Scientists at the University of Queensland in Australia are attacking antibiotics-resistant bacteria by teaching an old drug new tricks. The drug is the antibiotic vancomycin, and the team has early evidence that their revamped version could be used to treat methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE).
The scientists took vancomycin and re-engineered it to make it bind to the membranes of bacteria, rather than to human cells, according to a press release from the university. The technique resulted in a series of “supercharged” antibiotics, dubbed vancapticins.
The new molecules were active against vancomycin-resistant strains of bacteria in the lab, so the team went on to test the vancapticins in mouse models of multiple infections, they reported in the journal Nature Communications. They drugs were effective, unlikely to cause resistance, and exhibited a profile that could translate to once-daily dosing in people, they said.
Antibiotics resistance continues to raise concerns worldwide. In the U.S. alone, up to 2 million people become infected with drug-resistant bugs each year, and an estimated 23,000 people die because of a lack of effective treatments, according to the Centers for Disease Control.
The biotech industry has charted some progress in recent years, developing novel approaches to combating antibiotics resistance—and that has attracted the interest of investors. For example, San Diego-based Forge Therapeutics raised $15 million in a series A financing round last April to advance its antibiotics that target LpxC, a zinc metalloenzyme. In October, the company expanded a partnership with Evotec to accelerate the research.
Rather than developing entirely new compounds, the scientists at the University of Queensland saw potential in improving antibiotics that have already proven their value. "Drug development is normally focused on improving binding to a biological target, and rarely focuses on assessing membrane-binding properties,” said co-author Matt Cooper, a professor at the school’s Institute for Molecular Bioscience. His team figured that if they enhanced those properties, they could increase the amount of drug that hits the target bacteria, as well as improving the ability of drugs to selectively target superbugs, they said in their paper.
The team started with vancomycin because it is widely used to treat MRSA, a hospital-acquired infection that has become increasingly difficult to control because of drug resistance. But Cooper and his colleagues believe their approach could be used to revitalize many other existing antibiotics.
“Given the alarming rise of multi-drug resistant bacteria and the length of time it takes to develop a new antibiotic, we need to look at any solution that could fix the antibiotic drug discovery pipeline now,” Cooper said.