Bacteriophages: Nature's control of bacterial populations

Andrew Timms and Ian Connerton discuss how the use of phages could help in the management of food microbes. Phages are extremely abundant and are usually closely associated with their host organisms. Some phages can be eliminated because of their life-cycle, so called temperate phages occasionally integrate themselves into the bacterial chromosome thus rendering successive generations resistant to infection by closely related phages. The development of phage resistance has been observed in experimental systems, and such observations have been used to doubt the utility of such treatments. To be efficacious, phage intervention must be used judiciously and appropriately. Previous efforts at control were hampered by an incomplete understanding of the biology and mechanism of action of the agents used. There are also increasingly positive signs that regulatory bodies in Europe and North America are considering phage interventions as viable alternatives to 'traditional' treatments.