Bacteriophage: Therapeutic Uses

AbstractBacteriophages are viruses that grow within bacteria. Almost all bacteriophages can destroy (lyse) their bacterial host, although many are ‘temperate’ and can insert their genome into that of their bacterial host, a state referred to as lysogeny. Those that can only kill their host bacteria are termed ‘virulent’ and are preferred for therapeutic use. Lysis kills the bacterial host and releases the next generation of bacteriophages. This unique property allows localised amplification of a bacteriophage therapeutic, but only where its specific bacterial host is present. Bacteriophages are also able to target bacteria living within biofilms that can make them highly refractory to conventional antibiotics. Since their discovery in 1915, bacteriophages have been identified as having potential for the control of bacterial disease. Following the widespread appearance of resistance to conventional antibiotics, interest in this area has revived and the results of clinical trials of bacteriophage therapeutics are now being reported.Key Concepts:Bacteriophages are viruses that infect bacteria.Lytic bacteriophages kill their bacterial host rapidly, taking over host metabolism and producing a new generation of bacteriophages soon after infection.Newly produced bacteriophages can infect new host bacteria locally and can also spread to other sites of infection.This ability to kill bacteria led to their therapeutic use against bacterial infection in the pre‐antibiotic era.In most of the world, bacteriophages have been superseded since the 1940s by chemical antibiotics due to a combination of factors, including the limited understanding of basic bacteriophage biology and the far broader host ranges of chemical antibiotics.Despite many years of extensive clinical study in Eastern Europe and in earlier work in Europe and the United States, a lack of clinical trials meeting current regulatory requirements has limited the development of bacteriophage therapeutics.Interest in bacteriophages as therapeutics has been revived by the looming antibiotic resistance crisis, in an era when much more information is available about the older work and when phage biology is far better understood.Bacteriophage products for agricultural and food use are currently being marketed.