Download History of Microbiology C1

History of Microbiology
1
What Is a Microbe?
n  6
major groups studied by microbiologists
¨ Prokaryotes
n  Bacteria
¨ Eukaryotes
n  Algae
n  Archaea
n  Protists
n  Fungi
¨ Viruses
Microbiology: An Evolving Science
© 2009 W. W. Norton & Company, Inc.
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Microbes Shape Human History
n  Microbes
¨ Destroy
affect food availability
crops, but preserve food
n  Bread,
wine, cheese
n  Chocolate!
n  Microbial
diseases change history
¨ Black
plague in Europe
¨ Smallpox in Americas
Microbiology: An Evolving Science
© 2009 W. W. Norton & Company, Inc.
3
Discovery of Microbes
n  Light
microscope invented in 1600s
¨ Quality
improved continuously
n  Mid-1600s:
Robert Hooke observes
small eukaryotes
n  1676:
van Leeuwenhoek discovers
bacteria
Microbiology: An Evolving Science
© 2009 W. W. Norton & Company, Inc.
4
Antonie van Leeuwenhoek – Microscopes
Lazzaro Spallanzani – Tried to disprove the Theory of
Sponanteous Generation
Louis Pasteur – discovered anaerobes, disproved
spontaneous generation, fermentation done by microbes
Microbes Are Living Organisms
n  Microbes
arise only from other microbes
¨ No
spontaneous generation
¨ 1688: Redi shows that flies do not
spontaneously generate
¨ 1861: Pasteur shows that microbes do not
grow in liquid until introduced from outside
No growth
Microbiology: An Evolving Science
© 2009 W. W. Norton & Company, Inc.
Flask neck broken,
bacteria fall into and
grow in medium
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Joseph Lister – Sterile surgery techniques, inspired by
Louis Pasteur’s work on diseases in wine
Germ Theory of Disease
n  Observations:
¨ Germs
can infect and grow on food.
n  Hypothesis:
¨ Can
germs infect and grow on people?
¨ That is, do germs cause disease?
n  Hypothesis
is testable:
¨ Are
germs found in infected tissue?
¨ Can transmission of germs cause disease?
Microbiology: An Evolving Science
© 2009 W. W. Norton & Company, Inc.
16
Germ Theory of Disease
n  Pasteur’s
Theory:
¨ Transmission
disease
n  All
of germs causes
Scientific Theories:
¨ Explain
many known observations
¨ Provide
framework for understanding
n  For
example, transmission of rabies
n  Where
¨ Can
be tested further
n  Do
¨ A
do diseases come from?
germs cause anthrax?
scientific theory is NOT a “guess”
Microbiology: An Evolving Science
© 2009 W. W. Norton & Company, Inc.
17
Robert Koch – His postulates helped elucidate the
microbial cause of many infectious diseases
Koch’s Postulates
n 
Provides means of testing hypothesis:
¨ 
n 
“Does this germ cause that disease?”
Organism must meet 4 criteria:
1. 
Microbe always present in diseased
n 
2. 
Microbe grown in pure culture
n 
3. 
No other microbes present
Introduce pure microbe into healthy individual
n 
4. 
Absent in healthy
Individual becomes sick
Same microbe re-isolated from now-sick
An Evolving Science
individual © Microbiology:
2009 W. W. Norton & Company, Inc.
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Corollary to Germ Theory
n  Stop
¨ Kill
germ transmission, stop disease spread
germ, prevent disease
n  Antiseptics
¨  1865:
Antiseptic surgery
§  Joseph Lister
n  Antibiotics
¨  1929–1941:
Penicillin
§  Alexander Fleming
¨  Many newer antibiotics
¨  Bacteria become resistant
Microbiology: An Evolving Science
© 2009 W. W. Norton & Company, Inc.
21
Corollary to Germ Theory
n  Stop
germ transmission, stop disease spread
¨ Stop
spread of germs
n  Epidemiology,
¨ Resistant
n  1798:
public health measures
individuals prevent spread of germs
Vaccination with cowpox prevents smallpox
¨  Turkish
physicians, Lady Montagu, Edward Jenner
Microbiology: An Evolving Science
© 2009 W. W. Norton & Company, Inc.
22
Louis Pasteur – developed a method to attenuate
microorganisms to make vaccines
Paul Ehrlich – discovered the first antibiotic compounds,
used to treat syphilis
Alexander Fleming – Isolated penicillin, the first antibiotic
produced by another organism (mold)