White-nose syndrome in U.S. is less virulent strain

[cavergirl]

http://onlinelibrary.wiley.com/doi/10.1 ... 11007/full

Science News
Raloff, J. (2012), Life: Europe bat pest more potent: White-nose syndrome in U.S. is less virulent strain. Science News, 181: 9. doi: 10.1002/scin.5591811007

Publication History
Issue published online: 10 MAY 2012
Article first published online: 10 MAY 2012

The fungal species wiping out hibernating American bats also strikes their European kin—although it doesn't kill them. But that's not because the European strain of the white-nose syndrome fungus is less virulent, a new study finds.

“The European version is even nastier than the North American one,” says Craig Willis, a wildlife biologist at the University of Winnipeg in Manitoba.

The finding emerged from a trial infecting 36 healthy Canadian little brown bats with the fungus Geomyces destructans. Half of the animals got fungus isolated from North America, the others fungus from Europe. All animals quickly developed white-nose syndrome, a disease named for the mask of threadlike fungal growths it leaves on bat faces. Harder to see but more devastating, G. destructans eats through the skin of a bat's wings and begins digesting inner tissue.

Bats receiving the European strain of the fungus died about a month sooner than those infected with the American strain, Willis and colleagues report online April 9 in the Proceedings of the National Academy of Sciences. These findings suggest the American strain is a recent immigrant from Europe. Because the naïve populations the strain encounters in North America die so easily, Willis suspects that the American strain of the fungus has evolved to be less deadly.

Jeff Foster, a wildlife disease ecologist at Northern Arizona University in Flagstaff, agrees. His team compared the entire genetic blueprint of G. destructans from both continents, confirming they are nearly identical. But slight genetic variability showed up among strains from Europe, with no variability in those from North America. That suggests the fungus arrived in America recently.

Periodically, hibernating bats rouse, burning fat to bring their temperature to normal. Willis' study found that compared with healthy bats in the lab, those infected with the American fungal strain roused three times as often—and those with the European strain four times as often—during hibernation. Some white-nose victims become too weak to rouse at all. “They just run out of fuel,” Willis says.

Up to nearly 7 million North American bats have succumbed to white-nose syndrome since late 2005, the U.S. Fish and Wildlife Service estimated in January. And the disease continues to spread. On April 2, the Missouri Department of Conservation announced the disease had hit its state, the first time it has crossed the Mississippi River.

[driggs]

Jeff Foster, a wildlife disease ecologist at Northern Arizona University in Flagstaff, agrees. His team compared the entire genetic blueprint of G. destructans from both continents, confirming they are nearly identical. But slight genetic variability showed up among strains from Europe, with no variability in those from North America. That suggests the fungus arrived in America recently.

Interesting... assuming regional populations of the various European strains of G. d, I wonder how much effort it would take to sample caves/bats throughout Europe to find out where the invasive American strain originated.