A workshop at the Smithsonian Tropical Research Institute in
Panama has dramatically improved the ability of conservationists
and regulatory agencies to monitor the spread of chytridiomycosis -
one of the deadliest frog diseases on Earth.
Caused by the chytrid fungus, Batrachochytrium
dendrobatidis, this disease is probably responsible for the
extinction of nearly 100 frog species since the 1970s. During the
past decade, the epidemic swept from the highlands of Costa Rica
through western Panama. It is now moving toward eastern Panama from
Colombia.
"The fungus spreads so rapidly because humans ship nearly 100
million amphibians around the world each year, mainly for food and
pets, with virtually no disease testing," said Kerry Kriger,
executive director of the U.S. non-profit, Save The Frogs! and
course instructor with Sandra Victoria Flechas from Universidad de
los Andes in Colombia.
This hands-on course trained 22 scientists on the frontlines to
use a genetic technique called quantitative polymerase chain
reaction, PCR, which detects even single fungal spores.
"We've probably just doubled the number of people in the world
who know how to use this method to detect the pathogen," said
Kriger. "The beauty of PCR is that you don't have to kill the frog
or take a skin sample to test for the disease."
Researchers run a cotton swab over a frog to pick up any fungal
DNA, and use quantitative PCR to evaluate the sample. The technique
was developed by Donna Boyle and colleagues in Australia in 2004
and modified by Kriger who made it more rapid, cost-effective and
wrote a simplified protocol for scientists with no specialized
training.
Workshop participants included personnel from the three
institutions in Panama that have laboratory facilities for PCR:
STRI, Panama's Ministry of Agriculture and another government
research center. Students from the University of Panama and Florida
State University, staff from the El Valle Amphibian Rescue Center
and a local conservation organization, as well as scientists from
Panama, Costa Rica and Colombia, now form a regional
disease-testing team.
Darien Province in eastern Panama is one of the most
high-diversity amphibian habitats on the planet. Researchers have
counted more than 60 amphibian species at a single site. It seems
that eastern Panama has not yet been affected by the disease, but
scientists are worried. "We have a lot of swab samples from
expeditions to Darien, but we haven't had enough people who know
how to analyze them," said Andrew Crawford, former post-doctoral
fellow at STRI, now professor of biology at Universidad de los
Andes.
In Panama research efforts to stop chytridiomycosis are
underway. STRI has hosted many of the scientists who have
documented the decline. The Houston Zoo set up the El Valle
Amphibian Rescue Center to try to save Panama's emblematic golden
frog. "Quantitative PCR is extremely useful to us because it can
pinpoint the beginning of a die-off," said Edgardo Griffith,
director of the center and course participant.
The Panama Amphibian Rescue and Conservation Project, supported
by a consortium of zoos and research institutes and coordinated by
the Smithsonian's National Zoo, is building a new Amphibian Rescue
Center at Summit Nature Park near Panama City.
"During the next several months we will collect frog species on
the brink of extinction. We'll use quantitative PCR to make sure
that the center's rescue pods - frog habitats made from retrofitted
shipping containers - stay fungus free," said Roberto
Ibáñez, Smithsonian staff scientist and local
director of the project. "This workshop is a vital part of
controlling amphibian die-offs in Panama and ensuring that our
amphibian rescue efforts pay off."
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