PARMA, ITALY — The European Food Safety Authority’s BIOHAZ panel concluded in a recent opinion that under specific conditions, bacteriophages might be effective in eliminating specific pathogens from foods. However, based on peer-reviewed scientific literature, the panel could not conclude whether bacteriophages are effective in the event of re-contaminated.
E.F.S.A. relayed the efficacy of bacteriophages against re-contamination of food may vary according to the characteristics of the food itself, the type of bacteriophage and how it is used and environmental factors.
The organization was asked by the European Commission to provide advice on the use of bacteriophages on food of animal origin. It was specifically asked to describe the mode of action of bacteriophages on food of animal origin (be it carcasses, meat and dairy products) and also if these have a continuous action in the final food.
Some bacteriophages, under specific conditions, have been demonstrated to be very effective in the targeted elimination of specific pathogens from meat, milk and products thereof, concluded E.F.S.A.’s BIOHAZ Panel (Biological Hazards).
Bacteriophages infect specific hosts, and that these are generally limited to some bacterial species or strains, the BIOHAZ panel noted. Bacteriophages occur in nature, have a broad range of habitats and may be isolated in considerable numbers from meat, milk and derived products. While bacteriophages replicate best on growing bacterial cells, they have also been shown to reproduce on those cells, which are not in a growing phase.
Some mutants, which become insensitive to bacteriophages, might exist in the populations of target bacteria, the panel also noted. The frequency of these mutations and their consequences are likely to vary according to the specific bacteriophage, the mode of application and the bacteria concerned.
Regarding the length of their effect in the final product, the BIOHAZ panel noted bacteriophages behave as inert particles in the environment and tend to persist longer than their hosts. However, their long-term antibacterial activity is compromised on dry surfaces. The persistence in food also varies with each bacteriophage, and with the conditions of application, including dose, and physical and chemical factors associated with the food (e.g. pH, moisture levels etc.). For example, refrigeration temperatures enhance persistence of bacteriophages on the surface of meat and on/in dairy products.
In order to further assess the persistence of bacteriophages in foods and their ability to prevent recontamination with bacterial pathogens, research for specific combinations of bacteriophages, pathogens and foods should be encouraged, E.F.S.A.’s BIOHAZ panel recommended.
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