Collaborative Research (RAPID): Testing Intervention Strategies to Change the Outcome of Disease-caused Mass-mortality Events in a Declining Amphibian

新的疾病正在以越来越快的速度出现，并在许多情况下对野生动物物种产生毁灭性的影响。两栖类壶菌（Batrachochytrium dendroatidis; Bd）引起壶菌病，自其出现以来，已导致全世界数百种两栖动物灭绝或严重减少。在加州吗?在内华达山脉，壶菌病导致曾经常见的山黄腿蛙几乎灭绝。2012年夏季，该地区现存最大的山黄腿蛙种群将因近期Bd的到来而灭绝。在山黄腿蛙种群中，先前未受感染的种群中Bd的到来通常会导致青蛙种群灭绝，而拟议研究的目标是改变结果，使青蛙种群长期存在。这一疾病干预措施将采取实地试验的形式，在虫媒引起的青蛙死亡期间实施。在本实验中，两种治疗方法（1)抗真菌药物和(2)增加青蛙皮肤上天然存在的抗真菌细菌）的有效性将在整个青蛙种群的规模上进行评估。该实验还将为描述治疗效果的机制提供机会，包括青蛙免疫系统的作用、青蛙皮肤上的微生物群落以及青蛙的快速进化。根据以前实验室和小规模实地试验的结果，预计抗真菌药物和细菌增强治疗将提高青蛙的存活率，相对于未经治疗的青蛙。拟议研究的结果将对世界范围内受到新出现疾病威胁的野生动物物种（例如两栖动物、蝙蝠、猿类）的保护工作产生重要影响。这项研究还将为本科生和研究生提供培训机会，并尽一切努力尽可能包括来自代表性不足群体的学生。

New diseases are emerging at an increasing rate, and in numerous cases are having devastating effects on wildlife species. The amphibian chytrid fungus (Batrachochytrium dendrobatidis; Bd) causes the disease chytridiomycosis that since its emergence has resulted in the extinction or serious decline of hundreds of amphibian species worldwide. In California?s Sierra Nevada, chytridiomycosis has caused the near-extinction of the once-common mountain yellow-legged frog. During summer 2012, the largest remaining mountain yellow-legged frog population will suffer a die-off event caused by the recent arrival of Bd in the area. In mountain yellow-legged frog populations the arrival of Bd in a previously uninfected population typically results in frog population extinction, and the goal of the proposed study is to change the outcome to long-term frog population persistence. This disease intervention will take the form of a field experiment implemented during the Bd-caused frog die-off. In this experiment the effectiveness of two treatments, (1) an antifungal drug, and (2) the augmentation of antifungal bacteria that occur naturally on frog skin, will be assessed at the scale of an entire frog population. This experiment will also provide an opportunity to describe the mechanisms underlying treatment effectiveness, including the role of the frog immune system, the microbial community present on the skin of frogs, and rapid evolution in frogs. Based on results from previous laboratory and small-scale field trials it is expected that antifungal drug and bacterial augmentation treatments will increase frog survival relative to frogs that are left untreated. Results from the proposed study will have important implications for conservation efforts aimed at wildlife species worldwide that are threatened by emerging diseases (e.g., amphibians, bats, apes). The study will also provide training opportunities for undergraduate and graduate students, with every effort made to include those from underrepresented groups to the maximum extent possible.