Fungus showing promise as tick killer, say Acadia researchers

CBC

2 days ago

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Researchers have been studying the lethality of a common fungus on blacklegged and dog ticks
A common, naturally growing fungus that is harmless to humans but lethal to ticks in some cases is showing promise as a natural insecticide after a year of study at Acadia University.
Researchers at the Faraone Lab have been studying the effects of a soil fungus called Clonostachys rosea on blacklegged ticks — which can carry the bacteria that cause Lyme disease — as well as the hardier dog tick.
"We found that actually this fungus works really well at killing the blacklegged ticks," Nicoletta Faraone, the head of the lab and an associate professor in the chemistry department, told CBC Radio's Information Morning Nova Scotia on Monday.
The lab's findings could be a significant development in a province that has the most ticks in Canada, with populations growing in rural and urban areas. There is no vaccine for Lyme disease, which, if left untreated, can lead to severe heart, joint and nervous system symptoms.
The lethality of the fungus was discovered when Luís Anholeto, a research associate, noticed ticks collected from the Harvest Moon Trail in Coldbrook, N.S., and taken back to the Faraone Lab were unexpectedly dying after a few days.
Upon investigation, the researchers determined the fungus, which had attached to the tiny arachnids, was the culprit.
Fungus 'slowly disables' ticks
"In short, the fungus slowly disables and kills the ticks," Anholeto told Information Morning Nova Scotia. "So they won't be able to find a host … which can help also to reduce the transmission of the bacteria that causes the [Lyme] disease."
So far, the lab's research has shown the fungus is more effective at killing blacklegged ticks than dog ticks.
"We have observed that the fungus kill about 70 per cent of the blacklegged ticks. While for the dog tick, we see a 30 per cent of mortality," said Faraone.
"We were not very surprised of this because we know that the dog ticks are a little bit bigger, more resistant, more stubborn compared to the blacklegged ticks."
Anholeto said they are still trying to understand what happens from the time the fungus attaches to the tick's outer shell and grows into its body to when it ultimately causes death. It appears the fungus produces a substance that breaks down the tick and damages the internal tissues.
The process takes at least seven days, but the researchers have been observing better mortality after two weeks.
Could be used 'on your backyard'
The Faraone Lab is using nanatechnoloy in its research to isolate the active ingredient in the fungus. Spores can then be turned into a powder that can be sprayed for tick control.
"For example, on your backyard for managing a tick population," said Faraone. "So the idea is having this product potentially down the road to be developed."
Similar fungi are already used in agriculture for things like crop protection and pest management.
Faraone said they are now doing more in-depth studies to find the "most optimal concentration of spores."
"We want to see if we're able to improve the mortality of the dog tick, which is a little bit more resistant, so it can be easily applied for managing both the species that are very common and they are very present in Nova Scotia," she said.
The Canadian Lyme Disease Foundation provided funding for the initial research project, which is in collaboration with Laura Ferguson, an assistant professor in Acadia's biology department.
The bulk of the research has been conducted and the lab is now working to get it published and carry the research further.