Alexander Fleming
Born 1881 · Age 145
Scottish physician and microbiologist, discovered lysozyme (1921) and penicillin (1928). Joint Nobel Prize laureate in Physiology or Medicine 1945. Knighted 1944; Rector of Edinburgh University 1951–1954.
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Life & Career Timeline
Born at Lochfield Farm, Darvel, Ayrshire, Scotland
Alexander Fleming born to Hugh Fleming and Grace Stirling Morton at Lochfield Farm near Darvel.
Awarded scholarship to Kilmarnock Academy
Fleming earned a two-year scholarship to Kilmarnock Academy (part of his secondary education path).
Moved to London; attended Regent Street Polytechnic
Moved to London to live with his elder brother and attended the Royal Polytechnic Institution (Regent Street Polytechnic).
Joined London Scottish Regiment (Volunteer Force)
Served as a private in the London Scottish Regiment from 1900 to 1914 before WWI.
Entered St. Mary's Hospital Medical School
Used an inheritance and a scholarship to begin medical studies at St Mary's, London (medical training start).
Qualified MBBS with distinction
Qualified with an MB, B.S. (University of London) from St. Mary's Hospital Medical School with distinction.
Awarded BSc (Gold Medal) in bacteriology
Gained a BSc degree with the Gold Medal in bacteriology and became a lecturer at St Mary's.
Became Fellow of the Royal College of Surgeons (FRCS)
Passed the FRCS exam in 1909 but chose research rather than surgical practice.
Established private practice (venereology)
Ran a successful private practice as a venereologist while continuing research (approx. 1909–1914).
Commissioned in Royal Army Medical Corps; WWI service begins
Commissioned lieutenant (1914) and served in Army Medical Corps; worked at frontline laboratories in Boulogne.
Married Sarah Marion McElroy
Married Sarah Marion McElroy, a trained nurse from Killala, County Mayo, Ireland.
Promoted to Captain in RAMC
Promoted to captain in 1917 while serving with the Inoculation Department in the field.
Returned to St. Mary's Hospital after demobilisation
Returned to civilian academic and research work at St. Mary's following WWI service.
Awarded Hunterian Professorship
Received the Hunterian Professorship from the Royal College of Surgeons (recognition of early career achievement).
Developed sensitivity titration assays
Devised titration and assay methods in human blood and body fluids later used to titrate penicillin activity.
Observed bacteriolytic activity leading to discovery of lysozyme
Noted that nasal mucus dissolved bacteria on a culture plate; began experiments that led to lysozyme discovery.
Published paper describing lysozyme
Reported 'On a remarkable bacteriolytic element found in tissues and secretions' (Proc. R. Soc. B, May 1922).
Birth of son Robert Fleming
Robert Fleming, son of Alexander and Sarah Fleming, was born in 1924 and later became a GP.
Elected Professor of Bacteriology, University of London (St. Mary's)
Elected Professor of Bacteriology at St. Mary's in 1928, formal academic appointment.
Observed mould inhibition on staphylococcus plate (penicillin discovery)
Noticed Penicillium contamination creating a bacteria-free zone; began experiments on the mould's antibacterial substance.
Published 1929 paper on antibacterial action of Penicillium
Published findings in the British Journal of Experimental Pathology describing the antibacterial action of cultures of Penicillium.
Published description of penicillin's antibacterial action
Key 1929 scientific publication documented penicillin's inhibition of many Gram-positive pathogens.
Presented work to Medical Research Club on penicillin
Presented findings on penicillin (then called 'mould juice' / 'the inhibitor') before peers; received little immediate attention.
Named the active substance 'penicillin'
On 7 March 1929 he coined the name penicillin for the antibacterial substance from the Penicillium mould.
First recorded successful clinical use of penicillin (Cecil Paine)
Cecil Paine used penicillin to cure conjunctivitis in infants and an adult on 25 Nov 1930 using samples derived from Fleming.
Successfully treated severe conjunctivitis with penicillin
Fleming successfully used penicillin ointment for conjunctivitis in a colleague (reported in accounts of 1932).
Chain and Florey rediscover Fleming's 1929 paper; begin Oxford work
Ernst Chain and Howard Florey found Fleming's 1929 paper and in July 1939 began working with a Penicillium sample Fleming had shared years earlier.
Chain/Abraham determine molecular structure; purification efforts begin
Oxford team (Chain, Abraham, Heatley and others) developed purification techniques and advanced penicillin chemistry in 1940.
Oxford team reports therapeutic value; human trials start
Chain and Florey reported therapeutic value in mice (1940) and moved to human trials in early 1941; Florey promoted work in the US mid-1941.
US pharmaceutical mass production begins (early 1942)
American pharmaceutical industry began mass-producing penicillin for Allied forces by early 1942.
