Alexander Fleming | Biography of Famous Scientists

Biographies of Famous Scientists and Inventors in History

Lived 1881 – 1955.
Alexander Fleming discovered penicillin, whose use has saved untold millions of lives. Less well-known is that before making this world-changing discovery, he had already made significant contributions to medical science.


Alexander Fleming was born on August 6, 1881 at his parents’ farm located near the small town of Darvel, in Scotland, UK.
His parents, Hugh Fleming and Grace Stirling Morton, were both from farming families. His father’s health was fragile; he died when Alexander was just seven years old.
Alexander’s earliest schooling, between the ages of five and eight, was at a tiny moorland school where 12 pupils of all ages were taught in a single classroom.
Darvel School was Alexander’s next school, which involved an eight-mile round trip walk every school-day. At the age of 11 his academic potential was recognized and he was awarded a scholarship to Kilmarnock Academy, where he boarded for about two years before leaving for the city of London.
Alexander arrived in London early in 1895, aged 13. This was the year his fellow Scot, Arthur Conan Doyle, published The Memoirs of Sherlock Holmes, in which readers were horrified to learn that their hero had died falling over the Reichenbach Falls.
Alexander lived in the home of an older brother, Tom, who was a doctor of medicine. Most of the Fleming family ended up living with Tom, leaving the eldest brother, Hugh, running the farm.
Alexander attended the Polytechnic School, where he studied business and commerce. He started in a class appropriate to his age, but his teachers soon realized he needed more challenging work. He was moved into a class with boys two years older than him and finished school aged 16.

Work and Medical School

His business training helped him get a job in a shipping office, but he did not enjoy working there.
In 1901, at the age of 20, he inherited some money from his uncle, John Fleming. He decided to use the money to go to medical school; he wanted to become a doctor like his successful brother Tom.
First, he needed suitable qualifications to enable him to join a medical school. This did not present any great difficulties; he passed his exams with the highest marks of any student in the United Kingdom.
In 1903, aged 22, Alexander enrolled at London’s St Mary’s Hospital Medical School, graduating with distinction three years later as Bachelor of Medicine, Bachelor of Surgery.
Rather than follow in Tom’s footsteps, Alexander was persuaded by Almroth Wright, an authority in immunology, to become a researcher in his bacteriology group at St Mary’s Hospital Medical School. While carrying out this research Fleming graduated, in 1908, with a degree in bacteriology and the Gold Medal for top student. St Mary’s Hospital Medical School then promoted him to the role of bacteriology lecturer.
Almroth Wright was interested in our bodies’ natural ability to fight infection. Fleming became particularly fascinated by the fact that, although many people suffered bacterial infections from time to time, the majority of people’s natural defenses prevented infections from taking hold.

Fleming’s Most Significant Contributions to Science

Proving that Antiseptics Kill rather than Cure
In 1914 World War 1 broke out and Fleming, aged 33, joined the army, becoming a captain in the Royal Army Medical Corps, working in field hospitals in France.
There, in a series of brilliant experiments, he established that antiseptic agents used to treat wounds and prevent infection were actually killing more soldiers than the infections were!
The antiseptics, such as carbolic acid, boric acid and hydrogen peroxide, were failing to kill bacteria deep in wounds; worse, they were in fact lowering the soldier’s natural resistance to infection because they were killing white blood cells.
Fleming demonstrated that antiseptic agents were only useful in treating superficial wounds, but were harmful when applied to deep wounds.
Almroth Wright believed that a saline solution – salt water – should be used to clean deep wounds, because this did not interfere with the body’s own defenses and in fact attracted white cells. Fleming proved this result in the field.
Wright and Fleming published their results, but most army doctors refused to change their ways, resulting in many preventable deaths.
Nurses come to the aid of a wounded soldier. Fleming saved many soldiers’ lives in World War One by washing deep wounds with saline solution rather than the antiseptics recommended by medical textbooks.
Discovery of Lysozyme
In 1919 Fleming returned to research at St Mary’s Hospital Medical School in London. His wartime experience had firmly established his view that antibacterial agents should only be used if they worked with the body’s natural defenses rather than against them; in particular, they must not harm white blood cells.
His first discovery of such an agent came in 1922, when he was 41 years old.
Fleming had taken secretions from inside the nose of a patient suffering from a head cold. He cultured the secretions to grow any bacteria that happened to be present. In the secretions, he discovered a new bacterium he called Micrococcus lysodeikticus, now called M luteus.
A few days later, Fleming was examining these bacteria. He himself was now suffering from a head cold, and a drop of mucus fell from his nose on to the bacteria. The bacteria in the area the drop had fallen were almost instantly destroyed. Always on the lookout for natural bacteria killers, this observation excited Fleming enormously.
He tested the effect of other fluids from the body, such as blood serum, saliva, and tears, on these bacteria and found that bacteria would not grow where a drop of one of these fluids had been placed.
Fleming discovered the common factor in the fluids was an enzyme.
He named his newly discovered enzyme lysozyme. The effect of lysozyme was to destroy certain types of microbe, rendering them harmless to people. The presence of lysozyme in our bodies prevents some potentially pathogenic microbes from causing us harm. It gives us natural immunity to a number of diseases.
However, lysozyme’s usefulness as a medicine is rather limited, because it has little or no effect on many other microbes that infect humans.
It did, however, mean that Fleming had discovered a natural antibiotic which did not kill white blood cells. If only he could find a more powerful antibiotic, then medicine could be transformed.
Today, lysozyme is used as a food and wine preservative. It is naturally present in especially large concentrations in egg-whites, offering protection against infection to chicks.
It is also used in medicines, particularly in Asia, where it is used in treatments for head colds, athlete’s foot and throat infections.
Lysozyme is shown here in blue. It is an enzyme, meaning it is a type of protein. It destroys bacteria by breaking down their cell walls, shown in pink.
“The view has been generally held that the function of tears, saliva and sputum, so far as infections are concerned, was to rid the body of microbes by mechanically washing them away… however, it is quite clear that these secretions, together with most of the tissues of the body, have the property of destroying microbes to a very high degree.”
Alexander Fleming

