Kueneman Jordan G, Woodhams Douglas C, Van Treuren Will, Archer Holly M, Knight Rob, McKenzie Valerie J
Department of Ecology and Evolutionary Biology, University of Colorado, Boulder, CO, USA.
BioFrontiers Institute, University of Colorado, Boulder, CO, USA.
ISME J. 2016 Apr;10(4):934-44. doi: 10.1038/ismej.2015.168. Epub 2015 Nov 13.
Increasingly, host-associated microbiota are recognized to mediate pathogen establishment, providing new ecological perspectives on health and disease. Amphibian skin-associated microbiota interact with the fungal pathogen, Batrachochytrium dendrobatidis (Bd), but little is known about microbial turnover during host development and associations with host immune function. We surveyed skin microbiota of Colorado's endangered boreal toads (Anaxyrus boreas), sampling 181 toads across four life stages (tadpoles, metamorphs, subadults and adults). Our goals were to (1) understand variation in microbial community structure among individuals and sites, (2) characterize shifts in communities during development and (3) examine the prevalence and abundance of known Bd-inhibitory bacteria. We used high-throughput 16S and 18S rRNA gene sequencing (Illumina MiSeq) to characterize bacteria and microeukaryotes, respectively. Life stage had the largest effect on the toad skin microbial community, and site and Bd presence also contributed. Proteobacteria dominated tadpole microbial communities, but were later replaced by Actinobacteria. Microeukaryotes on tadpoles were dominated by the classes Alveolata and Stramenopiles, while fungal groups replaced these groups after metamorphosis. Using a novel database of Bd-inhibitory bacteria, we found fewer Bd-inhibitory bacteria in post-metamorphic stages correlated with increased skin fungi, suggesting that bacteria have a strong role in early developmental stages and reduce skin-associated fungi.
越来越多的研究发现，与宿主相关的微生物群能够介导病原体的定殖，这为健康与疾病提供了新的生态学视角。两栖动物皮肤相关的微生物群与真菌病原体——蛙壶菌（Batrachochytrium dendrobatidis，Bd）相互作用，但对于宿主发育过程中的微生物更替以及与宿主免疫功能的关联却知之甚少。我们对科罗拉多州濒危的北方蟾蜍（Anaxyrus boreas）的皮肤微生物群进行了调查，在四个生命阶段（蝌蚪、变态期个体、亚成体和成体）采集了181只蟾蜍的样本。我们的目标是：（1）了解个体和地点之间微生物群落结构的差异；（2）描述发育过程中群落的变化；（3）检测已知的抑制Bd细菌的流行率和丰度。我们分别使用高通量16S和18S rRNA基因测序（Illumina MiSeq）来表征细菌和微真核生物。生命阶段对蟾蜍皮肤微生物群落的影响最大，地点和Bd的存在也有一定作用。变形菌门在蝌蚪的微生物群落中占主导地位，但后来被放线菌门取代。蝌蚪上的微真核生物以囊泡虫类和不等鞭毛类为主，而在变态后真菌类群取代了这些类群。通过一个新的抑制Bd细菌数据库，我们发现变态后阶段抑制Bd的细菌较少，这与皮肤真菌增加有关，表明细菌在早期发育阶段发挥着重要作用，并减少与皮肤相关的真菌。
