Microbiology
Chapter 1
Part I
Introduction to Microbiology
Scope of Microbiology
Microbes
Life forms which require magnification for
viewing
Ubiquitous
Each group has a distinct set of biological
characteristics
Single celled vs. multi
-
celled
Prokaryotic vs. eukaryotic
Cell wall vs. no cell wall
Autotrophic vs. heterotrophic
Cellular vs. acellular
Prokaryotic vs. Eukaryotic
Assigning Characteristics
Bacteria
Protozoa
Fungi
Algae
Helminths
Viruses
Assign common characteristics to each group
(Top) Coccidioidomycosis Arthrospores
(Bottom) Development of Arthrospores
Into spherule in lung tissue
Fungal Infection of the lung
Schistosoma (worms) at
two different stages of
development
–
liver
Disease and other symptoms
Staphylococcus Aureus
Gram positive bacteria
Staph infections and MRSA
Trypanosoma
Eukaryotic pathogen
African Sleeping Sickness
Treponema pallidum
Bacterial spirochete
Causes syphilis
Mycobacterium tuberculosis. Acid
fast bacteria (shown in pink) like
this causes TB and leprosy. Light
blue is Staph epi, a common
bacteria cocci which inhabits the
Skin. Not a common pathogen
Herpes Virus
Size
Comparisons
What Do
Microbes Do?
Photosynthesis
Decomposition
Soil Fertility
&
Microbial
Ecology
Microbial
Physiology &
Fermentation of
Cheese
Wine
Bread
Genetics,
Gene
Regulation
&
Biotechnology
Bioremediation
Oil Eating
Bacteria &
Fungi
Water
Purification
Infectious
Disease
&
Immunology
Ch 4, 7, & 26
Ch 8 & 27
Ch 9 & 10
Ch 27 Briefly
Need an
Environmental
& Applied
Micro
Course
Ch 14
–
16
&
Ch 18
-
25
Part II
Historical Figures in
Microbiology
Superstition of Microbiology
Spontaneous generation
For thousands of years people believed that
living things arose from vital forces present in
non living matter
Mushrooms appearing on rotting wood
Afflicted people were thought to be cursed
Controversy between…
Abiogenesis and biogenesis
First Look at Microbes
In the 1600s
Robert Hooke (English)
reported that living things
were composed of little
boxes or cells
Antonie van Leeuwenhoek
construction microscopes
which could magnify 300X
Described microorganisms that
he observed in teeth scrapings
& rain water
Abiogenesis vs. Biogenesis
Franceso Redi
He wanted to ascertain whether maggots arose
from some “vital force” of the meat or were
offspring of flies
Abiogenesis vs. Biogenesis
Conclusions of Redi’s Experiment
This and related experiments proved that
complex animals such as insects and mice
develop through biogenesis
However, meat leaf out but covered with
gauze would still rot
Therefore, the idea that simpler organism
could arise from abiogenesis was still accepted
Proving that Microbes Are Present in
Dust Particles
Jablot’s vs. Needham’s Experiment
Jablots experiment supported the idea that
microbes are present in the air
Proving that Microbes Are Present in
Dust Particles
However, support for Jablot’s experiment
faltered when Needham’s results were
reported
Needham performed the same experiment
with mutton gravy
Microbial growth was in both containers
What do you think happened here?
These disputes would
be put to rest with
Louis Pasteur’s work
Proving that Microbes Are Present in
Dust Particles
Pasteurization
Pasteur also demonstrated that
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
Lister’s Work
English physician advanced the idea of
antisepsis in health care setting 1860’s
Dressed wounds with carbolic acid
(phenol)
Reduced deaths among patients by 2/3
Listerine Mouthwash
Koch’s Postulates
1876 Robert Koch provided proof that a
bacterium causes anthrax and provided
the experimental steps, postulates, used
to prove that a specific microbe causes a
specific disease
Koch was a physician and Pasteur’s young
rival
Koch’s Postulates
Mouse dies with sores
Take scraping and plate on agar
A heterogeneous population of bacteria
Grow
–
which one is the causative agent
Isolate all different strains and types and
inject into healthy mice and see which mice
develop similar phenotype and symptoms
Take a sample again from mice which died
of same symptoms and isolate the
causative agent again
Koch’s Postulates
A sequence of
experimental
steps to relate a
specific microbe
to a specific
disease
Koch’s Postulates
Used to prove the
specific causative
agent of an infectious
disease
Jenner’s Work
Observed that milkmaids did not acquire
smallpox
Milkmaids were exposed to chronic low
doses of cowpox and therefore acquired
specific immunity
1796 Jenner inoculated a person with
cowpox virus and found this person was
then protected against acquiring small pox
This protection is known as immunity
Called vaccinatin from vacca for cow
Alexander Fleming’s Work
In 1928 Fleming
discovered the first
antibiotic by accident
He observed that
Penicillium fungus
secreted a substance
which killed bacteria
Explain why a fungus
would do this
In 1940s penicillin was
tested clinically and
mass produced
Germ Theory of Disease
All of these aforementioned people and
others helped give rise to the germ theory
of disease
Germ Theory states that microorganisms
can invade other organisms and cause
disease
Before this many time politics and religion
would spur on erroneous theories
Part III
Introduction to Disease
Chronic vs. Infectious Disease
Chronic
Disease which persists over a long period of
time
Atherosclerosis, cancer & heart failure
Infectious
Organism enters and tissues & grows
Bacterial
–
Prokaryotic
Viral
–
Acellular
Protozoan
–
Eukaryotic
Causes symptoms in patients
Conquering Infectious Disease
The triumph over infectious disease?
