The benefits of coinfection: trematodes alter disease outcomes associated with virus infection.
The benefits of coinfection: trematodes alter disease outcomes associated with virus infection.
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混合感染的好处：吸虫改变与病毒感染相关的疾病结果。
DOI：
10.1111/1365-2656.12665
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发表时间：
2017
期刊：
影响因子：
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通讯作者：
Hoverman,JasonT
中科院分区：
文献类型：
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作者：
Wuerthner,VanessaP;Hua,Jessica;Hoverman,JasonT
合并感染日益被认为是疾病动态的重要驱动因素。因此，更加强调将群落生态学的原理与疾病生态学相结合，以了解寄生虫之间的宿主内相互作用。利用两栖类幼虫和两种两栖类寄生虫（蛙病毒和吸虫Echinoparyphiumsp.），我们检验了合并感染对疾病结果的影响。2我们的第一个目标是检验优先效应（寄生虫暴露的时间和顺序）如何影响实验室中的感染和疾病结果。我们发现寄生虫之间的相互作用是不对称的;先前感染棘顶孢菌可使Ranavirus载量减少9%，但先前感染Ranavirus对棘顶孢菌载量没有相互影响。此外，存活率的主机（幼虫灰树蛙;雨蛙）感染Echinoparyphium 10天前，病毒exposure相比，主机只暴露于virus.Our的第二个目标是要确定这些模式是否是generalizable多个两栖动物物种在更自然的条件下。我们进行了一个半自然的围隔实验，包括四个幼虫两栖动物宿主[灰树蛙，美洲蟾蜍（Anaxyrus americanus），豹蛙（Lithobates pipiens）和春天的偷窥者（Pseudacris crucifer）]，以研究先前Echinoparyphium感染如何影响社区内的蛙病毒传播，使用蛙病毒感染的幼虫林蛙（Lithobates sylvaticus）作为蛙病毒的来源。与实验室实验一致，我们发现，在四个物种中的三个物种中，先前的Echinoparyphium感染使Ranavirus载量降低了19%至28%。总的来说，这些结果表明，大型寄生虫感染可以降低多种两栖动物物种中的微寄生虫复制率，可能是通过交叉反应性免疫。虽然驱动这一结果的免疫机制需要进一步研究，吸虫感染似乎有利于暴露于蛙病毒的宿主。此外，这些结果表明，考虑优先效应和暴露时间对于了解宿主内寄生虫相互作用和疾病结果至关重要。
Coinfections are increasingly recognized as important drivers of disease dynamics. Consequently, greater emphasis has been placed on integrating principles from community ecology with disease ecology to understand within‐host interactions among parasites. Using larval amphibians and two amphibian parasites (ranaviruses and the trematodeEchinoparyphiumsp.), we examined the influence of coinfection on disease outcomes.Our first objective was to examine how priority effects (the timing and sequence of parasite exposure) influence infection and disease outcomes in the laboratory. We found that interactions between the parasites were asymmetric; prior infection withEchinoparyphiumreduced ranaviral loads by 9% but there was no reciprocal effect of prior ranavirus infection onEchinoparyphiumload. Additionally, survival rates of hosts (larval gray treefrogs;Hyla versicolor) infected withEchinoparyphium10 days prior to virus exposure were 25% greater compared to hosts only exposed to virus.Our second objective was to determine whether these patterns were generalizable to multiple amphibian species under more natural conditions. We conducted a semi‐natural mesocosm experiment consisting of four larval amphibian hosts [gray treefrogs, American toads (Anaxyrus americanus), leopard frogs (Lithobates pipiens) and spring peepers (Pseudacris crucifer)] to examine how priorEchinoparyphiuminfection influenced ranavirus transmission within the community, using ranavirus‐infected larval wood frogs (Lithobates sylvaticus) as source of ranavirus. Consistent with the laboratory experiment, we found that priorEchinoparyphiuminfection reduced ranaviral loads by 19 to 28% in three of the four species.Collectively, these results suggest that macroparasite infection can reduce microparasite replication rates across multiple amphibian species, possibly through cross‐reactive immunity. Although the immunological mechanisms driving this outcome are in need of further study, trematode infections appear to benefit hosts that are exposed to ranaviruses. Additionally, these results suggest that consideration of priority effects and timing of exposure are vital for understanding parasite interactions within hosts and disease outcomes.