Today the Standing Committee of the Berne Convention adopted a recommendation on the prevention and control of the Batrachochytrium salamandrivorans chytrid fungus. The recommendation is very important. Now it is up to the national governments to act.
Recommendation No. 176 (2015) of the Standing Committee, adopted on 4 December 2015, on the prevention and control of the Batrachochytrium salamandrivorans chytrid fungus
The Standing Committee to the Convention on the Conservation of European Wildlife and Natural Habitats, acting under the terms of Article 14 of the Convention,
Having regard to the aims of the convention, which are to conserve wild flora and fauna and their natural habitats;
Recalling that Article 3 of the convention requires Parties to take the necessary steps to promote national policies for the conservation of wild flora, wild fauna and natural habitats, with particular attention to endangered and vulnerable species, especially endemic ones, and endangered habitats;
Stressing that according to the Global Amphibian Assessment (GAA), 43% of amphibian species are declining in populations, and 32% are threatened;<(br />
Noting that emerging fungal and fungal-like diseases are an increasingly important threat, causing population declines and extinctions of amphibians, the most threatened class of vertebrates;
Taking note with apprehension of the mass mortality and massive population declines (96% decline) in populations of Salamandra salamandra in the Netherlands caused by a novel chytrid fungus, the Batrachochytrium salamandrivorans;
Worried about the fact that once the Batrachochytrium salamandrivorans emerges in an area there is no method to mitigate its effects or to treat amphibian populations against it, making this fungal disease likely to have devastating effect on European salamander and newt biodiversity;
Noting that the disease is native of Asia and that it was introduced into Europe through the importing of exotic species mainly for pet trade purposes;
Recalling that the epidemiological impact of the trade is significant and may negatively affect conservation and trade economics;
Recalling that under Article 11, paragraph 2.b of the Convention, each Contracting Party undertakes to strictly control the introduction of non-native species;
Recalling Recommendation No. 99 (2003) of the Standing Committee on the European Strategy on Invasive Alien Species (IAS);
Aware that there are bio-security risks associated to importing animals the provenance and pathogens of which may be unknown;
Recalling the CBD Technical Series No. 48 on Pets, Aquarium, and Terrarium Species: Best Practices for Addressing Risks to Biodiversity, which notes that there are significant gaps in global regulations of infectious disease and suggests risk assessment and screening approaches to potentially invasive pathogens;
Further recalling the Best Practices in Pre-Import Risk Screening for Species of Live Animals in International Trade, prepared by the Global Invasive Species Programme (GISP) focussing on “best practices” to address the risks associated with imports of live non-native animals and their parasites and pathogens in international trade;
Aware that pet trade may not necessarily be the only pathway of introduction of the Batrachochytrium salamandrivorans in Europe;
Noting that it is extremely important that the spread of the Batrachochytrium salamandrivorans is halted or at least slowed down and that the introduction into a Batrachochytrium salamandrivorans-negative region is prevented;
Stressing that the disease may spread across countries and that its effective prevention and control will necessarily require transnational cooperation and coordinated response to new outbreaks,
Recommends that Contracting Parties:
1. Apply biosafety rules to field-work (including licenses where appropriate), to visitors of breeding sites of fire salamander and newts, and to the conservation and captive collections of amphibians, against known or emerging pathogens that may be introduced – inter alia – through animal trade, and against the Batrachochytrium salamandrivorans as a matter of urgency. In order to ensure the implementation of biosafety measures in all relevant conservation programmes, effective protocols for the treatment of amphibians affected by the Batrachochytrium salamandrivorans should be developed and their prompt, wide and free circulation between Contracting Parties guaranteed;
2. Carry out appropriate science-based pre-import risk screening for infectious diseases of live animals in animal trade;
3. Impose immediate restrictions on salamander and newt trade while a scientific risk assessment is being developed and until necessary measures are designed, as a preventive measure against the introduction of Batrachochytrium salamandrivorans through pet trade;
4. Establish monitoring programmes to control the possible further spread of the disease, with the view of developing an early warning system for pan-Europe and enable the quick detection of disease driven loss of biodiversity;
5. Establish, as a matter of urgency, monitoring programs for salamander and newt populations in areas of high risk (e.g. areas near disease outbreaks; areas with endemic species such as the Alps, the Pyrenees and islands in the Mediterranean);
6. Restrict the human induced spreading as well as the transport of amphibians where controls of Batrachochytrium salamandrivorans diseases are applied in areas monitored under point 5;
7. Develop, as soon as possible, emergency action plans that will allow prompt responses should Batrachochytrium salamandrivorans approach high risk populations of salamander and newt species (e.g. endemic species in the Alps, the Pyrenees and islands in the Mediterranean);
8. Support research into the biology, epidemiology, and mitigation of Batrachochytrium salamandrivorans;
9. Support research on the conservation biology of European salamander and newt, particularly to improve knowledge on the demography and population dynamics;
