Bat white-nose syndrome (WNS), caused by the fungal pathogen Pseudogymnoascus destructans, has decimated North American hibernating bats since its emergence in 2006. Since its discovery, it is estimated that the disease has killed off over seven million bats in the eastern U.S. WNS has a mortality rate close to 80 percent.
The fungus was studied by researchers from the US Forest Service, US Department of Agriculture, and the University of New Hampshire, and in doing genomic analyses of the fungus researchers found that the fungus is highly sensitive to UV light (ultra-violet light). Their results were published on Jan. 2 in the journal Nature Communications titled “Extreme sensitivity to ultra-violet light in the fungal pathogen causing white-nose syndrome of bats.”
P. destructans is a true fungal pathogen
the research team suggests that P. destructans is a true fungal pathogen that has evolved among different bat species in Europe and Asia for millions of years, allowing Eurasian bats to develop defenses against it. The team compared P. destructans to six closely related non-pathogenic fungi.
They discovered that P. destructans is unable to repair DNA damage caused by UV light due to the lack of a critical enzyme that would allow it to repair damage caused by low-dose exposure to UV light. This discovery could possibly lead to novel treatments for the disease.
When samples of the fungus were exposed to a low dose of UV-C light from a handheld source, the survival rate was only about 15 percent – this dropped to less than 1 percent when the dose was moderate. Amazingly, UV exposure only lasted a few seconds in both cases.
“It is unusual that P. destructans appears to be unable to repair damage caused by UV-light,” said Jon Palmer, a research botanist in the Northern Research Station’s lab in Madison, Wis., and the lead author of the study. “Most organisms that have been found in the absence of light maintain the ability to repair DNA caused by UV light radiation. We are very hopeful that the fungus’ extreme vulnerability to UV light can be exploited to manage the disease and save bats.”
“This research has tremendous implications for bats and people,” said Tony Ferguson, Director of the Forest Service’s Northern Research Station and the Forest Products Laboratory. “Bats play a key role in the health of forests as well as the production of food in the United States, and developing an array of tools with which we can treat bats for white-nose syndrome is important to preserving these very important species.”
Follow-up research has already started on a possible treatment using UV light. Daniel Lindner, a research plant pathologist with the Northern Research Station in Madison, Wisconsin and the corresponding author on the study, is leading the follow-up research.
Basically, the study will measure the survival rate of little brown bats during hibernation after being treated with UV light compared to control groups. The research will also involve studying any side-effects of the UV treatments on the bat-skin microbiome (both fungal and bacterial communities).
Co-authors on the study include Kevin P. Drees and Jeffery T. Foster of the University of New Hampshire.
