Muletz-Wolz Carly R, DiRenzo Graziella V, Yarwood Stephanie A, Campbell Grant Evan H, Fleischer Robert C, Lips Karen R
Department of Biology, University of Maryland, College Park, Maryland, USA
Center for Conservation Genomics, Smithsonian Conservation Biology Institute, National Zoological Park, Washington, DC, USA.
Appl Environ Microbiol. 2017 Apr 17;83(9). doi: 10.1128/AEM.00186-17. Print 2017 May 1.
Diverse bacteria inhabit amphibian skin; some of those bacteria inhibit growth of the fungal pathogen Yet there has been no systematic survey of anti- bacteria across localities, species, and elevations. This is important given geographic and taxonomic variations in amphibian susceptibility to Our collection sites were at locations within the Appalachian Mountains where previous sampling had indicated low prevalence. We determined the numbers and identities of anti- bacteria on 61 salamanders (37 , 15 , 9 ) via culturing methods and 16S rRNA gene sequencing. We sampled co-occurring species at three localities and sampled along an elevational gradient (700 to 1,000 meters above sea level [masl]) at one locality. We identified 50 anti- bacterial operational taxonomic units (OTUs) and found that the degree of inhibition was not correlated with relatedness. Five anti- bacterial strains occurred on multiple amphibian species at multiple localities, but none were shared among all species and localities. The prevalence of anti- bacteria was higher at Shenandoah National Park (NP), VA, with 96% (25/26) of salamanders hosting at least one anti- bacterial species compared to 50% (7/14) at Catoctin Mountain Park (MP), MD, and 38% (8/21) at Mt. Rogers National Recreation Area (NRA), VA. At the individual level, salamanders at Shenandoah NP had more anti- bacteria per individual (μ = 3.3) than those at Catoctin MP (μ = 0.8) and at Mt. Rogers NRA (μ = 0.4). All salamanders tested negative for Anti- bacterial species are diverse in central Appalachian salamanders, and their distribution varied geographically. The antifungal bacterial species that we identified may play a protective role for these salamanders. Amphibians harbor skin bacteria that can kill an amphibian fungal pathogen, Some amphibians die from infection, whereas others do not. The bacteria that can kill , called anti- bacteria, are thought to influence the infection outcome for the amphibian. Yet how anti- bacterial species vary among amphibian species and populations is unknown. We determined the distribution of anti- bacterial species among three salamander species ( = 61) sampled at three localities. We identified 50 unique anti- bacterial species and found that all of the tested salamanders were negative for Five anti- bacterial species were commonly detected, suggesting a stable, functional association with these salamanders. The number of anti- bacteria per individual varied among localities but not among co-occurring salamander species, demonstrating that environment is more influential than host factors in structuring the anti- bacterial community. These anti- bacteria may serve a protective function for their salamander hosts.
多种细菌栖息于两栖动物的皮肤；其中一些细菌会抑制真菌病原体的生长。然而，尚未对不同地点、物种和海拔高度的抗菌细菌进行系统调查。考虑到两栖动物对（此处原文缺失相关内容）易感性的地理和分类学差异，这一点很重要。我们的采集地点位于阿巴拉契亚山脉内之前采样显示患病率较低的区域。我们通过培养方法和16S rRNA基因测序确定了61只蝾螈（37只[此处原文缺失相关内容]，15只[此处原文缺失相关内容]，9只[此处原文缺失相关内容]）身上抗菌细菌的数量和种类。我们在三个地点对共生物种进行了采样，并在一个地点沿着海拔梯度（海拔700至1000米）进行了采样。我们鉴定出50个抗菌细菌操作分类单元（OTUs），发现抑制程度与亲缘关系无关。五种抗菌菌株出现在多个地点的多种两栖动物物种身上，但没有一种在所有物种和地点中都存在。弗吉尼亚州谢南多厄国家公园（NP）的抗菌细菌患病率较高，96%（25/26）的蝾螈身上至少有一种抗菌细菌物种，而马里兰州卡托克廷山公园（MP）为50%（7/14），弗吉尼亚州罗杰斯山国家休闲区（NRA）为38%（8/21）。在个体层面，谢南多厄国家公园的蝾螈个体身上的抗菌细菌更多（μ = 3.3），而卡托克廷山公园的蝾螈（μ = 0.8）和罗杰斯山国家休闲区的蝾螈（μ = 0.4）则较少。所有测试的蝾螈对（此处原文缺失相关内容）检测均为阴性。阿巴拉契亚中部蝾螈身上的抗菌细菌物种多样，其分布存在地理差异。我们鉴定出的抗真菌细菌物种可能对这些蝾螈起到保护作用。两栖动物体内携带的皮肤细菌可以杀死两栖动物真菌病原体， 一些两栖动物死于 感染，而另一些则不会。能够杀死 的细菌，即抗菌细菌，被认为会影响两栖动物的 感染结果。然而，抗菌细菌物种在两栖动物物种和种群之间如何变化尚不清楚。我们确定了在三个地点采样的三种蝾螈物种（共61只）中抗菌细菌物种的分布。我们鉴定出50种独特的抗菌细菌物种，发现所有测试的蝾螈对（此处原文缺失相关内容）检测均为阴性。五种抗菌细菌物种被普遍检测到，表明与这些蝾螈存在稳定的功能关联。每个个体身上的抗菌细菌数量在不同地点有所不同，但在共生蝾螈物种之间没有差异，这表明在构建抗菌细菌群落方面，环境比宿主因素更具影响力。这些抗菌细菌可能对它们的蝾螈宿主起到保护作用。
