Identity and density of parasite exposures alter the outcome of coinfections: Implications for management
Identity and density of parasite exposures alter the outcome of coinfections: Implications for management
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寄生虫暴露的身份和密度改变了合并感染的结果：对管理的影响
DOI：
10.1111/1365-2664.14332
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发表时间：
2023
影响因子：
5.7
通讯作者：
Rohr, Jason R.
中科院分区：
文献类型：
--
作者：
Ramsay, Chloe;Rohr, Jason R.
尽管研究重点是宿主对单一寄生虫感染的密度依赖性反应，但宿主在自然条件下同时暴露于多种寄生虫，如果这些暴露导致感染，它们可能会威胁宿主种群和生态系统的稳定性。此外，同时存在的寄生虫丰度的时空变化可能会影响宿主感染强度。如果不同的共感染寄生虫之间的相互作用是一致的，那么这些模式可以为管理者提供另一种工具来控制疾病传播，甚至预测有问题的疾病的出现。我们研究了寄生虫密度和身份如何改变宿主内共感染动态。为了测试这一点，我们同时将古巴树蛙（Osteopilus septentrionalisa）（一种两栖动物模型）暴露于通常同时感染两栖动物的三种有问题的寄生虫的所有成对组合中：真菌Batrachochytrium dendrobatidis（Bd）、线虫Aplectana hamatospicula和Ranavirus。宿主以固定剂量接触一种寄生虫，并以五种剂量接触另一种寄生虫。较高剂量的 Bd 会降低 Ranaviral 和 A。 hamatospiculaloads，但 Bd 负载不受任一寄生虫剂量的影响。蛙病毒载量与A呈负相关。错构穗糖，但是A. Hamatospiculaload 不受 Ranaviral 剂量的影响。我们发现所有成对共感染都依赖于寄生虫密度，并且成对相互作用高度不对称——一个方向强，另一个方向弱——与主导食物网的相互作用一致。 合成和应用：我们还揭示了A.的暴露剂量。 hamatospicula 与宿主对 Bd 感染的耐受性呈正相关，与宿主中的蛙病毒载量呈负相关。蛙病毒和 Bd 导致两栖动物大规模死亡，butA。 Hamatospicula没有。因此，在这些寄生虫共存的系统中，维持或增加A的密度。 hamatospicula 可以减少 Bd 和蛙病毒感染的负面影响。此外，如果群落生态学中的这些不对称和密度依赖模式适用于其他两栖动物双重感染或其他系统中的双重感染，那么保护组织和资源管理者就可以通过改变可能更容易管理的双重感染寄生虫的丰度来预测爆发并管理与致命寄生虫相关的宿主下降。
Although research has focused on density‐dependent responses of hosts to single‐parasite infections, hosts are exposed to numerous parasites simultaneously under natural conditions and if these exposures lead to infections, they can threaten host populations and ecosystem stability. Moreover, spatiotemporal variation in abundance of co‐occurring parasites might influence host infection intensity. If interactions are consistent between different coinfecting parasites, then these patterns could give managers another tool to control disease spread and even predict problematic disease emergences.We investigated how parasite density and identity alter within‐host coinfection dynamics. To test this, we simultaneously exposed Cuban treefrogsOsteopilus septentrionalisas a model amphibian species to all pairwise combinations of three problematic parasites that commonly coinfect amphibians: the fungusBatrachochytrium dendrobatidis(Bd), the nematodeAplectana hamatospiculaand Ranavirus. Hosts were exposed to one parasite at a fixed dose and another parasite at a range of five doses.Higher doses of Bd decreased Ranaviral andA. hamatospiculaloads, but Bd load was not influenced by the dose of either parasite. Ranaviral load was negatively associated withA. hamatospiculadose, butA. hamatospiculaload was not affected by Ranaviral dose. We found that all the pairwise coinfections were dependent on parasite density and that pairwise interactions were highly asymmetric—strong in one direction and weak in the other—consistent with interactions dominating food webs.Synthesis and applications: We also revealed that the exposure dose ofA. hamatospiculawas positively associated with host tolerance to Bd infection and negatively associated with Ranaviral load in hosts. Ranavirus and Bd cause mass die‐offs in amphibians, butA. hamatospiculadoes not. Therefore, in systems where these parasites coexist, maintaining or increasing densities ofA. hamatospiculacould reduce the negative effects of Bd and Ranavirus infections. Additionally, if these asymmetric and density‐dependent patterns from community ecology are applicable to other amphibian coinfections or coinfections in other systems, this should allow conservation organizations and resource managers to predict outbreaks and manage host declines associated with deadly parasites by modifying the abundance of coinfecting parasites that might be easier to manage.