Researchers tested their food-safe antibacterial spray on foods including beef and romaine lettuce. Credit: McMaster University
Key Points:
- Researchers used bacteriophages to create a decontamination spray with many applications.
- First and foremost, it can be sprayed on food, showing great success against E. coli 0157 in lettuce and meat.
- The team says it can also be used against other bacteria that cause food poisoning.
This year was a tough one for lettuce. There were multiple outbreaks of E.coli linked to the leafy green found on dinner tables most nights. Engineers at McMaster University have developed a tool they hope will stop future recalls.
The team has developed a way to coax bacteriophages—harmless viruses that eat bacteria—into linking together and forming microscopic beads. Those beads can safely be applied to food and other materials to rid them of harmful pathogens such as E. coli. Each bead is about 20 microns in diameter and is loaded with millions of phages.
“They link together like microscopic LEGO pieces,” said study author and graduate student Lei Tian. “This organized natural structure makes them much more durable and easier to package, store and use. When we spray it on food, we basically gather billions of mini-soldiers to protect our food from bacterial contamination.”
When phages—which occur naturally in the body and the environment—contact target bacteria, they multiply, explosively increasing their antimicrobial power as they work.
“It’s a chain reaction, creating a dynamic and ongoing response that is even more overpowering than antibiotics,” explains study author Tohid Didar, who holds the Canada Research Chair in Nano-Biomaterials. “No other antibacterial product has the special properties that phages do.”
The paper, published in Nature Communication, shows the sprayable material can eliminate E. coli 0157 in lettuce and meat, which are often the sources of disease outbreaks. And, the researchers say the same approach can readily be used against other bacteria that cause food poisoning, such as salmonella and Iisteria—individually or in combination.
Another major advantage of using phages in agriculture and food production is that they can be directed very specifically to take out harmful strains of bacteria without killing beneficial bacteria that enhance foods’ taste, smell and texture.
Before the introduction of penicillin in the 1940s, research into phage disinfectants and therapies had been very promising, but interest in developing their potential dimmed once antibiotics made from penicillin came onto the market. With antimicrobial resistance now sapping the power of existing antibiotics, there is intense new interest in phage research.
Information provided by McMaster University.