Although antibiotics have been the gold standard for treating bacterial infections since the advent of penicillin some 90 years ago, our misuse of these drugs is gradually rendering them useless. Not finishing the course, prescribing them when they’re not needed and using them to increase the growth of livestock are all contributing factors. And the WHO have made it abundantly clear in a recent report that if we don’t buck up our ideas soon, medicine could soon be headed back to the dark ages where common infections and minor injuries become fatal.
But scientists aren’t sitting idle, and already we have seen some new and original strategies emerge in the battle against antibiotic resistance. Recently, researchers published promising results from a new animal study which demonstrated the effectiveness of their bacterial toxin-grabbing nanoparticles. Now, a Dutch biotech company has presented us their innovative idea, which involves taking machinery from bacteria-killing viruses, called phages, and using it to target the medically important bug Staphylococcus aureus.
You may not have heard of them before, but bacteriophages are all around us; our bodies are riddled with them, and they’re found in all aquatic and terrestrial environments. Rather than infecting us, these alien-like viruses are voracious predators of bacteria. After penetrating a bacterium’s cell wall, they inject their genetic material inside and hijack the host, essentially turning it into a phage-making factory.
To escape the host, newly formed phages degrade components of the bacterial cell wall using enzymes, or catalysts, called endolysins. Once the cell wall is breached, the contents of the cell spill out and consequently, the bacterium dies. Armed with this knowledge, scientists from biotech company Micreos developed a designer endolysin that’s specific to the pathogen S. aureus, which they have dubbed Staphefekt.
Laboratory studies demonstrated that the enzyme is capable of rapidly and specifically killing S. aureus, leaving beneficial species unscathed. Because it works in a totally different way to antibiotics, it means that even antibiotic resistant strains such as MRSA are susceptible. Furthermore, the researchers say that it’s very unlikely to encourage the emergence of resistance because it works independently from the host’s metabolism.
In human tests, local application of the enzyme onto skin lesions that tested positive for S. aureus was found to successfully eradicate the bug within one week, without affecting beneficial skin inhabitants. The treatment also reduced symptoms in 5 out of 6 patients presenting skin conditions such as eczema, which also previously tested positive for S. aureus.
“The results are exciting, and demonstrate the potential this technology has to revolutionize the way we treat certain bacterial infections,” Clinical Microbiology Dr. Bjorn Herpers said at Antibiotics alternatives for the new millennium. “With the increasing prevalence of multidrug-resistant bacteria, new strategies for the treatment of bacterial infections are needed.”
According to the Times, the researchers are hoping to develop either a pill or injectable version of the enzyme within the next five years, but it’s already available as a cream for skin infections.
[Via Micreos, the Times and the Telegraph]
