Are bacteriophages an alternative to antibiotics?

Practitioners in poultry farming are already using phages for barn disinfection. This can be beneficial when Salmonella bacteria hide somewhere after the disinfection process.

Dr. Hansjörg Lehnherr from PTC Phage Technology Center GmbH in Bönen recently explained at a professional event in Eindhoven, organized by the working group of poultry industry consultants, how bacteriophages are used to combat various germs in poultry farming and possibly even replace antibiotics.

Bacteriophages are viruses that need a specific bacterium to reproduce. After a phage has multiplied in the bacterium, it is destroyed.

Preventive use is possible. Phages are a normal part of our digestive tract and are harmless to humans and animals. Resistant strains do not develop. However, as Lehnherr pointed out, treatment with phages is too late if an infection has already broken out. In such cases, phages cannot fully combat the large number of bacteria.

Therefore, a preventive approach is necessary. Bacteriophages could be used against E. coli or Salmonella in the hatchery as a so-called "Hatchgel" to reduce or even eliminate the bacteria. The same applies to the hatch in the barn. Products against Clostridia and Staphylococci already exist, but none of these products currently have European approval.

Practitioners are already using phages for barn disinfection. Bacteriophages can be useful here if Salmonella are still hiding after standard disinfection. Because phages are smaller than bacteria, they can reach even the smallest hiding spots and critical areas. Bacteriophages are applied using a backpack sprayer or cold fogging.

For slowly growing germs like Clostridia or Staphylococci, bacteriophages could also be administered through the feed. Lehnherr considers a dose of 10 to the power of 6 bacteriophages per ml of drinking water at the nipple necessary. However, this concentration could not be maintained permanently in experiments.