The invaluable and great antibiotic Penicillin was discovered by Sir Alexander Fleming. It was the best-known important accidental discovery occurred, when Sir Alexander Fleming discovered an antibiotic that killed bacteria.   Sir Fleming  was born at Lochfield near Darvel in Ayrshire, Scotland on August 6th, 1881 in a farmer family. He was the seventh among the eight children of his parents. When he was 7, his father Hugh Fleming died. So his mother Grace  Fleming, a mentally strong woman took all pains to grow all her children.  

          Alexander Fleming attended Loodun Moor School, Darvel School, and Kilmarnock Academy before moving to London where he studied the Polytechnic. As his family was not financial sound, so he had to interrupt his further studies. Hence, at the age of 16, he joined in a shipping company and   worked there for  four years . But in 1901, his fortune shined and he  joined St. Mary’s Medical School, London University with the help of an uncle. He qualified with distinction and Gold Medal in 1906 and began research at St. Mary’s until 1914 under Sir Olmroth Wright, a renowned microbio- logist and researcher . He served through out World War I as a captain in the Army Medical Corps and  returned to St.Mary’s in 1918.

   In his search of a suitable antiseptic, Fleming tried to procure cultures of a wide variety of bacteria.  He collected many unusual specimens and maintained these in his laboratory in Petrib dishes containing artificial media. During this time he suffered from extreme cold and felt trouble in breathing. One of his plates colle- cted a sample from his nasal mucus. The plate contained many colonies of a golden-yellow bacterium. Fleming later named this bacterium  Micrococcus lysodekticus . He made an interesting observation. He found that the bacterial colonies immediately surrounding the mucus itself appeared destroyed.  Did it mean that the mucus contained an antibacterial agent? That was the question  which came to his mind. He later found that the mucus had a substance capable of killing the bacteria. He called this substance lysozyme. He found that lysozyme did not harm the host’s living tissues or the host’s own immune system. Lysozyme was harmful only to the invading bacteria. It acts as a first line of defense, preventing bacteria from colonizing the body. The discovery of lysozyme demonstrated the possibility of the existence of a substance harmless to the cells of the body but lethal to invading bacteria. Fleming demonstrated the presence of lysozyme to tears, saliva, blood serum, pus and muscle cells. He even discovered it in egg white, cow milk and in mother’s milk. In 1922, Fleming published a research article titled “A Remarkable Bacteriolytic Element found in Tissues and secretions”. It was about the discovery and isolation of a new natural enzyme called  lysozyme. He declared  lysozyme as an antibiotic  killing bacteria and it is present in almost all living organisms.

        In 1928 Fleming was appointed as Professor of Bacteriology at St. Mary’s.  In the same year he made his most important discovery , that is PENICILLIN. Fleming was very lazy about cleaning up his old culture dishes. On his working table in the laboratory often there used to be dozens of stacked plates. But this habit, resulted one of the most important discoveries in science. It was an accidental  discovery. One plate containing staphylococcus, spherical shaped bacteria that grow in culture, like grapes and which may cause infection leading to pimples, boils, or a skin disease called imperigo had contaminated. Fleming found that bacteria were everywhere in the place except in the near vicinity of the mould which was later identified as Penicillium notatum. Fleming realized that the mould must have been  screening an antibacterial substance. He named it as Penicillin.

        To prove that his observation was correct beyond any doubt,  Fleming  undertook a systematic observation.  He determined the level of concentration required to destroy the bacteria. For this he performed a series of dilutions. He  tested the bacterial effect of the mould on different bacteria and observed that it killed some bacteria. He experimented on rats and rabbits and confirmed that penicillin was harmless to living bodies. He also examined and discovered that it was not harmful to human cells. Fleming found that penicillin was effective against bacteria responsible for pneumonia, syphilis, gonorrhea, diphtheria, and fever. However he found that penicillin was not effective against bacteria causing influenza, whopping cough, typhoid, dysentery, and other intestinal diseases. Further Fleming observed that penicillin could be used as an injectable antibacterial and that it could also be used in the establishment of pure cultures of other bacteria.

        In 1937, Dr. Ernst Boris Chain and Prof. Howard Walter Florey  who had just finished their research on lysozyme, came across Fleming’s report on penicillin. They produced penicillin from this mould or fungus chemically and  successfully experimented it on animals. In 1941 they gave penicillin  to a septicemia patient  who had no chance of survival.  His condition visibly improved. But he died as there was no sufficient penicillin. So, the doctors became sure that penicillin saved the patient’s life for some days and he could be saved if there were sufficient of it. So in 1943, the production of penicillin started on a large scale.

        The widespread use of penicillin  from 1940s onward made a vast change in the treatment of many infections.  The discovery of penicillin was ranked by many as the most important discovery in the twentieth century. It is estimated that penicillin has saved  at least 200 million lives and in this respect no other discovery can match it.

        Sir  Fleming  was elected as  Fellow of the Royal Society in 1943 and knighted in 1944. He was awarded the Nobel  Prize in 1945 for Physiology or Medicine. He was honoured with  many prestigious awards for his great  discovery. He was also awarded doctorate and other degrees by almost thirty European and American Universities. The Americans presented him one lakh Dollars for saving million’s life. But he  donated the entire money to St. Mary’s for research. He even rejected the idea of patenting penicillin in the interest of humanity that would have earned him millions. He served as President of the Society for General Microbiology and Honorary Member of almost all the medical and scientific societies of the world. 

   Sir  Fleming had married Sarah Marion in 1915. As she died in 1949, he again married in 1953 to Dr. Amalia Koutsouri-Voureka, a Greek colleague at St. Mary’s. The great scientist left this world on March 11, in  1955. Even today he is rememb- ered as the ‘Father of Penicillin’.