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Referência: http://www.time.com/time/time100/scientist/profile/fleming.html
Alexander Fleming
A spore that drifted into his lab and took root on a culture dish started a chain of events that altered forever the The improbable chain of events that led Alexander bacteriologist." Although he went on to perform Fleming to discover penicillin in 1928 is the stuff of additional experiments, he never conducted the one which scientific myths are made. Fleming, a young that would have been key: injecting penicillin into Scottish research scientist with a profitable side infected mice. Fleming's initial work was reported in practice treating the syphilis infections of prominent 1929 in the British Journal of Experimental Pathology, London artists, was pursuing his pet theory — that his but it would remain in relative obscurity for a decade.
own nasal mucus had antibacterial effects — when he By 1932, Fleming had abandoned his work on left a culture plate smeared with Staphylococcus penicillin. He would have no further role in the bacteria on his lab bench while he went on a two-week subsequent development of this or any other antibiotic, aside from happily providing other researchers with When he returned, he noticed a clear halo surrounding samples of his mold. It is said that he lacked both the the yellow-green growth of a mold that had chemical expertise to purify penicillin and the accidentally contaminated the plate. Unknown to him, conviction that drugs could cure serious infections.
a spore of a rare variant called Penicillium notatum had However, he did safeguard his unusual strain of drifted in from a mycology lab one floor below. Luck Penicillium notatum for posterity. The baton of would have it that Fleming had decided not to store his antibiotic development was passed to others.
culture in a warm incubator, and that London was then In 1939 a specimen of Fleming's mold made its way hit by a cold spell, giving the mold a chance to grow.
into the hands of a team of scientists at Oxford Later, as the temperature rose, the Staphylococcus University led by Howard Florey, an Australian-born bacteria grew like a lawn, covering the entire plate — physiologist. This team had technical talent, especially except for the area surrounding the moldy contaminant.
in a chemist named Ernst Boris Chain, who had fled Seeing that halo was Fleming's "Eureka" moment, an Nazi Germany. Armed with funding from the instant of great personal insight and deductive Rockefeller Foundation, these scientists made it their reasoning. He correctly deduced that the mold must objective to identify and isolate substances from molds have released a substance that inhibited the growth of that could kill bacteria. The mission was inspired by the earlier work of Gerhard Domagk, who in 1935 It was a discovery that would change the course of showed that the injection of a simple compound, history. The active ingredient in that mold, which Prontosil, cured systemic streptococcal infections. This Fleming named penicillin, turned out to be an breakthrough demonstrated that invading bacteria infection-fighting agent of enormous potency. When it could be killed with a drug and led to a fevered search was finally recognized for what it was — the most in the late 1930s for similar compounds. Fleming's efficacious life-saving drug in the world — penicillin Penicillium notatum became the convenient starting would alter forever the treatment of bacterial infections. By the middle of the century, Fleming's In a scientific tour de force, Florey, Chain and their discovery had spawned a huge pharmaceutical colleagues rapidly purified penicillin in sufficient industry, churning out synthetic penicillins that would quantity to perform the experiment that Fleming could conquer some of mankind's most ancient scourges, not: successfully treating mice that had been given including syphilis, gangrene and tuberculosis.
lethal doses of bacteria. Within a year, their results Fleming was born to a Scottish sheep-farming family were published in a seminal paper in the Lancet. As the in 1881. He excelled in school and entered St. Mary's world took notice, they swiftly demonstrated that Hospital in London to study medicine. He was a short injections of penicillin caused miraculous recoveries in man, usually clad in a bow tie, who even in his patients with a variety of infections.
celebrity never mastered the conventions of polite The Oxford team did not stop there. Rushing to meet society. Fleming probably would have remained a the needs of World War II, they helped the government quiet bacteriologist had serendipity not come calling set up a network of "minifactories" for penicillin production. Florey also played a crucial role in In fact, Fleming was not even the first to describe the galvanizing the large-scale production of penicillin by antibacterial properties of Penicillium. John Tyndall U.S. pharmaceutical companies in the early 1940s. By had done so in 1875 and, likewise, D.A. Gratia in D-day there was enough penicillin on hand to treat 1925. However, unlike his predecessors, Fleming every soldier who needed it. By the end of World War recognized the importance of his findings. He would later say, "My only merit is that I did not neglect the Pneumonia, syphilis, gonorrhea, diphtheria, scarlet observation and that I pursued the subject as a fever and many wound and childbirth infections that once killed indiscriminately suddenly becametreatable. As deaths caused by bacterial infectionsplummeted, a grateful world needed a hero. Flemingalone became such an object of public adulation,probably for two reasons. First, Florey shunned thepress, while Fleming seemed to revel in the publicity.
Second, and perhaps more important, it was easier forthe admiring public to comprehend the deductiveinsight of a single individual than the technical feats ofa team of scientists.
Awards and accolades came to Fleming in rapidsuccession, including a knighthood (with Florey) in1944 and the Nobel Prize for Medicine (with Floreyand Chain) in 1945. By this time, even Fleming wasaware that penicillin had an Achilles' heel. He wrote in1946 that "the administration of too small doses .
leads to the production of resistant strains of bacteria."It's a problem that plagues us to this day.
When he died of a heart attack in 1955, he wasmourned by the world and buried as a national hero inthe crypt of St. Paul's Cathedral in London. AlthoughFleming's scientific work in and of itself may not havereached greatness, his singular contribution changedthe practice of medicine. He deserves our utmostrecognition. At the same time, we must bear in mindthat the "Fleming Myth," as he called it, embodies theaccomplishments of many giants of antibioticdevelopment. Fleming is but a chosen representativefor the likes of Florey, Chain, Domagk, SelmanWaksman and Rene Dubos, many of whom remain,sadly, virtual unknowns. Their achievements havemade the world a better, healthier place. Incommemorating Fleming, we commemorate them all.
Dr. David Ho is director of the Aaron Diamond AIDSResearch Center in New York City and TIME's 1996Man of the Year.

Source: http://www.l2f.inesc-id.pt/~ajs/Academia_Militar/PMI/Temas/A_Fleming.pdf