Bacteriophage therapy

Abstract

Bacteriophages or phages are bacterial viruses or viruses that infect bacteria. Bacteriophages can have either a lytic or a lysogenic life cycle. The lytic phages are the most suitable candidates for phage therapy because they can kill the bacterial host at the end of replication cycle. Bacteriophages are highly specific to their hosts. When a bacteriophage meets a suitable host bacterium, its specific surface molecule binds to the particular molecule on a host and then injects its genetic material into the cell. In the host cell, bacteriophage instructs the machinery of the host to make more bacteriophages. Fully viable progeny bacteriophages burst out and kill the bacteria. The released bacteriophages attack new bacteria. This process continues until all the bacteria are eliminated from the system. Bacteriophage therapy was used as therapeutic agents in 1920. It was tried extensively and many successes were reported for a variety of infectious diseases including dysentery, staphylococcal skin infection, lung and pleural infection, and gastrointestinal tract infection. Lytic phages are similar to antibiotics in that they have remarkable bactericidal activity. However, therapeutic phages have some unique advantages over antibiotics. Nowadays, drug-resistant bacteria emerge rapidly so phage therapy is more attractive to be an alternative strategy to treat those bacteria. However, there are some problems with phage treatment works that must be addressed before it can be widely approved for therapeutic use.