Phage Therapy: A Different Approach to Fight Bacterial Infections
Zigale Hibstu
Abstract
Phage therapy is one of the alternatives to treat infections caused by both antibiotic sensitive and resistant bacteria with no or low toxicity to patients. It was started a century back although rapidly growing bacterial antimicrobial resistance impacting large morbidity, mortality, and financial cost initiated the revival of it. It involves the use of live lytic, bio-engineered, phage-encoded biological products and in combination with chemical antibiotics to treat bacterial infections. Importantly, phages will be removed from the body after seven days of clearing infection. They target specific bacterial strains and cause minimal disruption of microbial balance in humans. Phages for medication must be screened for the absence of resistant genes, virulent genes, cytotoxicity, and their interaction with the host tissue and organs. Since they are immunogenic, applying high phage titer for therapy exposes them and activates the host immune system. Up to date, no serious side effects are reported with phage human therapy. In this review, we narrated phage - phagocyte interaction, bacterial resistance to phages, how phages conquer bacterial resistance, the role of genetic engineering and other technologies in phage therapy, therapeutic application of modified phages and phage-encoded products. We also highlighted the comparison of antibiotics and lytic phage therapy, pros and cons of phage therapy, determinants of human phage therapy trials, phage quality and safety requirements, phage storage and handling and current challenges in phage therapy.