(1881 – 1955)

 Scottish Biologist, Pharmacologist and Botanist

Alexander Fleming was looking for ways to destroy bacteria. In 1928, he was growing bacteria known as staphylococci on glass plates. Alexander Fleming could be a bit slapdash - his lab was rather untidy, and he sometimes left the lids off his plates for a long time, letting the air in. Before going on holiday in 1928 Alexander made two mistakes. He didn't put all of his plates in bleach to sterilise them, and he left the lab windows open. When he came back from a holiday, Alexander noticed that many of his culture plates were mouldy.

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A common mould that might have grown happily on a slice

of bread had landed on Alexander Fleming's plates – a stroke

of luck which has saved millions of lives!

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Fleming noticed something. Although bacteria was growing on his plates, there was a clear ring in the jelly around some of the spots of mould – no bacteria was growing. Something had killed the bacteria that was covering the jelly.

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Fleming worked hard on his mould, Penicillium notatum. He squeezed out some 'mould juice' which he called penicillin. But he couldn't get a lot of penicillin from the mould. It wouldn't keep - even in the fridge - and he couldn't prove it would actually kill bacteria and make people better. By 1934 Fleming gave up on penicillin and went on to do different work!

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In 1938 Howard Florey and Ernst Chain at Oxford University decided to do some work on penicillin. They infected eight mice with bacteria which would normally kill them. Four were given penicillin. The four treated mice stayed healthy – but the other four died. They went on to treat Albert Alexander, a 43 year old policeman dying of a blood infection. Florey and Chain gave him penicillin for five days, and Albert was well on the way to health again when the penicillin ran out. Florey and Chain tried everything – they even collected spare penicillin from Albert's urine - but the infection came back and Albert died. Florey and Chain didn't give up. They collected more penicillin and used it on a 15 year old boy who had an infection after an operation. He was completely cured.

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They showed the value of penicillin in destroying bacteria. The next problem was making enough of it to supply the demand of the soldiers in World War 2. In Britain all the big laboratories and factories were busy with the war effort. But Howard Florey knew many people in America, so the scientists took their mould to the United States where some of the big chemical companies helped them make penicillin on a large scale. Penicillin became available to everyone and the history of infectious diseases changed for ever.

Source: wikipedia/abpischools.org.uk

Images: Believed to be in the Public Domain or used with permission

Professor Alexander Fleming

Alexander Fleming receives the Nobel Prize from

King Gustaf V of Sweden.

Photo: IWM/UK Government/Wikimedia • Believed to be in the Public Domain (Age - Crown Copyright expired)