Phage therapy: an alternative or adjunct to antibiotics?

Phage therapy is currently discussed as an alternative or adjunct to antibiotics whose activity is increasingly compromised by the emergence of antibiotic-resistant bacterial pathogens. The idea to use lytic bacterial viruses as antimicrobial agents is nearly a century old and is common practice in Eastern Europe. However, safety concerns and lack of controlled clinical trials proving the efficacy of phage therapy have hampered its wider medical use in the West. The present review analyzes safety aspects and compares successful with unsuccessful phage therapy clinical trials to identify potential factors determining success and failure of this approach.