On this date in 1940, Howard Florey and Ernst Chain of the University of Oxford injected eight lab mice with lethal doses of streptococci bacteria. They then administered penicillin to four of those mice. The next day, the four mice that received penicillin were healthy. The other four were dead.
The effect of mold in fighting bacteria was first discovered (by accident) by Alexander Fleming in 1928. Fleming had just returned to his laboratory after a month-long vacation with his family. Before he left, he was working with cultures of staphylococci bacteria, which he stacked and stored before leaving for vacation. When he returned, he found that one of his cultures contained a moldy substance, around which the staphylococci colonies had been destroyed. He wrote up his observations, but little attention was given to his paper until Florey and Chain began their work.
The first human trial took place the year after Florey and Chain’s experiment. In its sole subject, penicillin had immediate effect. The only problem was limited supply.
During World War II, Florey managed to convince some chemical companies in the United States to start mass-producing penicillin, in time to treat Allied troops invading Europe. Production soon increased, and production costs plummeted.
Fleming, Florey, and Chain were recognized for their achievement with the Nobel Prize in 1945.
Today, penicillin and other antibiotics are considered miracle drugs that save countless lives. In 2010 alone, more than 7.3 billion standard units of penicillin were consumed worldwide.