[Texascavers] More on WNS

[Minton, Mark]

The following is excerpted from a rather lengthy report of conversations BCCS member and USGS geologist Chris Swezey had with David Blehert, a USGS microbiologist working on the White Nose fungus.  I found it to be quite interesting.  Part of it is now out of date, since the scientific description of the fungus has just been published.  The attached article that is mentioned is Science v. 323, p. 227 (2009).   Mark Minton     >I would like to communicate some information that I have gleaned during the past several days from telephone conversations with Dr. David S. Blehert, a USGS microbiologist who is working with a bat ecologist named Paul Cryan on White Nose Syndrome (WNS).  David Blehert lives and works in Madison (Wisconsin), he is the person who first identified the fungus that is associated with WNS, and he has published his results in two scientific articles (which I shall attach at the bottom of this email message). >>From my conversations with David Blehert, it appears to me that he is not a caver and he is not fully aware of all of the issues that concern cavers, but he is in contact with NSS folks (he mentioned Peter Youngbaer, specifically) and he is very appreciative of the assistance that he has received from cavers.  David is an extremely articulate scientist, and on 4 June 2009 he testified before the U.S. Congress on the White Nose Syndrome problem that is afflicting bats.  He is also an extremely cautious person scientifically, and is very careful to separate observations from interpretations and conclusions.  He is also working very hard to understand the WNS problem. >So, some information that David Blehert communicated to me: (1) The first evidence of bat WNS was documented at Howes Cave, 52 km west of Albany, New York, on 16 February 2006.  Howes Cave is a commercial cave that is visited by many people. (2) Bats afflicted during the winter by WNS show a tendency to shift to colder roost sites, such as cave entrances, and they exhibit erratic behavior such as flying around outside during the daytime in winter.  In 2006-2007, many of these bats exhibiting erratic behavior in New York were tested for rabies, and no bat tested positive for rabies. (3) So far, WNS appears to be a condition that affects only bats that hibernate in groups. (4) David Blehert performed autopsies on WNS affected bats, but he did not find any problems with bat internal organs.  Furthermore, with the afflicted bats, he was not able to identify any disease-causing parasites, any known viral pathogens, or any bacteriological problems. (5) Bats normally have lots of biota on their skin, and David was able to identify several white fungi on the skin of afflicted bats.  The problem that David faced was to identify which fungus was causing the problems.  He was able to see a white fungus in the field, but was having trouble identifying the fungus in the lab.  Eventually, he was successful, and David was able to identify the culprit as a specific fungus. >What David has learned about this fungus: - The fungus has only been found where WNS is seen, and it has only been identified conclusively in the WNS-affected area in the United States. - In caves with affected bats, the fungus is seen on sick bats but not on healthy bats. - The fungus is a new species that has not been named or described before. - The fungus has spores that have an unusual hook shape. - All isolates of the fungus are identical.  Interpretation: David says that this observation suggests that the fungus has disseminated from a point source (e.g., Howes Cave). - The fungus invades the skin of bats, and attacks the skin tissues. - The fungus requires cold for growth, and does not grow at temperatures above 24 degrees C (75 degrees Fahrenheit).  At high temperatures, the fungus goes dormant. - The fungus likes high humidity. >Other than attacking skin tissue, David does not yet know all of the ways in which the fungus affects bats.  It is not known if the fungus is the primary cause of bat mortality, or if the fungus is a secondary infection that is associated with something else that is killing the bats.  However, David noted that the fungus grows on bat wings, and that bat wings are very important for flight, heat dissipation, water control, gas exchange, and blood pressure regulation. >New information not yet published: David Blehert has identified a similar white fungus with the same unusual hook shape in several European countries.  It appears that this fungus may have existed in European bat populations since the 1980s, but in Europe this fungus is not associated with unusual bat mortality.  David plans to investigate this topic further.  A working hypothesis at the moment is that the European fungus is identical to the U.S. fungus, but European bats hibernate in smaller groups and there is something specific about bat hibernating behavior in the U.S. that causes bat mortality associated with this fungus.  