Salinity stress increases the severity of ranavirus epidemics in amphibian populations
Salinity stress increases the severity of ranavirus epidemics in amphibian populations
复制标题
盐度胁迫增加了两栖动物种群中蛙病毒流行的严重程度
DOI：
10.1098/rspb.2020.0062
复制
发表时间：
2020
期刊：
影响因子：
--
通讯作者：
Crespi, Erica J.
中科院分区：
文献类型：
--
作者：
Hall, Emily M.;Brunner, Jesse L.;Hutzenbiler, Brandon;Crespi, Erica J.
压力诱导的易感性假说，预测慢性压力会削弱免疫防御，被提出来解释传染病相关的大规模死亡率和人口下降的增加。以前的工作特点是湿地盐碱化作为一个慢性应激源的幼体两栖动物种群。因此，我们结合现场观察与实验暴露量化流行病学参数，以测试的作用，盐度胁迫发生的Ranavirus相关的大规模死亡事件。尽管普遍存在病原体（94%），但暴露于盐径流的人群中与Ranavirus相关的大规模死亡事件发生频率略高，致命感染率更高，病原体环境DNA增加了117倍。实验性暴露于慢性高盐度（0.8-1.6 g l−1Cl−）降低了对感染的耐受性，在较低剂量下导致更高的死亡率。我们发现了一个强有力的负相关关系，脾细胞增殖和皮质酮在Ranavirus感染的幼虫在适度升高的盐度，支持糖皮质激素介导的免疫抑制，但不是在高盐度。单独的盐度在相似的皮质酮水平和感染强度下进一步降低增殖。最后，在高盐度下饲养的幼虫感染强度是对照组的10倍，释放的病毒是对照组的5倍，病毒衰减率相似，这表明传播增加。我们的研究结果说明了栖息地质量的微小变化如何导致更致命的感染和潜在的更高的传播效率，增加了蛙病毒流行的严重性。
The stress-induced susceptibility hypothesis, which predicts chronic stress weakens immune defences, was proposed to explain increasing infectious disease-related mass mortality and population declines. Previous work characterized wetland salinization as a chronic stressor to larval amphibian populations. Thus, we combined field observations with experimental exposures quantifying epidemiological parameters to test the role of salinity stress in the occurrence of ranavirus-associated mass mortality events. Despite ubiquitous pathogen presence (94%), populations exposed to salt runoff had slightly more frequent ranavirus related mass mortality events, more lethal infections, and 117-times greater pathogen environmental DNA. Experimental exposure to chronic elevated salinity (0.8–1.6 g l−1Cl−) reduced tolerance to infection, causing greater mortality at lower doses. We found a strong negative relationship between splenocyte proliferation and corticosterone in ranavirus-infected larvae at a moderate elevation of salinity, supporting glucocorticoid-medicated immunosuppression, but not at high salinity. Salinity alone reduced proliferation further at similar corticosterone levels and infection intensities. Finally, larvae raised in elevated salinity had 10 times more intense infections and shed five times as much virus with similar viral decay rates, suggesting increased transmission. Our findings illustrate how a small change in habitat quality leads to more lethal infections and potentially greater transmission efficiency, increasing the severity of ranavirus epidemics.
登录
查看更多内容
食腐动物会预防还是促进疾病传播？
影响因子：
5.2
作者：
Mitchell Le Sage;Bailey D. Towey;J. Brunner
通讯作者：
J. Brunner
盐避难所的证据：暴露于盐的宿主中壶菌感染量受到抑制
影响因子：
2.7
作者：
M. Stockwell;J. Clulow;M. Mahony
通讯作者：
M. Mahony
影响因子：
1.2
作者：
Chang, P. H.;Plumb, J. A.
通讯作者：
Plumb, J. A.
寄生虫感染导致脊椎动物宿主体内糖皮质激素广泛增加：一项荟萃分析。
影响因子：
4.8
作者：
K. O'Dwyer;F. Dargent;M. Forbes;J. Koprivnikar
通讯作者：
J. Koprivnikar
抵抗力、耐受力和环境传播动态决定了负载依赖性两栖动物疾病的宿主灭绝风险。
影响因子：
8.8
作者：
M. Wilber;R. Knapp;Mary H. Toothman;C. Briggs
通讯作者：
C. Briggs