With the growing rise of antibiotic resistance there is a clear and desperate need for alternative treatments. Recently, scientists have turned to nature to look for inspiration to fight off bacteria. The methods, set to be discussed at the American Society for Antibiotics conference, involve predatory bacteria, antimicrobial peptides, phages, enzymes and metals.
Bacteria can be beneficial by acting as predators of their peers. A well-known example, currently being researched, is the soil bacterium Bdellovibrio bacteriovorus, which embeds itself between the prey bacterium’s inner and outer membranes. Additionally, other teams have engineered E.coli that produces peptides that kill the causal bacterium of pneumonia.
Antimicrobial peptides, small protein molecules which kill bacteria, are also a possible antibiotic alternative. These molecules are produced by a wide variety of organisms, from plants and animals to fungi. Therapies based on amphibian and reptile peptides have been shown to be effective in healing wounds in mice. A compound known as pexiganan, based on peptides found in frog skin, is currently in phase 3 trials for treatment of diabetic foot ulcers.
Phages, viruses which attack bacteria, have been researched as treatment since 1920s. Specific to one bacteria type, they provide an extra benefit in that they won’t harm beneficial species during their application. Furthermore, they are abundant in nature, meaning there are plenty of potential replacements if bacterial resistance develops.
A method bacteria use to defend themselves against phages could also be exploited to kill the bacteria themselves. Using a technique known as CRISPR scientists plan to generate short RNA sequences that target the bacterial genome, in particular the genes conferring antimicrobial resistance.
Finally, metals are the oldest known used antimicrobials dating back to ancient Persian kings and used by Hippocrates in 4th century BC. A research group is currently exploring the use of metal nanoparticles as treatments in particular gallium. Promising results have been found using this method in trials with patients who have cystic fibrosis, in bacterial biofilm degradation.
All of these potential treatments show that often Mother Nature knows best!