permaculture

["Lawrence F. London, Jr." <lflj@intrex.net>]

<http://news.bbc.co.uk/2/hi/science/nature/7067613.stm>
Last Updated: Monday, 29 October 2007, 15:51 GMT
Frog killer fungus 'breakthrough'
By Kim Griggs
Science reporter, Wellington

Frog (Image: Conservation International/Don Church)
The disease has had a devastating impact on frog populations (Conservation 
Int/D.Church)
New Zealand scientists have found what appears to be a cure for the disease that is responsible for wiping out many of 
the world's frog populations.

Chloramphenicol, currently used as an eye ointment for humans, may be a 
lifesaver for the amphibians, they say.

The researchers found frogs bathed in the solution became resistant to the 
killer disease, chytridiomycosis.

The fungal disease has been blamed for the extinction of one-third of the 120 
species lost since 1980.

Fearful that chytridiomycosis might wipe out New Zealand's critically endangered Archey's frog (Leiopelma archeyi), the 
researchers have been hunting for a compound that would kill off the disease's trigger, the fungus Batrachochytrium 
dendrobatidis.

        
We are losing an awful lot of these creatures now and if we don't do something intelligent, then we're going to lose an 
awful lot more
Professor Russell Poulter,
Researcher

They tested the chloramphenicol candidate on two species introduced to New Zealand from Australia: the brown tree frog 
(Litoria ewingii) and the southern bell frog (L. raniformis).

"We found that we could cure them completely of chytrids," said Phil Bishop 
from the University of Otago.

"And even when they were really sick in the control group, we managed to bring 
them back almost from the dead."

"You could put them on their back and they just wouldn't right themselves, they would just lie there. You could then 
treat them with chloramphenicol and they would come right," Dr Bishop explained.

Captive solution

The researchers tried using chloramphenicol as both an ointment, applied to 
the frogs' backs, and as a solution.

They found that placing the animals in the solution delivered the best results. The team has admitted it was surprised 
by the outcome.

"You don't usually expect antibiotics to do anything to fungi at all. And it does. We don't understand why it does, but 
it does," said Russell Poulter.

        
WHAT ARE AMPHIBIANS?
Frog (BBC)
Group includes frogs, toads, salamanders and caecilians
First true amphibians evolved about 250m years ago
Adapted to many different aquatic and terrestrial habitats
Present today on every continent except Antarctica
Undergo metamorphosis, from larvae to adults
Professor Poulter, the molecular biologist who hunted down chloramphenicol, added: "It's also got the great advantage 
that it's incredibly cheap."

The scientists are now making their research widely known ahead of formal publication in a science journal because of 
the pressing need for a safe and effective treatment for the chytrid disease.

The blow that chytrid has dealt to the frog population is already immense.

The disease has probably accounted for one-third of all the losses in amphibian species to date, says Professor Rick 
Speare, an expert in amphibian diseases who works with the University of Otago's frog research group.

These losses are huge - and this is in addition to other threats such as habitat destruction, climate change, pollution 
and hunting.

Since 1980, more than 120 amphibian species have disappeared; and according to the World Association of Zoos and 
Aquariums, in the near future many more species are in danger of vanishing.

        
AMPHIBIANS: THE ASSESSMENT
Salamanders (Conservation International/Don Church)
Conservation Int/D.Church

Amphibians in deep trouble
"We are losing an awful lot of these creatures now and if we don't do something intelligent, then we're going to lose an 
awful lot more," said Professor Poulter.

But a hopeful finding is that the introduced frogs that have been infected with chytrids are now more resistant to 
further infections.

"We haven't quite understood how that could happen," said Dr Bishop. "It might be a natural thing; if a frog survives a 
chytrid infection then it is resistant when it gets attacked again."

The researchers believe that zoos now will have more options, either to be able to control an outbreak or to rescue 
infected frogs from the wild, knowing that they can be cured.

The next challenge the research team has set itself is to find a treatment 
that will work in the wild.

"I would really feel quite satisfied if we could say, 10 years from now, that you have to be careful walking around 
[Australia's] Kosiuszko National Park or you might tread on a corroboree frog because they're all over the place," said 
Professor Poulter. "I would take real satisfaction from that."

SEE ALSO
Clarion call to save amphibians
07 Jul 06 |  Science/Nature
Bullfrog linked to fungus spread
24 May 06 |  Science/Nature
Global plan to rescue amphibians
19 Sep 05 |  Science/Nature
Frog action plan to cost millions
14 Sep 05 |  Science/Nature
Global amphibians in deep trouble
14 Oct 04 |  Science/Nature
Pregnancy test link to frog fall
18 Sep 05 |  Science/Nature

RELATED INTERNET LINKS
University of Otago
Conservation International
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