Penicillin, the first widely available antibiotic drug, was discovered by Sir Alexander Fleming 86 years ago today, on 28 September 1928. Upon its introduction into mainstream medicine in the 1940s, penicillin was hailed as a ‘miracle cure’. To this day, antibiotics are widely used to treat or prevent infections.
“One sometimes finds what one is not looking for”
—Sir Alexander Fleming
Fleming’s discovery was coincidental: his laboratory at St. Mary’s Hospital in London was notoriously messy, and he often left uncovered petri dishes containing bacteria that he no longer needed on his worktop. Upon returning from a holiday in Suffolk, he found that an old dish containing Staphylococcus aureus bacteria had been contaminated by a fungus, Penicillium notatum. Wherever the fungus grew, it was surrounded by bacteria-free zones where Staphylococcus could not grow. Upon further investigation, Fleming found that the ‘mould juice’ he derived from P. notatum effectively killed many kinds of bacteria. We went to the Fleming Museum in London to learn more about his work and how he made his famous discovery; you can listen the podcast we recorded here.
It was not until 1939 that three researchers at Oxford University turned penicillin from mould juice into a life-saving drug. Two years later, a devastating fire in the Cocoanut Grove nightclub in Boston became the first opportunity to test penicillin on a large scale: burn injuries and skin grafts are particularly susceptible to infection. Following the successful use of penicillin in the aftermath of the fire, the US government began to fund the mass production of the drug, which saved countless lives during World War II.
Fleming received his Knighthood in 1944 and a year later was jointly awarded the Nobel Prize for Medicine or Physiology, along with Howard Florey and Ernst Chain. In the same year, Sir Alexander became the first President of the Society for General Microbiology. Because the Nobel Prize can only be awarded to three people, Norman Heatley, the third Oxford pathologist instrumental in developing penicillin into a mass-produced, mainstream drug, missed out on the award. In 1990, partly to correct this oversight, he became the first non-medic to be awarded an honorary Doctorate of Medicine by Oxford University.
So how does this antibiotic actually work? Penicillin is a member of the β-lactam class of antibiotics and its chemical structure contains a ring of carbon and nitrogen that gives the class its name. Penicillin prevents bacteria from correctly building their cell wall, stopping them from dividing properly.
Antibiotic resistance was a problem even when penicillin was being developed. In fact, the first resistant bacterial strains were discovered before the drug was even available to the public. Alexander Fleming himself warned about the risks of antibiotic resistance in his Nobel Prize acceptance speech. Numerous derivatives and synthetic versions of penicillin have since been developed, and some of these, such as methicillin and amoxicillin, are widely used today.
Penicillin was the first of a great many antibiotics – over 100 have since been discovered. These drugs have saved innumerable lives, but there is a great need for new ones to be developed if we are to delay the threat of resistance and continue the legacy of Fleming, Florey, Chain and Heatley.