Alexander Fleming (doctor)

Alexander Fleming was born on 6 August 1881 at Lochfield farm near Darvel in Ayrshire, Scotland, the seventh of eight children of Hugh Fleming, a farmer, and Grace Stirling Morton.¹ He attended Loudoun Moor School and Darvel School before moving to London at age 13 to live with an elder brother. He worked as a shipping clerk for four years, then, inspired by a sickly brother, he enrolled at St Mary's Hospital Medical School in Paddington in 1901.² He qualified with distinction in 1906 and joined the research department of Almroth Wright, a pioneer in vaccine therapy and immunology.

In September 1928, Fleming returned from holiday to his cluttered laboratory at St Mary's and noticed that a petri dish containing Staphylococcus cultures had been contaminated by a mould, and that the bacteria surrounding the mould had been destroyed.³ He identified the mould as Penicillium notatum and named the active substance penicillin. He published his findings in 1929 in the British Journal of Experimental Pathology, but he was unable to purify or stabilize the compound, and the discovery languished for a decade.⁴

In 1940, Howard Florey and Ernst Chain at Oxford University succeeded in purifying penicillin and demonstrated its therapeutic efficacy in mice and then in humans.⁵ Fleming, Florey, and Chain shared the 1945 Nobel Prize in Physiology or Medicine. Fleming was knighted in 1944 and became a Fellow of the Royal Society in 1943. He died of a heart attack on 11 March 1955 and was buried in St Paul's Cathedral, London.

Beyond penicillin, Fleming made several notable contributions. During World War I, he demonstrated that antiseptics were ineffective in deep wounds and that they actually killed leukocytes, advocating for the use of saline solution and debridement.⁶ He discovered lysozyme in 1922, an antibacterial enzyme found in tears and mucus, which was the first natural antibiotic he identified. He also pioneered the use of vaccines in treating bacterial infections and was an early advocate for the use of penicillin as a topical agent. Fleming was known for his unkempt laboratory and his casual approach, which some attribute to his serendipitous discovery. He also served as a captain in the Royal Army Medical Corps during World War I and later as a civilian consultant.

Penicillin's introduction into clinical practice in the 1940s transformed the treatment of bacterial infections, saving countless lives and spurring the development of other antibiotics. Fleming's discovery is often cited as a landmark in the history of medicine, and his name is synonymous with the antibiotic era. The Alexander Fleming Laboratory Museum at St Mary's Hospital preserves his original laboratory, and his work continues to inspire research in antimicrobial resistance.

Penicillin

A group of antibiotics derived from Penicillium moulds, used to treat bacterial infections.

Lysozyme

An enzyme found in tears, saliva, and mucus that breaks down bacterial cell walls.

Antiseptic

A substance that inhibits the growth of microorganisms on living tissue.

Debridement

The surgical removal of dead, damaged, or infected tissue to promote healing.