For several decades, bacteriophages were not in the forefront when it came to developing treatments for bacterial infections. Antibiotics were the answer to all of our problems. While the Western world seemed to forget all about bacteriophages, the development and research into phages continued in dedicated research institutions around the world. Now, as antibiotic-resistant strains of bacteria become more and more common, the search for alternative treatments has brought phages back into the spotlight.
What is phage therapy and why the world needs it?
The over prescription, overuse and self-medication of antibiotics has created a situation, where scientists fear that conventional antibiotics are on the brink of losing their effectiveness. According to WHO, antibiotic resistance has become one of the most serious global health threats of the 21st century. The worsening situation has forced the medical and scientific communities to search for different solutions, which is why the interest and research into bacteriophages has picked up speed during the last few decades.
The bacteriophages’ enormous abundance and diversity make them a seemingly unlimited source of antibacterial agents. After the discovery of phages, phage therapy has been successfully used to treat infections with increasing success. Phage therapy refers to a form of treatment, where the patient is administered a carefully selected cocktail of lytic phages to combat and kill pathogenic bacteria.
One of the biggest challenges of phage therapy stems from the phages’ greatest advantage – specificity. Unlike antibiotics that work on a very broad range of bacterial infections, phages only attack the few selected types of bacteria they are specialized in. Finding the right phage-combinations to combat a specific infection is not an easy task. And not all phages are applicable to be used for therapeutic purposes – only lytic phages with a wider range of potential host cells are used in treatment. However, as phages evolve they can change their host specificity, and they can be trained or directed towards different targets.
The phage’s specificity also has other advantages. When it comes to antibiotics, their broad, nuclear power is not always the best choice. In addition to killing the harmful bacteria, antibiotics also destroy good bacterial communities living in our gut. And as the research into our gut microbiota has delved deeper into the connections between the gut-brain axis, we have come to realize how integral a healthy gut microbiota is for our overall health – both mental and physical. Unlike antibiotics, phages don’t harm the good bacteria in our gut, but only target the specific bacteria they have an affinity for.
As multi-drug resistant bacteria become more common we must develop alternative ways to combat them, and phages have proven to be one possible solution. Bacteriophage banks containing massive libraries of lytic phages may provide effective treatment solutions for patients who have bacterial infections that do not respond to conventional antibiotic therapies. Phages have the potential to treat hospital-acquired infections like Methicillin Resistant Staphylococcus aureus (MRSA), or chronic urinary tract infections caused by E.coli.
Current research and future developments
As mentioned previously, the interest in phages and phage therapy has been on the rise for the last decades. Phages are available as treatments for a few bacterial infections for example in Russia and Georgia, whereas in Europe and the United States they are available under special circumstances.
Outside of the few clinical trials that have taken place outside the former Eastern bloc, phage therapy has been used in Europe as a ‘last-resort’ treatment for individual patients with terminal illnesses. For example, in the United Kingdom, phage therapy was successfully used to treat a teenage girl with life threatening bacterial infection after a lung transplant. In the United States, there is an ongoing project to establish and commercialize a phage susceptibility test, that would help make phage therapy more easily and widely available. In Finland, Helsinki University Professor Mikael Skurnik has studied bacteriophages extensively and advocates for the further development of phage therapies in Finland.
However, pharmaceutical companies are still hesitant to invest millions of dollars to the development of phages because there is still not enough clinical research on the use of phage therapy. The current regulations in the pharmaceutical field are difficult to apply to phage therapy, which is why their use outside the few countries where phage therapy has been available for several decades is still not commonplace. Phage therapy also faces other challenges related to its safety and stability.
Other uses of phages, however, might be quicker to adapt into wider use.
There is still only little research available on the use of phages for purposes other than therapeutics. But that does not mean there are no other possible applications that could have a significant impact on the healthcare industry. At Aqsens Health, we have focused on the use of phages in screening tests and diagnostics, where their extreme specificity and adaptability play an important role. In the next PHAGES-blog post, we will delve deeper into the use of phages in screening.
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