Biocontrol of Fungi Causing White Nose Syndrome
White nose syndrome is caused by a cold-loving fungus, Pseudogymnoascus destructans, which grows on the bats’ skin. P. destructans is deadly to hibernating bats because it penetrates tissues of the nose and mouth as well as the wings, which are vital to bats’ ability to avoid dehydration and maintain body temperature. Infected bats wake up more frequently than normal, exhausting their limited energy reserves long before spring.
In affected hibernacula, 78 to 100% of bat populations have died; total overall deaths so far are estimated at between 5 and 6 million bats since WNS was first recorded in 2006-2007 in upstate New York.
Dr. Sybill Amelon, a research wildlife biologist with the Northern Research Station (NRS), is collaborating with Gary Knudsen of the University of Idaho, the NRS is evaluating the potential of naturally occurring fungi on bat skin to combat P. destructans and potentially provide protection for susceptible bat species. Amelon is working with Knudsen and others to evaluate fungi and bacteria normally found on bat skin to determine if they might have usefulness in biological control of WNS fungus.
Fungal disease in vertebrates is relatively rare, perhaps the most similar example is Chytridiomycoses found in amphibians. Biological control is one approach that has shown promise in that disease for several species. Animal skin contains a community of ‘normal microbiota' that provides a first line of defense against some pathogens. Current research on the complex interplay between the skin microbiota and the innate immune system of the skin indicates a beneficial role, much like that of the gut microbiota. It is likely that, under certain conditions, the normal microbiota of bat skin is preemptive or inhibitory to P. destructans, the degree to which this naturally occurs, and the possibility of augmenting any natural protective microbial communities, remain to be determined.
The focus of this research is to obtain representative isolates of skin bacteria and fungi from selected bat species, to screen them for antagonistic activity towards P. destructans, and ultimately to test the most promising antagonists as potential biological control agents for WNS in the laboratory. Environmental and nutritional growth requirements of these bacteria or fungi will then be further characterized.
The goal of this research is to identify potential bio-control agents that will increase the survival of bats exposed to white nose syndrome.
Initial tests recovered a large number and variety of fungi from the sampled bats, with a smaller representation of bacterial types. Some phenotypes were common among the bats in each group studied, and some were apparently present in samples from both locations. Additional identification will be needed to confirm this observation. These samples will be evaluated for their potential to help bats resist WNS. This work was a first step in identifying the microbiota found on healthy bats. By comparing and contrasting the microbiota of species highly susceptible to P. destructans to the microbiota of other species that are less susceptible, we hope to find isolates that can safely be used to increase resistance in the most susceptible bat species. We are collaborating with mycologists to develop an approach that targets the host-pathogen interrelationship.
Amelon has studied resource selection, relative abundance of 3 maternity colonies of Indiana bat before arrival of WNS in Missouri colonies; the second phase of this study will examine these same factors as WNS becomes more prevalent . Published as
Womack, K.M.; Amelon, S.K.; Thompson, F.R.. 2013. Resource selection by Indiana bats during the maternity season. The Journal of Wildlife Management: published online January 2013.
In another study that has not yet been published, Amelon and colleagues found that improved analysis of long-term monitoring data demonstrates marked regional declines of bat populations in the eastern United States before appearance of WNS.
- Sybill Amelon, Research Wildlife Biologist, US Forest Service, Northern Research Station
- Gary Knudsen, University of Idaho, Moscow
- Lori Eggert, University of Missouri, Columbia
- Last modified: August 10, 2018