Penicillin.

In the depths of wartime despair came a medical miracle - penicillin, which promised to defeat some of the diseases which were previously life-threatening. As this new age of antibiotics dawned, we used the new drugs for everything from cures for serious infections to penicillin lipstick for hygienic kissing. Now, a few decades later, as antibiotic-resistant 'superbugs' threaten hospitals, a lot of the initial optimism for drugs like penicillin has vanished. This look back at the development and use of antibiotics shows how a combination of ambitious doctors, demanding patients and a profit-hungry pharmaceutical industry all encouraged us to overlook the possibility that the bugs we were trying to conquer might begin to fight back if antibiotics were over-used.