Amphibian populations are suffering unprecedented global population declines. Although many factors contribute to these declines, overwhelming evidence links many declines to an emerging infectious disease, chytridiomycosis, caused by the skin fungus, Batrachochytrium dendrobatidis. This global ecological crisis provides a unique opportunity to study immune mechanisms of disease resistance in wildlife species. The project will investigate immune mechanisms that protect some resistant amphibian species in order to develop better strategies to protect more susceptible amphibians. One set of protective factors produced by frogs is the set of small skin proteins called antimicrobial peptides (AMPs). Another possible defense is provided by the community of bacteria that live on frog skin. A possible strategy to protect vulnerable amphibians is to transfer protective bacteria that can interfere with the fungus from resistant frogs to susceptible frogs. The project will identify new species of bacteria that inhabit frog skin and release antifungal products. These studies will advance our understanding of fundamental immune defense mechanisms in amphibians while promoting education and training. New AMPs or bacterial products may have therapeutic value for human medicine. The research will support amphibian conservation efforts by development of treatment or management strategies to protect rare endangered species in captivity until a time when founder populations can be returned to the wild.