FATAL FUNGIWarmer Climate May Drive Fungi to Be More Dangerous

>The world is filled with tiny creatures that find us delicious. Bacteria and viruses are the obvious bad guys, drivers of deadly global pandemics and annoying infections. But the pathogens we haven’t had to reckon with as much – yet – are the fungi.

Pathogenic fungi (Candida, Aspergillus, Cryptococcus and others) are notorious killers of immune-compromised people. But for the most part, healthy people have not had to worry about them, and the vast majority of the planet’s potentially pathogenic fungi don’t do well in the heat of our bodies.

But all that may be about to change.

A new study out of Duke University School of Medicine finds that raised temperatures cause a pathogenic fungus known as Cryptococcus deneoformans to turn its adaptative responses into overdrive. This increases its number of genetic changes, some of which might presumably lead to higher heat resistance, and others perhaps toward greater disease-causing potential.

Specifically, higher heat makes more of the fungus’ transposable elements, or jumping genes, get up and move around within the fungal DNA, leading to changes in the way its genes are used and regulated. The findings appeared Jan. 20 in the Proceedings of the National Academy of Sciences.

“These mobile elements are likely to contribute to adaptation in the environment and during an infection,” said postdoctoral researcher Asiya Gusa Ph.D. of Molecular Genetics and Microbiology in the Duke School of Medicine. “This could happen even faster because heat stress speeds up the number of mutations occurring.”

This may ring a bell with viewers of the new HBO series “The Last of Us,” where a dystopian hellscape is precipitated by a heat-adapted fungus that takes over humans and turns them into zombies. “That’s exactly the sort of thing I’m talking about — minus the zombie part!” said Gusa who just watched the first episode and who will join the Duke faculty as an assistant professor later this year.