Abstract Detail

Exploring the environmental side of the disease triangle in animal pathogens

Reynolds, Hannah T. [1], Ingersoll, Tom [2], Barton, Hazel A [3].

Environmental influences on bat colony persistence in White-nose Syndrome.

White-nose Syndrome (WNS), a fungal disease of hibernating bats, has killed millions of bats in North America since 2007. WNS is caused by the filamentous Leotiomycete fungus Pseudogymnoascus destructans (=Geomyces), a psychrophilic fungus with a broad distribution in European cave systems. It has been shown that Pd produces a wide array of saprotrophic enzymes and is a likely candidate for growth in the cave environment. We examined Pd response to five sterilized, geochemically diverse cave sediments, and found that it propagated in all sediments, with more growth in sediments with higher organic carbon. Should Pd grow in the hibernaculum, it could produce sufficient conidia to infect bats from the environment, inducing a WNS epidemic. To test the possible effect of Pd environmental growth on bat survival, we developed a model for WNS infection in a little brown bat (Myotis lucifugus) colony that incorporated published bat population data in addition to our data on sediment-specific Pd growth parameters. Our simulations indicate that WNS infection occurs more rapidly in hibernacula high in organic carbon. Additionally, we examined the potential effects of hibernation length on bat survival and found that bat colonies with a 150-day hibernation could persist long-term, albeit at a greatly reduced population size, while longer hibernation periods (175- and 200-days) led to extinction. Finally, we examined two possible “rescue” factors: bat summer recovery and the suppression of Pd growth rates from microbial competition.  We found that summer recovery had little effect on colony survival, but that 10 to 100-fold growth rate suppression of Pd could prevent environmentally induced WNS outbreaks.  Our results have important implications for WNS management, as the growth of Pd in hibernacula would lead to long-term persistence, environmentally induced WNS outbreaks, increased risk of human-mediated dispersal, and complications for bat reintroduction efforts.  

1 - The Ohio State University, Plant Pathology, Kottman Hall #477A, 2021 Coffey Rd, Columbus, Ohio, 43210, United States
2 - University of Tennessee, National Institute for Mathematical and Biological Synthesis, 1122 Volunteer Blvd, Ste 106, Knoxville, TN, 37996, USA
3 - University of Akron, Biological Sciences, Auburn W#172, 200 Carroll St, Akron, OH, 44325, USA

Keywords:
Pseudogymnoascus destructans
disease
White-nose Syndrome
ecological model.

Presentation Type: Symposium or Colloquium Presentation
Session: SY2
Location: Room 103 AB/Kellogg Hotel and Conference Center
Date: Monday, June 9th, 2014
Time: 5:00 PM
Number: SY2005
Abstract ID:117
Candidate for Awards:None