10. Design and implement public awareness campaigns focused on prevention, biosafety and surveillance;
11. Keep the Standing Committee informed of the measures taken to implement this recommendation.
The full text (PDF) of the recommendation can be found here:
https://wcd.coe.int/ViewDoc.jsp?id=2395245&Site=&BackColorInternet=B9BDEE&BackColorIntranet=FFCD4F&BackColorLogged=FFC679
Friday, 4 December 2015
Saturday, 21 November 2015
Sunday, 27 September 2015
Amphibians under threat
There is a great article by Trent Garner on chytrids (and some other pathogens) in "Planet Earth", the NERC newsletter.
Get the pdf here.
Get the pdf here.
Friday, 28 August 2015
Chytrid in the Pyrenees
RACE team leader Mat Fisher's report from the Pyrenees:
"Lac Arlet used to be the most amphibian rich Pyrenean lakes I knew. Chytrid continues to reap its grisly crop of metamorphs this August and the Alytes are now few and far between. More newt and Rana mortalities too compared against subsequent years."
Photo: (c) Mat Fisher.
"Lac Arlet used to be the most amphibian rich Pyrenean lakes I knew. Chytrid continues to reap its grisly crop of metamorphs this August and the Alytes are now few and far between. More newt and Rana mortalities too compared against subsequent years."
Photo: (c) Mat Fisher.
Saturday, 22 August 2015
Cyclone vs. chytrid
A new paper published in Scientific Reports shows that cyclones may reduce Bd prevalence. Cyclones reduce canopy cover which leads to warmer microclimates. Warmer microclimates reduce Bd infection.
http://www.nature.com/articles/srep13472
Photo: (c) Mat Fisher.
http://www.nature.com/articles/srep13472
Photo: (c) Mat Fisher.
Saturday, 1 August 2015
What It’s Like to Watch a Species Go Extinct - or why we study Bd
Karen Lips was a grad student when she came face to face with a mass extinction for the first time. It was the early 1990s, and she was doing research on frogs in the mountains of Costa Rica. At the beginning, they were everywhere. And then, poof: “I came back one year and there were no frogs,” she remembers. Puzzled, she explored other sites—and started turning up corpses. An area that had thrummed with amphibian life had morphed into a graveyard.
Read more here:
http://www.wired.com/2015/07/watching-species-go-extinct-frogs-bd-salamanders-bsal/
Red-bellied newt (Taricha rivularis) Emanuele Biggi/anura.it
Read more here:
http://www.wired.com/2015/07/watching-species-go-extinct-frogs-bd-salamanders-bsal/
Red-bellied newt (Taricha rivularis) Emanuele Biggi/anura.it
Friday, 31 July 2015
Averting a North American biodiversity crisis - a new policy paper in Science
In a new policy paper in Science, Yap et al. "demonstrate the likelihood of Bsal introduction to North America via international trade, the likelihood of species being exposed to Bsal, and the potential impact of species exposure to Bsal."
Wednesday, 3 June 2015
Bsal found in Alpine newts in Belgium
The salamander chytrid Batrachochytrium salamandrivorans was found in Alpine newts in Belgium.
http://deredactie.be/cm/vrtnieuws/wetenschap/1.2357495
http://deredactie.be/cm/vrtnieuws/wetenschap/1.2357495
Tuesday, 26 May 2015
Sunday, 17 May 2015
Can the US stop the spread of Bsal?
