氏杆菌(Batrachochytrium endrobatidis(Bd)) 模型系统。最近的证据表明，Bd可以感染各种各样的生物(除了 两栖动物)，Bd具有形成生物膜的能力(这可能增强其 环境持久性)，使其成为该项目的理想模型系统。 真菌疾病模型将被开发和参数化，包括通用病原体， 外部病原体储存库(包括将病原体并入 生物膜)，以及腐生性病原体生长的潜力。这些模型将用于 探讨真菌病原体的这些特征对病原菌流行率和 目标寄主物种的疾病严重程度，在两栖动物/Bd系统和其他 新兴的真菌病原体系统。具体地说，研究小组将(1)进行深入的 分析BD可能持续存在的替代宿主和环境水库 宿主，(2)在实验上测试这些替代宿主和环境水库对 Bd的生存和繁殖，Bd在环境中的持久性，以及Bd的传播 病原体对两栖动物的影响；(3)Bd生物膜形成对Bd持久性和Bd持久性的影响 繁殖，(4)探索Bd生物膜如何在极端环境(即温度)中持续存在 如果这使用新的方法影响了BD的传染性(元基因组学， (5)改进以真菌为基础的疾病模型以包括 以BD为案例研究的以生态系统为中心的方法，以及(6)创造一种新兴的真菌 数据库，进行荟萃分析，并将我们的疾病模型与其他新出现的真菌疾病相匹配。

Project Summary Many fungal pathogens have broad host ranges, long-lived environmental stages, and the potential for saprotrophic growth. New models are needed for this type of pathogen, in order to improve our ability to understand the dynamics and impacts of this unique, diverse, and abundant group of pathogens. The overall aim of this project is to expand our understanding of the dynamics of emerging fungal pathogens both amongst and outside of their hosts. Laboratory and field experiments and field surveys will be conducted to develop and fit disease models, utilizing the amphibian chytrid fungus, Batrachochytrium dendrobatidis (Bd), as the primary model system. Recent evidence that Bd can infect a wide diversity of organisms (in addition to amphibians), and that Bd has the ability to form biofilms (which may enhance its potential for environmental persistence), makes this an ideal model system for this project. Fungal disease models will be developed and parameterized, including generalist pathogens, external pathogen reservoirs (including the possibility of incorporation of the pathogen into biofilms), and the potential for saprotrophic pathogen growth. The models will be used to explore the implications of these features of fungal pathogens on pathogen prevalence and disease severity in target host species, in the both the amphibian/Bd system and in other emerging fungal pathogen systems. Specifically, the research team will (1) perform an in-depth analysis of alternative hosts and environmental reservoirs where Bd may persist outside of the host, (2) test experimentally the role of these alternative hosts and environmental reservoirs on survival and reproduction of Bd, persistence of Bd in the environment, and in transmission of the pathogen to amphibians, (3) test how Bd biofilm formation affects Bd persistence and reproduction, (4) explore how Bd biofilms persist in extreme environments (i.e., temperatures) and if this affects the infectiousness of Bd using novel approaches (metagenomics, metatranscriptomics, metaproteomics), (5) improve the fungal-based disease model to include an ecosystem-centric approach using Bd as a case study, and (6) create an emerging fungal database, conduct a metanalysis, and fit our disease models to other emerging fungal diseases.