Penicillin Serendipity

Penicillin

There were many fascinating serendipitous scientific discoveries in the 20th century. One of them was the discovery of penicillin by Sir Alexander Fleming. The discovery and development of penicillin totally changed the direction of approaches to treating infectious diseases and saved millions of lives ever since (1). It was the first antibiotic to successfully treat bacterial infections. Therefore, Alexander Fleming, Ernst B. Chain, and Sir Howard Florey together were awarded the Nobel Prize in Medicine in 1945 for the discovery and isolation of penicillin, an antibiotic medicine with great therapeutic potential (2). However, when talking about the discoverers of penicillin, the first person that comes to mind for most is Sir Alexander Fleming. Sir Alexander Fleming still remains a prominent individual in the records of medical history due to his remarkable contributions to science and medicine (1). The discovery, testing, and refinement of penicillin are a complex tale of accident, oversight, conflict, the pressure of war, and individual personalities (3).

Alexander Fleming, Ernst B. Chain, and Howard Florey had extremely similar personality and background. These three prominent individuals were all well educated, which made them competitive in their fields; they had a passion for what they were doing. They were knowledgeable in their field, too. Sir Howard Florey was considered by many to be the most intelligent among the three. After graduating from college, he was awarded a Rhodes Scholarship to Magdalen College, Oxford (4). Most critics agree that among these three scientists, Fleming was the most typical. He was very observant and paid close attention to intuition. He was also curious, as shown when he realized the abnormal phenomenon of the mold. Upon discovering penicillin, Fleming became dedicated and focused. He was confident about his unexpected discovery.

Sir Alexander Fleming was born in Ayrshire, Scotland on August 6th, 1881. He went to St. Mary's Medical School, London University. After a few years of study, Fleming qualified with distinction in 1906 and continued research at St. Mary's Hospital as a bacteriologist (5). In his career, Fleming received numerous honorable titles including Emeritus Professor of Bacteriology at the University of London. He was also elected Fellow of the Royal Society in 1943 and knighted in 1944 (5). Like most famous scientists, Fleming was a passionate typical modern scientist. He became interested in the natural bacterial action early in his medical life (5). Besides that, Fleming worked with humanitarian interests. He was motivated to find an effective antibiotic because he was depressed by the condition of World War II where more soldiers were dying of infection from wounds in hospitals rather than from bullets on the battlefields (3). So, based on his previous research experiment and personal interest, Fleming began researching on bacteria. His chance of discovering penicillin was considered by most to be Eureka intuition. His observation of the mold that grew in his Petri dish triggered an analogy between his previous experience with lysozyme (an enzyme that kills bacteria in human tears) and a lack of an effective antibiotic to treat millions of bacterial infectious patients. As a physician, Fleming combined a clinical practice with a bacteriologic study of cultural variants of species of pathogenic staphylococci (a kind of bacteria) (6).

As it was said earlier, discovering penicillin was a chance discovery. Nobody knew when it was going to happen. This amazing unforeseen discovery took place in the year of 1928. In late July 1928, Fleming left his lab work to take a vacation, so he safely placed his bacterial culture plates on a corner of his lab bench [7.]. When he returned almost a month later, about late August or early September, Fleming observed a very interesting phenomenon: several cultures were contaminated with a mold that produced a yellow bacterial substance. This substance was inhibiting the bacterial growth. Upon closer inspection of a random plate, Fleming found that the staphylococcal bacteria colonies for some considerable distance around the mold growth were obviously undergoing lyses (destruction of bacteria cell). What had originally been a well-grown staphylococcal colony (the bacteria Fleming used) was now a faint shadow of its former selfќ (6). Fleming said that none of his other plates showed this phenomenon. He and his other coworkers assumed that lysozyme, the antibiotic enzyme found in saliva and human tears (4), was produced by the mold because in 1922 while he was suffering from a cold, Fleming examined a culture dish filled with yellow bacteria; a drop of tear was accidentally dropped into the dish (8). At the time Fleming was continuing his study of lysozyme (6). Suddenly, Fleming's intuition was turned on; he and his coworkers quickly recognized the mold's similar action to that of lysozyme. Fleming reported:

After research and close examination, Fleming identified the mold as a species of Penicillium (6). His keen observation and inquisitiveness led him to the correct conclusion. Later, he called the substance produced by the mold penicillin. It could only cure local infections, treating systemic infections at the time was impossible (9). Penicillin targets bacteria by inhibiting its production of enzymes that synthesized the cell wall. Eventually penicillin breaks down the entire bacteria (10). Lysozyme is powerful, said Fleming; a thick milky suspension of bacteria could be completely cleared in a few seconds by a fraction of a drop of human tears (10). Amazed by this fascinating discovery, Fleming began growing mold colonies. Then he tested his extracted antibiotic against many kinds of disease viruses like gonorrhea and scarlet fever. The results turned out to be great (11).

The theme of collaboration was prominent in refining the production of penicillin. Shortly after Fleming's discovery of penicillin, Sir Howard Florey and Chain, who showed interest in biochemistry from an early age (12), were collaborating on investigating the properties of natural occurring lysozyme (4). Chain worked for Florey at Oxford University. Their interest quickly changed to antibiotics. In 1939 Florey and Chain headed a team of British scientists, financed by a grant from the Rockefeller Foundation, whose efforts led to the successful manufacture of the drug (4).

The first human trial of penicillin took place in 1941. Unfortunately, due to the limited supply of penicillin, the patient died. The patient was a London policeman by the name of Albert Alexander (13). Because the patient showed improvement in his health with the treatment of penicillin, its therapeutic efficacy

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