The formation of bacterial biofilms is a serious problem in the treatment of various types of wounds. Biofilms are often the cause of severe infections, resistance of pathogenic bacteria to antimicrobial treatment, and a significant delay in healing. Unsuccessful treatment can result in chronic wounds and ulcers, which are especially common among individuals with diabetes, obesity, and the elderly with low physical activity.

Phage therapy is a promising approach to combating bacterial biofilms, as bacteriophages are able to penetrate the biofilm matrix and infect bacteria, including those resistant to antibiotics.

The International Journal of Pharmaceutics recently published* the results of a study on the effectiveness of phage preparations in combating biofilms. To better simulate an infected wound, the authors used an ex vivo model—porcine skin explants. A depression was made in the skin to simulate damage. Polystyrene microplates were also used as a substrate for biofilm formation. Biofilms in both models were formed by multidrug-resistant strains of Acinetobacter baumannii, Pseudomonas aeruginosa, Proteus mirabilis, and Escherichia coli (monocultures were used in the experiment).

After 24 hours, the biofilms were treated with bacteriophages: either monopreparations or a phage cocktail containing bacteriophages specific against all four pathogens.

Both phage treatments resulted in a significant reduction in the number of viable bacteria, further demonstrating the effectiveness of bacteriophages in treating multidrug-resistant infections, including those in biofilms. The authors believe that when using phage preparations in humans, the effectiveness of therapy will be enhanced by the body's immune response.

The authors noted the advantages of using pig skin explants as being significantly better than plastic at reproducing the conditions in which wound infections develop, and are planning further experiments with the topical application of bacteriophages.

* Milho C, Andrade M, Vilas Boas D, Alves D, Sillankorva S. Antimicrobial assessment of phage therapy using a porcine model of biofilm infection. Int J Pharm. 2019 Feb 25;557:112-123. doi: 10.1016/j.ijpharm.2018.12.004.