Bacteriophages or phages are viruses that invade only bacterial cells and, in the case of lytic phages, disrupt bacterial metabolism and cause the bacterium to lyse. They are naturally occurring predators of bacteria, ubiquitous in the environment, with high host specificity and capacity to evolve to overcome bacterial resistance which makes them an appealing option for the control of pathogens. Phage therapy involves the use of bacteriophages, viruses that only attack bacteria and are very host specific, to kill pathogenic microorganisms. Phages are self replicating agents that are able to multiply by taking over their host’s DNA replication and protein synthesis machinery. They can possess two life cycles, lytic and lysogenic. Phages were predicted very early as therapeutic tools to fight pathogenic bacteria but the successful and generalized use of antibiotics to control bacterial infections and the difficulties in obtaining purified phage preparations, delayed the use of phages for therapy. Facing the fast emerging and widespread pathogenic bacteria that have acquired resistance to most or all available antibiotics, the World Health Organization warned that these multiple antibiotic resistant bacterial pathogens will very likely bring the world back to the pre-antibiotics era. The pressing public concern has triggered global efforts in developing novel alternative antibacterials, including bacteriophages and phage encoded lytic enzymes as two families of candidate antimicrobials. Therefore, phages and their products are currently believed to be a potential therapeutic option to treat bacterial infections that do not respond to conventional antibiotics.
Keywords: Antibiotic resistant bacteria, Bacteriophages, Phage encoded lytic enzymes, Phage therapy
