Tweaked 'magical' antibiotic to fight superbugs

Scientists have given more 'superpowers' to a lifesaving antibiotic, an advance that could eliminate the threat of drug-resistant infections for years to come.

Researchers from The Scripps Research Institute (TSRI) in the US discovered a way to structurally modify an already- powerful version of the antibiotic called vancomycin.

Tested against Enterococci bacteria, the new version of vancomycin killed both vancomycin-resistant Enterococci and the original forms of Enterococci, researchers said.

"Doctors could use this modified form of vancomycin without fear of resistance emerging," said Dale Boger from TSRI.

The antibiotic has been prescribed by doctors for 60 years, and bacteria are only now developing resistance to it, researchers said.

This suggests bacteria already have a hard time overcoming vancomycin's original "mechanism of action," which works by disrupting how bacteria form cell walls, they said.

Researchers call vancomycin "magical" for its proven strength against infections, and previous studies have shown that it is possible to add two modifications to vancomycin to make it even more potent.

"With these modifications, you need less of the drug to have the same effect," Boger said.

The new study shows that scientists can make a third modification - which interferes with a bacterium's cell wall in a new way - with promising results.

Combined with the previous modifications, this alteration gives vancomycin a 1,000-fold increase in activity, meaning doctors would need to use less of the antibiotic to fight infection.

The discovery makes this version of vancomycin the first antibiotic to have three independent mechanisms of action.

"This increases the durability of this antibiotic," Boger said.

"Organisms just can't simultaneously work to find a way around three independent mechanisms of action. Even if they found a solution to one of those, the organisms would still be killed by the other two," he said.

The study was published in the journal Proceedings of the National Academy of Sciences.