Molecular Techniques for the Identification of Commensal Fungal Populations on Cave Roosting Bats


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Publication Date

January 2014


Since the emergence of White-nose Syndrome (WNS) in 2006, North American bat populations have experienced devastating population declines. WNS is caused by the psychrophilic fungus Pseudogymnoascus destructans (Pd), which invades the wing tissues of bats during torpor, resulting in up to a 97% mortality rate. Yet some species, including the Indiana bat (Myotis sodalis) and the Virginia big-eared bat (Corynorhinus townsendii virginianus), appear to have reduced mortality from WNS, despite close proximity to infected bats. In an attempt to determine whether bats possess commensal fungal populations that confer resistance to WNS, we analyzed the culturable and non-culturable fungal communities of bat fur. To generate a library of the non-culturable fungal species, DNA was isolated from bat fur clippings, amplified by PCR of the internal transcribed spacer (ITS) region, sequenced, and identified using BLAST. Culturable fungal populations were obtained by swabbing and isolation in pure culture, and also identified using the ITS sequence. By comparing the communities of bats belonging to five species for four locations, we were able to determine that the species of the bat is the most important contributor to the composition of a bat’s fungal community, and this was best analyzed using molecular methods. While the majority of shared fungal species consisted of saprotrophic fungi, a small portion of these shared species consisted of yeast, the most abundant of which was Debaryomyces udenii; Virginia big-eared bats, which have a 0% mortality rate, have a fungal community that consists of 55% D. udenii. This data supports the hypothesis that bats harbor commensal fungal communities, and that these communities may confer resistance to WNS. Identifying whether commensal populations provide a mechanism of WNS resistance in bats could help in our understanding of the emergence of this pathogen, the future of the disease, and potential biological controls.


White-Nose Syndrome, Commensal, Fungi, Bats, Pseudogymnoascus, PCR Inhibition, Corynorhinus Townsendii

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