Researchers prepare to field test new treatment for bee disease

Monday, December 15, 2014

by SUSAN MANN

It will be at least a year before University of Guelph researchers know if their new treatment to fight American foulbrood disease in bees works.

“I don’t want to give bee farmers a false sense of security or hope just yet,” says Rod Merrill, a professor in the university’s department of molecular and cellular biology. He is one of the co-authors of a study published in the December issue of the Journal of Biological Chemistry outlining their finding of a toxin released by the pathogen that causes American foulbrood disease.

Researchers have developed a lead based inhibitor against the toxin but it still must undergo field testing, Merrill says, adding next winter they’ll be able to tell if beekeepers should be getting excited about their proposed treatment.

Merrill says they’re studying the bacterium that causes American foulbrood disease. In terms of the basic research that they’ve done so far, “we’ve determined the three- dimensional structure of one of the toxins that this bacterium uses to cause the disease. When you have structure then you’re able to design drugs, which we are doing, to inhibit it. But we need to test those drugs in the field to see whether they work” and also to determine if they cause any side effects that are harmful to bees.

American foulbrood disease is found throughout Ontario and Canada and affects both the honeybee industry and pollinator populations, according to a Dec. 16 university press release. Adult bee carriers spread the disease readily through spores they transmit within and between colonies. Developing larvae eat the spores and die but they also release millions of additional spores into the colony before dying.

The hives’ weakened state attracts ‘robber bees’ looking for honey and those bees spread the disease to other colonies, the release says.

Merrill says American foulbrood disease is the major brood disease of bees. “It’s very widespread and difficult to contain.”

It’s also hard to treat because there are antibiotic resistant strains. The only effective control method is to burn the hive and associated equipment. Burning destroys the spores, which otherwise may remain viable for 40 years.

In January 2015, University of Guelph researchers will begin collaborating with scientists at the Institute of Bee Research in Hohen Neuendorf, Germany. The German scientists specialize in American foulbrood disease and they do field work.

“They will study the effects of our proposed treatment methods on honey bee health but we don’t yet know the results of those studies,” Merrill notes. “We haven’t done the field work yet. The biochemistry works out well in the laboratory but now we need to see what it means for bee health.”

Without the field studies, researchers don’t know if their proposed new treatment is “going to be effective at all,” he says.

Merrill says this is their first study; that it has been picked up and reported by urban media shows the tremendous interest there is in honeybee health these days.

In other news related to bees, a poll released today and done by Friends of the Earth Canada, The Canadian Association of Physicians for the Environment and the Ontario Beekeepers’ Association found widespread support for the Ontario government’s proposed new regulations to dramatically cut neonicotinoid use by farmers by 2017. Support for the government’s plan to reduce usage by 80 per cent varies by region. The plan is supported by 85 per cent of southwestern Ontario residents, 81 per cent of Torontonians, 79 per cent of Niagara and Hamilton residents, 78 per cent of those living in the Greater Toronto Area, 77 per cent in Eastern Ontario, 63 per cent in Northern Ontario and 60 per cent in Central Ontario, according to the groups’ Dec. 16 press release.

The poll also found that 76 per cent of Ontarians are concerned about the future on honeybees and wild bees.

The poll was done by Oraclepoll Research Limited staff, which conducted telephone interviews with 1,000 people. The margin of error for this survey is plus or minus three per cent 19 of 20 times. BF