IX Международная студенческая научная конференция Студенческий научный форум - 2017

Alexander Fleming is credited with the discovery of penicillin; perhaps the greatest achievement in medicine in the 20^th Century.

Having grown up in Scotland Fleming moved to London where he attended medical school. After World War I, he returned to London where he began his career as a bacteriologist. There he began his search for more effective antimicrobial agents. Having witnessed the death of many wounded soldiers in the war, he noticed that in many cases the use of antiseptic did more harm than good. By 1928, Fleming was investigating the properties of staphylococci.

One day Fleming noticed that one culture was contaminated with a fungus, and that the colonies of staphylococci that had immediately surrounded it had been destroyed, whereas other colonies farther away were normal.

Fleming grew the mold in a pure culture and found that it produced a substance that killed a number of pathogenic bacteria. He identified the mold and after some months of calling it "mold juice" named the substance it released penicillin.

He investigated its positive antibacterial effect on many organisms, and noticed that it affected bacteria such as staphylococci and many other Gram positive pathogents that cause scarlet fever, pneumonia, meningitis and diphtheria, but not typhoid fever, which is caused Gram-negative bacteria, for which he was seeking a cure at the time.

Fleming published his discovery in 1929 in the British Journal of Experimental Pathology, but little attention was paid to his article.

Fleming continued his investigations, but found that cultivating penicillium was quite difficult. After having grown the mold, it was even more difficult to isolate the antibiotic agent.

It was Ernst Chain and Edward Abraham who finally developed the method to isolate and concentrate penicillin.

After the team had developed a method of purifying penicillin to an effective first stable form in 1940, several clinical trials began. Their amazing success inspired the team to develop methods for mass production and distribution in 1945, which was just in time to be of use in World War II.

In fact, several others reported the bacteriostatic effects of Penicillium earlier than Fleming. The use of bread with a blue mold as a means of treating infected wounds was a staple of folk medicine in Europe since the Middle Ages. However, Fleming was the first to discover the properties of the active substance.

The structure of the penicillin molecule inhibits the formation of the peptidoglycan cross-links in the bacterial cell wall, but has no direct effect on cell wall degradation. The relatively small size of the molecule allows it to deeply penetrate the cell wall. In the early days, before resistance developed, penicillin was widely used and effective in treating Staph and Strep infections.

Fleming warned not to use penicillin unless there was a properly diagnosed reason for it to be used, since these are the circumstances under which bacterial resistance to antibiotics develops. In 1942, the first patient was treated for streptococcal septicemia with U.S. made penicillin.

By 1945, over 646 billion units per year were being produced. Penicillin is actively excreted, and about 80% of a penicillin dose is cleared from the body within three to four hours of administration

Since this famous discovery in 1928, many more effective antimicrobials have been developed. For his important life saving discovery, he shared the Nobel Prize in Physiology or Medicine in 1945 with Howard Florey and Ernst Chain. And honestly speaking Alexander Fleming will be remembed forever as the discoverer of the first life-saving remedy penicillin.

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