Purdue University Graduate School
Nicholas Friedeman - May 2022.pdf (1.29 MB)


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posted on 2022-04-27, 21:33 authored by Nicholas Gerald FriedemanNicholas Gerald Friedeman


Emerging pathogenic fungi have become a topic of conservation concern due to declines seen in several host taxa. One newly emerging fungal pathogen, Ophidiomyces ophiodiicola, has been well documented as the causative agent of Snake Fungal Disease (SFD). SFD has been found in a variety of snake species across the United States, including the Eastern Massasauga (Sistrurus catenatus), a federally threatened rattlesnake species. Most work to date has involved detecting SFD for diagnosis of infection through direct sampling from snakes. Attempts to detect O. ophiodiicola in the environment to better understand its distribution, seasonality, and habitat associations are lacking. I collected topsoil and ground water samples from four macrohabitat types in northern Michigan at a site where SFD infection has been seen in Eastern Massasauga. I used a quantitative PCR (qPCR) assay targeting the internal transcribed spacer region (ITS) developed for diagnosis of SFD after extracting DNA from samples. Ophidiomyces DNA was successfully detected in topsoil, with minimal to no detection in groundwater samples. The frequency in which Ophidiomyces was detected in a sample did not differ between habitats, but samples grouped seasonally showed higher detection occurring during mid-summer. Investigation of the correlation of environmental parameters on Ophidiomyces occurrence recovered no relationships. Our data suggests that season has some effect on the presence of Ophidiomyces. Differences between habitats may exist but are likely more dependent on the time of sampling and currently uninvestigated soil parameters. These findings build on our understanding of Ophidiomyces ecology and epidemiology and inform where snakes like the Eastern Massasauga may be encountering the fungal pathogen. Furthermore, they assist with developing conservation practices aimed at reducing O. ophiodiicola exposure in imperiled snake species. 


Degree Type

  • Master of Science


  • Biological Sciences

Campus location

  • Fort Wayne

Advisor/Supervisor/Committee Chair

Mark Jordan

Additional Committee Member 2

Tanya T. Soule

Additional Committee Member 3

Bruce A. Kingsbury