Phage therapy: A clinician's guide

Bacteriophages, or phages, are the viruses of bacteria. Known to science for over 100 years, the use of phages as antibacterial agents predates the discovery and substantial clinical implementation of penicillin, the first antibiotic. Development of phage therapy generally involves three distinct stages, including (1) phage isolation and determination of phage properties in vitro, (2) preclinical testing of phage antibacterial properties via use of animal models, and (3) clinical phage therapy implementation. The ultimate goal of these efforts is effective eradication of bacterial infections including those that have previously resisted antibiotic treatments. Development of phage therapy approaches toward treatment of human bacterial infections is still evolving, however. In this chapter, we gather and analyze factors impacting phage therapy utility, as based in part on clinical treatment studies from the year 2000 through early 2021, toward laying a foundation for improvement in the efficiency and versatility of phage therapy against antibiotic-resistant bacterial pathogens.