Spraying an army of bacteria-eating viruses can save us from food poisoning

They have developed a food decontamination spray that employs food-safe microscopic beads containing bacteriophages (viruses that kill bacteria). The researchers claim, during the study, they were able to free lettuce and meat from E. coli 0157, a common food-borne pathogen that infects the human intestine and causes health issues such as diarrhea. 

Phages have always been there

The idea of using bacteriophages as disinfectants is not new. The authors of the current study suggest that before the discovery of the first antibiotic (penicillin) in 1928, a lot of research focused on employing phages against bacterial infection was going on. 

However, most scientists lost interest in those research works when antibiotics hit the market and soon became the go-to solution for overcoming bacteria-related illnesses. The popularity of antibiotics can be imagined from the fact that in 2021, the antibiotic industry alone was valued at $42 billion. 

Although phages lost their importance as preferred anti-bacterial substances, they were never forgotten because, every once in a while, they managed to prove their worth.  

For instance, in 2021, scientists discovered that pathogens that thrive on the plumbing network of hospitals and commercial buildings could be eliminated more effectively if phages are also used as disinfectants along with regularly used chemicals. Moreover, the increasing antibiotic resistance in bacteria in recent times has also sparked growth in phage research.

Using phage army to decontaminate food

What’s quite interesting is that the current study reveals a completely different phage-based approach. What would you prefer, getting sick and then taking an antibiotic to fix your health or spraying your food before it even makes you sick? Using phages as a food decontamination spray might prove to be the most convenient and effective way of curbing bacteria infection in our food.

The spray releases numerous microbeads. Each of them measures about 20 microns (20 x 10-6 m) in diameter and comes loaded with millions of bacteriophages. So basically, each microbead houses an army of bacteria-eating soldiers. “When we spray it on food, we basically gather billions of mini-soldiers to protect our food from bacterial contamination,” said Lei Tian, lead author of the study and researcher at McMaster University.

Tian and his team tested their spray on lettuce and meat, successfully decontaminating the food from E. coli 0157. They believe their spray can also save people from food-borne illnesses resulting due to Listeria and Salmonella infections. As far as food safety is concerned, the authors claim that phages don’t alter the taste or texture of a food item.

Even the FDA (Food and Drug Administration) has also approved the use of phages in food items. Interestingly, unlike antibiotics that kill both good and bad bacteria, phages can be designed to perform selective attacks. Meaning that the phages released from the spray will only harm pathogens and not other microbes that are beneficial to human health and taste. 

Moreover, the use of this spray is not just limited to disinfecting food, it can also be employed to clean water, food packaging, and even agricultural equipment. The researchers are currently testing the use of their spray in the treatment of injuries and wounds. 

These tests will further validate the safety of this product. However, we are still not sure when the spray will become commercially available.

The study is published in the journal Nature Communications.

Abstract:

Nanofilamentous bacteriophages (bacterial viruses) are biofunctional, self-propagating, and monodisperse natural building blocks for virus-built materials. Minifying phage-built materials to microscale offers the promise of expanding the range function for these biomaterials to sprays and colloidal bioassays/biosensors. Here, we crosslink half a million self-organized phages as the sole structural component to construct each soft microgel. Through an in-house developed, biologics-friendly, high-throughput template method, over 35,000 phage-built microgels are produced from every square centimetre of a peelable microporous film template, constituting a 13-billion phage community. The phage-exclusive microgels exhibit a self-organized, highly-aligned nanofibrous texture and tunable auto-fluorescence. Further preservation of antimicrobial activity was achieved by making hybrid protein-phage microgels. When loaded with potent virulent phages, these microgels effectively reduce heavy loads of multidrug-resistant Escherichia coli O157:H7 on food products, leading to up to 6 logs reduction in 9 hours and rendering food contaminant free.