Breaking The Mold: The invention of Penicillin
On Aug. 24, 1940 — 85 years ago today — Howard Florey and a team of other physicians at the University of Oxford published laboratory results showing the effectiveness of a new wonder drug antibiotic that was extracted from a type of mold accidentally discovered in an English hospital lab more than a decade before.
Later that year, they'd begin working to grow penicillin in medicinal quantity. It would grow into an entire family of drugs — many of which are still used today.
How Penicillin Was Developed
SEPT. 3, 1928
Bacteriologist Alexander Fleming of St. Mary’s Hospital in London returns from a summer vacation to discover a messy lab and a sample of staphylococcus bacteria that had been contaminated by a blue-green mold. When he looks closer, he notices that the colonies of bacteria grew normally except where the mold was — meaning the mold was killing or inhibiting the growth of the bacteria.
“That's funny,” Fleming remarks to a colleague.
SEPT. 28, 1928
Fleming confirms his observation with a new experiment. He names the mold penicillin.
Professor Alexander Fleming at work in his laboratory. Photo sourced from the Imperial War Museum
JAN. 9, 1929
Fleming performs his first clinical trial with penicillin on his research assistant, who had undergone surgery for a severe sinus infection. The penicillin has no observable effect. Fleming later discovers the particular infection his assistant had was immune to penicillin.
1929Fleming finds he is unable to isolate raw penicillin “from lack of sufficient chemical assistance.” This is possibly a reference to the fact that he lost his research assistants to other jobs. Fleming had no training in chemistry, once telling one of his assistants “I am a bacteriologist, not a chemist.” He ends his work with the mold but preserves his cultures.
SUMMER 1940
Australian scientist Howard Florey and a team of researchers at the Sir William Dunn School of Pathology, University of Oxford, succeed in manufacturing a concentrated form of penicillin. They experiment on 50 mice infected with deadly streptococcus. Half, treated with penicillin injections, survive. The untreated half die of sepsis.
AUG. 24, 1940
Florey publishes laboratory results in the medical journal, the Lancet, showing his team’s work with penicillin. Later that year, they begin working with penicillin spores to grow penicillin in medicinal quantities.
Howard Florey, photo sourced from Wikimedia Commons
FEB. 12, 1941
Florey’s team treats a policeman who has a severe face infection. The patient’s condition improves, but then the team’s supply of penicillin runs out. The patient dies.
JUNE 1941
Florey and one of his team members travel with their mold samples to America in hopes of interesting the U.S. government in large-scale production of penicillin. A facility is set up at a USDA lab in Peoria, Illinois.
NOV. 26, 1941
Scientists at the Peoria lab succeed in increasing the yield of penicillin tenfold.
MARCH 14, 1942
Anne Miller, near death in a hospital in New Haven, Connecticut, after miscarrying and developing an infection that leads to blood poisoning, becomes the first patient treated with U.S.-made penicillin produced by Merck & Co. Doctors use half the total amount of penicillin produced in the U.S. at that time to treat Miller, who recovers.
JUNE 1942
Enough penicillin is available in the U.S. to treat 10 patients.
AUGUST 1942
Harry Lambert, a colleague of Alexander Fleming, contracts streptococcal meningitis, a potentially fatal infection of the nervous system. He requests treatment from Lambert and his penicillin. Lambert, in turn, requests a sample of purified penicillin from Florey’s team, which he injects into Lambert’s spinal canal. Lambert shows signs of improvement the very next day and completely recovers within a week.
DECEMBER 1942
Survivors of the Cocoanut Grove fire in Boston become the first burn patients to be successfully treated with penicillin.
1943
Fleming publishes the results of his clinical trials in the Lancet.
APRIL 5, 1943
The British War Cabinet sets up a Penicillin Committee that leads to mass production in the U.K.
JULY 1943
The U.S. War Production Board draws up a plan for the mass distribution of penicillin to Allied troops fighting in Europe. The U.S. produces 2.3 million doses in time for the June 1944 invasion of Normandy.
SUMMER 1943
U.S. drugmaker Pfizer continues to research ways of producing large quantities of penicillin. After conducting a worldwide search for a better source of just the right kind of mold, a lab assistant stumbles across a cantaloupe in a Peoria market that is covered with a ”pretty, golden mold.” That turns out to be the fungus Penicillium chrysogeum, which yields 200 times the amount of penicillin as the species that Fleming had first discovered in 1928.
DEC. 10, 1945
Fleming, Florey and a member of Florey’s team, Ernst Chain, share the 1945 Nobel Prize in Physiology or Medicine for the development of penicillin.
MARCH 15, 1945
Penicillin is made available to the general public in the U.S.
The Bottles
A sealed glass vial of penicillin manufactured by Merck & Co. Inc. to be used in clinical trials in 1942 or 1943. The powder in the vial would be diluted and then injected into a patient.
Photo sourced from the Science Museum Group
A “Florey unit” or Oxford unit is roughly equalto 0.6 micrograms. There would be about 3 milligrams of penicillin in this vial.
Photo sourced from the Imperial War Museum
Above: A lab worker in 1943 sprays a solution containing penicillin mold into flasks of corn steep liquor in hopes of growing more penicillin mold.
The Downside
As Fleming found early in his work with penicillin, some bacteria are naturally resistant to penicillin. Other strains will produce enzymes when exposed to antibiotics that, over time, cause them to be resistant to penicillin and other commonly used antibiotics. The Centers for Disease Control and Prevention estimates that more than 2.8 million antibiotic-resistant infections occur in the U.S. each year, resulting in more than 35,000 deaths.