Bacteria-eating viruses clear infections in diabetic foot ulcers

Not Just Cold Feet

There is quite a long list of potential health complications for those people living with diabetes – especially long-term patients. One of the most concerning is diabetic neuropathy, usually described as a numbness or a loss of sensation in the feet. This is caused by a decrease in the amount of blood flow to the feet and nerve damage. In later stages, some patients with neuropathy experience extreme pain and sensitivity that has been described as “walking on broken glass that is on fire.” It is estimated that between 15%-25% of diabetics experience foot ulcers, of them, 40% – 80% become infected and ultimately contribute to the cause of death. (1)

While most may of us see a blister on our heel or an ingrown toenail as a little problem that will eventually go away, for those living with diabetes, such problems can lead to serious health complications, including losing a foot, or even death. 

A Viral Solution

Finding effective treatments for neuropathy, and diabetics foot ulcers that can occur, has been an ongoing challenge for scientists. Traditionally, antibiotics have been used, but bacterial resistance to the treatment becomes an issue. This is where a new kind of treatment using viral therapy is showing great promise. Turns out there is a group of viruses called bacteriophages (or, just phages), which prey on bacteria. This was discovered in the early 1900s by Frederick Twort and Felix d’Herelle who used phage therapy to treat dysentery. The success of this study led to a wider exploration of uses for phage therapy. In fact, for many parts of the world (including former Soviet Republic of Georgia and Poland), phage therapy is often the standard of care for bacterial infections. In the U.S. and other western medical communities, the discovery of antibacterial therapy would set the standard for treatment. (2)

There are many benefits to using phage therapy. One is that it is more specific in terms of the bacterial targets, another is how diverse it is in terms of its application across a variety of infections. Phage therapy has also been shown to heal wounds faster and have lower side effects. (3) 

This past year, a group of researchers with Australia’s Flinders University used phages to treat diabetic foot ulcers. “The phages effectively decreased the bacterial load and significantly improved wound healing in multi-drug resistant infections – similar or superior to the currently prescribed antibiotic treatment.” Given the prevalence of antibiotic resistance, this study presents a whole new way of approaching a dangerous infection that kills a large number of patients worldwide each year. There is no way to truly measure the impact this treatment can have – not just on a patient’s mental and physical health, but in the reduction of the astronomically high medical costs previously associated with foot ulcers/infections. (4) 

Phages in the Future

Phage therapy has a long history which has been ignored by much of the Western medical community. Most studies, like the one from Australia mentioned above, have used animal models to evaluate the effectiveness of phage treatment and show great promise. There is obviously more research that has to be done, specifically on humans, but the results, so far, are promising. (4)

In fact, there are already studies looking at how to apply this technology to the treatment of pneumonia, foodborne bugs or even food poisoning symptoms. Much of the research so far has been limited to animals. So the next step is to begin safely studying how phage therapy can be used with humans. Specifically, the different phage strains should be studied for their individual effectiveness and to identify which phages, in combination, can treat specific diseases and infections. (5)

References

1. Dunyach-Remy, C., et. al. Staphylococcus aureus toxins and diabetic foot ulcers: role in pathogenesis and interest in diagnosis. Toxins 2016 Jul: 8(7): 209. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4963842/
2. Abedon, S. T., Kuhl, S.J., Blasdel, B.G., Kutter, E.M. Phage treatment of human infections. Bacteriophage. 2011 Mar-Apr; 1(2): 66-85. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3278644/
3. Chan, Benjamin, K., Abedon, Stephan, T., Loc-Carillo, Catherine. Phage cocktails and the future of phage therapy. Future Microbiology. 23 May, 2013. Vol. 8, No. 6. https://www.futuremedicine.com/doi/full/10.2217/fmb.13.47
4. Moghadam, M.G., Khoshbayan, A., Chengini, Z., Farahani, I., Shariati, A. Bacteriophages, a new therapeutic solution for inhibiting multidrug-resistant bacteria causing wound infection: lesson from animal models and clinical trials. Drug Design, Development and Therapy. 2020 May 15; 14: 1867-1883. https://pubmed.ncbi.nlm.nih.gov/32523333/
5. Kifelew, L. G. et. at. Efficacy of phage cocktail AB-SA01 therapy in diabetic mouse wound infections caused by multidrug-resistant staphylococcus aureus. BMC Microbology. 2020; 20: 204. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7346408/