Bacteria-eaters to prevent food poisoning? Phages elim­in­ate Yersinia from food

February 21, 2018, University of Helsinki
"Our study can serve as a model for the prevention of other, more serious foodborne infections through phage treatment," says Professor Mikael Skurnik. Credit: Helena Hiltunen, University of Helsinki

Bacteria-killing viruses could be employed not just in health care, but also in the food industry, a study conducted at the University of Helsinki indicates.

Research focused on the utilisation of bacteriophages, viruses that infect and kill bacteria, in preventing infectious diseases has gained new traction as bacterial resistance to antibiotics has increased. Each individual bacteriophage only infects a handful of bacterial species or strains, which makes them veritable weapons of precision in the prevention of bacterial diseases.

Professor Mikael Skurnik from the University of Helsinki has studied bacteriophages and for a long time. Now, in cooperation with researchers at the Seoul National University in South Korea, he has been investigating the possibility of utilising phages also in eradicating foodborne pathogens and preventing food poisoning.

The researchers focused on the Yersinia enterocolitica bacterium, by far the most common cause for yersiniosis. The disease is usually transmitted through raw or undercooked pork. Another source of infection, although a much rarer one, is milk. Humans can also be infected by kitchenware used in handling .

Yersiniosis symptoms include fever, severe abdominal pain and diarrhoea, which may persist for up to three weeks. In some cases, yersiniosis may cause arthritis as a secondary disease, persisting potentially several weeks. Yersiniosis occurs all over the world.

Phage treatment effective in both food and kitchenware

Researchers identified four bacteriophages that infect the Y. enterocolitica bacterium. The most effective of this quartet proved to be the fHe-Yen9-01 phage. It was selected for the next stage of the study, in which its efficacy in decontaminating food and kitchenware contaminated by bacteria was investigated.

"We focused on those foodstuffs that most often transmit infections, as well as those kitchen utensils most often used to handle these foodstuffs," explains Skurnik.

Everyday products such as raw and grilled pork, as well as milk, were inoculated with Y. enterocolitica. The contaminated food was then subjected to phage treatment, after which the number of both bacteria and phages was monitored for three days.

"Phage treatment was effective in inhibiting bacterial growth in food, while the number of phages in the food grew, indicating that phages infect bacteria and grow in them also when refrigerated," says Skurnik.

Next, the researchers inoculated kitchen utensils, such as wooden and plastic cutting boards, knives and surgical gloves, with the bacteria and phages, after which the number of bacteria and phages in the utensils was monitored for two hours. In this case as well, the phages effectively inhibited .

Phage treatment to become routine in food production?

To the best of Skurnik's knowledge, corresponding studies on the application of phages in food treatment have not been conducted anywhere prior to this. Treating food with phages is not, however, an entirely novel idea. In the United States, a phage product already on the market is sprayed on raw food products to prevent Listeria bacteria growth.

"In Finland, there is no urgent need to prevent Yersinia infections, but our study can serve as a model for the prevention of other, more serious foodborne infections through phage treatment," says Skurnik.

In the future, decontamination with may well be part of the routine in processing food. "One option is a phage mixture effective against several bacteria, such as the Salmonella and Campylobacter species, as well as the most common poisoning in the gut. This mixture could also be administered in a preventive manner to farm animals, for example mixed in their drinking water," says Skurnik.

Explore further: Viruses that infect bacteria abound in bladder

More information: Jin Woo Jun et al, Bacteriophages reduce Yersinia enterocolitica contamination of food and kitchenware, International Journal of Food Microbiology (2018). DOI: 10.1016/j.ijfoodmicro.2018.02.007

Related Stories

Viruses that infect bacteria abound in bladder

January 29, 2018

Phages—viruses that infect bacteria—are abundant in the bacteria that inhabit the female bladder. This is good news, because phage could be used as alternative treatment when antibiotics become resistant to pathogenic ...

CRISPR-Cas9 may be a double-edged sword for bacteria

February 15, 2018

A team of researchers with the Catholic University of America has found evidence that suggests a defense mechanism used by bacteria to ward off phage attacks might also be benefiting the phages. In their paper published on ...

Bacteriophages cure bacterial infections

November 16, 2016

Phage therapy may be a solution to treating infections caused by antibiotic-resistant bacteria. Since 2013, researchers at the University of Helsinki in Finland have collected bacteriophages to combat antibiotic-resistant ...

Workbench for virus design

February 5, 2018

ETH researchers have developed a technology platform that allows them to systematically modify and customise bacteriophages. This technology is a step towards making phage therapies a powerful tool for combating dangerous ...

Phagevet-P: Applying viruses to treat bacterial diseases

September 20, 2012

The quest for enhanced food safety has driven research into novel treatments for bacterial diseases in livestock. A European consortium proposed the use of bacteriophages (bacteria-targeting viruses) to treat salmonella in ...

Recommended for you

Study shows city rats eat better than country rats

October 17, 2018

A pair of researchers, one with Trent University in Canada, the other the University of Manchester in the U.K. has found evidence that rats living in cities have a much richer diet than rats living in the country. In their ...

0 comments

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.