Fungus that causes white-nose syndrome in bats proves hardy survivor

Oct 25, 2013 by Diana Yates
Researchers found that the fungus that causes white-nose syndrome in bats can survive under a variety of conditions and can live and grow on most carbon and nitrogen sources in caves. Credit: L. Brian Stauffer

(Phys.org) —After taking an in-depth look at the basic biology of a fungus that is decimating bat colonies as it spreads across the U.S., researchers report that they can find little that might stop the organism from spreading further and persisting indefinitely in bat caves.

Their report appears in the journal PLOS ONE.

The aptly named Pseudogymnoascus (Geomyces) destructans causes white-nose syndrome in . The infection strikes bats during their winter hibernation, leaving them weakened and susceptible to starvation and secondary infections. The fungus, believed to have originated in Europe, was first seen in New York in the winter of 2006-2007, and now afflicts bats in more than two dozen states. According to the U.S. Fish and Wildlife Service, P. destructans has killed more than 5.5 million bats in the U.S. and Canada.

The fungus thrives at low temperatures, and spreads to bats whose body temperature drops below 20 degrees Celsius (68 degrees Fahrenheit) when they are hibernating in infected caves. Previous research has shown that the fungus persists in caves even after the bats are gone.

The new study, from researchers at the Illinois Natural History Survey at the University of Illinois, found that the fungus can make a meal out of just about any carbon source likely to be found in caves, said graduate student Daniel Raudabaugh, who led the research under the direction of survey mycologist Andrew Miller.

"It can basically live on any complex , which encompasses insects, undigested insect parts in guano, wood, dead fungi and cave fish," Raudabaugh said. "We looked at all the different nitrogen sources and found that basically it can grow on all of them. It can grow over a very wide range of pH; it doesn't have trouble in any pH unless it's extremely acidic."

"P. destructans appears to create an environment that should degrade the structure of keratin, the main protein in ," Raudabaugh said. It has enzymes that break down urea and proteins that produce a highly alkaline environment that could burn the skin, he said. Infected bats often have holes in their skin, which can increase their susceptibility to other infections.

The fungus can subsist on other proteins and lipids on the bats' skin, as well as glandular secretions, the researchers said.

"P. destructans can tolerate naturally occurring inhibitory sulfur compounds, and elevated levels of calcium have no effect on fungal growth," Raudabaugh said.

The only significant limitation of the fungus besides temperatures above 20 degrees Celsius has to do with its ability to take up water, Raudabaugh said. Its cells are leaky, making it hard for the fungus to absorb water from surfaces, such as dry wood, that have a tendency to cling to moisture. But in the presence of degraded fats or free fatty acids, like those found on the skin of living or dead animals, the fungus can draw up water more easily, he said.

"All in all the news for hibernating bats in the U.S. is pretty grim," Miller said.

"When the fungus first showed up here in Illinois earlier this year we went from zero to 80 percent coverage in a little more than a month," he said. The team led by U. of I. researchers that discovered the fungus in the state found a single infected bat in one northern Illinois cave, he said. Several weeks later most of the bats in that cave were infected.

Although many studies have been done on the fungal genome and on the bats, Miller said, Raudabaugh is the first to take an in-depth look at the basic biology of the fungus.

"Dan found that P. destructans can live perfectly happily off the remains of most organisms that co-inhabit the caves with the bats," Miller said. "This means that whether the bats are there or not, it's going to be in the caves for a very long time."

The paper is titled "Nutritional Capability of and Substrate Suitability for Pseudogymnoascus destructans, the Causal Agent of White-Nose Syndrome."

Explore further: Scientists identify key fungal species that help explain mysteries of white nose syndrome

More information: www.plosone.org/article/info:doi/10.1371/journal.pone.0078300

Related Stories

Bat-killing white-nose syndrome continues to spread

Apr 15, 2013

It was a typically cold winter day when Greg Turner, a wildlife biologist with the Pennsylvania Game Commission, unlocked the gate at the historic Durham Mine in upper Bucks County, Pa., and stepped into the darkness.

Recommended for you

Male monkey filmed caring for dying mate (w/ Video)

14 hours ago

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Orchid named after UC Riverside researcher

Apr 17, 2014

One day about eight years ago, Katia Silvera, a postdoctoral scholar at the University of California, Riverside, and her father were on a field trip in a mountainous area in central Panama when they stumbled ...

In sex-reversed cave insects, females have the penises

Apr 17, 2014

Researchers reporting in the Cell Press journal Current Biology on April 17 have discovered little-known cave insects with rather novel sex lives. The Brazilian insects, which represent four distinct but re ...

Fear of the cuckoo mafia

Apr 17, 2014

If a restaurant owner fails to pay the protection money demanded of him, he can expect his premises to be trashed. Warnings like these are seldom required, however, as fear of the consequences is enough to ...

User comments : 2

Adjust slider to filter visible comments by rank

Display comments: newest first

katesisco
1 / 5 (10) Oct 25, 2013
What about using sugar traps?
Since condensed sugar products like honey, molasses, sugar with low water activity which makes the product suck water from the air, a sugar trap should trap the fungus seeking water because the sugar product draws water.
Worth a try.
rkolter
not rated yet Oct 25, 2013
The logistics behind dehumidifying a cave system would be staggering in most cases. And the fungus does not move about in search of water.

Lastly, I am guessing (but haven't confirmed) that they probably tested what the humidity requirements for the fungus were too. If it had a narrow range of humidity levels that it strongly preferred, it would have been mentioned.

More news stories

Researchers successfully clone adult human stem cells

(Phys.org) —An international team of researchers, led by Robert Lanza, of Advanced Cell Technology, has announced that they have performed the first successful cloning of adult human skin cells into stem ...

Plants with dormant seeds give rise to more species

Seeds that sprout as soon as they're planted may be good news for a garden. But wild plants need to be more careful. In the wild, a plant whose seeds sprouted at the first warm spell or rainy day would risk disaster. More ...

Researchers develop new model of cellular movement

(Phys.org) —Cell movement plays an important role in a host of biological functions from embryonic development to repairing wounded tissue. It also enables cancer cells to break free from their sites of ...

Male monkey filmed caring for dying mate (w/ Video)

(Phys.org) —The incident was captured by Dr Bruna Bezerra and colleagues in the Atlantic Forest in the Northeast of Brazil.  Dr Bezerra is a Research Associate at the University of Bristol and a Professor ...

Impact glass stores biodata for millions of years

(Phys.org) —Bits of plant life encapsulated in molten glass by asteroid and comet impacts millions of years ago give geologists information about climate and life forms on the ancient Earth. Scientists ...