美国田纳西州和阿肯色州地狱溪螈（Crypto branchus alleganiensis）中的重要两栖动物病原体的地理和个体决定因素。

GEOGRAPHIC AND INDIVIDUAL DETERMINANTS OF IMPORTANT AMPHIBIAN PATHOGENS IN HELLBENDERS (CRYPTOBRANCHUS ALLEGANIENSIS) IN TENNESSEE AND ARKANSAS, USA.

机构信息

University of Tennessee, Center for Wildlife Health, 274 Ellington PSB, Knoxville, Tennessee 37996, USA.

Wildlife Ecology Laboratory, Department of Agricultural and Environmental Sciences, Tennessee State University, 3500 John A. Merritt Blvd., Nashville, Tennessee 37209, USA.

出版信息

J Wildl Dis. 2020 Oct 1;56(4):803-814. doi: 10.7589/2019-08-203.

DOI:10.7589/2019-08-203

PMID:32544028

Abstract

Wildlife diseases are a major threat for species conservation and there is a growing need to implement disease surveillance programs to protect species of concern. Globally, amphibian populations have suffered considerable losses from disease, particularly from chytrid fungi (Batrachochytrium dendrobatidis [Bd] and Batrachochytrium salamandrivorans [Bsal]) and ranavirus. Hellbenders (Cryptobranchus alleganiensis) are large riverine salamanders historically found throughout several watersheds of the eastern and midwestern US. Populations of both subspecies (Ozark hellbender, Cryptobranchus alleganiensis bishopi; eastern hellbender, Cryptobranchus alleganiensis alleganiensis) have experienced precipitous declines over at least the past five decades, and emerging pathogens are hypothesized to play a role. We surveyed Ozark hellbender populations in Arkansas (AR) and eastern hellbender populations in Middle Tennessee (MTN) and East Tennessee (ETN) for both chytrid fungi and ranavirus from swabs and tail tissue, respectively, from 2011 to 2017. Overall, we detected Bd on hellbenders from nine out of 15 rivers, with total prevalence of 26.7% (54/ 202) that varied regionally (AR: 33%, 28/86; MTN: 11%, 4/36; ETN: 28%, 22/80). Ranavirus prevalence (9.0%, 18/200) was comparatively lower than Bd, with less regional variation in prevalence (AR: 6%, 5/ 85; MTN: 11%, 4/36; ETN: 10%, 8/79). We did not detect Bsal in any hellbender populations. We detected a significant negative correlation between body condition score and probability of ranavirus infection (β=-0.13, SE=0.06, 95% confidence interval: -0.24, -0.02). Evaluation of infection load of positive individuals revealed different trends than prevalence alone for both ranavirus and Bd, with MTN having a significantly greater average ranaviral load than both other regions. We documented a variety of lesions that likely have multiple etiologies on hellbenders located within all geographic regions. Our data represent a multiyear pathogen dataset across several regions of C. alleganiensis, and we emphasize the need for continued pathogen surveillance.

摘要

野生动物疾病是物种保护的主要威胁，因此越来越需要实施疾病监测计划来保护受关注的物种。在全球范围内，两栖动物种群因疾病而遭受了相当大的损失，尤其是由真菌（贝氏壶菌[Bd]和蛙壶菌[Bsal]）和虹彩病毒引起的疾病。大鲵（Cryptobranchus alleganiensis）是一种大型河流蝾螈，历史上分布在美国东部和中西部的多个流域。这两个亚种（奥沙克大鲵，Cryptobranchus alleganiensis bishopi；东部大鲵，Cryptobranchus alleganiensis alleganiensis）的种群在过去至少五十年中都经历了急剧下降，而新兴病原体被认为是造成这种下降的原因之一。我们在 2011 年至 2017 年间，从阿肯色州（AR）的奥沙克大鲵种群和中田纳西州（MTN）和东田纳西州（ETN）的东部大鲵种群中，分别从拭子和尾部组织中检测到了真菌和虹彩病毒。总的来说，我们在 15 条河流中的 9 条河流中检测到了 Bd，总流行率为 26.7%（54/202），在不同地区存在差异（AR：33%，28/86；MTN：11%，4/36；ETN：28%，22/80）。虹彩病毒的流行率（9.0%，18/200）相对较低，在流行率方面的地区差异较小（AR：6%，5/85；MTN：11%，4/36；ETN：10%，8/79）。我们没有在任何大鲵种群中检测到 Bsal。我们发现，大鲵的身体状况评分与虹彩病毒感染的概率呈显著负相关（β=-0.13，SE=0.06，95%置信区间：-0.24，-0.02）。对阳性个体的感染负荷进行评估后发现，虹彩病毒和 Bd 的阳性率与流行率单独分析的结果不同，MTN 的平均虹彩病毒负荷明显高于其他两个地区。我们在所有地理区域的大鲵身上都发现了多种可能有多种病因的病变。我们的数据代表了 C. alleganiensis 多个地区多年的病原体数据，我们强调需要继续进行病原体监测。