Treats Harry Lambert with penicillin (life‑saving case)
In August 1942 Fleming used an incompletely purified sample sent by Florey to treat Harry Lambert with streptococcal meningitis; the patient recovered.
Elected Fellow of the Royal Society (FRS)
Fleming was elected a Fellow of the Royal Society, a major scientific honour (1943).
Member of Penicillin Committee (formation April 5, 1943)
Participated on Penicillin Committee established 5 April 1943 to coordinate mass production for Allied forces.
Knighted by King George VI
Fleming was knighted (Knight Bachelor) in recognition of his scientific achievements; he also received several awards in 1944.
Received John Scott Medal and other 1944 honors
Awarded the John Scott Medal (City of Philadelphia), Charles Mickle Fellowship and honorary fellowships in 1944.
Awarded Nobel Prize in Physiology or Medicine (shared)
Shared the 1945 Nobel Prize with Howard Florey and Ernst Chain for discovery and development of penicillin.
Received Cameron Prize, Moxon Medal and Cutter Lecture invitation
Multiple prestigious awards and honors in 1945 recognizing contributions to therapeutics and medicine.
Gave Nobel Lecture warning about antibiotic resistance (Dec 11, 1945)
In his Nobel lecture Fleming warned about under-dosing and the development of penicillin resistance.
Succeeded Almroth Wright as principal/director of Inoculation Department
Following Wright's retirement, Fleming became director/principal of the department (renamed Wright-Fleming Institute in 1947).
Awarded Albert Gold Medal and other honors (1946)
Received Albert Gold Medal (Royal Society of Arts), Honorary Gold Medal (Royal College of Surgeons) among 1946 honors.
Awarded Medal for Merit (U.S.) and Gold Medal RSM
Received the U.S. Medal for Merit and the Gold Medal of the Royal Society of Medicine in 1947.
Made Emeritus Professor of Bacteriology; Grand Cross (Spain)
Elected Emeritus Professor (University of London) and received the Grand Cross of Alfonso X the Wise (Spain) in 1948.
Death of first wife Sarah (Sareen)
Sarah Marion McElroy (first wife) died in 1949; Fleming continued public duties and research.
Elected Rector of the University of Edinburgh (1951–1954)
Served a three-year term as Rector of the University of Edinburgh, representing student and academic interests.
Married Amalia Koutsouri-Vourekas
Married his second wife, Dr. Amalia Koutsouri-Voureka, a Greek colleague from St. Mary's, on 9 April 1953.
Retired as director of the institute (December 1954)
Retired from directorship in December 1954 but continued to visit the laboratory until his death.
Died of a heart attack in London; ashes interred at St. Paul's Cathedral
Died at home in London on 11 March 1955; ashes buried in St. Paul's Cathedral; legacy cemented worldwide.
Public statuary and memorials begin (example: Barcelona sculpture)
Posthumous commemorations began; a notable statue in Madrid/plaza by matadors was erected by subscription (mid-1950s era).
Source of Fleming's original mould traced
Investigation (1966) established the likely source of the original Penicillium contaminant as La Touche's room below Fleming's lab.
Mount Fleming in New Zealand named
Mount Fleming in New Zealand's Paparoa Range was named in his honour in 1970.
Micrococcus lysodeikticus reclassified as Micrococcus luteus
Species originally named by Fleming (Micrococcus lysodeikticus) was reassigned as Micrococcus luteus in 1972.
Nobel Prize medal acquired by National Museums of Scotland
Fleming's Nobel Prize medal was acquired by National Museums of Scotland (acquisition 1989; displayed after 2011 reopening).
Historical assessments reinforce collaborative role in penicillin development
Historians and scientists clarified the joint roles of Fleming, Florey and Chain in discovery vs development of penicillin.
Named in Time magazine's 100 Most Important People of 20th Century
Time magazine included Fleming among the 100 Most Important People of the 20th century (1999 list).
International Historic Chemical Landmark plaque placed at Fleming Laboratory Museum
The Alexander Fleming Laboratory Museum was designated an International Historic Chemical Landmark on 19 Nov 1999.
Ranked among BBC's 100 Greatest Britons
In a BBC public poll Fleming was chosen in the 100 Greatest Britons list (2002).
Featured on Clydesdale Bank £5 note and STV 3rd Greatest Scot poll
In mid-2009 Fleming's image appeared on a new £5 note; he was also voted third 'greatest Scot' in an STV poll.
Fleming's penicillium strain reclassified as Penicillium rubens (2011 fungal systematics)
Modern mycological analysis clarified Fleming's original strain as P. rubens (publication 2011).
Mural unveiled in Darvel commemorating Fleming (2025)
A gable-end mural portrait of Fleming was unveiled in Darvel in March 2025 by artist Rogue One.
Sir Alexander Fleming pub named near St Mary's (2025)
A Wetherspoons pub branch opened near St Mary's Hospital in Sept 2025 named the Sir Alexander Fleming.
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