Alexander Fleming

Alexander Fleming was born on August 6, 1881, at Lochfield farm near Darvel in Ayrshire, Scotland, the seventh of eight children of the farmer Hugh Fleming ^[1]. His father died when Alexander was seven, and the family worked the hill farm while the younger children attended local schools. Fleming later credited the Ayrshire countryside with training his powers of observation, since farm children learned to notice small changes in animals, weather, and land ^[2].

At thirteen he moved to London to live with his elder brother Tom, a physician, and studied at the Regent Street Polytechnic. Money was short, so Fleming spent four years as a clerk in a shipping office, work he found dull. A small inheritance from an uncle in 1901, together with his brother's encouragement, allowed him to sit the entrance examinations for medical school ^[1].

He chose St Mary's Hospital Medical School in Paddington, reportedly because he had once played water polo against its team. Fleming proved an outstanding student, winning nearly every prize and scholarship available, and qualified with distinction in 1906 ^[3].

After qualifying, Fleming joined the Inoculation Department at St Mary's under Sir Almroth Wright, a forceful advocate of vaccine therapy. Fleming intended a career in surgery and passed the Fellowship of the Royal College of Surgeons in 1909, yet he never practised as a surgeon; the laboratory held him for the rest of his working life ^[1]. He became skilled in bacteriological technique and in the new science of chemotherapy, and he was among the first in Britain to administer Salvarsan, Paul Ehrlich's arsenical drug against syphilis ^[3].

The First World War shaped his research agenda. Serving as a captain in the Royal Army Medical Corps, Fleming worked in Wright's wound research laboratory at Boulogne in France. There he demonstrated that the chemical antiseptics then poured into deep wounds often killed the body's own white blood cells faster than they killed bacteria, and that infected wounds could fare worse for the treatment ^[2]. The experience convinced him that the ideal antibacterial agent would help, or at least not harm, the body's natural defences.

Back at St Mary's after the war, that conviction bore early fruit. In 1921 Fleming discovered lysozyme, an enzyme present in tears, saliva, mucus, and egg white that dissolves certain bacteria. The finding began, in a story he enjoyed telling, when material from his own nose dripped onto a culture plate during a cold. Lysozyme proved too weak against the microbes that cause serious disease, but the work established Fleming as a careful investigator of the body's own antibacterial substances ^[4].

The central event of any Alexander Fleming biography took place in September 1928. Returning from a holiday to his cluttered laboratory at St Mary's, Fleming examined a stack of discarded culture plates on which he had been growing Staphylococcus bacteria. On one plate a blue-green mould had grown, and around it the staphylococcal colonies had dissolved into transparent ghosts. Fleming famously remarked to a colleague that the effect was funny, then set about investigating it ^[2].

He grew the mould in broth, identified it as a species of Penicillium (later determined to be Penicillium notatum, now classified as Penicillium rubens), and showed that the filtered broth destroyed a range of dangerous bacteria, including those responsible for pneumonia, diphtheria, meningitis, and gonorrhoea, while leaving others such as the influenza bacillus untouched. He named the active substance penicillin and reported the work in the British Journal of Experimental Pathology in 1929 ^[5].

Fleming saw penicillin's promise but could not realise it. The substance was unstable and maddeningly difficult to purify, and he was a bacteriologist rather than a chemist. Through the 1930s he used crude penicillin mainly as a laboratory tool for isolating bacteria, and the paper attracted limited attention. The decisive development came at Oxford, where Howard Florey, Ernst Chain, Norman Heatley, and their colleagues purified penicillin, proved its astonishing power in mice in 1940 and in patients in 1941, and worked with American laboratories and companies to achieve mass production in time to treat Allied casualties in the Second World War ^[6].

Once penicillin's wartime successes became public, honours arrived in quantity, and most of the popular acclaim fixed on Fleming. He was elected a Fellow of the Royal Society in 1943 and knighted in 1944. In 1945 he shared the Nobel Prize in Physiology or Medicine with Florey and Chain for the discovery of penicillin and its curative effect in various infectious diseases ^[7].

Fleming handled fame with dry humour and repeatedly insisted that nature, not he, had made penicillin; he had merely noticed it. He also used his platform to issue a warning that reads today as prophetic. In his Nobel lecture he cautioned that careless underdosing could breed penicillin-resistant microbes, describing how easy it was to make bacteria resistant in the laboratory by exposing them to concentrations too weak to kill them ^[7]. Antibiotic resistance, now a major global health concern, unfolded much as he predicted.

Among Alexander Fleming's achievements beyond the Nobel Prize were honorary degrees from dozens of universities, the presidency of the newly founded Society for General Microbiology, and rectorship of Edinburgh University, an office to which the students elected him in 1951 ^[1].

In 1915 Fleming married Sarah Marion McElroy, known as Sareen, an Irish nurse who ran a private nursing home in London. Their only child, Robert, born in 1924, became a physician. The family divided time between London and The Dhoon, a country house at Barton Mills in Suffolk, where Fleming gardened, fished, and played endless games with visiting friends ^[1].

Colleagues described a short, quiet Scot with a blunt manner and a taste for games of every kind: golf, snooker, croquet, cards, and quizzes, often played by his own invented rules. He was a longstanding member of the Chelsea Arts Club and produced small paintings, sometimes using pigmented bacteria grown on agar as his medium, a hobby that fitted his lifelong habit of playing with microbes ^[2].

Sareen died in 1949, a loss that left Fleming visibly diminished. In 1953 he married Dr Amalia Koutsouri-Voureka, a Greek bacteriologist who had come to work in his laboratory at St Mary's. She later became a noted figure in Greek public life in her own right ^[3].

Fleming became Professor of Bacteriology at the University of London in 1928 and succeeded Almroth Wright as head of the Inoculation Department at St Mary's, renamed the Wright-Fleming Institute, in 1946. He remained active in research and administration into his seventies, retiring as principal of the institute in January 1955 ^[3].

His final decade was filled with travel. Universities, academies, and governments across Europe and the Americas invited him to lecture and collect honours, and he accepted with an appetite that surprised those who knew his reticence. Wherever he went, crowds treated the discoverer of penicillin as a public benefactor rather than a laboratory scientist ^[2].

On March 11, 1955, Fleming died of a heart attack at his home in London at the age of 73. He was cremated, and his ashes were interred in the crypt of St Paul's Cathedral, an honour reserved for a small number of national figures ^[1].

Penicillin opened the antibiotic era, and the numbers explain the reverence attached to Fleming's name. Infections that had routinely killed, including bacterial pneumonia, wound sepsis, and syphilis, became treatable within a few years of the drug's introduction, and penicillin remains in worldwide use nearly a century after the mouldy plate of 1928 ^[6]. In 1999 Time magazine named Fleming among the 100 most important people of the twentieth century ^[8].

The discovery also became a standard case study in the role of chance in science. Fleming himself observed that the prepared mind mattered as much as the accident: thousands of researchers had seen contaminated plates and thrown them away, while his experience with lysozyme primed him to investigate. Historians balance this account by restoring credit to the Oxford group, whose chemistry and clinical trials turned an interesting observation into a medicine ^[6].

His laboratory at St Mary's is preserved as the Alexander Fleming Laboratory Museum in Paddington, and institutions from a research centre in Greece founded by his widow to schools and streets across many countries carry his name. Among the more sobering Alexander Fleming facts is that his 1945 warning about resistance now frames global antibiotic policy, making him both the founder of the antibiotic age and its first, clearest critic ^[7].