The history of antibiotics began long before Fleming, although popular culture tends to attribute almost the entire breakthrough to him.
In 1877, Louis Pasteur and Jules Joubert observed that some microorganisms could suppress others and suggested that this phenomenon might be useful for treating infections.
In 1895, the Italian physician Vincenzo Tiberio studied the antibacterial effects of mold extracts.
In 1897, the French researcher Ernest Duchesne conducted similar experiments, including experiments on animals.
Half a century before Fleming, scientists had already observed microbial antagonism and the therapeutic potential of mold several times. But each observation looked like an isolated biological curiosity rather than the beginning of a new technological platform.
Around Fleming
In 1922, Fleming discovered lysozyme, a substance found in tears, saliva, and mucus that destroys certain bacteria.
In 1928, he noticed that mold had accidentally contaminated one of his Petri dishes and killed the bacteria around it. In 1929, he published the results and named the active substance penicillin.
Fleming understood that the substance might potentially be used against infections. But the practical emphasis of his paper was much more modest: penicillin could become a useful laboratory tool and perhaps a topical antiseptic. The path toward a systemic drug remained unclear.
In 1930, Fleming’s former student Cecil Paine used crude mold filtrate to treat eye infections. The effect already worked in patients, although only locally. But even this did not launch a major development program. Penicillin remained unstable, difficult to purify, and seemingly impossible to scale.
For almost a decade, the discovery had no owner.
Systematic search and manufacturing
In late 1938, Howard Florey and Ernst Chain at Oxford decided to expand their research from lysozyme to naturally occurring antibacterial substances as a broader class. They were not initially developing one specific drug. They were systematically searching for promising effects.
While reviewing older papers, Chain came across Fleming’s nearly forgotten 1929 publication. Penicillin became one of the candidates worth testing.
In May 1940, the team of Florey, Chain, and Norman Heatley showed that penicillin could save infected mice. Eleven years after Fleming’s paper, it became clear that the substance worked inside a living organism.
In February 1941, penicillin was administered systemically to a critically ill patient for the first time. He rapidly improved, but the supply ran out and he died. The bottleneck was no longer biology. It was manufacturing.
In 1941, Florey and Heatley traveled to the United States. The Department of Agriculture laboratory in Peoria improved the growth medium and increased penicillin yields roughly tenfold. The government and pharmaceutical companies then developed deep-tank fermentation and built industrial-scale production facilities.
Production in the United States rose from 21 billion units in 1943 to 1,663 billion units in 1944. By the time of the Normandy landings, enough penicillin was available to treat severely wounded soldiers.
Conclusion
For roughly 60 years, humanity circled around the idea of antibiotics without recognizing a technological platform in the repeated observations. Even Fleming identified an especially important signal, yet his paper also remained largely unnoticed.
The revolution happened when a team began systematically screening candidates on the basis of accumulated knowledge.
It is worth asking how many breakthroughs remain unnoticed around us simply because no team is conducting a systematic search within a specific field.
Before Fleming
The history of antibiotics began long before Fleming, although popular culture tends to attribute almost the entire breakthrough to him.
Half a century before Fleming, scientists had already observed microbial antagonism and the therapeutic potential of mold several times. But each observation looked like an isolated biological curiosity rather than the beginning of a new technological platform.
Around Fleming
In 1922, Fleming discovered lysozyme, a substance found in tears, saliva, and mucus that destroys certain bacteria.
In 1928, he noticed that mold had accidentally contaminated one of his Petri dishes and killed the bacteria around it. In 1929, he published the results and named the active substance penicillin.
Fleming understood that the substance might potentially be used against infections. But the practical emphasis of his paper was much more modest: penicillin could become a useful laboratory tool and perhaps a topical antiseptic. The path toward a systemic drug remained unclear.
In 1930, Fleming’s former student Cecil Paine used crude mold filtrate to treat eye infections. The effect already worked in patients, although only locally. But even this did not launch a major development program. Penicillin remained unstable, difficult to purify, and seemingly impossible to scale.
For almost a decade, the discovery had no owner.
Systematic search and manufacturing
In late 1938, Howard Florey and Ernst Chain at Oxford decided to expand their research from lysozyme to naturally occurring antibacterial substances as a broader class. They were not initially developing one specific drug. They were systematically searching for promising effects.
While reviewing older papers, Chain came across Fleming’s nearly forgotten 1929 publication. Penicillin became one of the candidates worth testing.
In May 1940, the team of Florey, Chain, and Norman Heatley showed that penicillin could save infected mice. Eleven years after Fleming’s paper, it became clear that the substance worked inside a living organism.
In February 1941, penicillin was administered systemically to a critically ill patient for the first time. He rapidly improved, but the supply ran out and he died. The bottleneck was no longer biology. It was manufacturing.
In 1941, Florey and Heatley traveled to the United States. The Department of Agriculture laboratory in Peoria improved the growth medium and increased penicillin yields roughly tenfold. The government and pharmaceutical companies then developed deep-tank fermentation and built industrial-scale production facilities.
Production in the United States rose from 21 billion units in 1943 to 1,663 billion units in 1944. By the time of the Normandy landings, enough penicillin was available to treat severely wounded soldiers.
Conclusion
For roughly 60 years, humanity circled around the idea of antibiotics without recognizing a technological platform in the repeated observations. Even Fleming identified an especially important signal, yet his paper also remained largely unnoticed.
The revolution happened when a team began systematically screening candidates on the basis of accumulated knowledge.
It is worth asking how many breakthroughs remain unnoticed around us simply because no team is conducting a systematic search within a specific field.