For decades, scientists have been tracking an alarming trend: the ability of bacteria to become resistant to antibiotics. Simply put, the few bacteria to survive an onslaught of antibiotics are the strong ones, the ones who may have a mutation that makes the mechanism of antibiotics ineffective against them. A recent study from the U.K. indicates that by 2050, antibiotic-resistant bacterial infections will have a resurgence, and are likely to kill up to ten million people per year, potentially costing $100 trillion globally each year. Doctors, healthcare workers, and alert citizens have been trying to reduce our use of antibiotics to slow the development of antibiotic resistance. However, the overall trend cannot be reversed, and science agencies have long acknowledged that a new approach to fighting bacterial infections is necessary.
A team of researchers from MIT, the University of Brasilia in Brazil, and the University of British Columbia, have been working with antimicrobial peptides, naturally occurring proteins that can kill not only bacteria, but some fungi and viruses as well. These antimicrobial peptides are created by cells as a form of self-protection against bacteria, fungi, and viruses. They work by poking holes in the outer membranes of invading cells and calling on existing immune processes, such as leukocyte production, to disrupt life-sustaining functions within the attacking cells. Antimicrobial peptides can interfere with DNA and RNA production, metabolism, reproduction and other critical activities.
Researchers tested this peptide, which they named clavanin-MO, on antibiotic-resistant strains of Escherichia coli and Staphylococcus aureus in mice. The synthetic peptides proved more effective than the naturally-occurring variety, leading to hopes that even greater improvements in their efficacy can be engineered. Besides direct action on bacteria and other infective agents, the researchers discovered that clavanin-MO additionally suppresses the runaway inflammatory response that can lead to sepsis. In nature, these peptides are comprised of 20 different amino acids. Researchers feel that creating them synthetically will allow them to experiment with a variety of sequences, which may enable effective treatment of a broad range of disease types.
“One of our main goals is to provide solutions to try to combat antibiotic resistance,” says MIT researcher Cesar de la Fuente. “This peptide is exciting in the sense that it provides a new alternative for treating these infections, which are predicted to kill more people annually than any other cause of death in our society, including cancer.”
The clavanin-MO peptide is not only a potential medicine for those already infected. Antimicrobial peptides, theoretically, could be manufactured into food-bearing surfaces such as kitchen countertops, ideally making them resistant to microbial growth and minimizing the possibility of kitchen infections. Similarly, these peptides could be used to coat catheters and other intrusive medical equipment, and added to ointments used to treat topical bacterial and fungal infections.