Download Introduction to Microbiology

BIO 162
Microbiology for Allied Health
D. Page Baluch
Microbiology
Many technical terms, names of cell structures are
formed from Latin or Greek roots
micro - very small; bio – life; ology – study
study of very small living organisms that cannot be
seen with unaided eyes
Microorganisms or microbes
They are virtually everywhere - ubiquitous
Types of Microorganisms
Bacteria
Fungus
Yeast & molds
Bacillus
E. coli
Algae
Archaebacteria
Diatom
Dead Sea salt pillar
Protozoa
Virus
Paramecium
HIV
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Why study microbiology?
We have trillions of living microbes in our bodies
– indigenous or normal microflora
3% known microbes are disease-causing
(pathogens)
Essential for life on planet e.g oxygen
production, nutrients recycling, food chain,
Industrial use e.g. bioremediation (decompose
industrial waste), genetic engineering (gene
transfer), food & beverage (bread, butter,
cheese, beer, wine), antibiotics (penicillin,
tetracycline)
Microbiology
Different specialties within microbiology
Bacteriology
Virology
Mycology
Phycology
Parasitology
Immunology
Applied microbiology – apply knowledge of
microbiology to different aspects of society,
medicine & industry.
Medical microbiology
Clinical microbiology
History of Microbiology
Oldest fossils of microbes – 3.5 billions years
old (compared to animal 630 millions years
old)
Earliest infectious disease was recorded in
3180 B.C. in Egypt (disease was also known
as pestilence)
Since microorganisms cannot be seen with
the naked eye, the development of
microbiology largely relies on the
development of microscopes
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History of Microbiology
Major contributors
Robert Hooke - the first cell in cork
“Observation XVIII" of the
Micrographia by Hooke,
Hooke, 1665
History of Microbiology
Major contributors
Robert Hooke - the first cell in cork
Anton van Leeuwenhoek - the first living microbe
“….very little animalcules….”
by Leeuwonhoek in Cornelis
Boutesteyn, Leyden, 1685
Early observations under primitive
microscopes
“Observation XVIII" of the
Micrographia by Hooke,
Hooke, 1665
“….very little animalcules….”
by Leeuwonhoek in Cornelis
Boutesteyn, Leyden, 1685
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History of Microbiology
Major contributors
Robert Hooke - the first cell in cork
Anton van Leeuwenhoek - the first living microbe
Edward Jenner - the first vaccine, 1796
Louis Pasteur
Pasteurization process
Disprove “Spontaneous Generation”
Germ Theory of Disease
Robert Koch
Germ Theory of Disease - Koch’s postulates
Pasteur Disproves “Spontaneous Generation”
Spontaneous generation - 400 B.C Greek myth formed the basis of this notion
which states that lifeless substance could give rise to living organisms
The swan-neck flask experiment
• fermentable juice was placed in a flask, heated and sealed sterile
What happened when:
1. flask remained sealed?
2. the end of the neck was nipped off and dust was trapped in the
neck?
3. the flask was tipped to allow the sterile liquid to touch the
contaminated walls and this liquid was then returned to the broth?
Germ Theory of Disease - Louis Pasteur, 1857
Wine and beer fermentation experiments
Grape juice
(naturally
contains
yeast)
Yeast killed
by heating
the juice
Cottom plug
prevents airborn
microbes, juice
fails to ferment
Yeast is
added back to
the juice
Juice is
fermented
into wine
Microorganisms (germs) are capable of causing
chemical change.
Can you think of some examples?
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History of Microbiology
Major contributors
Robert Hooke - the first cell in cork
Anton van Leeuwenhoek - the first living microbe
Edward Jenner - the first vaccine
Louis Pasteur
Pasteurization process
Disprove “Spontaneous Generation”
Germ Theory of Disease
Robert Koch
Germ Theory of Disease - Koch’s postulates
Koch’s Postulates
The organism must be found in all
animals suffering from the
disease, but not in healthy
animals.
