Canadian scientists trace deadly bat fungus to Europe
Biologist says pathogen was likely carried into North America on someone's shoes
By MARGARET MUNRO, montrealgazette.com
The death of millions of bats in Canada and the United States has been traced to an "invasive" pathogen from Europe, which may have been carried into North America on someone's shoes.
An international experiment, run on bats that hibernated in a bio-safety lab in Saskatchewan, has provided the strongest evidence yet that the bat killer is a fungus from Europe.
"And it's a reasonable hypothesis that it came in on someone's shoes," says biologist Craig Willis, at the University of Winnipeg, who led the study published Monday in the Proceedings of the National Academy of Sciences.
More than 90 per cent of bats have been wiped out in colonies in Eastern Canada and the U.S. as a result of white-nose syndrome, which is caused by the fungus.
"It's very bad news," Willis says of the syndrome that was first seen in North America in 2006 in a New York cave popular with tourists. The quickly spreading fungus has decimated colonies in the eastern U.S. as well as Nova Scotia, New Brunswick, Quebec and Ontario.
The syndrome, which kills bats while they hibernate, gets its name from the white, fuzzy fungal growths around the nose and wings of infected animals.
A fungus called Geomyces destructans is responsible, and scientists have suggested it's either a recent invader from Europe, where the microbe is known to occur, or it was in North America all along, but suddenly became a bat killer as a result of genetic mutation or environmental change. To try to find out, Willis and his colleagues from Saskatchewan, Europe and the U.S. ran a four-month long experiment on little brown bats.
The researchers collected 54 bats that had recently started hibernating in an uninfected cave in central Manitoba. They gingerly stashed the furry creatures into a cooler and drove them to the Western College of Veterinary Medicine at the University of Saskatchewan in Saskatoon.
There, the researchers infected one-third of the bats with fungus that has been killing bats in New York state, while another third were infected with fungus from Germany that was flown into Canada under special permit. The last third was the control group.
The bats were fitted with tiny heat sensors and, within 48 hours of being snatched out of their cave in Manitoba, they were put in simulated caves created in refrigeratorsized environmental chambers in a biosafety lab."We wanted to be extremely careful not to let the fungus escape," says Willis.
The bats snuggled up in the simulated caves and continued their hibernation.Post-doctoral fellows Lisa Warnecke and James Turner then kept a close watch for the next four months, using surveillance cameras.
The bats infected with fungus soon developed the telltale signs of white-nose syndrome, including powdery white fungal growths on their exposed skin and damage to their wings. "The fungus is essentially eating away at their wings," says Willis.
The scientists say the study "strongly supports" the idea that accidental introduction of the fungus from Europe "is responsible for the whitenose-syndrome-related mass mortality of bats in North America" because bats infected with both the European and New York fungus developed the syndrome.
"And it's a reasonable hypothesis that it came in on someone's shoes," says biologist Craig Willis, at the University of Winnipeg, who led the study published Monday in the Proceedings of the National Academy of Sciences.
More than 90 per cent of bats have been wiped out in colonies in Eastern Canada and the U.S. as a result of white-nose syndrome, which is caused by the fungus.
"It's very bad news," Willis says of the syndrome that was first seen in North America in 2006 in a New York cave popular with tourists. The quickly spreading fungus has decimated colonies in the eastern U.S. as well as Nova Scotia, New Brunswick, Quebec and Ontario.
The syndrome, which kills bats while they hibernate, gets its name from the white, fuzzy fungal growths around the nose and wings of infected animals.
A fungus called Geomyces destructans is responsible, and scientists have suggested it's either a recent invader from Europe, where the microbe is known to occur, or it was in North America all along, but suddenly became a bat killer as a result of genetic mutation or environmental change. To try to find out, Willis and his colleagues from Saskatchewan, Europe and the U.S. ran a four-month long experiment on little brown bats.
The researchers collected 54 bats that had recently started hibernating in an uninfected cave in central Manitoba. They gingerly stashed the furry creatures into a cooler and drove them to the Western College of Veterinary Medicine at the University of Saskatchewan in Saskatoon.
There, the researchers infected one-third of the bats with fungus that has been killing bats in New York state, while another third were infected with fungus from Germany that was flown into Canada under special permit. The last third was the control group.
The bats were fitted with tiny heat sensors and, within 48 hours of being snatched out of their cave in Manitoba, they were put in simulated caves created in refrigeratorsized environmental chambers in a biosafety lab."We wanted to be extremely careful not to let the fungus escape," says Willis.
The bats snuggled up in the simulated caves and continued their hibernation.Post-doctoral fellows Lisa Warnecke and James Turner then kept a close watch for the next four months, using surveillance cameras.
The bats infected with fungus soon developed the telltale signs of white-nose syndrome, including powdery white fungal growths on their exposed skin and damage to their wings. "The fungus is essentially eating away at their wings," says Willis.
The scientists say the study "strongly supports" the idea that accidental introduction of the fungus from Europe "is responsible for the whitenose-syndrome-related mass mortality of bats in North America" because bats infected with both the European and New York fungus developed the syndrome.
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