Louis Pasteur

What Did He Do?

How Did He Do It?

What did this lead to?

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Pasteur founded the science of microbiology and proved that most infectious diseases are caused by micro-organisms. This became known as the "germ theory" of disease. He was the inventor of the process of pasteurisation and also developed vaccines for several diseases including rabies. The discovery of the vaccine for rabies led to the founding of the Pasteur Institute in Paris in 1888.


How Did He Do It?

It happened by luck and chance- he noticed mould growing around his petri- dish however not in a place where he had certain chemicals he discovered further- 'germ theory is made'


What did this lead to?

Robert Koch worked alongside pasteur however pasteur got a brain hemourage leading to koch taking over creating vaccines against cholera etc

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Robert Koch

What Did He Do?

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What did he do? Robert Koch was a german Scientist. He used pasteur's findings of the late 1860's to begin his own study into the cause of disease.

Koch had the advantage of being a Doctor, so he could apply medical knowledge to his experimentation. By 1875 he had successfully identified the microbe that caused Anthrax. A link was now made between germs and diseases, which allowed for Jenner's earlier work to now be more fully understood and used. (Pasteur found the vaccine for Anthrax in 1881).

Koch used this new knowledge to begin a study of the causes of blood poisoning, or septicemia. He knew that a Microbe must be responsible for causing the spread of the disease, but at first couldn't see the microbe, even with the aid of the most powerful microscopes. Industrialisation however led to the development of dyes that could be used to stain microbes. Koch created a liquid that contained just one germ, and dyed it. Through testing on mice he could show that this specific micrbe, or germ, was responsible for the spread of the disease. (Koch photographed the spread of the dye, the start of the disease and it's spread to prove his theory).

Koch later developed a solid culture to grow germs on. this menat that germ theory could be done much more reliabily than with liquid cultures such as those by pasteur.Koch's work led him to discover the germs that caused tuberculosis and cholera.

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Edward Jenner

What Did He Do?

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Edward Jenner.

What did he do?

Edward Jenner was responsible for the first real break through in the fight against infectious disease. In 1796 he introduce a vaccine against Smallpox. Jenner spent a long time studying the inoculations carried out to prevent Cowpox and decided to experiment. His adaptations of the inoculation process resulted in a cure, or vaccine, for smallpox being developed.

Jenner's process was based initially upon inoculation procedures brought back from turkey by lady Mary Montague. He used these to conclude that injecting a form of the virus into the bloodstream would act as a vaccine against the disease. He experimented on animals and observed the success of the Cowpox vaccine. Later he chose to use his method on people. Jenner injected James Phillips with pus from the sores of a girl infected with Cowpox. Once the injection had time to circulate Jenner injected him with a dose of Smallpox. The infection did not take hold and Jenner became convinced that the vaccine worked.

Many doctors accepted Jenner's discovery although some were initially opposed to his work and disputed its success. Evidence was produced by some to show that patients given the vaccine later developed smallpox and died. Jenner though was hailed as a hero by people such as Thomas Jefferson, the president of the United States. Smallpox, one of the most deadly diseases known, was cured

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Alexander Fleming

What did he do?

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Alexander Fleming

What did he do?

Alexander Fleming was a scientist who was working on staphylococci. These are the germs that make wounds go septic. Whilst cleaning the culture dishes one day he saw a mould growing on one of the plates. This in itself was not unusual, but on this occasion there were no germs growing around the growth. Curious as to what caused the germs to stop growing, and eager to find out what the mould was, Fleming grew more of it and experimented. He found that the mould acted against anthrax and diphtheria without creating any harmful side effects. This was the first occasion that an antibiotic drug had been developed (an antibiotic is something naturally produced by living organisms, rather than being a chemical compound). The new drug was a member of the penicilium notatum family, known popularly as penicillin.

Fleming however did little with his discovery. It wasn't until 1935 when researchers Florey and Chain at Oxford University saw Fleming's research papers that the drug was developed further.

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Florey And Chain.

What did they do?

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Florey And Chain

What did they do: Florey and Chain were scientists. They stumbled across Flemings research papers and were intrigued by his findings. They were sure that, if Fleming was right, this discovery could save a lot of lives, prevent pain and make it much easier to fight infectious diseases and prevent oter infections.

Florey and Chain developed a system of growing penicillin: which was complicated initially, and tested its effectiveness on mice. The tests were successful and the two men became convinced that the drug would cure many people who would otherwise die.Florey and Chain were unable to expand on the development of the drug, as mass production was not financially feasible at the time. The penicillin drug became widely available following the United States introduction into the Second World War during 1941. Once involved in the conflict, the Americans were easily persuaded to develop and produce the drug for the benefit of Allied Servicemen. The experimentation and development of the research previously conducted by Fleming produced astounding results. Florey and Chain had discovered a drug that combatted the spread of infection, would allow sick and wounded men a chance of recovering and gave the medical profession a drug that kept the inside of the body as clean as the tools that were now being treated with antisceptics.

Florey and Chain, along with Alexander Fleming each received the Nobel Prize for the development of the penicillin drug in 1945

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Factors affecting the development of drugs and vac

 A number of factors influenced the changes and developments that occured in the search for a cure to infectious disease. In brief, these factors were:

Technology:The Industrial Revolution provided Scientists with new forms of microscope, dyes that could be used to track and identify germs, laboratories and techical equiptment for use in medical experimentation. Industrailisation and mechanistation also resulted in the rapid spread of ideas along with a faster rate of production.

Good Luck:Some of the discoveries were down to chance. Fleming, for example, wasn't searching for penicillin when he came across it.

Competition:Scientists were becoming very eager to make breakthroughs before their competitors did. An example of this drive to suceed is the repeated clashes between Pasteur and Koch.

War:Medical advancements were often funded by governments eager to reduce death rates during wars. The development of penicillin is an example of this

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Penicillin - The significance of the Breakthrough

The discovery, development and subsequent use of penicillin can be considered to be one of the most important breakthroughs in medical history.

Penicillin prevents a large number of germs from growing. As it is an organic substance it can be used on, or in, the human body. This meant that for the first time something was available that could, potentially, prevent the decay of the body or infection from germs whilst operating.

The immediate impact of the discovery is clear. The drug was developed quickly in the War years by the American government. By developing the drug so readily and so quickly the US Governemtn prevented many soliers from having war wounds becoming infected: the drug therefore saved a lot of lives and, it could be argued, played a role in helping to win the war for the Allies.

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