Genetically Engineered Bacteria to Protect Bees From Colony Collapse
Thu, April 22, 2021

Genetically Engineered Bacteria to Protect Bees From Colony Collapse

Researchers from the University of Texas (UT) developed a novel technique that can help protect honey bees from the so-called deadly colony collapse disorder by genetically engineering bacteria strains / Photo by: CSIRO via Wikimedia Commons

 

Researchers from the University of Texas (UT) developed a novel technique that can help protect honey bees from the so-called deadly colony collapse disorder by genetically engineering bacteria strains.

The new method, discussed in a report published in the journal Science, could scale up for agricultural use, the researchers said. They added that this possibility comes as the engineered bacteria can be grown easily, immunize the bees, and don't spread to non-bee species.

The study comes as an increasing number of bee colonies, particularly in the US, are dwindling in their adult bees, with records hitting the highest rate since a national survey on the species began.

Bee-Protecting Engineered Bacteria

The colony collapse disorder (CCD) is when a majority of worker bees disappear. Two of the identified causes are pests known as varroa mites and a virus that deforms the bee's wings, both of which usually come together. Varroa mites feed on the bees while also spreading the virus, weakening the bees, and making them more susceptible to pathogens around them.

These were the problems UT researchers were looking to address by genetically engineering a strain of bacteria found in honey bees to target the virus and another strain for the mites.

"We discovered there are very specialized bacteria that live in honey bees," Nancy Moran, the primary investigator of the study, told ABC News, the news division of the American Broadcasting Company. "They don't live anywhere else, but they're in honey bees all over the world."

The researchers then introduced these modified bacteria to hundreds of bees in a laboratory setting in a bid to promote helpful RNA interference response to viruses in bees while also stimulating a lethal response in the mites.

According to a press release, bees treated with the virus-targeting strain were 36.5% more likely to survive in 10 days compared to control bees. Bees with the bacteria strain targeting Varroa mites also showed promising results: Compared to mites feeding on control bees, Varroa mites feeding on the treated bees were 70% more likely to die by the 10th day of treatment.

Effective Bee Immunization

The researchers concluded that immunizing young worker bees with the modified bacteria improved the bees' immune systems to protect them against the deformed wing virus. The method also caused the Varroa mites' immune systems to fight against the engineered strains, ultimately killing them.

Moran said their work has direct implications for bee health and that it was the first time scientists were able to improve bee health through the genetically engineered microbiome. The investigators noted a "very low" risk of the engineered bacteria spreading into the wild and infecting other insects, which could provide some anti-pest or anti-pathogen abilities.

"The type of bacteria used are highly specialized to live in the bee gut, can’t survive for long outside of it and are protective for a virus that strikes only bees," the researchers said in a press release, noting another benefit of using the approach as a tool to study bee genetics.

"The engineered bacteria can knock down specific bee genes, enabling insights into the workings of the bee genome and possibly enabling new breeding strategies to produce more robust bee colonies," the researchers said.

They further emphasized that their work is still in infancy and that further studies are needed before testing the genetically modified bacteria in the field, ABC News reported. It added that other methods used to control the Varroa mite and deformed wing virus were more costly, short-lived, and generally ineffective compared to genetically engineering bacteria strains.

Declining Pollinator Population

The results of the new study come at a time of rapidly declining honey bee population, with numbers dropping further each year as bee colonies disappear due to CCD. Data from the Bee Informed Partnership (BIP), a non-profit associated with the University of Maryland, showed a decline of 37.7% of the managed honey bee population from October 1, 2018 to April 1, 2019. This figure was seven percentage points more compared to the same period during the winter of 2017-2018. The BIP also reported that the 2019 winter season also represented the highest level of bee population losses since the non-profit began the survey in 2006.

From April 2018 to April 2019, the overall loss of managed bee population plummeted by 40.7% or about the same average of what researchers and beekeepers recorded in 2006, Scott McArt, assistant professor of pollinator health at Cornell University, told ABC News.

McArt said the main takeaway from the report is that these declines are "unsustainably high losses" and that the figures are not causing panic among researchers, who have become "a little bit accustomed to these large loss rates."

Honey bees support about $20 billion worth of crop production in the US alone through pollination of flowers, fruits, and vegetables making them the "most important agricultural commodities in the country," BIP board of director Geoff Williams said.

Sign of the 6th Mass Extinction

Honey bee losses are concerning, and so do the decline of the number of other pollinators, which is also a dire threat that could lead to a catastrophic collapse of the ecosystem.

A 2019 study found that the total mass of all insects on Earth is decreasing at an alarming rate of 2.5% each year, a trend that could see the extinction of all insects by 2119. The loss of these bugs should raise alarms since they are the food source of other species like birds, fish, and some mammals. They also pollinate food crops.

The study also estimated that 41% of insect species are declining, with 31% under threat and 10% going locally extinct, reported the Business Insider, an American financial and business news, adding that the extinction rate is eight times faster compared to other species.

Among the insects in the study, the highest decline was recorded among caddisflies (68%), followed by butterflies (53%), beetles (49%), bees (46%), mayflies (37%), dragonflies (37%), stoneflies (35%), and flies (25%), data from online portal for statistics Statista showed.

This rapid biodiversity decline observed worldwide is sometimes called the sixth extinction, or the sixth time life on Earth is experiencing or has experienced a significant drop in numbers.

"As insects comprise about two-thirds of all terrestrial species on Earth, the above trends confirm that the sixth major extinction event is profoundly impacting life forms on our planet," the authors of the study wrote.

Despite what most people think, the loss of entire insect species will have a profound impact on the planet.