Department of Biology, Middle Tennessee State University, Murfreesboro, TN, 37132, USA.
Department of Biological Sciences, Idaho State University, Pocatello, ID, 83209, USA.
Microb Ecol. 2023 Jul;86(1):713-726. doi: 10.1007/s00248-022-02098-2. Epub 2022 Aug 11.
Understanding how host-associated microbial assemblages respond to pathogen invasion has implications for host health. Until recently, most investigations have focused on understanding the taxonomic composition of these assemblages. However, recent studies have suggested that microbial assemblage taxonomic composition is decoupled from its function, with assemblages being taxonomically varied but functionally constrained. The objective of this investigation was to understand how the Tri-colored bat, Perimyotis subflavus cutaneous microbial assemblage responds to fungal pathogen invasion within a functional context. We hypothesized that at a broad scale (e.g., KEGG pathways), there will be no difference in the functional assemblages between the white nose pathogen, Pseudogymnoascus destructans, positive and negative bats; and this pattern will be driven by the functional redundancy of bacterial taxa. At finer scales (e.g., gene models), we postulate differences in function attributed to interactions between bacteria and P. destructans, resulting in the production of antifungal metabolites. To test this, we used a combination of shotgun metagenomic and amplicon sequencing to characterize the bat cutaneous microbial assemblage in the presence/absence of P. destructans. Results showed that while there was a shift in taxonomic assemblage composition between P. destructans positive and negative bats, there was little overall difference in microbial function. Functional redundancy across bacterial taxa was clear at a broad-scale; however, both redundancy and variation in bacterial capability related to defense against pathogens was evident at finer scales. While functionality of the microbial assemblage was largely conserved in relation to P. destructans, the roles of particular functional pathways in resistance to fungal pathogens require further attention.
了解宿主相关微生物群落如何应对病原体入侵对宿主健康具有重要意义。直到最近，大多数研究都集中在理解这些群落的分类组成上。然而，最近的研究表明，微生物群落的分类组成与其功能是脱钩的，群落在分类上是多样化的，但在功能上是受限制的。本研究的目的是了解三色蝙蝠 Perimyotis subflavus 的皮肤微生物群落如何在功能背景下对真菌病原体入侵做出反应。我们假设，在广泛的范围内（例如，KEGG 途径），在白鼻综合征病原体 Pseudogymnoascus destructans 阳性和阴性蝙蝠之间，功能群落之间没有差异；这种模式将由细菌分类群的功能冗余驱动。在更精细的尺度上（例如，基因模型），我们假设功能上的差异归因于细菌和 P. destructans 之间的相互作用，导致抗真菌代谢物的产生。为了验证这一点，我们使用组合式鸟枪法宏基因组和扩增子测序来描述存在/不存在 P. destructans 时蝙蝠皮肤微生物群落。结果表明，虽然在 P. destructans 阳性和阴性蝙蝠之间，分类群组成发生了变化，但微生物功能总体上差异不大。细菌分类群之间的功能冗余在广泛的范围内是明显的；然而，与防御病原体相关的细菌能力的冗余和变化在更精细的尺度上也是明显的。虽然微生物群落的功能在很大程度上与 P. destructans 保持一致，但特定功能途径在抵抗真菌病原体方面的作用需要进一步关注。