As the scientific evidence base builds, pressure builds on the policy makers. The U.S. may actually move fast enough to prevent the spread of Bsal.
http://www.biologicaldiversity.org/news/press_releases/2015/salamanders-05-14-2015.html
http://mobile.nytimes.com/blogs/dotearth/2015/05/15/pressure-builds-for-swift-u-s-action-against-spreading-salamander-threat/?partner=rss&emc=rss&_r=0&referrer
(Source: NY Times/Pria N. Ghosh)
http://www.biologicaldiversity.org/news/press_releases/2015/salamanders-05-14-2015.html
http://mobile.nytimes.com/blogs/dotearth/2015/05/15/pressure-builds-for-swift-u-s-action-against-spreading-salamander-threat/?partner=rss&emc=rss&_r=0&referrer
(Source: NY Times/Pria N. Ghosh)
Saturday, 2 May 2015
And now for something completely different (almost)
There's a new edited book on Ranavirus. It is definitely worth reading if you are interested in amphibian diseases. You can acccess the book at Springer here: http://link.springer.com/book/10.1007/978-3-319-13755-1
Wednesday, 29 April 2015
The salamander-killing chytrid now in the UK
Read this story on BBC: http://www.bbc.com/earth/story/20150429-skin-eating-fungus-reaches-uk
Currently, the salamander chytrid is only found in captive salamanders. It is extremely important that it does not get into the wild.
Monday, 27 April 2015
PLOS ONE: Widespread Occurrence of Bd in French Guiana, South America
PLOS ONE: Widespread Occurrence of Bd in French Guiana, South America
The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) is a purported agent of decline and extinction of many amphibian populations worldwide. Its occurrence remains poorly documented in many tropical regions, including the Guiana Shield, despite the area’s high amphibian diversity. We conducted a comprehensive assessment of Bd in French Guiana in order to (1) determine its geographical distribution, (2) test variation of Bd prevalence among species in French Guiana and compare it to earlier reported values in other South American anuran species (http://www.bd-maps.net; 123 species from 15 genera) to define sentinel species for future work, (3) track changes in prevalence through time and (4) determine if Bd presence had a negative effect on one selected species. We tested the presence of Bd in 14 species at 11 sites for a total of 1053 samples (306 in 2009 and 747 in 2012). At least one Bd-positive individual was found at eight out of 11 sites, suggesting a wide distribution of Bd in French Guiana. The pathogen was not uniformly distributed among the studied amphibian hosts, with Dendrobatidae species displaying the highest prevalence (12.4%) as compared to Bufonidae (2.6 %) and Hylidae (1.5%). In contrast to earlier reported values, we found highest prevalence for three Dendrobatidae species and two of them displayed an increase in Bd prevalence from 2009 to 2012. Those three species might be the sentinel species of choice for French Guiana. For Dendrobates tinctorius, of key conservation value in the Guiana Shield, smaller female individuals were more likely to be infected, suggesting either that frogs can outgrow their chytrid infections or that the disease induces developmental stress limiting growth. Generally, our study supports the idea that Bd is more widespread than previously thought and occurs at remote places in the lowland forest of the Guiana shield.
The amphibian chytrid fungus Batrachochytrium dendrobatidis (Bd) is a purported agent of decline and extinction of many amphibian populations worldwide. Its occurrence remains poorly documented in many tropical regions, including the Guiana Shield, despite the area’s high amphibian diversity. We conducted a comprehensive assessment of Bd in French Guiana in order to (1) determine its geographical distribution, (2) test variation of Bd prevalence among species in French Guiana and compare it to earlier reported values in other South American anuran species (http://www.bd-maps.net; 123 species from 15 genera) to define sentinel species for future work, (3) track changes in prevalence through time and (4) determine if Bd presence had a negative effect on one selected species. We tested the presence of Bd in 14 species at 11 sites for a total of 1053 samples (306 in 2009 and 747 in 2012). At least one Bd-positive individual was found at eight out of 11 sites, suggesting a wide distribution of Bd in French Guiana. The pathogen was not uniformly distributed among the studied amphibian hosts, with Dendrobatidae species displaying the highest prevalence (12.4%) as compared to Bufonidae (2.6 %) and Hylidae (1.5%). In contrast to earlier reported values, we found highest prevalence for three Dendrobatidae species and two of them displayed an increase in Bd prevalence from 2009 to 2012. Those three species might be the sentinel species of choice for French Guiana. For Dendrobates tinctorius, of key conservation value in the Guiana Shield, smaller female individuals were more likely to be infected, suggesting either that frogs can outgrow their chytrid infections or that the disease induces developmental stress limiting growth. Generally, our study supports the idea that Bd is more widespread than previously thought and occurs at remote places in the lowland forest of the Guiana shield.
Thursday, 2 April 2015
There isn't a magic bacterial bullet
A new paper by Rachael E. Antwis and coauthors ("Amphibian symbiotic bacteria do not show universal ability to inhibit growth of the global pandemic lineage of Batrachochytrium dendrobatidis") shows that Bd mitigation using probiotics may be more complicated than currently thought. The study shows that "only a small proportion of candidate probiotics exhibit broad-spectrum inhibition across BdGPL isolates. Moreover, some bacterial genera show significantly greater inhibition than others, but overall, genus and species are not particularly reliable predictors of inhibitory capabilities."
