Department of Biology, Canadian Rivers Institute, University of New Brunswick, P.O. Box 5050, St. John, New Brunswick, E2L 4L5, Canada.
Conserv Biol. 2012 Feb;26(1):135-41. doi: 10.1111/j.1523-1739.2011.01801.x. Epub 2011 Dec 19.
Chytridiomycosis, caused by Batrachochytrium dendrobatidis (Bd), is widespread among amphibians in northeastern North America. It is unknown, however, whether Bd has the potential to cause extensive amphibian mortalities in northeastern North America as have occurred elsewhere. In the laboratory, we exposed seven common northeastern North American amphibian species to Bd to assess the likelihood of population-level effects from the disease. We exposed larval wood frogs (Lithobates sylvaticus) and postmetamorphic frogs of six other species to two different strains of Bd, a northeastern strain (JEL404) and a strain that caused die-offs of amphibians in Panama (JEL423), under ideal in vitro growth conditions for Bd. Exposed American toads (Anaxyrus americanus) all died; thus, this species may be the most likely to die from Bd-caused disease in the wild. Both Bd strains were associated with mortalities of wood frogs, although half the metamorphs survived. The Bd strain from Panama killed metamorphic green frogs (L. clamitans), whereas the northeastern strain did not, which means novel strains of Bd may lead to death even when local strains may not. No mortality was observed in four species (bullfrogs [L. catesbeianus], northern leopard frogs [L. pipiens], spring peepers [Pseudacris crucifer], and blue-spotted salamanders [Ambystoma laterale]) and in some individuals of green frogs and wood frogs that we exposed. This finding suggests these six species may be Bd vectors. Our results show that systematic exposures of amphibian species to Bd in the laboratory may be a good first step in the identification of species susceptible to Bd-caused declines and in directing regional conservation efforts aimed at susceptible species.
蛙壶菌病由蛙壶菌（Batrachochytrium dendrobatidis，Bd）引起，广泛存在于北美洲东北部的两栖动物中。然而，尚不清楚 Bd 是否有在北美洲东北部造成广泛两栖动物死亡的潜力，就像在其他地方发生的那样。在实验室中，我们将七种常见的北美洲东北部两栖物种暴露于 Bd 之下，以评估该疾病对种群水平产生影响的可能性。我们将幼年林蛙（Lithobates sylvaticus）和其他六种物种的幼体暴露于两种不同的 Bd 菌株，一种是来自东北部的菌株（JEL404），另一种是导致巴拿马两栖动物死亡的菌株（JEL423），这些菌株在理想的体外生长条件下对 Bd 具有感染力。暴露于 Bd 的美洲牛蛙（Anaxyrus americanus）全部死亡；因此，这种物种可能是在野外最有可能死于 Bd 引起的疾病的物种。两种 Bd 菌株都与林蛙的死亡有关，尽管有一半的变态期个体幸存下来。来自巴拿马的 Bd 菌株杀死了变态期的绿蛙（L. clamitans），而东北部的菌株则没有，这意味着即使当地的菌株可能不会导致死亡，新型 Bd 菌株也可能导致死亡。在四种物种（牛蛙[L. catesbeianus]、北方豹蛙[L. pipiens]、春蛙[Pseudacris crucifer]和斑点钝口螈[Ambystoma laterale]）和我们暴露的一些绿蛙和林蛙个体中没有观察到死亡率。这一发现表明这六种物种可能是 Bd 的载体。我们的结果表明，在实验室中对两栖物种进行系统的 Bd 暴露可能是识别易受 Bd 引起的下降影响的物种的良好第一步，并为针对易受影响的物种的区域保护工作提供指导。
