Culprit behind bat scourge confirmed
A cold-loving fungus is behind an epidemic decimating bat populations in North
America.
Susan Young
White-nose syndrome is killing bats throughout eastern North America.Greg
Turner / Pennsylvania Game Commission
Researchers have confirmed that a recently identified fungus is responsible for
white-nose syndrome, a deadly disease that is sweeping through bat
colonies in eastern North America.
The fungus, Geomyces destructans, infects
the skin of hibernating bats, causing lesions on the animals' wings and a
fluffy white outgrowth on the muzzle. When white-nose syndrome takes
hold of a hibernating colony, more than 90% of the bats can die (see Disease
epidemic killing only US bats). The disease was first documented in February
2006 in a cave in New
York, and has spread to at least 16 other US states and four Canadian
provinces.
The culpability of G. destructans for this
sudden outbreak was thrown into question when the fungus was found on
healthy bats in Europe, where it is not associated with the grim
mortality levels seen in North America1. Some proposed that the fungus was not
the primary cause of the
catastrophic die offs, and that another factor — such as an undetected
virus — must be to blame. But a study published today in Nature2 reveals that
G. destructans is indeed guilty.
"The fungus alone is sufficient to recreate all the pathology
diagnostic for the disease," says David Blehert, a microbiologist at the
National Wildlife Health Center in Madison, Wisconsin, and senior
author on the report.
Bat-to-bat spread
Blehert and his colleagues collected healthy little brown bats (Myotis
lucifugus) from Wisconsin, which is well beyond the known range of white-nose
syndrome. They infected the bats by direct administration of G. destructans
spores to the skin or by contact with infected bats from New York. By
the end of the 102-day experiment, the tell-tale white fungus was
growing on the muzzles and wings of all of the directly infected
Wisconsin bats and 16 of the 18 exposed to sick bats.
This is the first experimental evidence that white-nose syndrome can be passed
from bat to bat, and is very worrying from a conservation
point of view because bats huddle together in large numbers in caves and mate
in large swarms, says Emma Teeling, a bat biologist at University
College Dublin in Ireland. "If a bat has this fungus on them, it's going to
spread quickly throughout the population," says Teeling, who was not involved
with the study. "It's like a perfect storm."
The infected Wisconsin bats did not die during the experiment, which may be due
to the limited timeline of infection, the authors suggest.
Although the study does not directly show that a healthy bat will die
from infection with G. destructans, the results
did show that the fungus alone was sufficient to cause lesions
diagnostic of white-nose syndrome to form on previously healthy bats,
indicating that the fungus is the cause of the deaths so often
associated with white-nose syndrome in the wild.
To stop a scourge
<div><div style="" align="center">
<a rel="nofollow" target="_blank"
href="http://ad.doubleclick.net/click%3Bh%3Dv8/3bac/3/0/%2a/e%3B243339106%3B0-0%3B0%3B9916591%3B4307-300/250%3B44718627/44736415/1%3B%3B%7Esscs%3D%3fhttp://www.eyewonderlabs.com/ct2.cfm?ewbust=0&guid=0&ewadid=170058&eid=1581357&file=NOSCRIPTfailover.gif&pnl=MainBanner&type=0&name=Clickthru-NOSCRIPT&num=1&time=0&diff=0&clkX=&clkY=&click=http://ad.doubleclick.net/click%3Bh%3Dv8/3bac/3/0/%2a/e%3B243339106%3B0-0%3B0%3B9916591%3B4307-300/250%3B44718627/44736415/1%3B%3B%7Esscs%3D%3fhttp://www.scientificamerican.com/sponsored/energyforthefuture/?id=poll-5&WT.mc_id=SA_shell_p5_300x250ros_n">
<img width="300" height="250"
src="http://cdn.eyewonder.com/100125/771435/1581357/NOSCRIPTfailover.gif"
border="0" alt=""/>
</a>
<div style="display:none;">
<img
src="http://cdn.eyewonder.com/100125/771435/1581357/ewtrack.gif?ewadid=170058"
border="0" width="1" height="1"/>
</div>
<div style="display:none;">
<img
src="http://cdn.eyewonder.com/100125/771435/1581357/ewtrack_f.gif?ewadid=170058"
border="0" width="1" height="1"/>
</div></div></div> <div><a rel="nofollow" target="_blank"
href="http://ad.doubleclick.net/jump/n...@nature.com/;abr=!NN2;artid=article-one;pos=left;sz=300x250;ptile=2;ord=123456789?"><img
src="http://ad.doubleclick.net/ad/n...@nature.com/;abr=!NN2;tile=1;ord=123456789?"
alt="Advertisement"/></a></div>
Since it first appeared, white-nose syndrome has behaved like a novel
pathogen spreading from a single origin through a naive population, says
Jonathan Sleeman, director of the National Wildlife Health Center, who
was not involved in the study. Proof that G. destructans is the primary cause
of white-nose syndrome will "help us focus our actions or management efforts
into the future", he says.
Although little can be done to control the spread of the disease
through bat-to-bat transmission, the US Fish and Wildlife Service (FWS)
has asked people to stay out of caves in and near affected areas, and
has closed some caves on agency-managed land.
On 21 October, the FWS announced that up to $1 million in funding will be made
available for research on white-nose syndrome. Projects
covering topics such as how the fungus proliferates within caves and
mines, and the potential for biological means or environmental
manipulations to improve bat survival, are among the service's top
priorities.
Carol
_______________________________________________
SWR mailing list
s...@caver.net
http://caver.net/mailman/listinfo/swr_caver.net