It’s a well known story and example of medical serendipity. Alexander Fleming (1881-1955) a Scottish microbiologist who returned to his laboratory following his summer holiday and found his growth plates of Staphylococcal bacteria had been contaminated with mould. Wherever the mould was growing the bacterial cells had been killed. Antibiotics had been discovered. Except this wasn’t the first antibiotic to be made. Medication with antibacterial action dates back to before the medieval period. When it came to penicillin Fleming’s discovery was only the beginning. And the penicillin still in use today owes much to an unsung hero called Mary and a mouldy cantaloupe.
Fleming surmised that the mould must be making some sort of chemical which was killing the Staphylococcus. The mould in question was Penicillium notatum and so Fleming called this chemical Penicillin. Fleming wasn’t skilled at chemistry and so was only able to extract small amounts of this penicillin which he demonstrated did kill bacteria and was safe in humans.
Sample of penicillin mould presented by Alexander Fleming, 1935. From https://blog.sciencemuseum.org.uk/oxford-and-the-forgotten-man-of-penicillin/
Fleming was a poor public speaker and despite presenting his findings at a Medical Research Club and publishing his results in the British Journal of Experimental Pathology in 1929 there was little recognition amongst his peers. It wouldn’t be until 1939 that Ernst Chain and Sir Howard Florey managed to distil concentrated penicillin from the mould. In 1940 they completed their first animal trials. By 1941 they were ready to treat their first human patient but due to the experimental nature of their drug they needed someone who was seriously if not terminally ill. In 1941 Albert Alexander, a police constable in Oxford, scratched his face on a rose thorn (although this explanation for the injury has been described as apocryphal). The scratch became infected with both Staphylococcus and Streptococcus bacteria. Abscesses covered his face and he lost an eye.
On 12th February Alexander was given an intravenous infusion of 160mg of penicillin. Within 24 hours his fever resolved and he regained strength and his appetite. Sadly, it was already clear that Penicillium notatum made very little amounts of penicillin; it took gallons and gallons of the mould to make enough penicillin to even cover a fingernail. After 5 days of treatment the team ran out of penicillin. Alexander’s condition worsened again and he died.
Whilst penicillin was clearly promising there needed to be a more efficient way to produce the antibiotic, especially at the height of the Second World War when demand couldn’t have been higher. A solution would be found in America.
Mary Hunt worked at the Department of Agriculture’s Northern Regional Research Laboratory (NRRL) in Peoria, Illinois. It was her job to search our for mould strains which might produce more penicillin than Penicillium notatum. This earned her the nickname, ‘Mouldy Mary’. One day in 1943 she found a mouldy cantaloupe in a grocery store. Bringing it to the lab she found it was infected with Penicillium chrysogenum, a strain which produced two hundred times the amount of penicillin as notatum. The next step sounds like it came right out of science fiction. The chrysogenum was zapped with X-rays to cause mutation. This mutated mould now produced a thousand times the amount of penicillin. By D-Day in 1944 there was enough penicillin to treat every soldier in need. By 1945 a million people had been treated with penicillin compared to fewer than 1000 in 1943.
After the war Fleming, Florey and Chain received the Nobel Prize in Physiology and Medicine for the ‘discovery of penicillin and its curative effect in various infectious diseases’. As for Mary Hunt, whilst researching this blog I couldn’t even find out when she was born or what she looked like. She isn’t the first woman to be sidelined in history despite her massive contribution. But all penicillin used today is related to that mouldy cantaloupe and owes its existence to ‘Mouldy’ Mary Hunt.
