Transcript What is Microbiology?

Introduction to Microbiology
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Microbiology
What is Microbiology?
Microbiology -The science of microorganisms (very small, unicellular
organisms).Usually requires a magnification tool – the microscope.
Microorganisms or microbes- these microscopic organisms
Commonly called “germs, viruses, agents…” but not all cause
disease and many more are useful or essential for human life
Some organisms are large though – Helminths – worms
Sub groups of Microbes we will study
Bacteria
Archaea
Fungi
Protozoans
Algae
Viruses
Multicellular animal parasites – Helminths
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Bacteria
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Fungi
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Giardia
Protozoans
Ameba
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Viruses
Bacteriophage
Avian Flu
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Helminth
Tapeworm
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Why Do We Study Microorganisms?
• We study microbiology because bacteria, viruses
and fungi are the leading cause of death in the
history of mankind.
• Some Microorganisms Benefit Man:
- Many microorganisms are involved in the
production of food or are directly edible.
- The presence of bacteria (normal flora) in our
bodies inhibits the growth of potentially
pathogenic bacteria helping to keep us
healthy..
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Why Do We Study Microorganisms?
• Some Microorganisms Benefit Man:
- Modern biotechnology is often associated with the use of
genetically altered microorganisms such as E. coli or yeast for
the production of substances like synthetic insulin or
antibiotics.
Biotechnological advances in agriculture also require the
help of microorganisms to form Transgenic Plant with
increased yield, reduced vulnerability to environmental and
pathogenic stresses, and improved taste.
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Why Do We Study Microorganisms?
• Some Microorganisms Benefit Man:
- Microbes are involved in cycling vital elements such
as carbon and nitrogen,
breaking down wastes and
dead organisms into simpler substances plants can use in
photosynthesis. Other species are at the base of the
food chain, especially in aquatic
ecosystems. Even
pathogens have a role in
controlling the populations
of their host
species. Microbes are even used to
digest oil from oil spills.
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Brief History of Microbiology
 The Microscope
 Fermentation and Pasteurization
 Germ Theory
 The Birth of Modern Chemotherapy
 Antiseptics and Hand Washing
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The First Microscope
Microbes were first observed by
Antonie van Leeuwenhoek using a
simple microscope (ca. 1676)
Reported his “animalcules” to the
Royal Society of London
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History
• 1676 –first observation of bacteria
“animalcules”
Anton Von Leeuwenhoek
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Antoni van Leeuwenhoek
• Inventor of the first microscope (1675)
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The Golden Age of
Microbiology
• 1857-1914
• Beginning with Pasteur’s work,
discoveries included the relationship
between microbes , Fermentation
and Pasteurization
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Fermentation and
Pasteurization
• Pasteur showed that microbes are responsible
for fermentation.
• Fermentation is the conversation of sugar to
alcohol to make beer and wine.
• Microbial growth is also responsible for spoilage
of food.
• Bacteria that use alcohol and produce acetic acid
spoil wine by turning it to vinegar (acetic acid).
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Fermentation and
Pasteurization
• Pasteur demonstrated that
these spoilage bacteria
could be killed by heat that
was not hot enough to
evaporate the alcohol in
wine. This application of a
high heat for a short time is
called pasteurization.
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Figure 1.4
Louis Pasteur
 Showed microbes caused
fermentation
 Studied spoilage and
introduced “Pasteurization” to
prevent it
 Used cotton plugs in his
cultures to prevent air borne
contamination, devised Aseptic
Technique.
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History
Louis Pasteur
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Louis Pasteur put an end to
Abiogenesis debate with his
Goose Neck Flask Experiment
He is the father of Microbiology
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Germ Theory of Disease
• Proof that microorganisms caused disease
• Robert Koch demonstrated that anthrax was caused
by Bacillus anthracis
– Blood from a diseased animal caused disease in a healthy
animal
– Cultivated the disease causing agent outside the animal’s
body, then introduced the agent into a healthy animal
which subsequently developed the disease
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Germ Theory of Disease
 1876 - Robert Koch provided
proof that a bacterium causes
anthrax using experimental
steps now called the Koch’s
Postulates
 He was the first to use agar as
solid culture medium in
bacteriology.
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Koch’s Postulates
 The microbe must always be present in every case of
the disease
 It must be isolated in pure culture on artificial media
 When inoculated into healthy animal host it should
produce the same disease
 It must be isolated from the diseased animal again
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History
• 1884 Koch’s Postulates of
Disease Transmission
Robert Koch
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The Birth of Modern
Chemotherapy
• Treatment with chemicals is chemotherapy.
• Chemotherapeutic agents used to treat infectious
disease can be synthetic drugs or antibiotics.
• Antibiotics are chemicals produced by bacteria and
fungi that inhibit or kill other microbes.
• Quinine from tree bark was long used to treat malaria.
• 1910: Paul Ehrlich developed a synthetic arsenic drug,
salvarsan, to treat syphilis.
• 1930s: Sulfonamides were synthesized.
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The Birth of Modern
Chemotherapy
• 1928: Alexander
Fleming discovered
the first antibiotic.
• He observed that
Penicillium fungus
made an antibiotic,
penicillin, that killed S.
aureus.
• 1940s: Penicillin was
tested clinically and
mass produced.
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Similar to
Figure 1.5
History
• 1929 Discovery of Penicillin
(first antibiotic)
Alexander Fleming
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Antiseptics and Hand Washing
 1860s -Joseph Lister used, carbolic acid, a chemical
antiseptic to prevent surgical wound infections
 Ignaz Semmelweis, a Hungarian physician
introduced hand washing as a means of preventing
transfer of puerpueral sepsis in obstetrical patients
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Lister
• Antisepsis in surgery
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History
• 1867 Antiseptic Surgery
Joseph Lister
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Semmelweis
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History
• 1938 – First Electron
Microscope
• The electron microscope is capable of
magnifying biological specimens up to one
million times. These computer enhanced
images of 1. smallpox, 2. herpes simplex,
and 3. mumps are magnified, respectively,
150,000, 150,000 and 90,000 times.
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History
• 1885 - Vaccine against
Rabies
Louis Pasteur
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History
• 1796 – First vaccine (smallpox)
Edward Jenner
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History
1954 Polio Vaccine
Jonas Salk
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