Department of Environmental Science, Policy, and Management, University of California Berkeley, Berkeley, California, United States of America.
One Health Research Group, Faculty of Veterinary and Agricultural Sciences, University of Melbourne, Victoria, Australia.
PLoS One. 2022 Mar 14;17(3):e0261047. doi: 10.1371/journal.pone.0261047. eCollection 2022.
Host-pathogen specificity can arise from certain selective environments mediated by both the host and pathogen. Therefore, understanding the degree to which host species identity is correlated with pathogen genotype can help reveal historical host-pathogen dynamics. One animal disease of particular concern is chytridiomycosis, typically caused by the global panzootic lineage of the amphibian chytrid fungus (Batrachochytrium dendrobatidis, Bd), termed Bd-GPL. This pathogen lineage has caused devastating declines in amphibian communities around the world. However, the site of origin for the common ancestor of modern Bd-GPL and the fine-scale transmission dynamics of this lineage have remained a mystery. This is especially the case in North America where Bd-GPL is widespread, but disease outbreaks occur sporadically. Herein, we use Bd genetic data collected throughout the United States from amphibian skin swabs and cultured isolate samples to investigate Bd genetic patterns. We highlight two case studies in Pennsylvania and Nevada where Bd-GPL genotypes are strongly correlated with host species identity. Specifically, in some localities bullfrogs (Rana catesbeiana) are infected with Bd-GPL lineages that are distinct from those infecting other sympatric amphibian species. Overall, we reveal a previously unknown association of Bd genotype with host species and identify the eastern United States as a Bd diversity hotspot and potential site of origin for Bd-GPL.
宿主-病原体特异性可能来自于宿主和病原体共同介导的某些特定环境。因此，了解宿主物种身份与病原体基因型的相关程度有助于揭示历史上的宿主-病原体动态。一种特别引人关注的动物疾病是蛙壶菌病，通常由全球性泛生的两栖动物壶菌病原体（Batrachochytrium dendrobatidis，Bd）引起，被称为 Bd-GPL。这种病原体谱系已经在全球范围内导致了两栖动物群落的毁灭性下降。然而，现代 Bd-GPL 的共同祖先的起源地以及该谱系的精细传播动态仍然是一个谜。在北美洲尤其如此，Bd-GPL 广泛分布，但疾病爆发却零星发生。在此，我们使用从美国各地的两栖动物皮肤拭子和培养分离样本中收集的 Bd 遗传数据来研究 Bd 的遗传模式。我们强调了宾夕法尼亚州和内华达州的两个案例研究，其中 Bd-GPL 基因型与宿主物种身份密切相关。具体来说，在某些地方，牛蛙（Rana catesbeiana）感染的 Bd-GPL 谱系与感染其他同域两栖动物物种的谱系不同。总体而言，我们揭示了以前未知的 Bd 基因型与宿主物种的关联，并确定美国东部是 Bd 多样性热点地区和 Bd-GPL 的潜在起源地。
