Hamilton researchers part of team studying bats' wing fungus to help them 'survive and prosper'

A McMaster University researcher hoping to "help bats survive and prosper" said he and his colleagues had to become nocturnal for a few nights in order to conduct newly published research.

Fungal biologist Jianping Xu, a professor in the Hamilton university's department of biology, is part of a team studying the bacteria and fungi that grow on bats' wings.

Ultimately, Xu said, this work could help scientists learn which micro-organisms inhibit the growth of Pseudogymnoascus destructans, a fungus that causes white-nose syndrome in bats — "the largest and most devastating disease on mammals by a fungus."

According to the Canadian Wildlife Health Cooperative, which is a partnership of veterinary colleges and the British Columbia Animal Health Centre, white-nose syndrome is thought to have killed over six million bats since 2006.

The fungus infects bats' wings, then grows on their wings and muzzles, Xu said. The infection can wake bats from hibernation during the winter, causing them to use more energy than they've budgeted and then starve.

Teams identify 'cocktail' of bacteria to inhibit fungus

To sample the bacteria and fungi on bats' wings, Xu's team went to Lillooet, B.C. That province has the most diverse population of bats in Canada, Xu said. Officials detected Pseudogymnoascus destructans there last year. 

"If they are affected [by white-nose syndrome], it will probably be much worse than in eastern North America," Xu said.

Over the course of five days, Xu's team slept during the day and set up six-by-nine-metre nets to trap bats all night. Working with conservationists, the researchers checked the nets every 10 minutes. When they caught a bat, they'd put it in a cloth bag to warm up and calm down. Then, the researchers would measure the bat, identify its species, age and sex, and swab its wings. 

Back at the lab, Xu's team analyzed the samples and cultured the bacteria. Xu said they found dozens of strains that could inhibit Pseudogymnoascus destructans in a petri dish. 

According to a paper co-authored by Xu and McMaster researcher Chadabhorn Insuk that was published in the journal Microbiology Spectrum, little was previously known about the bat microbiome, and now, their knowledge can help the creatures. 

Working with Wildlife Conservation Society Canada (WCS Canada) and Thompson Rivers University, Xu's team has identified a "cocktail" of four bacteria that work well to inhibit the harmful fungus and can harmlessly live on bats' wings, he said.

"We believe this approach is going to be much more effective than other approaches including vaccination, fumigation, chemical or physical treatment."

Research on bats' diets in Newfoundland

For the last two years, they've been working in B.C. and Washington to apply the cocktail to natural and artificial bat roosts, and then monitor the results.

The team has learned the bacteria that grow on bats vary substantially by species and location, Xu said.

For example, there's one that's abundant in Lilloeet but not elsewhere. He said understanding which naturally occurring bacteria inhibit the fungus will be important because scientists would then deploy it without disturbing the native environment. 

"It's a balance in that we're trying to make the cocktail effective … but not impact the microbiome that much."  

Xu said future steps in this research include studying whether genetics affect bats' microbiomes, and how similar their wing and gut microbiomes are. His team is also studying bats' diets in Newfoundland to learn if modifying what they eat would offer protection against white-nose syndrome.