Golden logoGolden logo
Advanced Search
Phage therapy

Phage therapy

Phage therapy is the use of bacteriophages or phages therapeutically as antimicrobial treatments against bacteria. Bacteriophages, also known as phages are viruses that infect bacteria.

Natural phages have been used in phage therapy since 1919, shortly after their discovery, when they were used by Félix d'Hérelle to treat children with dysentery. The rise of antibiotic resistance and low rate of discovery of new antibiotics lead to a renewed interest in phages as antibacterial agents.

Phage therapies are specific to certain bacterial strains or species and have less off-target effects on commensal microbes compared with antibiotics. However the specificity of phages means that cocktails with combinations of various phages might be necessary for clinical infections, and regulatory approval for such therapeutic cocktails can be a challenge.

The first multicentric, randomised, single blind and controlled clinical trial for phage therapy performed in accordance with Good Manufacturing Practices (GMP) and Good Clinical Practices (GCP) took pace in Europe in 2013-2017, called Phagoburn. Phagoburn was evaluated for treatment of burn wound infections. No adverse effects were observed from the phage cocktail. Efficacy needs to be improved as the phage treatment decreased bacteria in burn wounds at a slower pace than standard of care.

Potential drawbacks to phage therapy are that when phage cause lysis of bacteria, cell wall components can cause adverse immune responses in humans, bacterial biofilms may block phages from infecting the bacteria and bacteria can evolve resistance to phage infection. Researchers are attempting to overcome some of these limitations through genetic engineering of phages.

Techniques for engineering phages include Homologous Recombination, Bacteriophage Recombineering of Electroporated DNA (BRED), In Vivo Recombineering, CRISPR-Cas-Mediated Genome Engineering, rebuilding phage genomes in vitro and synthetic biology approaches such as whole-genome synthesis from synthetic oligonucleotides.

The CRISPR-Cas adaptive immune systems of bacteria protect them against viruses including phages. In the arms race between bacteria and phages, phages evolved inhibitors called anti-CRISPR proteins, also known as Acr proteins. Anti-CRISPR proteins have applications in phage therapy because engineered expression of certain anti-CRISPR proteins (Acr proteins) could potentially increase the host range of phage therapeutics and make phage therapies more effective against pathogenic bacteria that have active CRISPR-Cas systems.

Companies developing phage therapies


Further Resources



Diana Gitig
July 12, 2021
Ars Technica
Even though viruses attack harmful bacteria, the immune system attacks viruses.
Clément Girardot
September 21, 2020
the Guardian
Bacteriophages were superseded by modern antibiotics, but scientists believe they could be key to conquering antimicrobial resistance
Charles Schmidt
November 1, 2019
Scientific American
Scientific American is the essential guide to the most awe-inspiring advances in science and technology, explaining how they change our understanding of the world and shape our lives.


Golden logo
By using this site, you agree to our Terms of Service.