Penicillin | Research & Encyclopedia Articles

Penicillin

The discovery of penicillin may be one of the greatest accidents in medical history. Penicillin, found in common molds, is a potent antibacterial medication. Its discovery opened the door to a variety of new "miracle drugs" that have saved the lives of millions. In the early twentieth century, scientists had been looking for some kind of antibacterial agent to treat infections that could attack nearly every organ in the body. The only drugs that had been used to treat bacterial infections were quinine, arsenic and sulfa drugs, but these were highly toxic. Scottish bacteriologist Alexander Fleming discovered penicillin by accident in 1928. He was conducting research using several petri dishes of bacteria cultures, and one of the cultures was accidently left uncovered for several days. When Fleming found that the dish had become contaminated with a mold, he was about to discard the culture until he noticed that the mold was dissolving all the bacteria near it. Recognizing the importance of what was happening in the petri dish, Fleming kept a sample of the mold growing in a test tube and examined it with a microscope. He tested it against several types of bacteria and found that something in the mold inhibited the growth of the bacteria. The mold was from the genus Penicillium, so Fleming named the presumed antibacterial component penicillin. However, Fleming was unsuccessful in his attempts to isolate the bactericidal material and eventually abandoned his efforts. In 1935 at Oxford University, pathologist Howard Florey and biochemist Ernst Chain had been researching antibacterial substances when they stumbled across an article by Fleming about his work with penicillin. After obtaining a culture of Fleming's original mold, Florey and Chain were able to extract and purify the penicillin. Florey began testing the substance on animals and found that it was nontoxic as well as an effective antibiotic. Furthermore, it did not harm living cells or interfere with the activity of white blood cells. Chain and Forey began clinical trials in humans in 1941, and their patients by and large recovered completely from bacterial infections. One of the first patients to be treated with penicillin was an English policeman with a bacterial infection that had spread from his mouth to his face, shoulder, and lungs.

For a time his condition improved, but the Oxford facility could not produce enough penicillin to overcome the infection and the policeman eventually died. In subsequent human trials the results were so successful that penicillin was rushed into production so it could be used to treat infection suffered by soldiers during World War II. England could not take on new manufacturing ventures due to its involvement in the war, so Florey traveled to the United States and convinced the government to sponsor research on the mass production of penicillin. Florey's effort bore fruit when American microbiologist Andrew J. Moyer (1899-1959), working with the U.S. Department of Agriculture's Northern Regional Research Laboratory in Peoria, Illinois, soon developed an efficient method of mass-producing penicillin using fermentation and a cornstarch medium. His basic techniques are still used to produce many antibiotics. By 1943, several American pharmaceutical companies were producing the drug for use in treating war injuries. The availability of penicillin during the war prevented thousands of deaths from gas gangrene and other infections. Once the penicillin production had begun, the race was on to discover its molecular structure so that it could be synthetically produced. In the mid-1940s, English researcher Dorothy Crowfoot Hodgkin began a single- crystal study of penicillin using x-ray crystallography. This technique obtains data from repeated x-rays to calculate the positions of the atoms in the basic unit of the crystal. Hodgkin was able to use an early IBM card-punch computer to complete the many mathematical computations required to carry out the experiment. Once Hodgkin determined the chemical structure of penicillin, the door was opened to other scientists to develop methods to synthesize it. Robert Burns Woodward, an organic chemist at Harvard University, completed the first penicillin synthesis in the 1950s. Still considered the most powerful of the antibiotics, penicillin is used to treat diseases such as syphilis, meningitis, and pneumonia. In addition, by eliminating the threat of bacterial infection during medical procedures, it has spurred the development of surgical operations, organ transplants, and open heart surgery, as well as improved the treatment of burns. The discovery and development of penicillin is rightly regarded as one of the greatest achievements in medical history, and many of the scientists who worked on it have been highly honored. Fleming, Florey, and Chain shared the 1945 Nobel Prize in Medicine for the development of penicillin. For their work with penicillin as well as other research, Hodgkin and Woodward also received the Nobel Prize in 1964 and 1965, respectively.