Bacteriophages and their endolysins for control of pathogenic bacteria

Bacteriophages (phages) are viruses that specifically infect bacterial cells. Phages were first discovered in the early 1900s and soon after, the concept of phage therapy was conceived. Phage therapy involves the application of bacterial viruses to eliminate pathogenic bacteria. The results of early human trials were hampered by limited knowledge of phage biology, poor experimental design and in some cases a lack of understanding of the causative nature of the illness being treated. As a result, antibiotics, which became widely available in the 1940s, replaced phage as antibacterials. However, with an increase in antibiotic resistance in pathogenic bacteria in recent decades, it is now widely recognised that alternative bactericidal agents for the prevention and treatment of bacterial infections are urgently required. With this in mind and with a better understanding of phage biology, the concept of phage therapy has been revisited and expanded upon over the past twenty years. This chapter presents an overview of phage-based approaches which have been employed for the elimination of pathogenic bacteria.