The Fight against Germs

• The Fight against Germs

  Pasteur and Koch weren't friends - in 1871 Germany beat France in the Franco-Prussian War, so there was a great national and personal rivalry between the two scientists. This competition fuelled their next discoveries
• Pasteur started to compete in the race to find and combat new microbes after hearing of Koch's discovery of the anthrax bacteria


  1877
• Pasteur's assistant, Charles Chamberland, injected some chickens with a cholera culture that had been weakened by being accidentally left out on the desk while he was on holiday</b>
• The chickens survived the weakened (attenuated) cholera culture
• Chamberland's error had produced a chance discovery
• Producing an attenuated version of the anthrax bacteria

  1. To make sheep immune

  2. Showed this in a public experiment in 1881
• Finding a vaccine for rabies

  Used a similar method to the attenuated anthrax bacteria
• Pasteur


  Developed Vaccines for Anthrax and Rabies
• Koch's Methods


  Helped other Microbe Hunters
• How other scientists used Koch's methods

  Find and combat bacteria that caused other diseases
• Diphtheria germ


  Discovered by Edwin Klebs in 1883
• Friedrich Loeffler's work on diphtheria

  1. Cultured the diphtheria germ

  2. Thought its effect on people was due to a toxin (poison) it produced
• Emile Roux


  Proved Loeffler right
• Emil von Behring's work on diphtheria

  1. Produced an antitoxin (a substance that cancels out the toxins produced by the germs) from the blood of animals that had just recovered from diphtheria

  2. This could be used to reduce the effect of the disease
• Ronald Ross


  Received the Nobel Prize in 1902 for his discovery of how malaria is transmitted
• Ross' Nobel Prize was disputed by Giovanni Battista Grassi


  Grassi also discovered how malaria is transmitted
• Koch


  Supported Ross' claim and so he retained the prize
• Magic Bullet


  A chemical that can target and kill specific microbes without harming the rest of the body
• Antibodies


  • Natural defence mechanism of the body against germs
  • Only attack specific microbes
• Paul Ehrlich set out to find chemicals that could act as synthetic antibodies


  1889
• Ehrlich's discovery of magic bullets

  1. Discovered dyes that could kill malaria and sleeping sickness germs

  2. Searched for an arsenic compound that was a magic bullet for syphilis

  3. Tried over 600 compounds

  4. Compound number 606 appeared to work
• The bacteria that causes the sexually transmitted disease syphilis was identified


  1905
• Sahachiro Hata joined the team and rechecked the results, seeing that compound number 606 actually appeared to work


  1909
• Compound 606 was first used on a human under the trade name Salvarsan 606


  1911
• Salvarsan 606


  The first magic bullet discovered by Paul Ehrlich
• Gerhard Domagk discovered the second magic bullet, prontosil


  1932
• Prontosil


  The second magic bullet, used to combat streptococcus bacteria