Again, David plans to investigate this further. >I specifically asked David how he thought that the fungus spread, and I stated that this question was of great concern to cavers.  In response, David said that it appears to be able to spread by at least two ways: (1) Bat-to-Bat Transmission, especially in large groups of hibernating bats.  Regarding this method of transmission, David made an analogy of children in school (lots of individuals in close contact) spreading colds from one to another. (2) Human-to-Bat Transmission.  Regarding this method of transmission, David thinks that the fungus was transmitted from Europe to Howes Cave, and then it spread from Howes Cave to many other locations in the eastern U.S.  David noted that bats do not migrate from Europe to New York, and that the sudden first appearance of the fungus in Howes Cave (a commercial cave) suggests that the initial transmission to the U.S. was by humans. >I specifically asked David if he knew of ways to kill the fungus.  He said that he had not done much work on this topic, but he thought that bleach and standard antimicrobial compounds might be effective.  He seemed to think that some other people might be working on this question. >I specifically asked David if he thought that other mammals are (or could be) affected by the fungus.  He said that he did not know, and that he did not think that anyone was working on this question. >David Blehert is a microbiologist, he is being bombarded by questions from a lot of people right now, and he does not have all of the answers to these questions.  Nevertheless, here is a list of some analyses that he would like to do and some questions that he would like to answer: (1) Additional analyses of the white fungus in Europe, in order to determine if it is indeed the same fungus. (2) Genome analysis of the fungus in the U.S.  This analysis would help David predict and model the spread of the fungus, and it might tell us how long the fungus has been in European bats (if it is indeed the same fungus in Europe). (3) What specific environmental conditions does the fungus prefer?  There may be certain temperature and humidity conditions that could slow down or stop the spread of the fungus.  David noted that at present the Appalachian Mountains appear to be a temporary barrier to westward movement of the fungus. (4) Are there biological or chemical means to control WNS? (5) Do some bats survive? – If so, then is the survival because of development of antibodies, changes in hibernating behavior, or something else.   >What can BCCS do to help? David was talking to me about WNS because I am a geologist, and he wanted information about the geology and general environmental conditions of caves. Specifically, we talked about the following four items: >(1) Plotting the distribution of WNS-infected caves on topographic maps, in order to see if there is any correlation with elevation.  In other words, there may be a need for good cave elevation data.  Personally, I do not think that there is a correlation with elevation, but it would be worthwhile to look at this with real numbers. >(2) Plotting the distribution of WNS-infected caves on geologic maps, in order to see if there is any correlation with stratigraphy.  In other words, there may be a need for good geologic maps of caves.  I suspect that there may not be much of a correlation with stratigraphy, but it would be worthwhile to look at this in a rigorous manner.  FYI – To my knowledge, George Deike’s map of Breathing Cave is the most detailed geologic map of any of the WNS-infected caves.  In addition, I have geologic maps of two other infected caves (Hamilton Cave, and Cave Mountain Cave) and three non-infected caves (Haynes Cave, Sinnett Cave, and Trout Cave). >(3) Is there a relation between fungal infection and chemistry of cave soil?  To answer this question, we would need soil samples from caves prior to fungal infection.  We want to think about this idea some more, and then we may submit a proposal for a grant to collect and analyze soil samples from caves that are currently not in the infected areas.  Nadine Piatak (USGS) and I already have some soil samples that we collected in 2002-2004 for a study of nitrate concentrations in cave soil (Organ Cave, Sinnett Cave, Trout Cave, Cave Mountain Cave). >(4) The WNS fungus appears to prefer certain temperature and humidity conditions in caves.  Thus, detailed data on cave temperature and humidity might help David to predict the spread of the fungus.  However, such information is not available for most caves. --------------------------------------------------------------------- Visit our website: http://texascavers.com To unsubscribe, e-mail: texascavers-unsubscr...@texascavers.com For additional commands, e-mail: texascavers-h...@texascavers.com