The Discovery of Penicillin
The mold that saved hundreds of millions of lives.
Explore this event on the interactive timeline →Scottish researcher Alexander Fleming accidentally left a petri dish of Staphylococcus bacteria uncovered while on vacation. Upon returning, he found that a stray mold spore (Penicillium) had grown and secreted a substance that actively killed the surrounding bacteria—the world's first true antibiotic.
Verified Facts
- Before penicillin, a simple scratch from a rose bush or a minor surgical infection was frequently a death sentence.
- It took over a decade for other scientists (Florey and Chain) to figure out how to purify and mass-produce the unstable drug in time for World War II.
- Fleming predicted the modern crisis of antibiotic resistance way back in his 1945 Nobel Prize speech, warning that using the drug incorrectly would make bacteria immune to it.