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As superbugs spread, researchers are turning to microbes that kill bacteria
This year the world awakened to the fact that the most powerful and sophisticated species on earth is tragically vulnerable to the tiniest and most basic of creatures. Infectious disease specialists have been warning about this for decades. And the threat comes not only from novel viruses, such as the one causing COVID-19, that jump from animals to humans but also from microbial monsters that we have helped to create through our cavalier use of antibiotics […]
But in a splendid irony, it may turn out that viruses, so often seen as nemeses, could be our saviors in fighting a host of killer infections. As the threat from drugresistant bacteria has grown and the development of new antibiotics has stalled, researchers have turned their attention to bacteriophages—literally, bacteria eaters. Viruses in this class are believed to be the oldest and most numerous organisms on earth. And like guided missiles, each type has evolved to seek and destroy a specific type of bacteria. […] With modern techniques, virologists can precisely match just the right phages to a specific strain of superbug—with sometimes astonishing results. […]
For now phage therapy remains experimental. In most cases, it involves making custom cocktails of several phages shown to be active in vitro against an individual patient’s bug. […]
The effort that is furthest along, however, relies on a phage enzyme called a lysin rather than on whole phages. After multiplying inside a bacterium, phages use lysins to break through the cell wall of their host, instantly killing it. […]
Lysins work synergistically with standard antibiotics, […], they can pierce the walls of superbugs, enabling the drugs to do their job. Lysins also clear up biofilms
– slimy layers of bacteria, carbohydrates and gunk
– that cause lasting infections not readily cured by antibiotics. Another advantage is specificity: lysins kill their target without collateral damage to the microbiome.
Phage and lysin therapies still have a way to go, but at a time when much of the world is besieged by a virus, it’s good to know that these tiny invaders may someday save us.
Claudia Wallis, Scientific American, June 2020
According to TEXT, viruses