Friday, 13 March 2015
On the chytrid fungus in Romania
A nice blog on research on the chytrid fungus in Romania.
https://ideas4sustainability.wordpress.com/2015/03/13/disease-and-biodiversity-conservation-the-case-of-chytrid-fungus-in-romania/
The paper will soon be published in Animal Conservation.
Saturday, 28 February 2015
Killer frog fungus could actually help amphibians survive disease
Killer frog fungus could actually help amphibians survive disease
The loss of amphibian species across the world from chytridiomycosis, an infectious disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), has been described
as “the most spectacular loss of vertebrate biodiversity due to disease
in recorded history”. So it’s of grave concern that the pathogen has
been discovered in Madagascar, an incredibly biodiverse region
previously thought free of the fungus.
Madagascar has the 12th highest rate of amphibian species richness in
the world, with more than 400 species, 99% of which are indigenous to
the region. But this biodiversity hotspot is already under severe
pressure – a quarter of its species are under threat, according to the
latest Global Amphibian Assessment. It’s rightly feared that the arrival of Bd, as reported
in the journal Scientific Reports, could bring about mass amphibian
decline – and even extinctions – as has been seen elsewhere.
Testing of the samples of the Bd fungus found in Madagascar reveals the strain is closely related to BdGPL,
the hyper-virulent lineage behind all the known outbreaks of the
chytrid fungus pathogen that have decimated amphibian populations.
However what’s interesting is that the rate of infection is extremely
low and there’s no clinical signs of chytridiomycosis: the frogs have
the fungus, but they haven’t developed the disease.
Perhaps the comprehensive monitoring plan put in place by A Conservation Strategy for the Amphibians of Madagascar (ACSAM) has worked as planned, in that the presence of the Bd pathogen has been detected – for the first time in 2010 – before amphibian declines have occurred.
Perhaps the strain of Bd detected in Madagascar is not a
virulent kind that poses a serious threat to amphibians. This was seen
with the introduction of the BdCape fungus lineage into Mallorca, where it had little effect on the population of Alytes muletensis toads there.
It’s possible that the Bd detected in Madagascar has been
present on the island for a long time, but undetected. It may be an
endemic, non-virulent lineage as seen in Brazil and Asia, where certain
lineages endemic to the regions appear to have evolved alongside the
native amphibians.
Or perhaps there is an endemic, previously undetected chytrid fungus on the island, related or not to Bd, which could be acting as a buffer for local amphibians against the invasion of BdGPL – acting, in effect, as a natural vaccine.
Alternatively, Malagasy amphibians may have developed some intrinsic resistance to Bd,
for example through protective bacteria in their skin. This could
explain the low infection rates and the ambiguous test results reported
in the paper showing that some Bd-positive samples did not conform to
any known lineage of the fungus. Although rare, resistance to BdGPL is not unprecedented – this has been seen and documented in Brazil.
this turns out to be the case, the survival of Malagasy amphibians
could depend on the conservation and scientific groups involved in ACSAM
managing to restrict the spread of the disease. Tackling invasive
species such as the Asian Toad that might spread the disease and
ensuring tourists and researchers stick to strict hygiene protocols
would be necessary. Perhaps even more drastic conservation measures,
such as capturing animals from particularly vulnerable species for
raising in captivity.
On the other hand, the fourth scenario presents an intriguing
possibility: if it’s the case that Malagasy amphibians are resisting a
fungal invasion, discovering how this works could provide crucial
information to help save amphibians elsewhere from the disease.
The research on the amphibian skin microbiome, for example, and its
role in the creature’s immune system is producing some exciting results.
It’s also apparent that the diversity of the Chytrid fungus species as a
whole, and in particular of Bd, has not been appreciated. It’s
possible there are many types of chytrid fungus associated with
amphibians that we’re not yet aware of which provide some protection
against BdGPL.
So without a doubt, this report will sound warning bells loud and clear for conservationists, and Bd’s
appearance in Madagascar could still result in a huge loss of
amphibians. However, the lack of chytridiomycosis symptoms also suggest
there’s something special in Madagascar that could yield a breakthrough
in how the disease spreads – something that may not only benefit
Malagasy amphibians, but those throughout the world.
