Department of Biological Sciences, University of Arkansas, Fayetteville, Arkansas, USA.
Department of Integrative Biology, University of South Florida, Tampa, Florida, USA.
Ecol Lett. 2024 May;27(5):e14431. doi: 10.1111/ele.14431.
There is a rich literature highlighting that pathogens are generally better adapted to infect local than novel hosts, and a separate seemingly contradictory literature indicating that novel pathogens pose the greatest threat to biodiversity and public health. Here, using Batrachochytrium dendrobatidis, the fungus associated with worldwide amphibian declines, we test the hypothesis that there is enough variance in "novel" (quantified by geographic and phylogenetic distance) host-pathogen outcomes to pose substantial risk of pathogen introductions despite local adaptation being common. Our continental-scale common garden experiment and global-scale meta-analysis demonstrate that local amphibian-fungal interactions result in higher pathogen prevalence, pathogen growth, and host mortality, but novel interactions led to variable consequences with especially virulent host-pathogen combinations still occurring. Thus, while most pathogen introductions are benign, enough variance exists in novel host-pathogen outcomes that moving organisms around the planet greatly increases the chance of pathogen introductions causing profound harm.
有大量文献强调，病原体通常更善于感染当地宿主而非新宿主，而另一部分看似矛盾的文献则表明，新病原体对生物多样性和公共卫生构成最大威胁。在这里，我们使用与全球范围内两栖动物减少有关的真菌——蛙壶菌，检验了这样一个假设，即在“新”宿主（通过地理和系统发育距离来量化）与病原体的关系中，存在足够的差异，尽管常见的本地适应现象，仍会造成病原体引入的巨大风险。我们的大陆尺度的公共园林实验和全球尺度的荟萃分析表明，当地的两栖动物-真菌相互作用导致更高的病原体流行率、病原体生长和宿主死亡率，但新的相互作用导致了不同的后果，尤其是在宿主-病原体组合具有特别强毒性的情况下。因此，尽管大多数病原体的引入是良性的，但在新的宿主-病原体关系中存在足够的差异，使得在全球范围内转移生物会大大增加病原体引入并造成严重危害的机会。