Antibiotics discovered in 1940s
Vaccinations routinely delivered in the 1950s
through today
Eradication of polio and small pox
But then…
MRSA
Drug resistant TB
HIV
Ebola
Avia Flu
And more
Conquering Infectious Disease
What went wrong?
Medical advances
Older and sicker people live longer
More susceptible to garden variety microbes
Population is more mobile
Emerging diseases
Encroachment of humans into wild habitat
Rapid evolution and biochemical changes to
microbes
Microbes have a quick generation time
All Diseases
Old Standards
Syphilis
Measles
Staph Infections
Chicken Pox
Emerging
Avia Flu
Antigenic shift event
HIV in the 80’s
West Nile in US in 2001
Continental travel
Reemerging
Tuberculosis
-
TB
New drug
resistant strains
Immunocompromised
patients
Top Causes of Death
United States
Deaths
Worldwide
Deaths
1. Heart Disease
696,950
1. Heart Disease
8.12 x 10
6
2. Cancer
557,270
2. Stroke
5.51 x 10
6
3. Stroke
162,670
3. Res infection
3.88 x 10
6
4. Chronic LRD*
124,800
4. Cancer
3.33 x 10
6
5. Accidents
106,740
5. HIV/AIDS
2.78 x 10
6
6. Diabetes
73,250
6. Chronic LRD*
2.75 x 10
6
7. Flu & Pneumonia
65,680
7. Diarrheal disease
1.80 x 10
6
8. Alzheimer disease
58,870
8. Tuberculosis
1.57 x 10
6
9. Kidney problems
40,970
9. Malaria
1.27 x 10
6
10.Septicemia
33,865
10. Accidents
1.19 x 10
6
* Stands for lower respiratory disease
Infectious Diseases are shown in
red
Infectious
Disease
Statistics
Part IV
Taxonomy & Biological
Classification
Organizing Life
Classification
Orderly arrangement of organisms into groups
that indicate evolutionary relationships
Nomenclature
Assigning names to various taxonomic
rankings
Identification
Correct placement of organism into taxonomic
scheme
Taxonomy
Origins of organizing biological life
Carl von Linne or Linnaeus 1701
–
1778
System of recognizing and defining properties
of living organism followed by the placement
into specific slots
Grouped according to similar properties
Grouped according to evolutionary relatedness
Constantly being revised and refined
Taxonomy
Nomenclature
Scientists use a standard binomial system
Overseen by an international group
Verify that standard procedures were followed
Ascertain the uniqueness of each name
Make sure no other name exists
Nomenclature
Staphylococcus aureus
Staphule
–
bunch of grapes
Aureus
–
golden
Campylobacter jejuni
Kampylos
–
curved
Bakterion
–
little rod
Jejunum
–
section of small intestine
Giardia lamblia
Alfred Giard
–
French microbiologist
Vilem Lambl
–
Bohemian physician
Evolution & Phylogeny
Evolution
All new species originate from preexisting
species
Closely related organism have similar feature
due to evolution from common ancestral forms
Phylogeny
Tree of life
Classification based on evolutionary
relatedness
Whittaker’s
System
Whittaker’s System
Although used for many years this system
has problems in terms of evolutionary
relatedness
Kingdom Protista
Autotrophs & heterotrops are groups together
Archaea
Although these organisms are prokaryotic they
are more closely related to eukaryotic cells
Solution to Whittaker’s Tree
Biologist no longer group organisms into a
5 kingdom system
Currently a three domain system
Many original kingdoms still work
Plants, animals, fungi
However, Kingdom Protista & Kingdom Monera
have been extensively reorganized into many
different kingdoms
Three Domain System
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