Researchers have come up with Billions of nano soldiers, a way to induce bacteria – harmless bacteria that feed on bacteria – to stick together and form microscopic beads. These beads can be safely added to food and other items to rid them of harmful bacteria such as E. coli 0157. Each bead is about 20 microns (one-fiftieth) in diameter and filled with millions of phages.
The McMaster engineering team behind this invention (Billions of nano soldiers), led by Professor Zeinab Hosseinidoust, Canada Research Chair in Bacteriophage Bioengineering, and Tohid Didar, Canada Research Chair in nano-biomaterials, and graduate student Lei Tian, developed a vaporizer that use nothing but microbeads.
The researchers’ new super-sanitizer spray is food safe and highly effective, as they explain in an article published in the influential journal Nature Communications. Vanier Scholar graduate student Shadman Khan worked with Tian to test the spread of antibiotics in food products.
“When we spray it on food, we gather billions of little soldiers to protect our food from pathogens,” said Tian, who led the study as part of his doctoral research.
The research builds on the same chemistry work previously used by Hosseinidoust’s lab to induce phages to associate with each other in sufficient numbers to form a gel.
“They fit together like little Lego pieces,” he says. “The organized nature makes them more durable and easier to pack, store and use.”
Before the introduction of penicillin in the 1940s, research into phage-based infectious diseases and therapies was very promising, but interest in developing their potential stopped once phage-based penicillins came on the market. With antimicrobial resistance now undermining the effectiveness of existing antibiotics, phage research is attracting strong new interest. When phages – which are common in the body and environment – enter the target bacteria, they multiply, increasing their antimicrobial power during their activity.
“It’s a chain reaction, creating a powerful, continuous response that’s more powerful than antibiotics,” Didar says. “No other antibacterial product – not even bleach – has the unique properties of phages.”
Another important advantage of using phages in agriculture and food production is that they can be directed specifically to eliminate harmful bacteria without killing beneficial bacteria that contribute to taste, smell and texture.
The new phage spray has promising potential for commercial applications, researchers say, especially since phages have received approval from the United States Food and Drug Administration for use in food.
The research paper shows that these sprays can eliminate E. coli 0157 from lettuce and meat, which is often the cause of outbreaks.
The researchers said the same method could easily be used against other bacteria that cause food poisoning, such as Salmonella and Listeria – individually or in combination.
According to researchers, phage sprays can be used in food processing, packaging and drying, and even as a treatment for water and wastewater, stopping contamination at the source.
The research, conducted under the umbrella of McMaster’s Global Nexus for Infectious Diseases and Biothreats, combines and expands on previous work from Hosseinidoust’s lab and work done by Didar and McMaster colleagues to develop sensors in space little to detect and expel foodborne pathogens.
The co-writers also include Leon He, Kyle Jackson, Ahmed Saif and Zeqi Wan.
The team plans to test the promising new application in medicine, where it can be used to eliminate wounds, for example. Medical devices will take a long time to prove their safety and effectiveness, but products designed for elimination and food processing can quickly hit the market.
