Department of Plant Pathology and Environmental Microbiology, Center for Infectious Disease Dynamics, Pennsylvania State University, University Park, Pennsylvania, United States of America.
Pennsylvania Game Commission, Harrisburg, Pennsylvania, United States of America.
PLoS Pathog. 2021 Mar 17;17(3):e1009236. doi: 10.1371/journal.ppat.1009236. eCollection 2021 Mar.
Understanding the dynamics of white-nose syndrome spread in time and space is an important component for the disease epidemiology and control. We reported earlier that a novel partitivirus, Pseudogymnoascus destructans partitivirus-pa, had infected the North American isolates of Pseudogymnoascus destructans, the fungal pathogen that causes white-nose syndrome in bats. We showed that the diversity of the viral coat protein sequences is correlated to their geographical origin. Here we hypothesize that the geographical adaptation of the virus could be used as a proxy to characterize the spread of white-nose syndrome. We used over 100 virus isolates from diverse locations in North America and applied the phylogeographic analysis tool BEAST to characterize the spread of the disease. The strict clock phylogeographic analysis under the coalescent model in BEAST showed a patchy spread pattern of white-nose syndrome driven from a few source locations including Connecticut, New York, West Virginia, and Kentucky. The source states had significant support in the maximum clade credibility tree and Bayesian stochastic search variable selection analysis. Although the geographic origin of the virus is not definite, it is likely the virus infected the fungus prior to the spread of white-nose syndrome in North America. We also inferred from the BEAST analysis that the recent long-distance spread of the fungus to Washington had its root in Kentucky, likely from the Mammoth cave area and most probably mediated by a human. The time to the most recent common ancestor of the virus is estimated somewhere between the late 1990s to early 2000s. We found the mean substitution rate of 2 X 10-3 substitutions per site per year for the virus which is higher than expected given the persistent lifestyle of the virus, and the stamping-machine mode of replication. Our approach of using the virus as a proxy to understand the spread of white-nose syndrome could be an important tool for the study and management of other infectious diseases.
了解白鼻综合征在时间和空间上的传播动态是疾病流行病学和控制的一个重要组成部分。我们之前曾报道过，一种新型的二分病毒 Pseudogymnoascus destructans partitivirus-pa 已经感染了导致蝙蝠白鼻综合征的真菌病原体 Pseudogymnoascus destructans 的北美分离株。我们表明，病毒外壳蛋白序列的多样性与其地理起源相关。在这里，我们假设病毒的地理适应性可以作为表征白鼻综合征传播的一个指标。我们使用了来自北美的多个不同地点的 100 多个病毒分离株，并应用系统发生地理分析工具 BEAST 来描述该疾病的传播。BEAST 中的严格时钟系统发生地理分析表明，白鼻综合征的传播是由包括康涅狄格州、纽约州、西弗吉尼亚州和肯塔基州在内的少数几个来源地驱动的，呈斑块状扩散。来源州在最大简约可信度树和贝叶斯随机搜索变量选择分析中得到了显著支持。尽管病毒的地理起源尚不确定，但它很可能是在白鼻综合征在北美传播之前感染了真菌。我们还从 BEAST 分析中推断出，真菌最近向华盛顿的远距离传播起源于肯塔基州，很可能来自猛犸洞穴地区，而且极有可能是由人类传播的。病毒的最近共同祖先的时间估计在 20 世纪 90 年代末到 21 世纪初之间。我们发现病毒的平均替换率为每年每个位点 2X10-3 个替换，这高于预期，因为病毒的生活方式是持续的，而且复制模式是冲压机模式。我们使用病毒作为代理来理解白鼻综合征传播的方法可能是研究和管理其他传染病的重要工具。