Discovery of Penicillin

In the month of August 1928, Fleming did something very important. He enjoyed a long vacation with his wife and young son.
On Monday, September 3, he returned to his laboratory and saw a pile of Petri dishes he had left on his bench. The dishes contained colonies of Staphylococcus bacteria. While he was away, one of his assistants had left a window open and the dishes had become contaminated by different microbes.
Annoyed, Fleming looked through the dishes and found something remarkable had taken place in one of them.
A fungus was growing and the bacterial colonies around it had been killed. Farther from the fungus, the bacteria looked normal. Excited by his observation, he showed the dish to an assistant, who remarked on how similar this seemed to Fleming’s famous discovery of lysozyme.
Hoping he had discovered a better natural antibiotic than lysozyme, Fleming now devoted himself to growing more of the fungus. He identified that it belonged to the Penicillium genus and that it produced a bacteria-killing liquid. On March 7, 1929 he formally named the antibiotic – it would be known as penicillin.
Fleming published his results, showing that penicillin killed a variety of bacteria which were then the scourge of humanity, including those responsible for scarlet fever, pneumonia, meningitis and diphtheria. Furthermore, penicillin was non-toxic and it did not attack white blood cells.
Unfortunately, the scientific world was largely underwhelmed, ignoring his discovery.
Fleming faced a number of problems:
  • it was difficult to isolate penicillin from the fungus producing it
  • he could not find a way of producing penicillin in high concentrations
  • penicillin seemed to be slow acting
  • clinical tests of penicillin as a surface antiseptic showed it was not especially effective
  • Fleming’s boss, Almroth Wright, had a generalized dislike of chemists and refused to allow them in his laboratory. The presence of a skilled chemist would have been a huge benefit in terms of isolating, purifying, and concentrating penicillin.
Regardless of these issues, Fleming continued with some work on penicillin in the 1930s, but never made the breakthrough he needed to produce it in large, concentrated quantities. Others, however, did.
In the early 1940s a large team of University of Oxford scientists led by pharmacologist Howard Florey and biochemist Ernst Boris Chain finally transformed penicillin into the medicine we know today.
In 1945 Alexander Fleming shared the Nobel Prize in Medicine or Physiology with Florey and Chain. The award was made:
“for the discovery of penicillin and its curative effect in various infectious diseases.”
In his Nobel Prize winning speech in 1945, Fleming warned of a danger which today is becoming ever more pressing:
“It is not difficult to make microbes resistant to penicillin in the laboratory by exposing them to concentrations not sufficient to kill them, and the same thing has occasionally happened in the body. The time may come when penicillin can be bought by anyone in the shops. Then there is the danger that the ignorant man may easily underdose himself and by exposing his microbes to non-lethal quantities of the drug make them resistant.”
Alexander Fleming
Fleming was always fulsome in his praise for Florey, Chain, and their team, and he downplayed his own role in penicillin’s story. Despite his modesty, he became a worldwide hero. Millions of people owed their lives to the antibiotic he had discovered.
In 1945 he toured America, where chemical companies offered him a personal gift of $100,000 as a mark of respect and gratitude for his work. Typically of Fleming, he did not accept the gift for himself: he donated it to the research laboratories at St Mary’s Hospital Medical School.
Some Personal Details and the End
In 1915, while a captain in the Medical Corps, Fleming married Sarah Marion McElroy. Their only son, Robert, became a general medical practitioner.
In 1944 he was knighted and became Sir Alexander Fleming.
His wife Sarah died in 1949.
In 1953 Fleming married Dr. Amalia Koutsouri-Voureka, who was working in his research group at St Mary’s Hospital Medical School.
Alexander Fleming died aged 73 of a heart attack in London on March 11, 1955. His ashes were placed in St Paul’s Cathedral.
Extracted from the website: Famous Scientists for educational purposes