- Pranita Poudyal
Bacterial infection is one of the leading causes of death. Bacteria can be killed either physically (By using heat, freezing, acids, alkalis, radiation), chemically (using antibiotics) or biologically(using viruses). The physical agents that destroy bacteria have adverse effect on human health. Likewise, antibiotics knock down the bacteria but antibiotic resistant strain of these microorganisms are emerging day by day resulting in the formation of superbugs. Now that more and more bacteria have become immune to antibiotics,scientists around the world consider non-antibiotic therapies to treat bacterial infections.One possible option is the therapeutic use of bacteriophages that target bacteria.
More than a century ago (1915), English bacteriologist Frederick William Twort discovered “Bacteriophages”. Bacteriophages are viruses that attack bacteria by denaturing their DNA.They are shortly termed as “phages”. In spite of its early discovery phage therapy was abandoned due to the introduction of antibiotics.
An interesting aspect about phages is that, they affect specific bacterial cells and are harmless to other living beings. Phages can only multiply and grow inside a bacterium. So,the crucial step is to recognize the target bacteria. After finding the target, phage binds and infects the bacteria by injecting its genes (DNA or RNA). Several copies of these genes are formed and the phage multiplies. Ultimately, phage kills bacteria by producing toxins and the new phages are released to infect other. Rather than stopping bacteria from doing one specific process like in the case of antibiotics, phages actively destroy the bacteria’s cell wall and cell membrane and kill bacteria by making many holes from the inside out.
Phage therapy can be a viable solution because of its specificity. In addition, there are several success stories of phage.
There is a riveting account of Tom Patterson, 68 year-old-man in San Diego,California who had accidently suffered from pancreatic pseudo cyst due to the infection of multidrug-resistant strain of Acinetobacter baumannii in 2017. After more than three months of trying antibiotics, his doctors were able to stop the infection with bacteriophages successfully. Back then an emergency approval was received from the Food and Drug Administration but it was not validated globally.
The clinical trial of intravenously administered bacteriophage therapy has received FDA approval only in January, 2019. Following the approval, Patients with cystic fibrosis and a double-lung transplant have also received genetically engineered 3-phage cocktail to treat life-threatening antibiotic-resistant Mycobacterium abscessus infection.
To conclude, phage therapy can stand as personalized medicine to those drug resistant bacteria for which all standard therapeutic options had been exhausted.