A DISCOVERY THAT CHANGED EVERYTHING

While studying bacteria in his laboratory, Fleming noticed something unusual: a mold had contaminated one of his petri dishes, and around that mold, the bacteria had died. Instead of discarding the sample, he investigated further. What he had discovered was penicillin—the first true antibiotic.

Before this breakthrough, even minor infections could be deadly. A simple cut or sore throat could escalate into life-threatening illness. Hospitals were filled with patients suffering from infections that doctors had no reliable way to treat.

Penicillin changed everything.