Antibiotics & Penicillin (AQA GCSE History)

The significance of penicillin for medicine in Britain - Summary

Penicillin was one of the most significant discoveries in medicine and had a huge impact on Britain during World War Two and beyond. Discovered by Alexander Fleming in 1928 and developed further by Howard Florey and Ernst Chain in the 1940s, penicillin became the first effective antibiotic. During World War Two, it was mass-produced to treat infected wounds and save the lives of soldiers who might have died from blood poisoning or gangrene. Its success in fighting bacterial infections revolutionised medicine, allowing doctors to cure illnesses that had once been fatal, such as pneumonia and syphilis.

However, the success of penicillin came with challenges. Over time, some bacteria have developed resistance to antibiotics, including penicillin, making these infections harder to treat. This resistance is caused by the overuse and misuse of antibiotics, which has led to the evolution of "superbugs". While penicillin remains a vital medicine and is still used for many infections today, scientists are constantly working to create new antibiotics to stay ahead of resistant bacteria.

The influence of Ehrlich & Domagk

• Antibiotics could not have happened without the development of 'magic bullets' such as:

  • Salvarsan 606

  • Prontosil

Paul Ehrlich and Salvarsan 606

• Paul Ehrlich began the hunt for a medical cure for syphilis

• In 1909, Japanese scientist Hata retested the arsenic compounds Ehrlich had experimented with

  • He discovered that compound 606 cured syphilis

  • He named the chemical cure Salvarsan 606

    • This became the world's first 'magic bullet'

Domagk and Prontosil

• Scientist Gerhard Domagk discovered in 1932 that a red dye called Prontosil killed infections in mice

• Domagk did not know if this would cure bacterial infections in humans

  • He tested Prontosil on his daughter, who was dying from blood poisoning. Prontosil saved her life

  • Queen Charlotte's Maternity Hospital in London used Prontosil to treat puerperal fever

    • Death rates in puerperal fever dropped from 20% to 4.7%

Who was Alexander Fleming?

• Fleming was a Scottish doctor working at St. Mary's Hospital in London

• Alexander Fleming:

  • pioneered the use of Salvarsan 606 to treat syphilis

  • worked in battlefield hospitals during World War One and saw men who died of syphilis infection

• During the 1920s, Fleming began to study a type of bacteria called Staphylococcus

  • Staphylococcus was resistant to the 'magic bullets' available at the time

    • It is a deadly bacteria which can cause blood poisoning and toxic shock syndrome

The discovery of penicillin

• In 1928, Fleming accidentally discovered penicillin

  • Fleming went on a holiday, forgetting to clean a petri dish which contained the Staphylococcus bacteria

  • On his return, Fleming noticed mould in the petri dish. This mould prevented Staphylococcus from growing

    • Medieval people observed that mouldy bread had healing qualities. Fleming's examination demonstrated that mould could fight bacteria

    • Fleming published his findings in 1929

• Fleming didn't realise the potential impact of his discovery on humans

  • Scientists at the time were more interested in looking for chemical cures for disease

  • Germ Theory states that microbes are dangerous and they do not possess the ability to heal

  • Fleming's first experiment showed penicillin was ineffective when combined with blood

Who were Florey & Chain?

• Florey and Chain worked together at Oxford Medical School

  • Howard Florey was an Australian pathologist

  • Ernst Chain was a German biochemist who had escaped from Nazi Germany

• In 1939, during their study of antibiotics, Florey and Chain discovered Fleming's work on penicillin

  • Both scientists believed that penicillin could be an important discovery

  • Chain was able to grow mould and extract enough penicillin to run tests

Florey & Chain's development of penicillin

Animal trials

• In 1940, Florey and Chain successfully tested penicillin on mice

  • Eight mice were infected with staphylococcus  

  • Four mice received penicillin while four mice did not receive treatment

  • The four mice without treatment died

  • Penicillin saved the other four mice

Government support

• Florey and Chain's research caught the attention of the British government

• At this time, Britain was fighting Germany in the Second World War

  • In the First World War, many soldiers died from their wounds becoming infected

  • The British government knew that the effective treatment of wounds could be the difference between winning or losing the Second World War

  • Florey and Chain received £25 from the government to fund their research into penicillin

    • Today, this would be approximately £1100

Human trials

• By 1941, penicillin was ready for human trial

• Albert Alexander was a local policeman

  • He was in hospital suffering from septicaemia, a deadly blood poisoning

  • Alexander had developed the infection after scratching himself on a rose thorn

• Albert took penicillin and showed signs of recovery

• Florey and Chain ran out of their supply of penicillin and Albert died

  • Despite Albert's death, the trial proved that penicillin worked on humans

Mass production

• In July 1941, Florey flew to America to persuade pharmaceutical companies to mass-produce penicillin

  • Florey had approached British companies but, due to the Second World War, they did not have the time or resources to grow penicillin

• The mass production of penicillin required growing the mould in beer vats

• It was a slow process

  • After a year, the American companies had only produced enough penicillin for ten doses

• America recognised the potential of penicillin

  • The US government gave money to 21 pharmaceutical companies to produce the drug

  • British pharmaceutical companies began to mass-produce penicillin in 1943

A storyboard of the development of penicillin

Factors which enabled the development of penicillin

• Government

  • The US government funded Florey and Chain's research

  • The British government invested in medical research for the first time

• Science and technology

  • Scientists were able to observe how penicillin mould killed Staphylococcus

  • The scientific team at Oxford worked together to test and produce penicillin

  • The use of beer vats and milk churns to mass-produce penicillin

• The role of individuals

  • Alexander Fleming discovered penicillin

  • Florey and Chain proved the impact penicillin could have on infections in humans

  • Florey persuaded American pharmaceutical companies to mass-produce penicillin

  • Florey refused to patent penicillin, believing it should be readily available to all

• War

  • The Second World War gave Florey and Chain a purpose for their development

  • The government funded Florey and Chain's research due to the war

• Chance

  • Fleming had discounted the human application of penicillin

  • Florey and Chain took a chance testing the drug on mice and on humans

The significance of penicillin

Short-term significance

• Towards the end of the Second World War, penicillin became vital

  • By 1945, the US Army had access to two million doses of penicillin per month

• An estimated 50% of wounded soldiers survived their injuries because of penicillin

Long-term significance

• Penicillin inspired scientists to research other moulds and fungi for their antibiotic abilities

  • Selman Wakston discovered Streptomycin in 1943

    • This was effective against tuberculosis

  • Dorothy Hodgkin mapped the chemical structure of penicillin in 1945

    • This allowed other scientists to create synthetic antibiotics which were adapted to treat different bacteria

  • John C. Sheehan created the first chemical copy of penicillin in 1957

• Penicillin marked the beginning of the pharmaceutical industry

  • Antibiotics were distributed in capsule form

    • This is an easier method to administer medicine

  • Pharmaceutical companies gained significant funding from governments

    • This allowed companies to design and make machinery to mass-produce medicine

• In the 21st century, some bacteria have become resistant to penicillin

  • This requires scientists to discover new antibiotics for these diseases