The discovery of penicillin was a milestone moment in medical history, changing the way doctors treat life-threatening illnesses and saving an estimated 500 million lives to date.
Used to cure serious infections such as meningitis, bacterial endocarditis and pneumococcal pneumonia, penicillin was discovered by accident after mould grew on a staphylococcus culture plate in a laboratory.
Hailed as a “miracle drug”, it has changed the course of medicine, leading to the widespread availability of antibiotics and enabling physicians to treat infections that may have led to fatalities in years gone by.
Who discovered penicillin?
A Scottish physician, Sir Alexander Fleming, discovered penicillin by chance in 1928 at his laboratory at St Mary's Hospital in London.
Born in 1881 in Ayrshire, the farmer’s son qualified with a Bachelor of Medicine and Surgery degree from St Mary’s Hospital Medical School in Paddington in 1906. He joined the research department at St Mary’s as assistant bacteriologist, attaining a BSc in bacteriology in 1908 and becoming a lecturer to medical students.
His career was interrupted in 1914 by the start of World War I. As a private in the London Scottish Regiment of the Volunteer Force since 1900 and a member of the hospital’s rifle club, he joined the Army as a commissioned lieutenant.
Promoted to captain in 1917, he worked in makeshift battlefield hospitals on France’s Western Front in the Royal Army Medical Corps. After the war ended in 1918, he returned to the hospital to continue his research into bacteriology.
How was penicillin discovered?
Fleming had been researching the properties of the bacteria staphylococcus since 1927. Although he was a brilliant physician, he wasn’t renowned for being tidy; left his laboratory in a mess when he went to Suffolk on a family holiday in September 1928.
On his return, he noticed petri dishes containing inoculated staphylococci had become contaminated with fungus. Strangely, the staphylococci around the fungus had been destroyed, but the remaining clusters further away looked normal.
Recognising the mould as being of the genus Penicillium, he began growing it in a pure culture, resulting in the creation of an antibacterial substance. Further tests showed it offered a potential cure for staphylococci and other pathogens that caused pneumonia, scarlet fever, diphtheria and meningitis.
Later, he admitted it had been discovered by accident, saying, “When I woke up on 28th September 1928, I didn’t plan to revolutionise all medicine by discovering the world’s first antibiotic.” However, this was exactly what he had done.
Fleming presented his findings to the Medical Research Club on 13th February 1929, also publishing his research in the British Journal of Experimental Pathology.
Penicillin in World War II
The significance of penicillin wasn’t realised at first and Fleming’s words fell on deaf ears. Even delegates at the International Congress of Microbiology failed to see its relevance, leaving him bitterly disappointed.
After World War II broke out in 1939, the true value of penicillin was finally appreciated, as it helped reduce the number of troops who died or suffered amputations as a result of battlefield injuries.
Researchers Ernst Chain and Howard Florey assembled a team of scientists in Oxford to develop the Penicillin Project through trial and error, publishing a paper in 1940 detailing successful trials. However, they were limited by how long it took to produce even tiny amounts of penicillin. Unfortunately, due to the war, Britain wasn’t able to proceed with mass production, so Florey took their project to the United States instead in June 1941.
Setting up a new team in Peoria, Illinois, at the Department of Agriculture’s research laboratory, the project gathered pace, developing new, more efficient production techniques to create a larger volume of penicillin.
American pharmaceutical companies had reservations about committing to large scale production, but after the US joined the war in December 1941, demand for the new “wonder drug” rocketed. The US produced enough penicillin to satisfy the needs of their own troops and those of the other Allied nations, with Schenley Laboratories and Pfizer playing a major role.
Records show 400 million units of penicillin were available at the start of 1943, but as demand grew, it was mass produced in the United States for the Allied troops, with companies manufacturing 650 billion units per month by the end of the war in 1945.
Healthcare industry transformation
After the war, the wide scale production of penicillin continued, transforming the healthcare industry after it became available in the UK for public use for the first time in 1946. Infections that were previously severe or fatal, including bacterial meningitis, bacterial endocarditis and pneumococcal pneumonia, could be treated.
The success of penicillin led to more pharmaceutical companies screening other natural products to detect antibacterial activity. New antibiotics such as tetracycline, aminoglycosides and streptomycin were created as a result of penicillin leading the way.
Penicillin also saved the lives of soldiers in global conflicts, such as the war in Iraq in 2003, by successfully treating serious injuries that may have otherwise been fatal.
The late Theodore Eickhoff, professor emeritus at the University of Colorado School of Medicine’s infectious diseases division, said it was “impossible to imagine what the world would be like without penicillin”.
He noted that penicillin was never subject to controlled clinical trials to gauge its suitability for treating infections such as pneumococcal pneumonia because the difference it made was “so clearly apparent” from the outset.
Importance of hygiene in healthcare
Penicillin and antibiotics, combined with high quality hygiene supplies and good practices, play a vital role in the care sector to help keep vulnerable people safe from infections. Many will have compromised immune systems that make them susceptible to infection, such as flu and common colds.
Contaminated hands are a primary source of pathogenic bacteria, so washing and sanitising frequently can help prevent the spread of dangerous microorganisms. Maintaining high standards of hygiene, including the use of healthcare supplies such as protective equipment and cleaning products, can help keep care home residents safe.
Future of penicillin
To date, penicillin has become the most widely used antibiotic in the world, but the pharmaceutical sector faces ongoing challenges, such as antibiotic resistance, highlighting the need for continued innovation in medicine.
Since Fleming discovered penicillin, more than 150 types of antibiotics have been developed, but resistance has emerged to the majority. Using one antibiotic to treat a bacterial infection means any resistant genes can be incorporated into another bacteria. In turn, this can then lead to other types of bacteria becoming antibiotic-resistant.
According to research published by the National Library of Medicine, there has been an increase in multi-resistant strains in recent years, leading to a higher mortality rate and the spread of “superbug” infections, representing a serious threat to health globally.
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