Scientists working to understand the devastating bat disease known as white-nose syndrome (WNS) now have a new, non-lethal tool to identify bats with WNS lesions —ultraviolet, or UV, light.
If long-wave UV light is directed at the wings of bats with white-nose syndrome, it produces a distinctive orange-yellow fluorescence. This orange-yellow glow corresponds directly with microscopic skin lesions that are the current “gold standard” for diagnosing white-nose syndrome in bats.
“When we first saw this fluorescence of a bat wing in a cave, we knew we were on to something,” said Greg Turner from Pennsylvania Game Commission (USA), who has been using this technique since 2010. “It was difficult to have to euthanize bats to diagnose WNS when the disease itself was killing so many. This was a way to get a good indication of which bats were infected and take a small biopsy for testing rather than sacrifice the whole bat.”
Millions of bats in the United States have died from the fungal disease called white-nose syndrome, which is caused by the fungus Pseudogymnoascus (Geomyces) destructans (Pd). White-nose syndrome was first seen in New York during the winter of 2006. Since then, the disease has spread to 25 US states and 5 Canadian provinces. The team of Czech scientists proved the disease also in the Czech Republic, but without the mass mortality.
A significant problem in studying WNS has been the unreliability of visual onsite inspection when checking for WNS in bats during hibernation; the only way to confirm presence of disease was to euthanize the bats and send them back to a laboratory for testing.
“Ultraviolet light is used for the diagnosis of fungal infections of the skin of humans and farm animals, traditionally in the form of the so-called Wood's lamp," said Jiri Pikula of Veterinary and Pharmaceutical University in Brno. "An exciting fact is that the UV light can be used also in the diagnosis of skin diseases of bats. In particular, the new diagnostic method helps guide the biopsy sampling.
Scientists from the Academy of Sciences of the Czech Republic, Veterinary and Pharmaceutical University in Brno and Masaryk University tested the technique of UV-guided sampling on live animals in the field simultaneously with colleagues from the USA. The traditional histological techniques were then used to verify the UV light’s accuracy.
Laboratory testing showed that 98.8 percent of bats with the orange-yellow fluorescence in the USA and 95.5 percent of bats in Europe tested positive for white-nose syndrome. All animals (100 percent) that did not fluoresce tested negative for the disease. Targeted biopsies showed that pinpoint areas of fluorescence coincided with the microscopic wing lesions that are characteristic for WNS.
Combining research from two continents demonstrates that UV diagnostics might be applicable worldwide with great sensitivity and specificity in detecting WNS.
“Moreover, the technique hurts the animal minimally and bats fly away after providing data for research,” said Natalia Martinkova from the Academy of Sciences of the Czech Republic. “This makes UV fluorescence an ideal tool for studying endangered species.”
Additional information: Mgr. Jan Zukal, Dr., MBA, Institute of Vertebrate Biology AS CR, Brno, mobil: +420 777 201 776, e-mail: zukal@ivb.cz
Publication: Gregory G. Turner, Carol Uphoff Meteyer, Hazel Barton, John F. Gumbs, DeeAnn M. Reeder, Barrie Overton, Hana Bandouchova, Tomáš Bartonička, Natália Martínková, Jiri Pikula, Jan Zukal, and David S. Blehert (2014) NONLETHAL SCREENING OF BAT-WING SKIN WITH THE USE OF ULTRAVIOLET FLUORESCENCE TO DETECT LESIONS INDICATIVE OF WHITE-NOSE SYNDROME. Journal of Wildlife Diseases In-Press.
doi: http://dx.doi.org/10.7589/2014-03-058
Link to original: http://www.usgs.gov/newsroom/article.asp?ID=3906&from=rss#.U48Pd_l_vBx
4 Jun 2014
