Bacteriophages have solved many mysteries of biotechnology. There is a lot of progress in this field for using these predators for benefits of human population.
Century back, natural predators of bacterial species were used to treat infection caused by pathogenic strains of bacteria. But as the time turns its pages, after World War ll magic bullets (antibiotics) were discovered, their use become limited. Years ago, bacteria start modifying their genome due to which they are becoming resistance to effects of antibacterial drugs which is an international threat for provision of better health to community.
So, to cope up this situation bacteria killers are again in consideration as alternative to bacterial drugs for many resistance strains. Phages are diversified groups of species, which can be easily manipulated and can be used in therapeutics, research and biotechnology. They can be used as vaccine vehicle, as display system for many antibiotics and for detecting strains of pathogenic bacteria. Their importance can never be denied at any cost due to their harmless effects on human body.
Here are the roles of bacteriophages in field of biotechnology.
Bacteriophages are extremely specific to their host cells. This specificity enables them to be used for detection and typing of bacterial strains. If the bacterial specie is unknown, then its culture is provided with different know phages and if the clear zones i.e. plaques appear, it indicates that bacterial cell have been lysed by a phage specific for it which make it easier to identify specific bacterial strain.
The other way of detection of pathogenic strain is the use of phage antibodies and peptides which will binds to bacterial toxins specifically.
After the emergence of antibiotics, phages became limited in research laboratory. They gain attention when these antibacterial drugs fails to provide the desired results. Phage therapy is used n plants, animals and humans with little or no side effects.
Phage therapy has many advantages over antibacterial drugs but also have certain side effects. Phages are very specific for targeting bacteria which reduce the risk of damage of normal flora of host.
If the targeting bacteria is not recognized, a cocktail (combination) of bacteria can be used. They replicate at the site of infection and if bacteria become resistant to phage they naturally evolve to infect that resistant bacteria results in minimizing the bacterial escape due to which it can be used over antibiotics.
Phages can be used as vaccine vehicles. In case of DNA vaccines, the vaccine antigen synthesis sequences are incorporated in genome of phage and the it will act as vehicle for DNA vaccine delivery. Phages can be constructed by using phage display due to which they will display specific peptide on their specific peptide on their surface.
For the identification of vaccines, phage display libraries are screened against serum of convalescents (someone who is recovering from an illness). In certain animal models, the whole phage particle with antigenic peptide will be used as vaccine.
This technique was introduced in 1985. It is used for synthesizing polypeptides of unique characteristics. For the expression of desired protein on the surface of phage particle, DNA that encodes the polypeptide is combined with phage’s genes of coat protein. Mostly M13, lambda and T7 phages are used for phage display. For the screening and isolation of highly specific peptides phage display libraries are used.
For research purposes, these libraries are used and also used for treatment of cocaine addiction for which phages are administered nasally from where they can enter into central nervous system. In CNS, antibodies will be displayed and bind to cocaine molecules results in inhibition of its action on brain.
Phages have been successfully play their role in bio controlling of plant pathogens like bacteria which are found in association with fungi and plants. Phages are used to control; Xantthomonas compestris which cause tomato spots and Ralstonia solanacearum which spoils tobacco. Controlling of food pathogens by phages will increase the shelf life of product.
Above mentioned uses of phages are only a few blessings which they are giving to community in upcoming years phages will provide great services to humans in many ways. It would become easier to treat a variety of pathogenic bacteria which become resistance to several classes of antibiotics by making phage cocktails.
Phages are also good to limit food spoilage issues and treat infections of plant and fruits caused by bacteria.
There are certain issues related to safety, efficacy as well as immune response to the administration of phages. Rapid progress in field of biotechnology will sort out all such issues of Bacteriophages to make the use of phages easy and safe.