Researchers have just identified a powerful new antibiotic – in a significant discovery made not by breaking new ground, but by revisiting familiar territory.

The compound, pre-methylenomycin C lactone, was discovered by a team from Warwick University in the UK and Monash University in Australia. While it’s never been spotted before, it comes from a type of bacteria that scientists have studied for decades.

Potentially, it could help fight bacteria that have become increasingly resistant to modern treatments – and it’s actually an intermediate chemical that’s created during the process of making another antibiotic, methylenomycin A.