In 1871 the scientist Joseph Lister by chance noticed that the mould which grows on cheese and fruit can make microbes (germs) grow weaker. He made some successful experiments on patients but did not, it seems, fully recognize the implications of his findings.
In 1906 the young physician Alexander Fleming became a research assistant at St Mary's Hospital in London. Fleming went to France during the First World War to treat wounded soldiers and could see for himself that there was no effective way of treating many infections. Back at St Mary's after the war, Fleming was determined to find a better way of killing germs. In 1928 he was studying staphylococci bacteria (that can, among other things, infect wounds). By pure luck, he noticed that on a dish containing agar on which he had been growing germs, near some mould, the germs were less common. He grew more of the mould, naming it penicillin from its Latin name Penicillium.
Fleming discovered the mould was effective against bacteria that caused diseases such as anthrax, meningitis and diphtheria. He published his discoveries but did not have the resources to experiment more widely with penicillin.
In 1938 Howard Florey, professor of pathology at Oxford University, started work on some of the mould that Fleming had grown. Florey was an Australian doctor who had already made a number of important discoveries and was also studying natural substances that could kill bacteria. He had been impressed by an article that Fleming had published in 1929 describing the effects of penicillin. Unlike Fleming, Florey had a large research department, including Ernst Chain, a German Jew who had fled the Nazis.
By 1939 Florey and Chain had begun to realize the importance of penicillin and they had saved a number of people's lives with it as of 1942.
The widespread use of penicillin was hastened by the advent of World War II. The governments of the US and Britain resolved to produce all the penicillin they could and by then, the manufacture of other drugs had become big business, so many major companies were eager to produce penicillin. In 1943 Florey went to Russia to help it make penicillin and by 1944, there was enough penicillin for all the allied troops wounded in the D-Day invasion of Europe.
In 1945 Chain, Fleming and Florey shared the Nobel Prize in Physiology or Medicine "for their discovery of penicillin and its curative effect in various infectious diseases."
The name of Norman G. Heatley (1911-2004) is rarely mentioned in this context. An Oxford University biochemist, Dr. Heatley developed a technique for isolating penicillin during World War II but it only yielded minuscule amounts of the precious substance.
To make more penicillin, Dr. Heatley had to assemble an apparatus from bottles, containers and hospital bedpans Against enormous odds, Dr. Heatley's machine worked. It separated enough penicillin to test on a human, but the limited supply ran out before the patient could fully recover.
In June 1941, Drs. Heatley and Florey went with samples of their penicillin mold to a Department of Agriculture research laboratory in Peoria, Illinois, where, working with some of the top biologists in the US, they set in motion the research that led to large-scale production of penicillin.
"Not only did Heatley make a crucial contribution, but without him the enterprise may not have succeeded at all," said Sir James Gowans, a former professor of pathology at Oxford. "He was the one that came up with the key step in the isolation of penicillin." Dr. Heatley, however, was not included in the Nobel Prize Physiology or Medicine for the development of penicillin. Nobel Prizes honor great scientists, but they often omit great contributors.