An international team from the UK and Australia has made a remarkable discovery in the fight against antibiotic resistance, identifying the compound pre-methylenomycin C-lactone – a completely new antibiotic, hidden in the well-known bacterium Streptomyces coelicolor. This is the first antibiotic of a new class in years, creating real prospects for dealing with the most dangerous resistant pathogens.

Laboratory tests show that pre-methylenomycin C-lactone is 100 times more active than methylenomycin A against a wide range of Gram-positive bacteria, including MRSA (methicillin-resistant Staphylococcus aureus) and VRE (vancomycin-resistant Enterococcus). Strikingly, the compound is obtained as a biosynthetic intermediate in the production of another antibiotic that scientists have been studying for more than half a century.

"Finding such a powerful antibiotic in a microorganism that we have been researching for generations was a complete surprise," says chemist Lona Alhalaf from Warwick University. Her colleague Greg Challis adds: "The change in approach – analysis of biosynthetic pathways and intermediate stages, instead of just the final product – opens up entirely new possibilities for antibiotic discoveries."

The new antibiotic has no reported resistance from major hospital pathogens under laboratory conditions, even in situations typical of developing drug resistance. This offers hope for a new effective tool against infections that cause about 1.1 million deaths worldwide each year.

Monash University is already working on a technology for the industrial synthesis of pre-methylenomycin C-lactone, which will allow the launch of large-scale preclinical studies.