Finally, there is some hopeful news in the battle against white-nose syndrome!
Last week a team of researchers from UC San Francisco and Brown University published a ground-breaking study in the Proceedings of the National Academy of Sciences about white-nose syndrome.
This disease, which is caused by the fungus Pseudogymnoascus destructans, has devastated cave-dwelling bat populations across eastern North America. It causes bats to prematurely wake from hibernation during the winter – this uses up their limited energy stores and results in starvation.
The researchers discovered that P.destructans releases digestive enzymes that break down bat tissues, and then the fungus imports the break-down products for its food. Of the enzymes identified by the study, the most likely culprit for tissue breakdown was named “Destructin-1.”
The team then attempted to find a way to block this enzyme. They found that a class of drugs known as protease inhibitors, which are currently used to treat HIV/AIDS, appear to also be effective at knocking out Destructin-1. “Protease” refers to enzymes that break down proteins and peptides. Since the fungus releases enzymes that break down bat tissues, inhibiting these enzymes with protease inhibitors or something similar may be an effective way to prevent bat deaths among infected populations.
Specifically, the team tested a protease inhibitor called chymostatin. When tested in a lab setting, using chymostatin resulted in a 77% reduction in tissue breakdown. The team suspects that the remaining tissue breakdown may be caused by other substances excreted by the fungus that do not respond to chymostatin.
Although it’s not clear if the findings will lead to ways to prevent fatalities caused by white-nose syndrome, it is certainly a major breakthrough in understanding how P. destructans works on a biochemical level and will be extremely beneficial in further studies.
In the meantime, the conservation community must continue its efforts to conserve bat populations in other ways, such as by enhancing bat habitat and implementing accepted decontamination protocols to prevent the spread of white-nose syndrome.