Davis Leyla R, Bigler Laurent, Woodhams Douglas C
Institute of Evolutionary Biology and Environmental Studies.
Institute of Organic Chemistry, University of Zurich, Winterthurerstrasse 190, Zurich, CH-8057, Switzerland.
Environ Microbiol. 2017 Apr;19(4):1502-1517. doi: 10.1111/1462-2920.13707. Epub 2017 Mar 17.
Improving host health through microbial manipulation requires untangling factors that shape the microbiome. There is currently little understanding of how initial community structure may drive the microbiota trajectory across host development or influence bacterial therapy outcomes. Probiotic baths of surface symbionts, Pseudomonas fluorescens and Flavobacterium johnsoniae were administered to 240 tadpoles of the midwife toad, Alytes obstetricans in semi-natural outdoor mesocosms originating from geographically and genetically distinct populations in Switzerland. Host bacterial and fungal assemblages were compared in tadpoles from the pond of origin, across metamorphosis, and in toadlets via microbial fingerprinting. Bacterial and fungal community structures differed significantly among populations and a microbial population signature persisted from the tadpole stage, through metamorphosis, and following probiotic treatment. A minimal core surface microbiota is described by persistence through development and by shared membership across populations. The impact of F. johnsoniae on the tadpole surface microbiome was assessed with shotgun metagenomics. Bacterial therapy reduced abundance, diversity, and functional repertoire compared to untreated controls. A correlation between host skin peptides and microbiota suggests a mechanism of host-directed symbiosis throughout development. Early developmental stages are ideal targets for amphibian bacterial therapy that can govern a microbiome trajectory at critical timepoints and may impact susceptibility to disease.
通过微生物调控改善宿主健康需要理清塑造微生物组的各种因素。目前对于初始群落结构如何驱动宿主发育过程中的微生物群轨迹或影响细菌治疗效果知之甚少。在瑞士，从地理和基因上不同的种群采集的半自然户外中型生态箱中，给240只产婆蟾（Alytes obstetricans）蝌蚪施用了表面共生菌荧光假单胞菌（Pseudomonas fluorescens）和琼氏黄杆菌（Flavobacterium johnsoniae）的益生菌浴。通过微生物指纹图谱比较了来自原生池塘的蝌蚪、变态过程中的蝌蚪以及幼蟾的宿主细菌和真菌群落。种群间细菌和真菌群落结构存在显著差异，并且微生物种群特征从蝌蚪阶段持续到变态过程以及益生菌处理之后。通过发育过程中的持续性和种群间的共享成员身份描述了一个最小核心表面微生物群。用鸟枪法宏基因组学评估了琼氏黄杆菌对蝌蚪表面微生物组的影响。与未处理的对照组相比，细菌治疗降低了丰度、多样性和功能库。宿主皮肤肽与微生物群之间的相关性表明了整个发育过程中宿主定向共生的机制。早期发育阶段是两栖动物细菌治疗的理想靶点，这种治疗可以在关键时间点控制微生物组轨迹，并可能影响疾病易感性。
