That bees are downright awesome is not up for debate. After all, they pollinate about a third of all the crops that we consume and help to support ecosystems worldwide. Yet the bees are in trouble, with a phenomenon known as colony collapse disorder (CCD) causing an alarming drop in numbers. Fortunately, a solution may be on the horizon in the form of genetically modified bacteria.
One thing that is a topic of great debate is the cause of CCD. Some studies point the finger at a particular class of pesticides called neonicotinoids, although many within the scientific community agree that multiple factors are probably at play.
What we do know is that CCD first became an issue once the Varroa mite became widespread, largely thanks to a global trade in European honeybees that brought them into contact with Asian parasites. At first, it was assumed that the mites were simply killing bees by sucking on their blood, although it later transpired that they also carried the lethal deformed wing virus (DWV), transmitting it into the bloodstream of the bees they feasted on.
Publishing their work in the journal Science, a team of researchers genetically modified the gut bacteria of honeybees in order to protect them from both the Varroa mite and DWV, with extremely positive results.
First, they inoculated week-old bees with a strain of the bacteria that had been genetically modified to boost the insects’ immune response to certain types of viruses via a process called RNA interference (RNAi). This occurs when healthy cells recognize molecules called RNA that are produced by invading viruses, triggering a defense against these pathogens.
Bees that were treated with the modified bacteria were found to be 36.5 percent more likely to survive for 10 days than those that hadn’t been inoculated.
The study authors then produced a second strain of bacteria that was modified to trigger a lethal immune response in Varroa mites. Results showed that mites feeding on the blood of bees that had been treated with this bacteria were 70 percent more likely to die within 10 days than mites feeding on bees that lacked the modified bacteria.
“This is the first time anyone has improved the health of bees by genetically engineering their microbiome,” said study author Sean Leonard in a statement.
And because these bacteria are relatively easy to produce and can’t be spread to other organisms, the researchers believe that their work could pave the way for a safe and effective solution to dwindling bee colonies across the world.