Department of Infectious Disease Epidemiology, Imperial College London, London, W2 1PG, UK.
Institute of Zoology, Zoological Society of London, Regent's Park, London, NW1 4RY, UK.
Nat Commun. 2018 Feb 15;9(1):693. doi: 10.1038/s41467-018-02967-w.
Host-associated microbes are vital for combatting infections and maintaining health. In amphibians, certain skin-associated bacteria inhibit the fungal pathogen Batrachochytrium dendrobatidis (Bd), yet our understanding of host microbial ecology and its role in disease outbreaks is limited. We sampled skin-associated bacteria and Bd from Pyrenean midwife toad populations exhibiting enzootic or epizootic disease dynamics. We demonstrate that bacterial communities differ between life stages with few shared taxa, indicative of restructuring at metamorphosis. We detected a significant effect of infection history on metamorph skin microbiota, with reduced bacterial diversity in epizootic populations and differences in community structure and predicted function. Genome sequencing of Bd isolates supports a single introduction to the Pyrenees and reveals no association between pathogen genetics and epidemiological trends. Our findings provide an ecologically relevant insight into the microbial ecology of amphibian skin and highlight the relative importance of host microbiota and pathogen genetics in predicting disease outcome.
宿主相关微生物对于抵抗感染和保持健康至关重要。在两栖动物中，某些皮肤相关细菌可以抑制真菌病原体蛙壶菌（Bd），但我们对宿主微生物生态学及其在疾病爆发中的作用的理解还很有限。我们从表现出地方性或流行性疾病动态的比利牛斯山蟾蜍种群中采样了皮肤相关细菌和 Bd。我们证明，细菌群落在生命阶段之间存在差异，共享的分类群很少，表明在变态过程中发生了重组。我们检测到感染史对变态皮肤微生物组有显著影响，流行种群的细菌多样性降低，群落结构和预测功能存在差异。Bd 分离株的基因组测序支持了它在比利牛斯山脉的单一引入，并揭示了病原体遗传与流行病学趋势之间没有关联。我们的研究结果为理解两栖动物皮肤的微生物生态学提供了一个生态相关的视角，并强调了宿主微生物组和病原体遗传在预测疾病结果方面的相对重要性。
