Today in History: Penicillin Was Discovered

by M.C. Millman

Alexander Fleming, a Scottish physician-scientist, discovered one of the most significant advances in therapeutic medicine, giving doctors a tool to cure patients of deadly diseases. 

In 1928, Fleming was working on experiments with the S. aureus bacteria at a hospital in London. On September 28, Fleming noticed a Petri dish contaminated with mold spores. The bacteria within close proximity to the mold were dying on the dish. He then isolated the mold and identified it as a member of the Penicillium genus. Fleming realized that the mold "juice" killed the bacteria, and he named the juice "penicillin".

Fleming has been quoted saying, "I did not invent penicillin. Nature did that. I only discovered it by accident".

Fleming published his discovery in 1929 in the British Journal of Experimental Pathology. At that point, the discovery did not enthuse the scientific community and didn't attract much attention. Scientists at the time were unsure what the medical application penicillin had aside from preventing unwanted bacteria on Petri dishes and allowing for the isolation of penicillin-insensitive bacteria. 

To make matters bleaker, Fleming had difficulty isolating large quantities of penicillin from mold. 

In 1939, when Fleming was contemplating retirement, a chemist named Ernst Boris Chain told his supervisor, Howard Florey, about Fleming's paper. Florey acquired a $25,000 research grant from the Rockefeller Foundation to study antibiotics. He assembled a research team including Chain and Norman Heatley, a fungal expert, and others.

The team worked together to purify penicillin. They had to make large quantities of mold to process it into penicillin. To do this, the scientists grew mold in various strange vessels, such as bedpans, food tins, and baths. The lab even employed a team of "penicillin girls" for £2 a week who were responsible for looking after the mold fermentation. 

Due to World War II, the chemical industry was absorbed in the war effort, making it challenging to produce penicillin on an industrial level. The scientists required a significant increase in penicillin production to perform clinical trials to see if it could be used as a treatment. 

In the summer of 1941, Oxford scientists Howard Florey and Norman Heatley visited the US to encourage a collaborative effort. The US played a major role in developing large-scale drug production during the war. This transformed the limited supply of the life-saving antibiotic from a limited supply medicine to something widely available. 

In 1945, Fleming, Florey, and Chain (but not Heatley) were awarded the Nobel Prize in Physiology or Medicine for the discovery and development of penicillin, which saved millions of lives. In 1990, Oxford University attempted to correct the Nobel's oversight. It awarded Heatley the first honorary Doctorate of Medicine to a non-medic in Oxford's 800-year history.