What does your doctor prescribe when you are down with fever, or if you cut yourself badly? Have you ever been told to take antibiotics? Various antibiotics are used to treat a number of diseases  and to prevent the onset of infections when our skin-the first barrier to disease-is somehow broken through a simple cut or a serious wound. Today, we take antibiotics for granted, but they are a relatively recent discovery.

Pencillin was the first practical antibiotic, which was not available until the early 1940s. The discovery of penicillin gave doctors new ammunition to fight diseases. Before its discovery, minor wounds that became infected or trivial injuries could lead to death.

There is a famous story about how penicillin was discovered by Alexander Fleming at St Mary's Hospital, London. Fleming had a bit of a reputation as an absent-minded scientist. Cultures that he worked on were constantly forgotten in his laboratory, which was normally in a state of great disorder.

Returning from a month-long vacation in 1928, Fleming noticed that many of his culture plates were contaminated with a fungus which was a species of Penicillium. Although the species of the mould was unknown to Fleming at the time, he observed that it was inhibiting the growth of bacteria.

Fleming realised that this could be something important and continued to study the anti-bacterial properties of the mould. Finally, he isolated an extract from the mould and named it penicillin. It was certainly a historic moment, but the story does not begin or end there.

To understand the importance of Fleming's discovery, we have to go back to the late nineteenth century when Louis Pasteur discovered that many diseases were caused by micro-organisms. This resulted in a determined effort among scientists, who was searched for ways to destroy these micro-organisms without harming the person who was infected. While the scientists were carrying out their experiments in this field, they often found that their bacterial cultures in the laboratory had been contaminated by other micro-organisms, especially fungi.

Thus, before Fleming, the same opportunity came to others who had observed a chance contamination in bacterial culture, but their only response was to think that it had ruined their experiment and they discarded the cultures and thought nothing more of it.

Fleming, on the other hand, followed up on his observation, and that was where the difference lay. However, even after his discovery was published, not much attention was paid to it. Fleming did not become famous overnight, and there were, in fact, many people who doubted that the discovery would be of any value. Initially, Fleming was unable to prove that it had any therapeutic value and he began to doubt his own research. But as further tests continued, he began to realise that penicillin was extremely powerful as an anti-bacterial compound. His extracts could be diluted 1,000 times and still be effective in killing bacteria. Further tests were done to be certain that penicillin was not toxic. These results were, again, very interesting, but how could they be translated to practical use?

It was not Fleming, but one of his former students, Dr Cecil Paine, who was the first to demonstrate the value of penicillin in medicine. Paine's first effort at using penicillin was in treating patients with sycosis barbae. This proved to be a failure, but did not dampen his enthusiasm to continue working with penicillin. His next attempt at using penicillin was made while treating the lacerated eye of a miner. There was a stone embedded in the infected eye, and normally the eye would have to be removed. However, after Paine applied penicillin extract, the miner's eye and eyesight were saved. It was a dramatic success.

But Paine did not make his success public. By the mid-1930s, several new discoveries in medicine took place and made Fleming wonder whether he should continue his work with penicillin. A class of synthetic chemical drugs-called sulpha drugs-was developed in Germany and was effective in treating some bacterial infections. Another synthetic drug was effective against pneumonia.

Fleming now began working with these new drugs. Though he had stopped working with penicillin by 1934, he did not lose his interest.

Other scientists became interested in penicillin around this time. Dr Howard Walter Florey was the foremost among them. Florey, however, did not work alone-he had a team that included Dr Ernst Boris Chain, another scientist who would become famous in the process of developing penicillin. Florey also had the advantage of working with a well-staffed and equipped lab, which Fleming did not have.

The first real test for the Florey lab came when Albert Alexander, a 48-year-old London policeman, cut himself while shaving. The cut was ignored for several days, and became septic. Alexander was taken to hospital and given sulpha drugs, but without success. When the doctors believed that he was going to die within a few hours, Florey and Chain requested that they be given permission to treat this patient. This would be their first human subject to whom penicillin was applied. The two scientists administered the injections themselves. After five days, Alexander was recovering. But then, there was no more penicillin available, the policeman had a relapse and died five days later.

However, the experiment did demonstrate that penicillin was not harmful to humans. In fact, it was effective. The scientists were more successful with their next patients. Around the same time, Fleming was also treating a patient with penicillin. But the shortage of penicillin kept hindering the treatment. By 194, it was acknowledged that penicillin was indeed a worthwhile drug and could save thousands of lives.

With the number of injuries increasing during the Second World War and the related diseases, the demand for penicillin was greater than before. Scientists started researching ways and means to boost the production of penicillin to match the demand.

During this period, when mass production of penicillin was being perfected, Fleming had little to do with it. He was almost forgotten as the discoverer of penicillin by the time it was being mass produced. However, he was rescued from oblivion in 1943, when he was knighted along with Howard Florey. Two years later, Fleming, Flory and Chain were awarded the Nobel Prize in Physiology and Medicine for their discovery and development of penicillin.

One illness after another, that was tested, was cured by penicillin, which was by this time called a 'wonder-drug.' Before its discovery, the major causes of death in hospitals, during the war, were pneumonia, blood poisoning, scarlet fever, diphtheria, tonsillitis, rheumatic fever and many other diseases. All of these were successfully treated with penicillin.

The discovery of penicillin brought about one of the biggest searches in medical history. It was reasoned that if there was one antibiotic in nature, there must be many more; and many more would indeed be found later. However, few would be fungal in origin-most of them would be derived from bacteria. Yet, without the discovery of penicillin, all these other antibiotics would possibly never have been discovered.

Penicillium : A type of fungus or mould

sycosis barbae : Also known as barber's itch, this is an infection that occurs in the bearded area of the face.

antibiotics : drugs that are used to kill bacteria and cure diseases

ammunition : a means of attacking

culture : a group of cells especially grown for scientific study

contaminated : made dirty or impure; has dangerous or harmful substances in it

inhibiting : preventing (something) from happening

micro-organisms : living things that are too small to be seen without a microscope

therapeutic : intended to treat or cure; healing

lacerated : (here) wounded; skin or flesh that is torn or cut with a sharp object

synthetic : artificial; not obtained from nature

septic : infected with bacteria