Addition of bacteriophages: with viruses against bacteria in food
Yersinia are bacteria that can also be found in pork, among other things. Eating foods contaminated with them can lead to painful gastrointestinal infections. Researchers have now found that the pathogens can be killed by viruses.
Kill pathogens with viruses
Doctors always warn of the health risks from pork fat. After all, raw meat is the most common cause of hepatitis E infections. But there is another danger: Mett can be contaminated with Yersinia. Eating foods contaminated with these bacteria can lead to painful, febrile diarrhea, so-called yersiniosis. Researchers from Finland and South Korea have now found a way to kill the pathogens: using viruses.
Infection from eating raw pork products
"The biggest risk factor for an infection with Yersinia is the consumption of raw pork products, for example as Mett or Hackepeter," writes the Federal Institute for Risk Assessment (BfR) on its website.
“Consumers can protect themselves from Yersinia infections by observing the rules of kitchen hygiene when preparing food: They should heat meat to at least 70 ° C for at least two minutes before eating and transfer the bacteria from the raw meat to other foods avoid, ”the experts explain.
Finnish and South Korean microbiologists have now found that yersinia in food can also be killed by viruses.
Viruses attacking bacteria
Professor Mikael Skurnik from the University of Helsinki has long been concerned with bacteriophages (short: phages).
From a biological point of view, these are "viruses that, however, only attack and dissolve bacteria (eat, ie" bacteria eaters ")", says the website of the Leibniz Institute DSMZ - German Collection of Microorganisms and Cell Cultures GmbH.
Professor Skurnik, in collaboration with researchers from Seoul National University in South Korea, has now investigated the possibility of using phages in the eradication of pathogens in food and thus preventing food poisoning.
The scientists focused on the bacterium Yersinia enterocolitica, by far the most common cause of yersiniosis.
People can also be infected through kitchen appliances
According to a statement from the University of Helsinki, the disease is usually transmitted through raw or undercooked pork.
Another source of infection, although a much rarer one, is milk. People can also become infected through kitchen appliances that are used when handling contaminated food.
Yersiniosis symptoms include fever, severe abdominal pain and diarrhea, which can last up to three weeks. In some cases, yersiniosis can also cause arthritis that lasts for weeks.
Destroy Yersinia by bacteriophages
According to the researchers, the addition of bacteriophages could destroy Yersinia. This treatment is effective in both food and kitchen appliances.
"We focused on the foods that most commonly transmit infections and the kitchen utensils that are most commonly used to treat these foods," said Skurnik.
The scientists added yersinia to raw and grilled pork and milk, then treated the foods with phages and monitored development for three days.
They found: "Phage treatment inhibited bacterial growth in food, while the number of phages in food increased, which suggests that phages infect bacteria and grow in them in the refrigerator," said Skurnik.
The researchers then inoculated kitchen appliances such as wooden and plastic cutting boards, knives and surgical gloves with the bacteria and phages and monitored the utensils for two hours. In this case too, the phages effectively inhibited bacterial growth.
The results of the study were recently published in the "International Journal of Food Microbiology".
Routine in food processing
According to Skurnik, no studies on the use of phages in food treatment have yet been carried out.
However, the treatment of food with phages is not a completely new idea: There is a phage product on the market in the USA that is sprayed onto raw food products to prevent the growth of listeria.
In the future, decontamination with phages could become routine in food processing, the university said.
“One option is a phage mixture that is effective against several bacteria such as Salmonella and Campylobacter and the most common food poisoning bacteria in the intestine. This mixture could also be administered as a precaution to farm animals, for example via their drinking water, ”said Skurnik. (ad)