In pictures: Penicillin: The first 'wonder drug'

Dr Robert Bud, curator of medicine at the Science Museum, said the development of drug resistant strains of bacteria became a problem relatively quickly.

"Less than 30 years after Alexander Fleming had discovered penicillin, the public learned the reality of resistance."

This is an early version of a fermenter, in which mould was treated with a chemical brew to produce penicillin.

Photo Credit: Science Museum/SSPL