Assessing the Impact of Temperature and Innate Immune Priming on Batrachochytrium salamandrivorans Infection in Eastern Newts (Notophthalmus viridescens)
McCartne, J., D. Woodham, and M. J. Gray.  2020.  International Conference of the Wildlife Disease Association, Cuenca, Spain.

Abstract:
Rapid losses in global amphibian biodiversity have been in part due to the spread of chytridiomycosis, caused by the fungal pathogens Batrachochytrium dendrobatidis (Bd) and Batrachochytrium salamandrivorans (Bsal). The latter was identified in 2010 and has been detrimental to several salamander populations throughout Europe. With the highest global level of salamander biodiversity found in the United States, the spread of the Bsal to the Americas stands to severely impact existing populations. A better understanding of the biological and environmental factors that contribute to Bsal severity at multiple life stages is foundational to creating effective treatment plans and reducing the spread to preserve existing biodiversity. The Eastern Newt (Notophthalmus viridescens) has a broad geographic range across the eastern half of the United States and parts of Canada, and chytridiomycosis development is delayed compared to that of the original Fire Salamander populations Bsal was identified in. These factors make N. viridescens a favorable model to study the pathogenís epidemiology. Prior work demonstrates that at 6 C and 14 C, N. viridescens are susceptible to Bsal, but not at 22 C, implying that there could be a seasonality to infection. Identifying a temperature at which some individuals can successfully clear the infection is invaluable for studies involving repeated exposures and for developing seasonal treatment plans. Additionally, while work had been done to understand the role of the adaptive immune system in combating pathogenic chytrids, the role of the innate immune response remains understudied. Juvenile, terrestrial N. viridescens were exposed to Bsal at 17.5 C, prior to which a subset underwent a skin abrasion treatment to assess the impact of priming the innate immune system in a way the mimics potential natural injury. The impacts of temperature and innate immune priming on survival and their implications for policy creation will be discussed.