Timing and order of exposure to two echinostome species affect patterns of infection in larval amphibians
Timing and order of exposure to two echinostome species affect patterns of infection in larval amphibians
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DOI：
10.1017/s0031182020001092
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发表时间：
2020-11-01
期刊：
影响因子：
2.4
通讯作者：
Hoverman, Jason T.
中科院分区：
文献类型：
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作者：
Billet, Logan S.;Wuerthner, Vanessa P.;Hoverman, Jason T.
关于合并感染的优先效应的研究仍处于起步阶段。此外，现有的共感染研究通常集中在感染结果与暴露于不同的寄生虫物种，尽管功能和形态相似的寄生虫物种通常共存于自然界。因此，了解相似寄生虫之间的相互作用如何影响感染结果非常重要。在宾夕法尼亚州西北部的七个池塘进行的调查发现，多个物种的棘口动物通常同时出现。使用幼虫无尾类主机（蛙pipiens）和两个最常见的棘口类物种从我们的实地调查（Echinostoma trivolvis和Echinoparyphium谱系3），我们研究了如何物种组成和曝光时间影响感染模式。当蝌蚪同时暴露于两种寄生虫时，感染负荷高于单独暴露于棘皮虫时，但与单独暴露于棘口吸虫时相似。当蝌蚪依次暴露于寄生虫物种，蝌蚪第一次暴露于Echinoparyphium有23%的感染负荷比蝌蚪第一次暴露于棘口线虫。这些发现表明，暴露的时间和顺序，即使是类似的寄生虫，可以影响合并感染的结果，并强调使用分子方法来识别寄生虫的生态研究的重要性。
The study of priority effects with respect to coinfections is still in its infancy. Moreover, existing coinfection studies typically focus on infection outcomes associated with exposure to distinct sets of parasite species, despite that functionally and morphologically similar parasite species commonly coexist in nature. Therefore, it is important to understand how interactions between similar parasites influence infection outcomes. Surveys at seven ponds in northwest Pennsylvania found that multiple species of echinostomes commonly co-occur. Using a larval anuran host (Rana pipiens) and the two most commonly identified echinostome species from our field surveys (Echinostoma trivolvis and Echinoparyphium lineage 3), we examined how species composition and timing of exposure affect patterns of infection. When tadpoles were exposed to both parasites simultaneously, infection loads were higher than when exposed to Echinoparyphium alone but similar to being exposed to Echinostoma alone. When tadpoles were sequentially exposed to the parasite species, tadpoles first exposed to Echinoparyphium had 23% lower infection loads than tadpoles first exposed to Echinostoma. These findings demonstrate that exposure timing and order, even with similar parasites, can influence coinfection outcomes, and emphasize the importance of using molecular methods to identify parasites for ecological studies.