The loss of amphibian species across the world from chytridiomycosis, an infectious disease caused by the fungal pathogen Batrachochytrium dendrobatidis (Bd), has been described
as “the most spectacular loss of vertebrate biodiversity due to disease
in recorded history”. So it’s of grave concern that the pathogen has
been discovered in Madagascar, an incredibly biodiverse region
previously thought free of the fungus.
Madagascar has the 12th highest rate of amphibian species richness in
the world, with more than 400 species, 99% of which are indigenous to
the region. But this biodiversity hotspot is already under severe
pressure – a quarter of its species are under threat, according to the
latest Global Amphibian Assessment. It’s rightly feared that the arrival of Bd, as reported
in the journal Scientific Reports, could bring about mass amphibian
decline – and even extinctions – as has been seen elsewhere.
Testing of the samples of the Bd fungus found in Madagascar reveals the strain is closely related to BdGPL,
the hyper-virulent lineage behind all the known outbreaks of the
chytrid fungus pathogen that have decimated amphibian populations.
However what’s interesting is that the rate of infection is extremely
low and there’s no clinical signs of chytridiomycosis: the frogs have
the fungus, but they haven’t developed the disease.
What could this mean?
This discovery presents us with a number of scenarios, which need further investigation.Perhaps the comprehensive monitoring plan put in place by A Conservation Strategy for the Amphibians of Madagascar (ACSAM) has worked as planned, in that the presence of the Bd pathogen has been detected – for the first time in 2010 – before amphibian declines have occurred.
Perhaps the strain of Bd detected in Madagascar is not a
virulent kind that poses a serious threat to amphibians. This was seen
with the introduction of the BdCape fungus lineage into Mallorca, where it had little effect on the population of Alytes muletensis toads there.
It’s possible that the Bd detected in Madagascar has been
present on the island for a long time, but undetected. It may be an
endemic, non-virulent lineage as seen in Brazil and Asia, where certain
lineages endemic to the regions appear to have evolved alongside the
native amphibians.
Or perhaps there is an endemic, previously undetected chytrid fungus on the island, related or not to Bd, which could be acting as a buffer for local amphibians against the invasion of BdGPL – acting, in effect, as a natural vaccine.
Alternatively, Malagasy amphibians may have developed some intrinsic resistance to Bd,
for example through protective bacteria in their skin. This could
explain the low infection rates and the ambiguous test results reported
in the paper showing that some Bd-positive samples did not conform to
any known lineage of the fungus. Although rare, resistance to BdGPL is not unprecedented – this has been seen and documented in Brazil.
A potential threat or a potential benefit
The first scenario would be a disaster – and should be a priority. Ifthis turns out to be the case, the survival of Malagasy amphibians
could depend on the conservation and scientific groups involved in ACSAM
managing to restrict the spread of the disease. Tackling invasive
species such as the Asian Toad that might spread the disease and
ensuring tourists and researchers stick to strict hygiene protocols
would be necessary. Perhaps even more drastic conservation measures,
such as capturing animals from particularly vulnerable species for
raising in captivity.
On the other hand, the fourth scenario presents an intriguing
possibility: if it’s the case that Malagasy amphibians are resisting a
fungal invasion, discovering how this works could provide crucial
information to help save amphibians elsewhere from the disease.
The research on the amphibian skin microbiome, for example, and its
role in the creature’s immune system is producing some exciting results.
It’s also apparent that the diversity of the Chytrid fungus species as a
whole, and in particular of Bd, has not been appreciated. It’s
possible there are many types of chytrid fungus associated with
amphibians that we’re not yet aware of which provide some protection
against BdGPL.
So without a doubt, this report will sound warning bells loud and clear for conservationists, and Bd’s
appearance in Madagascar could still result in a huge loss of
amphibians. However, the lack of chytridiomycosis symptoms also suggest
there’s something special in Madagascar that could yield a breakthrough
in how the disease spreads – something that may not only benefit
Malagasy amphibians, but those throughout the world.
Friday, 27 February 2015
Widespread presence of the pathogenic fungus Batrachochytrium dendrobatidis in wild amphibian communities in Madagascar : Scientific Reports : Nature Publishing Group
The chytrid fungus, which is fatal to amphibians, has been detected
in Madagascar for the first time. This means that the chytridiomycosis
pandemic, which has been largely responsible for the decimation of the
salamander, frog and toad populations in the USA, Central America and
Australia, has now reached a biodiversity hotspot. The island in the
Indian Ocean is home to around 290 species of amphibians that are not
found anywhere else in the world. Another 200 frog species that have not
yet been classified are also thought to live on the island. Researchers
from the Helmholtz Centre for Environmental Research (UFZ) and TU
Braunschweig, together with international colleagues, are therefore
proposing an emergency plan. This includes monitoring the spread of the
pathogenic fungus, building amphibian breeding stations and developing
probiotic treatments, say the scientists, writing in Scientific Reports, the acclaimed open-access journal from the publishers of Nature.
