Oral Presentation- Symposium 12th International Mammalogical Congress

The effects of epidermal fatty acid profiles, triacyl- and monoacylglycerols, and wax esters on the susceptibility of hibernating bats to infection with P. destructans (#216)

Melissa R. Ingala 1 2 , Anna J. Hudson 3 , Johanna J. Monro 3 , Craig L. Frank 1
  1. Department of Biological Sciences, Fordham University, Bronx, New York, United States
  2. Department of Mammalogy, Division of Vertebrate Zoology, American Museum of Natural History, New York, NY, United States
  3. Environmental Sciences Program, Fordham College at Rose Hill, Bronx, New York, United States

White nose syndrome (WNS) is a cutaneous infection caused by the psychrophilic fungus Pseudogymnoascus destructans (Pd). WNS has caused extensive mortality in hibernating North American bats, particularly Myotis lucifugus, M. septentrionalis, M. sodalis, and Perimyotis subflavus. The epidermis of M. lucifugus contains free fatty acids (FFAs) that have been shown to inhibit the growth of Pd in laboratory experiments – they are 14:0, 16:1, 18:1, and 18:2. However, the effects of other cutaneous lipids which contain these fatty acids on the growth of Pd has not been tested. In addition, the relationship between FFA depletion during hibernation and WNS susceptibility is also unclear. We thus hypothesised that 1) the FFA profile of M. lucifugus during mid-hibernation cannot inhibit the growth of Pd as well as at the onset of hibernation, 2) epidermal monoacyl- and triacylglycerols containing inhibitory FFAs may also reduce Pd growth, and 3) epidermal wax esters containing inhibitory FFAs reduce Pd growth. We conducted laboratory culture experiments with Pd maintained on media varying in lipid composition to test our hypotheses. We found that the early hibernation FFA profiles more effectively inhibited the growth of Pd than mid-hibernation profiles. We also discovered that triacylglycerols have no effect on Pd growth, but 1-oleoglycerol greatly reduced Pd growth. Finally, we found that wax esters containing 18:1, 16:1, and 18:2 can also inhibit the growth of Pd. These findings suggest that multiple epidermal lipids contribute to the susceptibility of bats to infection with Pd during hibernation.