Eighty-three years ago today Sir Alexander Fleming discovered penicillin, one of the most widely used antibiotics.
Inspired by what he saw on the battlefields of World War I, he returned to his laboratory at St. Mary’s Hospital in London to devise a way to fight bacterial infections.
In 1928 he accidentally left a Petri dish in which he was growing the bacterium Staphylococcus aureus uncovered. He later noticed that mold was growing on the plate and that the staph bacteria had died around the mold. Fleming isolated it and identified the mold as Penicillium notatum, a species of fungus similar to the mold that grows on bread. Fleming published his results in the British Journal of Experimental Pathology in 1929, but the report did not generate much interest.
In 1938 Ernst Chain, a biochemist who worked with pathologist Howard Florey at Oxford University, came across Fleming's work while researching antibacterial compounds. Scientists in Florey's lab started with penicillin, which they eventually injected into mice to see if it could treat bacterial infections. Their experiments were successful and they tested it on humans, where they also saw positive results.
In 1941 there was an injectable form that could be used to treat patients, which was particularly useful for soldiers in World War II.
Today penicillin, considered the first miracle drug, is used to treat sore throats, meningitis, syphilis and other bacterial infections. It works by inhibiting enzymes that are involved in building bacterial cell walls and by activating other enzymes that break down these protective barriers. Some bacteria have developed resistance to penicillin, which underscores the importance of careful use of antibiotics.
In 1945 Fleming, Chain and Florey received the Nobel Prize in physiology or medicine to discover penicillin and its healing properties in various infectious diseases.
Fleming died in 1955.
See Richard Sykes' essay for more information Penicillin: From Discovery to Product .
- Daniela Hernandez