The entire amphibian class is currently afflicted by a global pandemic that is accelerating extinction at an alarming rate. Although habitat loss caused by human activity still constitutes the main threat to amphibian populations, habitat protection no longer provides any guarantee of amphibian survival. Infectious diseases are now threatening even seemingly secluded habitats. The most devastating of the known amphibian diseases is chytridiomycosis, which is caused by a deadly chytrid fungus (Batrachochytrium dendrobatidis, or Bd). The fungus attacks the skin, which is particularly important in amphibians because they breathe through it. A large number of species have already been lost in this way - particularly in tropical Central America, where two-thirds of the colourful harlequin frog species have already been decimated across their entire area of distribution. Bd has now been identified in over 500 amphibian species, 200 of which have seen a significant decline in numbers. The pathogen is therefore classified worldwide as one of the greatest threats to biodiversity.
Until now, however, a few islands like Madagascar were thought not to have been affected. The last series of tests from 2005 to 2010 found no trace of the pathogenic fungus there. However, an analysis of the latest series of tests shows that the chytrid fungus also poses a threat to amphibians in Madagascar. "This is sad news for amphibian-lovers around the world," says Dr Dirk Schmeller of the UFZ, who was involved in analysing the samples. "Firstly, it means that an island that is home to a particularly high number of amphibian species is now at risk. Several hundred species live only on this island. And, secondly, if the pathogen has managed to reach such a secluded island, it can and will occur everywhere."
For the study that has just been published, the research team analysed samples from over 4000 amphibians from 50 locations in Madagascar taken since 2005. Samples from four species of Madagascan frog (Mantidactylus sp.) taken in 2010, and from one Mascarene frog (Ptychadena mascareniensis) taken in 2011 from the remote Makay massif tested positive for the fungus. In samples from 2013 and 2014 the pathogen was found in five different regions. Prof. Miguel Vences from TU Braunschweig says, "The chytrid fungus was found in all four families of the indigenous Madagascan frogs, which means it has the potential to infect diverse species. This is a shock!" The study also shows that the disease affects amphibians at medium to high altitudes, which ties in with observations from other parts of the world, where the effects of the amphibian epidemic have been felt primarily in the mountains.
The fact that the fungus has been identified in a very remote part of the island has puzzled the researchers. There is some hope that it may prove to be a previously undiscovered, native strain of the pathogen, which may have existed in the region for some time and have gone undetected because of a lack of samples. In this case, Madagascar's amphibians may have developed resistance to it. However, further research is needed to confirm this hypothesis before the all-clear can be given. It is also possible that the fungus was brought to the island in crustaceans or the Asian common toad (Duttaphrynus melanostictus), carried in by migratory birds or humans. "Luckily, there have not yet been any dramatic declines in amphibian populations in Madagascar," Dirk Schmeller reports. "However, the pathogen appears to be more widespread in some places than others. Madagascar may have several strains of the pathogen, maybe even the global, hypervirulent strain. This shows how important it is to be able to isolate the pathogen and analyse it genetically, which is something we haven't yet succeeded in doing." At the same time, the researchers recommend continuing with the monitoring programme across the entire country to observe the spread of the disease. The scientists also suggest setting up extra breeding stations for key species, in addition to the two centres already being built, to act as arks, so that enough amphibians could be bred to recolonise the habitats in a crisis. "We are also hopeful that we may be able to suppress the growth of the Bd pathogen with the help of skin bacteria," says Miguel Vences. "It might then be possible to use these bacteria as a kind of probiotic skin ointment in the future." A high diversity of microbial communities in the water could also reduce the potential for infection, according to earlier investigations conducted by UFZ researchers and published in Current Biology.
The outbreak of amphibian chytridiomycosis in Madagascar puts an additional seven per cent of the world's amphibian species at risk, according to figures from the Amphibian Survival Alliance (ASA). "The decline in Madagascan amphibians is not just a concern for herpetologists and frog researchers," says Dr Franco Andreone from the International Union for Conservation of Nature (IUCN), who is one of the study authors. "It would be a great loss for the entire world." In the coming months, the scientists therefore plan to work with the government to draw up an emergency plan to prevent this scenario.
