Latitudinal variation in the prevalence and intensity of chytrid (Batrachochytrium dendrobatidis) infection in Eastern Australia
Latitudinal variation in the prevalence and intensity of chytrid (Batrachochytrium dendrobatidis) infection in Eastern Australia
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DOI：
10.1111/j.1523-1739.2007.00777.x
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发表时间：
2007-10-01
影响因子：
6.3
通讯作者：
Hero, Jean-Marc
中科院分区：
文献类型：
--
作者：
Kriger, Kerry M.;Pereoglou, Felicia;Hero, Jean-Marc
壶菌病是一种最近出现的两栖动物传染性皮肤病，与世界范围内的大规模死亡、人口下降和物种灭绝直接相关。迫切需要了解限制 Batrachochytrium dendrobatidis（壶菌病的病原体）分布和丰度的因素。我们对分布在澳大利亚东海岸 2315 公里（纬度 20.8 度）南北方向的 31 个低地进行了疾病调查。总共对863只成年雄性石溪蛙（Litoria lesueuri Complex）进行了采样，B. dendrobatidis感染的总体患病率为26%。 77% 的地点检测到 B. dendrobatidis，包括纬度样带北部和南部边界的地点。来自温带地区的青蛙，无论多么糟糕，感染程度都比热带青蛙严重得多，通常携带一个数量级的树突芽孢杆菌游动孢子，这表明在低海拔地区，温带青蛙因壶菌病引起的死亡风险比热带青蛙更高。在降雨量高（采样前 30 天内 >33 毫米）和气温较低（日落后 1 小时溪流温度 < 23 摄氏度）的地点，树突芽孢杆菌感染的流行率和强度明显更高。尽管气候变量解释了感染和未感染地点之间树突芽孢杆菌感染的流行率和强度的大部分差异，但青蛙口鼻部的长度始终是感染地点感染水平的最佳预测因子。小青蛙比大青蛙更容易被感染，并且携带更严重的感染，这表明青蛙可以通过生长摆脱壶菌感染，或者该疾病会引起限制生长的发育应激。我们的研究结果将直接帮助两栖动物疾病研究人员和野生动物管理者，他们的保护工作应集中于生活在我们所描述的 B. dendrobatidis 气候范围内的两栖动物种群。
Chytridiomycosis is a recently emerged, infectious skin disease of amphibians that has been linked directly to mass mortalities, population declines, and species extinctions worldwide. An understanding of the factors that limit the distribution and abundance of Batrachochytrium dendrobatidis (the etiological agent of chytridiomycosis) is urgently required. We conducted disease surveys at 31 lowland sites distributed north-south along 2315 km of the Australian east coast that encompassed 20.8 degrees of latitude. A total of 863 adult male stony creek frogs (Litoria lesueuri complex) were sampled, and the overall prevalence of B. dendrobatidis infection was 26%. B. dendrobatidis was detected at 77% of the sites, including sites at the northern and southern limits of the latitudinal transect. Frogs from temperate regions, however bad significantly more intense infections than did their tropical counterparts, often carrying an order of magnitude more B. dendrobatidis zoospores, suggesting that at low elevations, temperate frogs are at higher risk of chytridiomycosis-induced mortality than are tropical frogs. The prevalence and intensity of B. dendrobatidis infections were significantly greater at sites with high rainfall (>33 mm in the 30 days prior to sampling) and cool temperatures (stream temperature 1 h after sunset < 23 degrees C). Although climatic variables explained much of the variation in the prevalence and intensity of B. dendrobatidis infections between infected and uninfected sites, frog snout-vent length was consistently the best predictor of infection levels across infected sites. Small frogs were more likely to be infected and carried more intense infections than larger frogs, suggesting either that frogs can outgrow their chytrid infections or that the disease induces developmental stress that limits growth. Our results will directly assist amphibian disease researchers and wildlife managers, whose conservation efforts should focus on those amphibian populations living within the B. dendrobatidis climatic envelope that we have described.