The research team aims to deliver antibodies to swine E. coli through plants

Inspired by the success of a Belgian research team looking for a new approach to “immune therapy” for post-weaning diarrhea in pigs, a Canadian team is working to develop an antibody to prevent E. coli 0157: H7 from being delivered to pigs. with their help. feed.

The work began more than five years ago, after researcher Dr. Rima Menassa learned about E. coli contamination at a meat processing plant in Alberta. She was aware of the Belgian team’s efforts to bio-engineer an antibody that will grow into a plant’s cellular structure and secured three years of AAFC funding to explore the possibility of using the same technology to bio-engineer E. coli 0157 : H7, a bacterial pathogen of significant concern in the pork sector.

Why does it matterPrevention of E. coli in pig pens has direct economic benefits for farmers by promoting healthy pigs, but the pathogen can also be transmitted through manure and poses risks to both human health and food safety.

“I was very impressed with the work done (the Belgian team) and I took a very similar approach,” said Menassa. Farmer.

In the first three years of the study, Menassa, based at the AAFC Research and Development Center in London, worked on a single-stranded DNA antibody that is unique to blades and camels. Single-chain proteins, called “nanobodies”, are characterized by a very strong binding to the target cell.

Blade-derived nanobodies are well known for their potential in medical research, including much ongoing work on COVID-19.

Nicotiana benthamiana plants grown on AAFC produce antibodies to E. coli.

Kind regards AAFC

Through bio-engineering, she fused nanobodies that were exposed to E. coli with antibodies commonly found in pigs. Subsequent engineering created antibodies that will grow in the cellular structure of plants.

The goal, according to an AAFC edition, is to create an herbal food additive with plants that grow antibody. “The cell walls of plant matter can protect the antibody during digestion,” it says. “This helps the antibodies reach the gut, where they bind to E. coli bacteria and can prevent further colonization of the pathogen in the digestive tract.”

“This is a new approach,” Menassa said of the plant-grown antibody. “This is not something that happens in nature.” In her first three years of study, she published three scientific papers explaining her work.

An inexperienced plant biologist, Menassa knew from this preliminary work that he would have to bring in animal expertise. She managed to attract interest PlantForm biotech start-up, which then applied for further funding through OMAFRA. This is what pays for future studies in mice, and Menassa is confident that additional funding will be provided to continue testing in pigs.

PlantForm, she explained, has explored similar therapies for use in humans. But getting approval for human testing can be more difficult than getting approval for use in animals. And these studies can be significantly more expensive in humans than in animals.

The start-up saw the opportunity to join forces with Menassa and begin its explorations with the pig antibody. Menassa and PlantForm then partnered with Dr. Patti Kiser, a veterinary pathologist at Western University, to begin testing this antibody specifically for E. coli in pigs.

Attempts, she says, should be simple.

“You feed the animal with antibodies and then challenge the animal with the pathogen. Then collect the feces and see if E. coli continues to be present. ”

At the end of the experiment, Kiser will examine the mouse intestines for signs of colonization by E. coli bacteria.

“It simply came to our notice then. It just depends on how many results we need to get to make sure they are accurate. ”

Kiser will lead the process. The goal, Menassa said, “is to determine if the antibody can prevent E. coli colonization in mice and / or prevent the elimination of E. coli from colonized mice.”

The team hopes to “stabilize a baseline for the minimum dose required for efficacy. The more antibodies that survive the digestive tract in the animal, the lower the dose required to achieve the desired results in preventing colonization and elimination, ”she said.

Menassa has not spoken directly with any representative of the Canadian pork industry about the team’s work, but expects interest to grow as they move to pig testing. And if they go well, there will be excitement to see a feed additive on the market.

“Feeding antibodies directly to animals using a plant-based food additive, rather than a purified, injected formula, will have cost benefits for the industry,” she said, adding that the purification and formulation of such a treatment in an injectable form it could be up to 80 to 90 percent of the total cost of the drug. The research team aims to deliver antibodies to swine E. coli through plants

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