The Accidental Invention of Penicillin

Lexile: 1060 | Grade: 9

Passage

In 1928, a scientist named Alexander Fleming returned to his laboratory after a vacation and noticed something unusual. He had left several petri dishes containing bacteria on a bench, and one of them had developed a patch of mold. Around that mold, the bacteria had stopped growing. Fleming realized he had stumbled upon something remarkable: a mold that killed bacteria. That mold would later be known as penicillin—the world’s first true antibiotic.

At the time, bacterial infections like pneumonia or infected wounds could be fatal. There were no reliable treatments. Doctors could do little more than hope the patient recovered on their own. Fleming’s discovery marked the beginning of a revolution in medicine. However, it took more than a decade for other scientists to figure out how to grow penicillin in large enough quantities to use in hospitals. By World War II, penicillin was saving thousands of lives on the battlefield and beyond.

What makes the story of penicillin so extraordinary is not just its scientific value, but the fact that it was found by accident. Fleming wasn’t trying to find a cure for infection—he simply observed something unexpected and decided to investigate it. This kind of discovery highlights the importance of curiosity and paying attention to the unexpected, even when it seems small.

Today, penicillin and other antibiotics are common, but antibiotic resistance is a growing concern. Bacteria are evolving ways to survive these once-powerful drugs, making some infections harder to treat. Scientists continue to search for new solutions, but Fleming’s discovery remains a powerful example of how observation, chance, and curiosity can change the world.