Bacteria and fungi from the wings of bats could play a significant role in saving them from white-nose syndrome (WNS), a fungal disease affecting the skin of wings and muzzle, which has nearly wiped out vulnerable bat populations across North America.
Researchers at McMaster University have gathered and analyzed samples from the community of microorganisms, or microbiome, on the wings of several bat species in Lillooet, British Columbia, which they hope will reveal new information about how WNS affects bats and, more important, how to stop it.
Lillooet is of special interest to scientists because its rich and diverse bat population, concentrated in a relatively small geographic area and diverse ecological niches, has shown no signs of infection, even though the disease-causing agent is present elsewhere in B.C. and WNS is widespread in Canada and the US.
“We see a very high number of bat species in the Rockies and west of the Rockies,” explains Jianping Xu, a professor in the Department of Biology at McMaster University and lead author of the paper, newly published in Microbiology Spectrum, a journal of the American Society for Microbiology.
“If there is a new frontier for preserving bat species, it will likely be found in western North America, yet we know very little about the wing microbiome of these bats.”
Healthy wings are critical for the survival and reproduction of bats and the wing microbiome is believed to play a major role in their susceptibility to WNS, say the researchers, who will use the new data to refine a probiotic cocktail they developed in collaboration with scientists at the Wildlife Conservation Society of Canada and Thompson Rivers University.
The cocktail is one of a handful of experimental treatments — including vaccines and fumigation — which are being tested as the scientific community races to treat and prevent WNS. The disease has spread rapidly since it was first detected in New York State in 2006 and has killed millions of bats throughout eastern North America.
White-nose syndrome is caused by Pseudogymnoascus destructans or pd, a fungus that thrives in cold temperatures. It tends to hit smaller species which include the little brown bat, northern long-eared bat and the tricolored bat, all of which have suffered dramatic population declines of as much as 90 per cent in affected areas.
The fuzzy white fungal growth typically appears on the muzzles or wings of infected bats during hibernation, when their metabolic rate and body temperature are low. WNS interrupts hibernation and wakes the bats, causing them to use precious fat reserves, which leads to starvation.
In Lillooet, Xu and his team captured and tested 76 bats and subsequently identified thousands of bacteria and fungi, many of them previously unknown.
They previously isolated over 1000 bacterial strains from bat wings and identified over a dozen strains which appear to fend off the fungus responsible for WNS. Further testing of four strains showed those individual strains of bacteria to be more effective against the fungus when combined.
“To develop a powerful probiotic cocktail that will work and will have an effect against the fungus in nature, we must understand the microbiome of the bats, or what exactly is on their wings,” explains Xu.
Over the last three years the team has administered the cocktail to roosts in British Columbia and in Washington State with promising results.
“This kind of information will allow us to refine potentially region-specific probiotic cocktails and manipulate the microbiome to help the survival of bats,” says Xu.