How was penicillin discovered
and developed?
So what
exactly are
bacteria?
Bacteria are tiny living beings
(microorganisms) - they are neither
plants nor animals - they belong to
a group all by themselves. Bacteria
are tiny single-cell microorganisms,
usually a few micrometres in length
that normally exist together in
millions.
Bacteria are the simplest of
creatures that are considered alive.
Bacteria are everywhere. They are
in the bread you eat, the soil that
plants grow in, and even inside of
you. Bacteria are small single cells
whose whole purpose in life is to
replicate.
A germ is a type of bacteria
So what is an
antibiotic?
Antibiotics are powerful medicines
that fight bacterial infections. Used
properly, antibiotics can save lives.
They either kill bacteria or keep them
from reproducing. Your body's natural
defences can usually take it from
there.
The Big Picture to help you
In the 1860’s.
Louis Pasteur
discovered that
micro organisms
(bacteria/germs)
caused disease.
Robert Koch developed
Pasteur's theory by
creating a way of
staining the different
microbes to identify
which bacteria caused
which disease. Vaccines
could then be developed
to target specific
diseases.
Paul Ehrlich and Gerhard
Domagk took Koch’s
work further and
developed chemical
based medicines that
would target specific
diseases (bacteria) eg
syphilis. These became
known as magic bullets
Penicillin
is a magic
bullet
The penicillin went
straight to attack
the bacterial
infection in my
body and I am
better.
Who was Alexander Fleming?
• A scientist from Scotland
• During the First World War he studied soldiers
wounds infected with streptococci, a bacteria.
• Back home Fleming tried to find a way of
dealing with these bacteria
• 10 years later Fleming was working at St
Mary’s hospital in London and he went on
holiday for a month!
Chance?
• Fleming was not the tidiest of scientists and
he had left a pile of petri dishes containing
bacteria on his laboratory bench.
• On his return Fleming noticed one of them
had grown mould
• Around the mould the
staphylococci bacteria
had disappeared
Chance exam questions
• Briefly describe one example of chance from
the nineteenth or twentieth century which
affected the development of medicine (5)
• Explain why chance has been important in the
development of medicine (7)
What did Fleming do next?
• Fleming carried out more experiments testing
the penicillin mould on living cells
• Diluted penicillin killed bacteria
• He made a list of the germs it killed
• He even used it to treat another scientist's eye
infection
So why did he stop any further work?
• Fleming saw that penicillin did not seem to
work on deeper infections
• He wrote about his findings in a medical
journal but nobody thought he article was
important
• Fleming did not test penicillin on animals so
there was no evidence of it “being useful”
• This is evidence to show Florey and Chain
were more important
Briefly describe how Fleming
discovered penicillin (5)
The next stage in the development of
penicillin
• Florey and Chain
Research and trials
• 1938- Florey and Chain were researching how germs
could be killed.
• They read Fleming's work on penicillin
• They tried to get funding from the British government
to carry on where Fleming left off
• They got £25!
• War was
approaching and
Govt had other
things to spend
money on
Florey and Chain did not stop their
research however
• They experimented on mice
• They discovered the quantity of penicillin
needed for humans was a lot more than mice
• There was no money to fund this kind of
production
1941
• Attack on Pearl Harbour
• The USA joins the war
• Florey and Chain had successfully shown
penicillin kills the streptococci bacteria
• Florey and Chain went to America
Role of war and government
• The American government realised the potential
of penicillin in saving the lives of their soldiers
now that they had entered the war after the
Japanese attack on Pearl Harbour in 1941.
• The US government gave interest free loans to US
companies to buy the expensive equipment to
mass produce penicillin.
• The British Government started to mass produce
the drug in time for D Day in 1944 – 2.3 million
doses.
Role of war and government exam
questions
• Explain how war helped the development of
medicine in the period 1800 to 1918 (7)
• “Governments have been more important
than individuals in bringing about
developments in medicine. How far do you
agree with this statement? Explain your
answer (8)
Explain why penicillin was so
important
• Eg ‘The discovery of penicillin was really important
because there were germs that the drugs developed by
people like Pasteur and Koch could not kill.
• Penicillin was a different kind of drug because it was
natural, it came from a mould. It could kill the worst
germs.
• It was really important during the Second World War
when it saved the lives of thousands of soldiers who
otherwise would have died. They were suffering from
wounds that were infected by streptococci.
• Penicillin was like a wonder drug because it worked.‘
• For D Day the British mass produced 2.3 million doses
Who made the most important contribution towards
the development of penicillin, Fleming or Florey and
Chain? Explain your answer
Fleming
• Describe his achievements
• Explain why they are
important
Florey and Chain
• Describe their research and
achievements
• Explain why they are
important
Conclusion:
Eg 'I think that Florey and Chain were more important that Fleming. This is
because Fleming had given up on his work and forgotten about it. Penicillin
would have been forgotten about if it wasn't Florey and Chain reading
Fleming's work and starting the work on penicillin again. Without them
nothing would have happened. They made great inroads in to the use of
penicillin as they experimented on animals and worked tirelessly on how to
produce the quantities needed for it to be effective on humans. Fleming did
none of this.
“Governments have been more important than individuals in
bringing about developments in medicine. How far do you agree
with this statement? Explain your answer
Governments
• Examples might include:
government – Roman
government and public health,
• government action against the
plague, government action
over public health in
nineteenth century, the
reforms of the Liberal
government 1906–12,
• The American government and
penicillin;
Individuals
• Could include Hippocrates,
Galen, Vesalius, Pare,
Harvey, Jenner, Pasteur,
Koch, Simpson, Lister,
Nightingale, Fleming, Florey
and Chain.
• The list is endless. Just make
sure you EXPLAIN their
importance to medicine for
ones you choose
Conclusion: Governments once the individuals have made the discovery – They have the
finance to do more, power and the law …