Widespread presence of the pathogenic fungus Batrachochytrium dendrobatidis in wild amphibian communities in Madagascar : Scientific Reports : Nature Publishing Group
The entire amphibian class is currently afflicted by a global pandemic that is accelerating extinction at an alarming rate. Although habitat loss caused by human activity still constitutes the main threat to amphibian populations, habitat protection no longer provides any guarantee of amphibian survival. Infectious diseases are now threatening even seemingly secluded habitats. The most devastating of the known amphibian diseases is chytridiomycosis, which is caused by a deadly chytrid fungus (Batrachochytrium dendrobatidis, or Bd). The fungus attacks the skin, which is particularly important in amphibians because they breathe through it. A large number of species have already been lost in this way - particularly in tropical Central America, where two-thirds of the colourful harlequin frog species have already been decimated across their entire area of distribution. Bd has now been identified in over 500 amphibian species, 200 of which have seen a significant decline in numbers. The pathogen is therefore classified worldwide as one of the greatest threats to biodiversity.
Until now, however, a few islands like Madagascar were thought not to have been affected. The last series of tests from 2005 to 2010 found no trace of the pathogenic fungus there. However, an analysis of the latest series of tests shows that the chytrid fungus also poses a threat to amphibians in Madagascar. "This is sad news for amphibian-lovers around the world," says Dr Dirk Schmeller of the UFZ, who was involved in analysing the samples. "Firstly, it means that an island that is home to a particularly high number of amphibian species is now at risk. Several hundred species live only on this island. And, secondly, if the pathogen has managed to reach such a secluded island, it can and will occur everywhere."
For the study that has just been published, the research team analysed samples from over 4000 amphibians from 50 locations in Madagascar taken since 2005. Samples from four species of Madagascan frog (Mantidactylus sp.) taken in 2010, and from one Mascarene frog (Ptychadena mascareniensis) taken in 2011 from the remote Makay massif tested positive for the fungus. In samples from 2013 and 2014 the pathogen was found in five different regions. Prof. Miguel Vences from TU Braunschweig says, "The chytrid fungus was found in all four families of the indigenous Madagascan frogs, which means it has the potential to infect diverse species. This is a shock!" The study also shows that the disease affects amphibians at medium to high altitudes, which ties in with observations from other parts of the world, where the effects of the amphibian epidemic have been felt primarily in the mountains.
The fact that the fungus has been identified in a very remote part of the island has puzzled the researchers. There is some hope that it may prove to be a previously undiscovered, native strain of the pathogen, which may have existed in the region for some time and have gone undetected because of a lack of samples. In this case, Madagascar's amphibians may have developed resistance to it. However, further research is needed to confirm this hypothesis before the all-clear can be given. It is also possible that the fungus was brought to the island in crustaceans or the Asian common toad (Duttaphrynus melanostictus), carried in by migratory birds or humans. "Luckily, there have not yet been any dramatic declines in amphibian populations in Madagascar," Dirk Schmeller reports. "However, the pathogen appears to be more widespread in some places than others. Madagascar may have several strains of the pathogen, maybe even the global, hypervirulent strain. This shows how important it is to be able to isolate the pathogen and analyse it genetically, which is something we haven't yet succeeded in doing." At the same time, the researchers recommend continuing with the monitoring programme across the entire country to observe the spread of the disease. The scientists also suggest setting up extra breeding stations for key species, in addition to the two centres already being built, to act as arks, so that enough amphibians could be bred to recolonise the habitats in a crisis. "We are also hopeful that we may be able to suppress the growth of the Bd pathogen with the help of skin bacteria," says Miguel Vences. "It might then be possible to use these bacteria as a kind of probiotic skin ointment in the future." A high diversity of microbial communities in the water could also reduce the potential for infection, according to earlier investigations conducted by UFZ researchers and published in Current Biology.
The outbreak of amphibian chytridiomycosis in Madagascar puts an additional seven per cent of the world's amphibian species at risk, according to figures from the Amphibian Survival Alliance (ASA). "The decline in Madagascan amphibians is not just a concern for herpetologists and frog researchers," says Dr Franco Andreone from the International Union for Conservation of Nature (IUCN), who is one of the study authors. "It would be a great loss for the entire world." In the coming months, the scientists therefore plan to work with the government to draw up an emergency plan to prevent this scenario.
