Reseach project: Bsal

The highly infectious, parasitic and until recently unknown skin fungus Batrachochytrium salamandrivorans was first recorded in 2016 in The Netherlands. This “salamander-eating” chytrid fungus – named after its host the fire salamander – has triggered mass mortalities of fire salamanders in Belgium, The Netherlands and more recently also in Germany. This fungus was probably introduced from Asia.

Aim

This project was initiated by Schönbrunn Zoo in cooperation with Alpenzoo Innsbruck, Österreichische Zoo Organisation (OZO), Technisches Büro Florian Glaser, Haus der Natur Salzburg, Arge Naturschutz Kärnten, iNatura Vorarlberg, the Natural History Museum Vienna, the University of Veterinary Medicine Vienna, the Austrian Herpetological Society, and the Office of the Tyrolean Government (Department of Environmental Protection). It has been examining the possible infection status of Austrian salamanders and newts. The random sampling of Alpine und fire salamanders in Vienna, Lower and Upper Austria, Carinthia, Salzburg, Tyrol and Vorarlberg has enabled a preliminary assessment of the current threat posed by Bsal in Austria. Repeated monitoring efforts will be required to determine the long-term spread and impact of the fungus.

Relevance

Although this fungus is harmless for humans and has not yet been reported in Austria, the alarm bells are ringing nonetheless. The populations of fire- and Alpine salamanders along with all native newt species (smooth- and palmate newts, Danube crested-, northern crested-, Alpine crested- and Italian crested newts) are threatened by this skin fungus. This pathogen can survive in moist soil (and other materials) as well as in water and can therefore very easily be spread via these media. Frogs remain unaffected but serve as carriers of the pathogen.

Method

The sampling of free-living adult fire salamanders and Alpine salamanders (Tyrol and Vorarlberg) involves swabbing with sterile pads. The ventral side and the undersides of the salamanders‘ feet are swabbed a total of 20 times. If possible, the animals are measured of photographed on graph paper, weighed and their sex determined. All animals are then released unharmed on site. The swabs are stored at 4°C and then analyzed using dublex-qPCR by Dr. Steve Smith (Department of Integrative Biology and Evolution") and his team from the University of Veterinary Medicine Vienna. After the sampling procedure at each site, the equipment (buckets, rubber boots, measuring instruments) are completely dried and disinfected in order to minimize the risk of potentially spreading Bsal.

Results

In 2016 the first controls were conducted in Vienna and Tyrol. Thanks to the help of herpetologists from other Austrian provinces, the monitoring was expanded and the salamanders in Vienna, Lower Austria, Upper Austria, Salzburg, Carinthia and Tyrol were also randomly sampled. Up until 2020, the analysis and evaluation revealed no Bsal cases in any of the tested animals. This effort is now being conducted on an annual basis.

References

Blooi M. et al. 2015. Treatment of urodelans based on temperature dependent infection dynamics of Batrachochytrium salamandrivorans. Scientific Reports 5: 8037. https://www.nature.com/articles/srep08037?WT.feed_name=subjects_herpetology

Blooi M. et al. 2015. Successful treatment of Batrachochytrium salamandrivorans infections in salamanders requires synergy between voriconazole, polymyxin E and temperature. Scientific Reports 5: 11788. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4485233/

Martel A. et al. 2013. Batrachochytrium salamandrivorans sp. nov. causes lethal chytridiomycosis in amphibians. Proceedings of the National Academy of Sciences of the United States of America 110 (38): 15325–15329. http://www.pnas.org/content/110/38/15325.full

Mutschmann F. 2015. Chytridiomycosis in amphibians. Journal of Exotic Pet Medicine 24 (3): 276–282.

Schmidt B.R. et al. 2017. Dynamics of host populations affected by the emerging fungal pathogen Batrachochytrium salamandrivorans. Royal Society Open Science 4(3) http://rsos.royalsocietypublishing.org/content/4/3/160801

Spitzen-van der Sluijs A. et al. 2016. Expanding Distribution of Lethal Amphibian Fungus Batrachochytrium salamandrivorans in Europe. Emerg Infect Dis 22 (7):1286-1288. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4918153/

Van Rooij P. et al. 2017. Efficacy of chemical disinfectants for the containment of the salamander chytrid fungus Batrachochytrium salamandrivorans. PLoS One 12 (10):e0186269. doi:10.1371/journal.pone.0186269. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0186269

Project leader:

Dr. Doris Preininger
d.preininger@zoovienna.at

Associated researchers:

Dr. Florian Glaser, Dr. Gerda Ludwig, Thomas Wampula, Dr. Silke Schweiger, Peter Kaufmann MSc, Mag. Karina Smole-Wiener, Mag. Markus Grabher, Dr. Andreas Maletzky, Dr. Steve Smith, Gopi Munimanda MSc, Prof. Chris Walzer.