Powerful New Weapon Against Contamination and Infection – Food Spray Deploys “Billions of Tiny Soldiers”

Bacteriophage Virus Attacking Bacteria

Illustration of bacteriophage viruses attacking bacterium.

Scientists harness bacteria-eating viruses to create a powerful new weapon against contamination and infection.

Researchers have 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 O157. Each bead is about 20 microns, (one 50th of a millimeter) in diameter and is loaded with millions of phages.

E. coli O157 is one of hundreds of strains of the bacterium Escherichia coli. Most strains of E. coli are harmless and live in the intestines of healthy humans and animals. However, the O157 strain produces a powerful toxin that can cause severe illness. Symptoms of infection include severe diarrhea (often bloody) and abdominal cramps. 

The McMaster engineering team behind the invention has created a spray using nothing but the microbeads. The team is led by professors Zeinab Hosseinidoust, who holds the Canada Research Chair in Bacteriophage Bioengineering, and Tohid Didar, who holds the Canada Research Chair in Nano-Biomaterials, and graduate student Lei Tian.

Their sprayable new super-disinfectant is food-safe and highly effective, as they describe in an article published today (December 5) in the influential journal Nature Communications.

Food-Safe Antibacterial Spray Testing

Researchers tested their food-safe antibacterial spray on foods including beef and romaine lettuce. Credit: McMaster University

Graduate student and Vanier scholar Shadman Khan worked with Tian to test the antibacterial spray on food products.

“When we spray it on food, we basically gather billions of mini-soldiers to protect our food from bacterial contamination,” says Tian, who led the study as part of his PhD research.

The research builds on the same chemistry work that Hosseinidoust’s lab had previously used to trigger phages to connect to one another in quantities sufficient to form a gel.

“They link together like microscopic LEGO pieces,” she says. “This organized natural structure makes them much more durable and easier to package, store and use.”

Lei Tian

McMaster University researcher Lei Tian. Credit: McMaster University

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.

When phages – which occur naturally in the body and in 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,” Didar says. “No other antibacterial product – not even bleach – has the special properties that phages do.”

Zeinab Hosseinidoust

McMaster University researcher Zeinab Hosseinidoust. Credit: McMaster University

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.

The new phage spray has promising potential for commercial application, the researchers say, especially since phages have already earned approval from the US Food and Drug Administration for use in food.

The research paper shows the sprayable material can eliminate E. coli O157 in lettuce and meat, which are often the sources of disease outbreaks.

Tohid Didar

McMaster University researcher Tohid Didar. Credit: McMaster University

The researchers say the same approach can readily be used against other bacteria which cause food poisoning, such as Salmonella and Listeria – individually or in combination.

Phage sprays could be used in food processing, packaging, and cleaning, and even as a treatment for irrigation water and equipment, stopping contamination at the source, the researchers say.

The research, completed under the umbrella of McMaster’s Global Nexus for Pandemics and Biological Threats, combines and extends the previous work of Hosseinidoust’s lab with work that Didar and other McMaster colleagues had done to create microscopic sensors and surfaces to detect and repel food pathogens.

Reference: “Self-assembling nano!brous bacteriophage microgels as sprayable antimicrobials targeting multidrug-resistant bacteria” 5 December 2022, Nature Communications.
DOI: 10.1038/s41467-022-34803-7

Co-authors on the paper also include Leon He, Kyle Jackson, Ahmed Saif, and Zeqi Wan.

The group next plans to test the new material’s promising applications in medicine, where it might be used in disinfecting wounds, for example. Medical applications will take more time to be proven safe and effective, but a product made for disinfection in food processing could make it to market much more quickly.

5 Comments on "Powerful New Weapon Against Contamination and Infection – Food Spray Deploys “Billions of Tiny Soldiers”"

  1. Used for this purpose are modified filamentous bacterophages M13 (genus Inovirus, class Faserviricetes). The article here pictures non-filamentous bacteriophages with head-tail-structure instead. These are of class Caudoviricetes, which are not subject of the study.

    NB: AFAIK toxin genes of strain E. coli O157 ar coded in a plasmid (prosumably a prophage, see ViralZone https://viralzone.expasy.org/3967) – these might be descendents of phages of class Caudoviricetes but seemingly do no longer build virions.

    https://en.wikipedia.org/wiki/Ff_phages (i. e. genus Inovirus)

  2. The cynical side of me can’t help but wonder how many years it’s going to take before we discover ingesting these phages is causing something terrible in humans?

  3. Longathan Browning | December 6, 2022 at 5:32 am | Reply

    Yeah. That sounds like a freaking great idea. I’m sure it’s perfectly safe and won’t cause people health issues later in life. *Sarcasm*

  4. An uneducated person leaves a comment it’s obvious.

  5. Elizabeth Butler | December 7, 2022 at 5:06 pm | Reply

    I got a better idea let’s get safe food processing from start to finish and we shouldn’t have to worry about antibacterial gels that we don’t know the long term affects of… why is doing things correctly never an option?? Why must we try to come up with an antidote to the antidote.
    THE FDA IS LIKE DR.EVIL IN THE SPY WHO SHAGGED ME. Dumbest movie ever but it’s the first thing I thought of the FDA in this article.

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