we work on a disease it's a fungus that affects frogs and this disease has been
found out to be a major contributor to the global declines and amphibians that
we are unfortunately currently seeing this fungus I'm going to say the name it's
called Batrachochytrium Dendrobatidis but for obvious reasons we call it BD
it's a bit of a mouthful has been spreading around the world and these
frogs that you see around you are affected by this fungus. The frogs we use
here they're called Midwife toads and this species is found widely across
Europe. The zoo spores that are produced by BD swim through the water and when
they strike the amphibian skin they deploy some very potent enzymes called
Proteases, the zoo spores literally burn their way into the amphibian skin and
they then become intracellular and go through subsequent reproductive cycles
to colonize the skin of the amphibian and it's that point that skin function
is disrupted and that the animal will fall sick. These Midwife toads are the
most susceptible species to the fungus so we work in the high pyrenees above
2,000 meters we see very aggressive die-offs of these elites in a number
of populations and in the number of populations they now no longer exist
because the fungus has killed them all. So until 2014 we thought this was a
single disease BD in fact we thought it was a single lineage of the single
disease which we call BD GPL which is the global panzootic lineage this is
the bad guy which has been extirpating amphibians around the world but then
scientists working in the Netherlands discovered that the fire salamanders
there were going extinct and that they discovered that there was another key
trait which has subsequently been called Batrachochytrium Salamandrivorans
the salamander killer there's now at least two chytrids which kill amphibian
species what we're finding that in these amphibians
which had taken out of tropical rainforests and traded around the world
quite a high proportion of these are infected with BD and we've actually
shown that some of these infected trade animals when released into the
environment have spread their infection for the environment so we believe that
the amphibian trade is a very important vector of this infection around the
world. What the United States has done is they've thrown up a trade barrier to all to
201 species of salamander from Southeast Asia and from Europe in an effort to
prevent that infection coming in on traded animals. It's perfectly possible
to breed amphibians in facilities like this and to have them certified as
pathogen free and then to be bought as pets. The treatment that we have
developed here at these laboratories is an antifungal drug called itraconazole
this is commonly used in humans and in pets but we've found that if we use very
dilute concentrations of this antifungal with tadpoles all these metamorphs then
they will clear infection the chytrids is thankfully very very susceptible to our
itraconazole so by finding the exact dose that we can use on an animal
without harming it we can then go into natural environments and try those doses
on infected animals and then to clear them. So I have a fantastic collaborator
in Spain called Jaime Bosh and he works on the island of Majorca, Jaime Bosh went
there year after year sometimes he had helicopters to lift his tadpoles out
sometimes it was just backpacks with water bottles with tadpoles in and air
bubblers once these tadpoles were in a captive environment they then got the
itraconazole treatment they were kept until we were sure that they were clear
of infection and then were reintroduced back into the environment in association
with this we also use some chemical disinfection in the environment where we
wash rocks with this compound called Virkon which cleared any residual stages
that was of the fungus that were clinging to the rocks and by doing this we
eventually cleared the infection from the island of Majorca so this is
this is a massive coup because this is the first
time that a wildlife disease has actually been combated and eradicated in
nature we have now moving to mainland Spain where there are larger populations
and they're more connected than this isolated island community and we're
going to now try this treatment on a much wider set of population to see if
it has any utility in a more real world context so already scientists are using
our itraconazole treatment protocol in other species in Panama, in Costa
Rica in South Africa they're having some success in at least being able to create
captive amphibian arks where they have clean animals without a fungal infection
that are breeding so that when we do come up with a mitigation approach that
we can use in an environment then we actually have these captive species that
which you can then reintroduce to the wild