Penicillin

Discovered by : Alexander Fleming

Discovered in year : 1928

Penicillin, also abbreviated as PCN and know as Pen, is a group of antibiotics derived from Penicillium Fungi. It is one of the earliest discovered and widely used antibiotic agents. Antibiotics are natural substances that are released by Bacteria and Fungi into the their environment, as a means of inhibiting other organisms. Penicillin Antibiotics are historically significant because they are the First Drugs that were effective against many previously serious diseases such as Syphilis and Staphylococcus infections. Penicillins are still widely used today, though many types of bacteria are now resistant. All penicillins are Beta-lactam antibiotics and are used in the treatment of bacterial infections caused by susceptible, usually Gram-positive, organisms.

History of the Discovery

Penicillium Fungi was originally noticed by a French medical student, Ernest Duchesne, in 1896.  Scottish scientist and Nobel laureate Alexander Fleming discovered Penicillin in 1928. He showed that, if Penicillium notatum was grown in the appropriate substrate, it would exude a substance with antibiotic properties, which he dubbed Penicillin. Fleming recounted that the date of his breakthrough was on the morning of Friday, September 28, 1928. The Discovery was an accidental one and a fortuitous accident. Alexander Fleming was a well-known name as a result of his earlier work and brilliant research. At that  time, Fleming was investigating the properties of staphylococci. After having spent a vacation with his family, he went to to his laboratory in the basement of St. Mary's Hospital in London (now part of Imperial College). There he noticed a petri dish containing Staphylococcus plate culture he had mistakenly left open, which was contaminated by blue-green mould, which had formed a visible growth. There was a halo of inhibited bacterial growth around the mould. Fleming concluded that the mould was releasing a substance that was repressing the growth and lysing the bacteria. He grew a pure culture and discovered that it was a Penicillium mould, now known to be Penicillium notatum.

Charles Thom, an American specialist working at the U.S. Department of Agriculture, was the acknowledged expert, and Fleming referred the matter to him. Fleming coined the term "penicillin" to describe the filtrate of a broth culture of the Penicillium mould. Even in these early stages, penicillin was found to be most effective against Gram-positive bacteria, and ineffective against Gram-negative organisms and fungi. He expressed initial optimism that penicillin would be a useful disinfectant, being highly potent with minimal toxicity compared to antiseptics of the day, and noted its laboratory value in the isolation of "Bacillus influenzae" (now Haemophilus influenzae). After further experiments, Fleming was convinced that penicillin could not last long enough in the human body to kill pathogenic bacteria, and stopped studying it after 1931. He restarted clinical trials in 1934, and continued to try to get someone to purify it.

Development in the Discovery of Penicillin

In 1939, Australian scientist Howard Florey (later Baron Florey) and a team of researchers (Ernst Boris Chain, A. D. Gardner, Norman Heatley, M. Jennings, J. Orr-Ewing and G. Sanders) at the Sir William Dunn School of Pathology, University of Oxford, began intensive research and were able to demonstrate Penicillin's ability to kill infectious bacteria.

By November 26, 1941, a team of Oxford research scientists led by Australian Howard Florey and including Ernst Boris Chain and Norman Heatley devised a method of mass-producing the penicillin. Andrew J. Moyer, the lab's expert on the nutrition of molds, succeeded, with the assistance of Dr.Norman Heatley who suggested transferring the active ingredient of Penicillin back into water by changing its acidity, in increasing the yields of penicillin 10 times.

In 1943, the required clinical trials were performed and penicillin was shown to be the most effective antibacterial agent to date. Penicillin production was quickly scaled up and available in quantity to treat Allied soldiers wounded on D-Day.

Role of the Discovery of Penicillin in the Improvement of Human Life

• During World War II, Penicillin made a major difference in the number of deaths and amputations caused by infected wounds among Allied forces, saving an estimated 12%–15% of lives.

• The Dicovery led to the search for derivatives of Penicillin that could treat a wider range of infections. Ampicillin was thus made, which offered a broader spectrum of activity than either of the original Penicillins.

• Penicillin was produced in huge quantities during the war and the medicine industry prospered.

• A large number of Penicillium strains are being studied and researched for their further widespread usage in science.