This dissertation consists of three manuscripts for publication: Appendix A presents a genomic comparison of Aspergillus flavus isolates with different morphologies, and Appendices B and C present the identification and systematics of an emerging snake pathogen, Ophidiomyces ophiodiicola. The comparative genomics project of A. flavus tests the hypothesis that isolates with different morphologies within the species are adapted to different niches. Our results reveal differences in genome structure and protein content that are implicated in niche adaptation to the soil and phyllosphere. The systematics project of O. ophiodiicola was initiated to resolve the frequent misidentification of emerging reptilian diseases that is occuring in the literature. One of these emerging pathogens, O. ophiodiicola, was incorrectly described in the genus Chrysosporium due to its resemblance in spore morphology; therefore, the taxonomy of the genus was revised. We hope the review will aid in accurate identification and tracking of emerging reptilian diseases to better understand their epidemiology.

Emerging wildlife diseases represent a serious threat to conservation efforts. Impacts of emerging multi-host pathogens can vary greatly among species as well as geographically, and understanding which populations will be at greatest risk is essential for conserving biodiversity. Snake fungal disease (SFD), caused by the fungal pathogen Ophidiomyces ophidiicola, is responsible for lethal infections in snakes and has contributed to the decline of multiple North American snake populations. However, which species are most affected by this disease and how infections vary regionally remains unknown. Here we sampled 44 different species across 14 sites throughout the Southeastern and Mid-Atlantic United States. We found a strong effect of latitude on both pathogen prevalence and severity, with more severe infections at more northern latitudes. We also found high variability in pathogen prevalence and infection severity among species. There was a strong positive relationship between pathogen prevalence and disease severity, suggesting that SFD is not just highly prevalent in some populations but also highly virulent. More broadly, our results support that SFD likely has continued impacts on snake populations with some species experiencing greater disease than others attributed to spatial and host variation. / Master of Science / Conserving biodiversity is a significant challenge. Wildlife species are under multiple threats including habitat loss, changing climate, species introductions, pollution, and infectious diseases. Emerging wildlife diseases can pose a major problem for wildlife as they often go undetected until they cause substantial declines for the affected species, sometimes leading to population extirpations and extinction events. Snake fungal disease (SFD) is an emerging disease caused by the fungal pathogen Ophidiomyces ophidiicola, which has contributed to the decline of some North American snake populations. However, little is known about differences in infection, transmission, and host responses to SFD in a broader community context. To investigate the dynamics of this pathogen, we collected swab samples from 44 species from a total of 14 sites in New Jersey, Virginia, North Carolina, South Carolina, Georgia, Florida, and Louisiana. We sampled individual snakes to examine variation over a geographic gradient and among species. We found high variability among sites with more severe disease at northern sites. There was also high variability among species and some populations experienced both high pathogen prevalence and disease severity. Our results show that SFD is highly variable within snake communities and may still be causing population level effects.

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