Date of Award

12-14-2017

Degree Type

Dissertation

Degree Name

Doctor of Philosophy (PhD)

Department

Biology

First Advisor

George Pierce

Second Advisor

Sidney Crow, jr

Third Advisor

Robert Simmons

Fourth Advisor

Eric Gilbert

Abstract

Pseudogymnoascus destructans is the causative agent of white-nose syndrome in bats and since its discovery in 2006 it is known to have caused the death of over 5.5 million bats in North America. As with all diseases there is a cycle that perpetuates the disease at the cost of the host’s health. Currently, the majority of the research into this disease has been focused on the host organism. Therefore, in this research with the rational to further elucidate the complete disease cycle we concentrate on the pathogen with specific focus on its ability to utilize lipids found in bat wing sebum and in wing membranes as a substrate for growth and energy. In vitro growth experiments were conducted with the three most common fatty acids that comprise bat sebum, oleic, palmitic and stearic acid. None of the fatty acids were seen to have a significant difference in mean growth from the control group on SDA. Singularly, the control group, when growing on high nutrient content SDA media, was seen to produce an exudate. This exudate was analyzed and discovered to be fluorescent which is an important characteristic as UV trans-illumination is used as a diagnostic tool in the field. Additionally, as an accompaniment to the growth experiments bat wing explants from tri-color bats were fluorescently stained to visualize the difference in distribution of 16 and 18 carbon chain fatty acids in the wing membrane. Lastly, GC-MS analysis was conducted to determine what mVOCs are produced by P. destructans during growth on wing membrane tissue, during production of conidia and during production of exudate. High confidence compound identifications from the NIST spectral database were collected to create VOC profiles at these critical times in the disease cycle. Known fungal VOCs in published studies were compared to the GC-MS results to start understanding their possible function in the disease cycle and impact upon bat health. Which substrates contribute to the growth of P. destructans and the physiological changes that occur during growth are important to understanding the progressive impact P. destructans has on bat health through the course of the disease cycle.

Available for download on Sunday, December 08, 2019

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