Discovery of Penicillin
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medicine20th Century

Discovery of Penicillin

Year1928
LocationSt Mary's Hospital, London, England
Key figuresAlexander Fleming, Howard Florey, Ernst Boris Chain
Impact
99
Difficulty
72

Context

Before antibiotics, even minor wounds could become fatal infections. Surgeons operated in conditions that bred bacteria, and pneumonia, tuberculosis, and sepsis killed millions annually. Scientists had long searched for a 'magic bullet' that could kill bacteria without harming human cells, but none had succeeded at scale.

The Deed

Fleming noticed a mold colony had contaminated a Petri dish of Staphylococcus bacteria and was destroying the colonies around it. He identified the mold as Penicillium notatum and called the active substance penicillin. Over a decade later, Florey and Chain at Oxford developed methods to purify and mass-produce the drug. By D-Day in 1944, enough penicillin existed to treat every wounded Allied soldier.

Why It Matters

Penicillin didn't just save lives; it restructured medicine entirely. Surgery became far safer. Diseases that had been death sentences became routine treatments. It launched the pharmaceutical industry's golden age and inspired the discovery of dozens of other antibiotics.

Brutal Truth

Fleming himself warned that misuse would breed resistant bacteria. Today, antibiotic-resistant 'superbugs' kill over 1.2 million people per year. The golden age of antibiotics may be ending because of the very overuse Fleming predicted decades ago.

By the Numbers

  • 200+ million lives saved since discovery
  • 1.2 million annual deaths from antibiotic-resistant infections
  • By 1945, penicillin production reached 650 billion units per month
  • Fleming, Florey, and Chain shared the 1945 Nobel Prize
antibioticsmicrobiologyWorld War IINobel Prize

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