An investigation of the prevalence of Giardia agilis in anuran amphibians from fourteen areas in China
An investigation of the prevalence of Giardia agilis in anuran amphibians from fourteen areas in China
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我国14个地区无尾两栖动物敏捷贾第鞭毛虫流行情况调查
DOI：
10.1016/j.ijppaw.2020.04.009
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发表时间：
2020-08-01
影响因子：
1.8
通讯作者：
Wen, Jianfan
中科院分区：
文献类型：
--
作者：
Lyu, Zhangxia;Cheng, Jiaoni;Wen, Jianfan
敏捷贾第鞭毛虫是一种贾第鞭毛虫，它的滋养体非常狭窄和细长，形态上可区分。虽然自1882年首次报道以来，对其形态学进行了一些研究，但迄今为止尚未报道其流行情况。我们调查了G.利用形态学和分子生物学方法对中国五省25种无尾两栖类中的agilis进行了研究。在463份检测样本中，195份（42.1%）为阳性。195份阳性样品来自9种两栖动物，分散分布于4个无尾两栖类科。不同蛙种的成虫和蝌蚪间的感染率差异不显著。因此，G. agilis可能能够感染所有无尾两栖动物，没有物种偏见。更有趣的是，蝌蚪的患病率明显高于成年人。同一地区疣突狭口蛙蝌蚪无足期和两足期的患病率差异不显著，但两足期的患病率显著高于四足期。四足期患病率仍远高于成人。在蝌蚪尾退化期出现流行转折点。阳性样本均来自海拔较高地区（870 m以上）。G. Agilis很容易感染生活在高海拔地区的青蛙，表明它已经进化出适应温度急剧变化的能力。因此，G. Agilis已经进化出一些特殊的成功的寄生策略，用于寄生具有变态的变形体宿主，例如无尾两栖动物。
Giardia agilis is a Giardia species which is morphological distinguishable for its very narrow and elongated trophozoite. Although there were a few studies about its morphology since its first report in 1882, none investigations about its prevalence have ever been reported to date. We investigated the prevalence of G. agilis in 25 anuran amphibian species from five provinces of China using both morphological and molecular methods. Of the 463 tested samples, 195 (42.1%) were positive. The 195 positive samples were from nine species, which are scatteredly distributed in four anuran amphibian families. The statistical prevalence among adults of different frog species showed no significant difference, and so did among tadpoles. Thus, G. agilis is probably able to infect all anuran amphibians without species-bias. More interestingly, the prevalence in the tadpoles is significantly higher than in their adults. The prevalence in Kaloula verrucosa tadpoles from the same area showed no significant differences between none-legged stage and two-legged stage, but the prevalence in these two developmental stages is significantly higher than in the four-legged stage. And the prevalence in four-legged stage is still much higher than in adults. A turning point of prevalence appeared in the period of tadpole tail degeneration. Moreover, all the positive samples were from the areas with relatively high altitude (more than 870 m). The fact that G. agilis tends to easily infect the frogs living in high altitude areas indicated it has evolved the ability to adapted the dramatic temperature change in poikilothermal animals. Therefore, G. agilis has evolved some special successful parasitism strategies for parasitizing the poikilothermal hosts with metamorphosis such as anuran amphibians.