COS 90-9
Effects of temperature on cutaneous antifungal bacteria of amphibians
Amphibians have been undergoing declines and extinctions on a global scale since the early 1970’s. Chytridiomycosis, the amphibian disease caused by the chytrid fungus Batrachochytrium dendrobatidis (Bd), is responsible for some of these declines with certain species being harder hit than others. It remains unclear why variation in susceptibility and mortality exists within and among species. It has been suggested that the effects of temperature and different aspects of the immune system of amphibians are major drivers of this variation, specifically antifungal cutaneous bacteria of amphibians. This study addressed whether differences in temperature resulted in different levels of effectiveness of the antifungal bacteria. This was done by collecting bacterial isolates from two species of frogs (Acris crepitans and Lithobates sphenocephala), incubating them under three different temperatures (14, 20 or 26°), collecting the metabolites produced during growth, and then challenging the metabolites collected against Bd under the same temperatures (14, 20 or 26°).
Results/Conclusions
Some of the metabolites caused total inhibition across all three temperatures, while others showed varying levels of inhibition. There was an effect of bacterial incubation temperature on Bd growth as well as an effect of challenge temperature, indicating that temperature does have an impact on the microbial communities of amphibians and their interaction with Bd.