Patterns of Clinostomum marginatum infection in fishes and amphibians: integration of field, genetic, and experimental approaches
Patterns of Clinostomum marginatum infection in fishes and amphibians: integration of field, genetic, and experimental approaches
复制标题
DOI：
10.1017/s0022149x18001244
复制
发表时间：
2020-01-01
影响因子：
1.6
通讯作者：
Johnson, P. T. J.
中科院分区：
文献类型：
--
作者：
Calhoun, D. M.;Leslie, K. L.;Johnson, P. T. J.
斜口吸虫属的双发育吸虫是世界性寄生虫，以鱼类、两栖动物、爬行动物和蜗牛为中间宿主感染。尽管该属的地理分布广泛，但关于物种数量以及它们在宿主用途上如何变化的争论仍然存在。为了更好地了解宿主物种之间和整个生命阶段的感染模式，我们使用大规模实地调查和分子工具检查了来自加州 125 个池塘的 5 种两栖动物和 7 种鱼类。在接受检查的 12,360 名宿主中，感染情况很少见，两栖动物的总体患病率为 1.7%，鱼类的总体患病率为 9.2%。分子证据表明两组都感染了边缘斜口线虫。使用广义线性混合效应模型，宿主物种身份和宿主生命阶段对感染状态有很大影响，例如Lepomiscyanellus（绿色太阳鱼）（49.3％）和Taricha capsulosa（粗皮蝾螈）（9.2％）支持最高的总体流行率值，而成年两栖动物相对于幼年动物往往具有更高的感染流行率（分别为13.3％和2.5％）。通过实验，我们测试了两种两栖动物宿主（太平洋合唱蛙和Anaxyrus boea）对不同水平尾蚴暴露的敏感性，并测量了囊蚴随时间的生长情况。 Pseudacris regilla 对感染的敏感性高出 1.3 倍，而两种物种的感染成功率均随着尾蚴暴露剂量的增加而增加。平均而言，20 天内，掌蚴大小增加了 650%。我们的研究强调了整合实地调查、遗传工具和实验方法的重要性，以更好地了解宿主与寄生虫相互作用的生态学。
Digenetic trematodes of the genus Clinostomum are cosmopolitan parasites infecting fishes, amphibians, reptiles, and snails as intermediate hosts. Despite the broad geographical distribution of this genus, debate about the number of species and how they vary in host use has persisted. To better understand patterns of infection among host species and across life stages, we used large-scale field surveys and molecular tools to examine five species of amphibians and seven species of fishes from 125 California ponds. Among the 12,360 examined hosts, infection was rare, with an overall prevalence of 1.7% in amphibians and 9.2% in fishes. Molecular evidence indicated that both groups were infected with Clinostomum marginatum. Using generalized linear mixed effects models, host species identity and host life stage had a strong influence on infection status, such that Lepomis cyanellus (green sunfish) (49.3%) and Taricha granulosa (rough skinned newt) (9.2%) supported the highest overall prevalence values, whereas adult amphibians tended to have a higher prevalence of infection relative to juveniles (13.3% and 2.5%, respectively). Experimentally, we tested the susceptibility of two amphibian hosts (Pseudacris regilla [Pacific chorus frog] and Anaxyrus boreas [western toad]) to varying levels of cercariae exposure and measured metacercariae growth over time. Pseudacris regilla was 1.3x more susceptible to infection, while infection success increased with cercariae exposure dose for both species. On average, metacarcariae size increased by 650% over 20 days. Our study highlights the importance of integrating field surveys, genetic tools, and experimental approaches to better understand the ecology of host-parasite interactions.