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MOST IMPORTANT SCIENTIFIC DISCOVERIES
Penicillin. History and essence of scientific discovery
Directory / The most important scientific discoveries The discovery of penicillin belongs to Alexander Fleming. When he died, he was buried in St. Paul's Cathedral in London - next to the most revered Britons. In Greece, where the scientist visited, national mourning was declared on the day of his death. And in Spanish Barcelona, all the flower girls of the city poured out bunches of flowers from their baskets to a memorial plaque with his name. Scottish bacteriologist Alexander Fleming (1881–1955) was born in Ayrshire to Hugh Fleming, a farmer, and his second wife, Grace (Morton) Fleming. Alexander attended a small rural school located nearby, and later Kilmarnock Academy, early learned to carefully observe nature. At the age of 13, he followed his older brothers to London, where he worked as a clerk, attended classes at the Polytechnic Institute in Regent Street, and in 1900 joined the London Scottish Regiment. On the advice of his older brother, he applied for a national competition for admission to medical school. In the exams, Fleming received the highest scores and became a fellow of the medical school at St. Mary. Alexander studied surgery and, having passed the exams, in 1906 became a member of the Royal College of Surgeons. Staying to work in the pathology laboratory of Professor Almroth Wright at St. Mary, he received his Master's and Bachelor of Science degrees from the University of London in 1908. At that time, doctors and bacteriologists believed that further progress would be associated with attempts to change, strengthen or supplement the properties of the immune system. The discovery in 1910 of salvarsan by Paul Ehrlich only confirmed these assumptions. Ehrlich was busy looking for what he called a "magic bullet", meaning by this a means that would destroy bacteria that had entered the body without harming the tissues of the patient's body and even interacting with them. Wright's lab was one of the first to receive salvarsan samples for testing. In 1908, Fleming began experimenting with the drug, also using it in private medical practice to treat syphilis. Well aware of all the problems associated with salvarsan, he nevertheless believed in the possibilities of chemotherapy. For several years, however, the results of the studies were such that they could hardly confirm his assumptions. After Britain's entry into the First World War, Fleming served as a captain in the Royal Army Medical Corps, participating in the war effort in France. While working in the Wound Research Laboratory, Fleming worked with Wright to determine if antiseptics were of any benefit in treating infected lesions. Fleming proved that antiseptics such as carbolic acid, then widely used to treat open wounds, killed white blood cells, which created a protective barrier in the body, which helped bacteria survive in tissues. In 1922, after unsuccessful attempts to isolate the causative agent of common colds, Fleming accidentally discovered lysozyme, an enzyme that kills some bacteria and does not harm healthy tissues. Unfortunately, the prospects for medical use of lysozyme were rather limited, since it was very effective against non-causative bacteria and completely ineffective against disease-causing organisms. This discovery, however, prompted Fleming to look for other antibacterial drugs that would be harmless to the human body. Another happy accident, Fleming's discovery of penicillin in 1928, was the result of a combination of circumstances so incredible that it is almost impossible to believe in them. Unlike his meticulous colleagues who cleaned bacterial culture dishes after they were done, Fleming didn't throw away the cultures for two or three weeks in a row until his laboratory bench was cluttered with 2 or 3 dishes. Then he set to work cleaning, looking through the cultures one by one, so as not to miss anything interesting. In one of the cups, he found mold, which, to his surprise, inhibited the inoculated culture of bacteria. After separating the mold, he found that "the broth on which the mold has grown ... has acquired a distinct ability to inhibit the growth of microorganisms, as well as bactericidal and bacteriological properties." Fleming's slovenliness and his observation were just two of the many accidents that contributed to the discovery. The mold, which turned out to be infected culture, belonged to a very rare species. It probably came from a laboratory downstairs, where mold samples taken from the homes of asthmatic patients were grown in order to make desensitizing extracts from them. Fleming left the cup that later became famous on the laboratory table and went to rest. The cold snap in London created favorable conditions for the growth of mold, and the subsequent warming for bacteria. As it turned out later, the famous discovery was due to the coincidence of these circumstances. Fleming's initial research provided a number of important insights into penicillin. He wrote that it is "an effective antibacterial substance ... having a pronounced effect on pyogenic cocci ... and diphtheria bacilli. Penicillin, even in large doses, is not toxic to animals ... It can be assumed that it will be an effective antiseptic for external treatment of areas affected by microbes sensitive to penicillin, or when it is administered orally. Knowing this, Fleming, strangely enough, did not take the obvious next step, which twelve years later was taken by Howard W. Florey, to find out whether mice would be saved from a lethal infection if they were treated with injections of penicillin broth. Fleming only prescribed it to a few patients for external use. However, the results were inconsistent and discouraging. The solution was not only difficult to purify if large quantities were involved, but also proved to be unstable. Like the Pasteur Institute in Paris, the vaccination department at St. Maria, where Fleming worked, existed by selling vaccines. Fleming discovered that during the preparation of vaccines, penicillin helps to protect cultures from staphylococcus aureus. This was a small technical achievement, and Fleming took full advantage of it, giving weekly orders to make large batches of broth. He shared culture samples of penicillin with some colleagues in other laboratories, but he never mentioned penicillin in any of the 27 articles or lectures he published in the 1930s and 1940s, even if they were about substances that cause the death of bacteria. Penicillin might have been forever forgotten were it not for Fleming's earlier discovery of lysozyme. It was this discovery that led Flory and Ernst B. Chain to study the therapeutic properties of penicillin, as a result of which the drug was isolated and subjected to clinical trials. All honors and glory, however, went to Fleming. The accidental discovery of penicillin in a bacterial culture dish gave the press a sensational story that could capture the imagination of any person. The 1945 Nobel Prize in Physiology or Medicine was awarded jointly to Fleming, Cheyne and Flory "for the discovery of penicillin and its curative effects in various infectious diseases". Goran Liliestrand from the Karolinska Institute said in his welcoming speech: "The history of penicillin is well known throughout the world. It is an excellent example of the joint application of various scientific methods for the sake of a great common goal and once again shows us the enduring value of basic research." In the Nobel lecture, Fleming noted that "the phenomenal success of penicillin has led to intensive study of the antibacterial properties of molds and other lower representatives of the plant world." "Only a few of them, he said, have such properties. There is, however, streptomycin, discovered by (Zelman A.) Waksman ... which will certainly find application in practical medicine; there will be other substances that have yet to be studied." Today, the treatment of many diseases without antibiotics is simply impossible. Author: Samin D.K.
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