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."
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