Kira Miller

San Francisco State University

“Investigating the roles of skin microbiota and reservoir hosts in amphibian disease in the Sierra Nevada”

Chytridiomycosis is a cutaneous amphibian disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), which has resulted in amphibian declines worldwide. However, susceptibility to Bd infection varies between amphibian host species. In the Sierra Nevada, endangered mountain yellow-legged frogs (Rana sierrae and Rana muscosa) are highly susceptible to Bd. In contrast, the co-occurring Pacific chorus frog (Pseudacris regilla) is less susceptible and has been proposed as a Bd reservoir host. Recent studies of amphibian skin microbiomes indicate that in some amphibian species, symbiotic skin bacteria may facilitate survival against Bd infection by producing antifungal compounds. Although P. regilla are one of the most abundant and widespread amphibians in western North America, this species and its interactions with Bd are understudied. At sites with different amphibian compositions, I investigate and compare Bd infection prevalence and intensity between R. sierrae and P. regilla in the Sierra Nevada. Continuing work will utilize 16s rRNA sequencing data to characterize the skin microbial communities of both anuran hosts, and determine how microbiome composition may influence disease outcomes for these species.


The emergent fungal pathogen Batrachochytrium dendrobatidis (Bd) causes the amphibian disease chytridiomycosis, yet susceptibility to this disease varies among amphibian hosts. My research investigates how compositional differences in the amphibian skin microbiome (symbiotic bacteria) may contribute to disease susceptibility or resistance between two frog species in the Sierra Nevada.

2 + 5 =