Phage therapy: The era of personalized medicine

 

        

                                                                 Image by Dr Graham Beards CC BY-SA 3.0. At: https://commons.wikimedia.org/w/index.php?curid=5035798

A post by Raphael Hans

One hundred years ago scientist called d’Hérelle thought of using phages for the treatment of human diseases. However, in the middle of the last century, the introduction of antibiotics led to the banishment of phage therapy from mainstream clinical practice, whereas it remained in use in Eastern Europe, for instance in several institutes in Russia, in the Eliava Institute of Bacteriophage, Microbiology, and Virology in Tbilisi (Georgia) and the Hirszfeld Institute in Wroclaw (Poland). The disappearance of phage for therapy a few decades back nearly indicated the full eradication of this idea in the western world till when antibiotics resistance became a serious problem.

 

Phage therapy is witnessing an increasing return of interest all over the world after a period of disregard in many countries for the past decades. The pharmaceutical legislation that has since been implemented is designed for regulating industrially-made pharmaceuticals like the way common antibiotics are mass-produced, devoid of any patient customization, and intended for large-scale distribution. The breakthrough made in the 21st century allowed phages to be used on "hard-to-treat" bacterial infections due to their outstanding ability on clearing bugs. The booming of antibiotics resistance is one of the many strong reasons for the popularity of phage therapy in recent years, many bacteria so-termed as "super-bugs" tend to resist the drugs available on market, and sometimes it has been reported that even those in a pipeline.

Despite the growing popularity of phages as a potential alternative to antibiotics, there are still some disadvantages of choosing phage therapy over chemical antibiotics that we use today. The same reasons made antibiotics to be preferred over phages in clinical applications decades ago. Scientists have tried to minimize some of the properties that make phage therapy lag behind antibiotics. Phages have a narrow host range due to their specificity, they attack only their hosts, meaning that phage for Klebsiella won't be able to attack Vibrio, unlike antibiotics which have wide host ranges. To increase the host range of the preparation scientists tend to mix different phages to make a cocktail. The advantage of phage cocktails is that they will contain phages that infect more types of bacteria, so a cocktail can treat more strains or species and thus have broader applications. These preparations are sold as standard drugs in pharmacies in some countries while other preparations depend on the patient’s bacteria to make his/her phage for treatment, and this is what I term as “personalized medication”.

Phages as "personalized medicine" have so far helped a lot of serious cases of bacterial infections all over the world. Mostly personalized medicine is done afterward if the antibiotics have failed. Once reported that a patient needs phage for therapy, it will take 7-21 days for preparation to be ready although the duration may vary depending on the bug to deal with. To streamline the production of high-quality and clinically safe phage preparations, scientists developed a systematic procedure for medicinal phage isolation, liter-scale cultivation, concentration, and purification compared to methods used before. As the world is still naive regarding these beneficial viruses, maybe one day we might depend on phage therapy just the way we do antibiotics these days.

 Pharmaceutical Microbiology Resources (http://www.pharmamicroresources.com/)