Widespread presence of the pathogenic fungus Batrachochytrium dendrobatidis in wild amphibian communities in Madagascar : Scientific Reports : Nature Publishing Group
Wednesday, 28 January 2015
Treatment of urodelans based on temperature dependent infection dynamics of Batrachochytrium salamandrivorans : Scientific Reports : Nature Publishing Group
Treatment of urodelans based on temperature dependent infection dynamics of Batrachochytrium salamandrivorans
The recently emerged chytrid fungus Batrachochytrium salamandrivorans currently causes amphibian population declines. We hypothesized that temperature dictates infection dynamics of B. salamandrivorans,
and that therefore heat treatment may be applied to clear animals from
infection. We examined the impact of environmental temperature on B. salamandrivorans infection and disease dynamics in fire salamanders (Salamandra salamandra). Colonization of salamanders by B. salamandrivorans
occurred at 15°C and 20°C but not at 25°C, with a significantly faster
buildup of infection load and associated earlier mortality at 15°C.
Exposing B. salamandrivorans infected salamanders to 25°C for 10
days resulted in complete clearance of infection and clinically cured
all experimentally infected animals. This treatment protocol was
validated in naturally infected wild fire salamanders. In conclusion, we
show that B. salamandrivorans infection and disease dynamics are
significantly dictated by environmental temperature, and that heat
treatment is a viable option for clearing B. salamandrivorans infections.
The recently emerged chytrid fungus Batrachochytrium salamandrivorans currently causes amphibian population declines. We hypothesized that temperature dictates infection dynamics of B. salamandrivorans,
and that therefore heat treatment may be applied to clear animals from
infection. We examined the impact of environmental temperature on B. salamandrivorans infection and disease dynamics in fire salamanders (Salamandra salamandra). Colonization of salamanders by B. salamandrivorans
occurred at 15°C and 20°C but not at 25°C, with a significantly faster
buildup of infection load and associated earlier mortality at 15°C.
Exposing B. salamandrivorans infected salamanders to 25°C for 10
days resulted in complete clearance of infection and clinically cured
all experimentally infected animals. This treatment protocol was
validated in naturally infected wild fire salamanders. In conclusion, we
show that B. salamandrivorans infection and disease dynamics are
significantly dictated by environmental temperature, and that heat
treatment is a viable option for clearing B. salamandrivorans infections.
Treatment of urodelans based on temperature dependent infection dynamics of Batrachochytrium salamandrivorans : Scientific Reports : Nature Publishing Group
Treatment of urodelans based on temperature dependent infection dynamics of Batrachochytrium salamandrivorans
The recently emerged chytrid fungus Batrachochytrium salamandrivorans currently causes amphibian population declines. We hypothesized that temperature dictates infection dynamics of B. salamandrivorans,
and that therefore heat treatment may be applied to clear animals from
infection. We examined the impact of environmental temperature on B. salamandrivorans infection and disease dynamics in fire salamanders (Salamandra salamandra). Colonization of salamanders by B. salamandrivorans
occurred at 15°C and 20°C but not at 25°C, with a significantly faster
buildup of infection load and associated earlier mortality at 15°C.
Exposing B. salamandrivorans infected salamanders to 25°C for 10
days resulted in complete clearance of infection and clinically cured
all experimentally infected animals. This treatment protocol was
validated in naturally infected wild fire salamanders. In conclusion, we
show that B. salamandrivorans infection and disease dynamics are
significantly dictated by environmental temperature, and that heat
treatment is a viable option for clearing B. salamandrivorans infections.
The recently emerged chytrid fungus Batrachochytrium salamandrivorans currently causes amphibian population declines. We hypothesized that temperature dictates infection dynamics of B. salamandrivorans,
and that therefore heat treatment may be applied to clear animals from
infection. We examined the impact of environmental temperature on B. salamandrivorans infection and disease dynamics in fire salamanders (Salamandra salamandra). Colonization of salamanders by B. salamandrivorans
occurred at 15°C and 20°C but not at 25°C, with a significantly faster
buildup of infection load and associated earlier mortality at 15°C.
Exposing B. salamandrivorans infected salamanders to 25°C for 10
days resulted in complete clearance of infection and clinically cured
all experimentally infected animals. This treatment protocol was
validated in naturally infected wild fire salamanders. In conclusion, we
show that B. salamandrivorans infection and disease dynamics are
significantly dictated by environmental temperature, and that heat
treatment is a viable option for clearing B. salamandrivorans infections.
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