According to the World Health Organization, around 700.000 people across the globe die each year because of antibiotic-resistant bacteria, a number that could rise to 10 million by 2050. According to researchers, unless we develop new ways to kill these types of bacteria, our antibiotics will not be able to treat common infections that can become deadly.
The most obvious solution would be to develop new antibiotics, but this is not as simple as it sounds. Not only is it difficult and expensive to develop new antibiotics, but pharmaceutical companies see no incentive to invest in them.
In addition to creating new antibiotics, we need to support research into phage therapy. A phage is a virus that naturally infects and kills a certain type of bacteria. If a suitable 'phage cocktail' is created, these phages can be injected into the bloodstream in large numbers, which ideally will eliminate the infection. Each bacteriophage infects only a specific type of bacteria, so they have no harmful effects on cells and beneficial bacteria found in human, animal and plant organisms.
Like phages, another new technique for killing antibiotic-resistant bacteria involves peptides - amino acid chains - that can target and kill certain types of bacteria, leaving beneficial bacteria alone.
Any peptide that effectively kills bacteria is called an antimicrobial peptide. Experts believe that using peptides to kill bacteria may be better than using phages, because phages typically target specific receptors or ligands to find and kill bacteria. However, bacteria can evolve to change these characteristics to avoid phages. In contrast, peptides attack the cell envelope - making it difficult for bacteria to adapt - and then interact with the cell membrane. The researchers are convinced that it is much harder for bacteria to adapt evolutionarily to this type of attack.
Researchers hope to develop specific peptides that can kill a wide range of bacteria. In time, bacteria are still likely to be able to find ways to ward off the effects of antimicrobial peptides, so it is not enough to rely on them alone: new antibiotics need to be developed, investment in phage therapy is needed and antibiotic overuse in general should be avoided.