Foley Laboratory in Infectious Disease Ecology

Jonah Piovia-Scott

I worked as a postdoctoral researcher on the epidemiology and ecology of chytrid in Cascades frogs.

Batrachochytrium dendrobatidis (Bd), an emerging fungal pathogen of amphibians, has been implicated in die-offs and extinctions worldwide. I examined the effect of Bd on native amphibians in the mountains of northern California, focusing on the following questions:

What is the impact of Bd on the Cascades frog (Rana cascadae) in California?

The Cascades frog (Rana cascadae), has experienced dramatic declines in the vicinity of Lassen Volcanic National Park, in the southernmost part of its range. We investigated the role of Bd in these declines, as well as its effect the Cascades frog in other parts of California.

How do microbial symbionts influence the effect of Bd on the Cascades frog?

Naturally-occurring skin bacteria can limit the effect of Bd on amphibians. We catalogued the diversity of bacteria that occur on the skin of Cascades frogs and conducted experiments to determine if any of these bacteria have anti-fungal activity. These trials were followed up with experimental infections of amphibians to determine if skin microbes can influence the outcome of Bd infection.

How does environmental context influence the effect of Bd?

Bd can infect at least four of the seven amphibians that are common in lakes and ponds in the mountains of northern California. The effect of this pathogen on populations of any one amphibian species likely depend on which other amphibian species are present, as well as the physical and chemical characteristics of the habitat. We have conducted extensive sampling for Bd throughout the mountains of northern California in order to investigate the biotic and abiotic environment influences the relationship between Bd and its amphibian hosts.