Shedding light on environmentally transmitted parasites: lighter conditions within lakes restrict epidemic size
Shedding light on environmentally transmitted parasites: lighter conditions within lakes restrict epidemic size
复制标题
揭示环境传播的寄生虫：湖泊内较轻的条件限制了流行病的规模
DOI：
10.1002/ecy.3168
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发表时间：
2020
期刊：
影响因子：
4.8
通讯作者：
Duffy, Meghan A.
中科院分区：
文献类型：
--
作者：
Shaw, Clara L.;Hall, Spencer R.;Overholt, Erin P.;Cáceres, Carla E.;Williamson, Craig E.;Duffy, Meghan A.
寄生虫的适应性取决于从一个宿主到另一个宿主的成功旅程。对于环境传播的寄生虫来说，非生物条件可能会影响这一旅程的成功。在这里，我们评估光这一关键的非生物因素如何影响浮游动物疾病的时空模式，其中光随季节、湖泊和湖泊深度的变化而变化。在使用这三种变异源的原位实验中，我们测试了两种寄生虫的孢子对环境光的敏感性。与暴露在黑暗中类似条件下的寄生虫相比，暴露在环境光下的两种寄生虫的传染性较低。即使在深秋（11 月）较低的环境光线下，更敏感的寄生虫（真菌 Metschnikowia）也会受到损害。通过建立这种不同的敏感性，我们评估了光环境与湖泊自然爆发之间的联系。与孵化过程一致，不太敏感的寄生虫（巴氏杆菌）的流行在秋季早些时候开始（在较高的环境光下），并且这两种寄生虫在透明度较高的湖泊中爆发规模较小。总体而言，光环境可能会影响疾病爆发的时间和规模。因此，人类活动使水域变暗，包括与气候变化和富营养化相关的湖泊褐变，可能会加剧疫情的爆发。
Parasite fitness depends on a successful journey from one host to another. For parasites that are transmitted environmentally, abiotic conditions might modulate the success of this journey. Here we evaluate how light, a key abiotic factor, influences spatiotemporal patterns of zooplankton disease where light varies seasonally, across lakes, and with depth in a lake. In anin situexperiment using those three sources of variation, we tested sensitivity of spores of two parasites to ambient light. Infectivity of both parasites was lower when exposed to ambient light in comparison to parasites exposed to otherwise similar conditions in the dark. The more sensitive parasite (the fungus,Metschnikowia) was damaged even under lower ambient light during late fall (November). With this differential sensitivity established, we evaluated links between light environment and natural outbreaks in lakes. Consistent with the incubations, epidemics of the less sensitive parasite (the bacterium,Pasteuria) started earlier in the fall (under higher ambient light), and both parasites had smaller outbreaks in more transparent lakes. Overall, light environment may impact the timing and size of disease outbreaks. Outbreaks could thus become exacerbated by human activities that darken waters, including lake browning associated with climate change and eutrophication.