The organism must be isolated
from a diseased animal and
grown in pure culture
The cultured organism should
cause disease when introduced
into a healthy animal.
The organism must be re-isolated
from the experimentally infected
animal.
Exceptions to Koch’s Postulates
Pathogen cannot be cultured in vitro
Pathogen may be host-specific
Certain diseases are caused by multiple
microorganisms
Pathogen may mutate in vitro
*Useful terms to know:
In vitro – something that occurs outside the living body (ie cell
culture)
In vivo – something that occurs inside the living body
Obligate intracellular pathogens – pathogens that can only
survive within a living host.
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Spontaneous generation
Originally thought to exist because of the
observations of decomposition by
decomposers or saprophytes.
Abiogenesis – another word for spontaneous
generation.
Biogenesis – theory proposed by Rudolf
Virchow in 1858 that suggested that life could
only arise from preexisting life.
How big are microorganisms?
measurement unit micrometer (µ
µm = 1
millionth of a meter)
Organisms
Size (µ
µm)
Viruses
0.01-0.3
Bacteria
1-3
Yeast
3-5
Protozoa
5-2000
Benefits of Microbes
Microorganisms play essential roles in elemental
cycles such as nitrogen, oxygen and carbon.
Photosynthetic algae and bacteria produce much of
the oxygen in the atmosphere.
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Pathogens
Algae – Rarely cause disease or infections. Can
cause intoxication by consumption.
Bacteria
Fungi
Protozoa
Viruses
Pathogens
Algae
Bacteria – Cause diseases such as botulism, cholera,
food poisoning, tetanus, tuberculosis, lyme disease…
Fungi
Protozoa
Viruses
Pathogens
Algae
Bacteria
Fungi – Can cause allergies, intoxications,
meningitis, pneumonia, ringworm, thrush…
Protozoa
Viruses
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Pathogens
Algae
Bacteria
Fungi
Protozoa – Can cause amebic dysentery,
diarrhea, malaria, meningoencephalitis,
trichomoniasis…
Viruses
Pathogens
Algae
Bacteria
Fungi
Protozoa
Viruses – Can cause AIDS, Bird flu, cancer,
chickenpox, cold sores, herpes,
hemorrhagic fevers, hepatitis, measles,
polio, warts…
Categories of Disease caused by
Pathogens
Infectious Disease – Results when a
pathogen colonizes within a host.
Microbial Intoxication – Results when a
person ingests a toxin that was produced by
a microorganism.
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Careers in Microbiology
Bacteriologist – scientist that specializes in
the structure, function and activities of
bacteria.
Careers in Microbiology
Bacteriologist – scientist that specializes in
the structure, function and activities of
bacteria.
Phycologists – Scientists that study various
types of algae.
Careers in Microbiology
Bacteriologist – scientist that specializes in
the structure, function and activities of
bacteria.
Phycologists – Scientists that study various
types of algae.
Protozoologists – Scientists who study
protozoa and their activities.
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Careers in Microbiology
Bacteriologist – scientist that specializes in
the structure, function and activities of
bacteria.
Phycologists – Scientists that study various
types of algae.
Protozoologists – Scientists who study
protozoa and their activities.
Mycologists – Those who specialize in the
study of fungi.
Careers in Microbiology
Bacteriologist – scientist that specializes in the
structure, function and activities of bacteria.
Phycologists – Scientists that study various
types of algae.
Protozoologists – Scientists who study
protozoa and their activities.
Mycologists – Those who specialize in the
study of fungi.
Virologists – Those who study viruses and their
related functions (ie genetic engineering).
Applied Microbiology
Applied microbiology – apply knowledge
of microbiology to different aspects of
society, medicine & industry.
Medical microbiology – Study of
pathogens, the disease they cause and the
body’s defenses.
Clinical microbiology – Concerned with
laboratory diagnosis of infectious
diseases.
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