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Microbiology 2421
Terry Austin Office NSB 306
Phone 298-8405
email – taaustin@templejc.edu
Please send me an email to this address containing your:
Name
Social Security Number
Phone number (optional)
email address
email will be used to remind you of exam dates, to send relevant class
information and to send grades if you so request. Grades will ONLY be
sent on your request.
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Lab Supplies List
lint free cloth (ie flour-sack dish towel) for cleaning slides
ultra-fine permanent marker (culture labeling)
alcohol based hand cleaner
latex ('surgical') gloves
lab coat or apron
Many items may be shared with table partners
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Classroom Performance System
Please obtain your CPS Remote from
the TC bookstore before the end of
the second week of classes.
This unit will be used to
Take attendance
Review for exams
Take Exams
You will need to go online to activate
your CPS remote
www.einstruction.com
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Lecture Notes Available Online
The lecture presentations will be made available on my page of the
Temple College web site.
Students are encouraged to go online and print the lectures.
Having these printed and ready before class time will make your note
taking far more efficient. The printouts are NOT an adequate substitute
for good note taking.
http://www.templejc.edu
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Online Presentations
These can be viewed in slide show format – just as you will see them during
class. (instructions to follow)
Each slide can be viewed in detail and, if desired, printed one slide per page
from your home computer. Please DO NOT print these presentations at TC
Library computer! (at librarian’s request)
A text only ‘handouts’ version can be printed for ease of study (instructions
to follow)
A printed version of the presentation will save you valuable class time
allowing you to be far more efficient in your note taking. Such a printout IS
NOT an adequate substitute for a good set of notes.
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Chapter 1
The Microbial World &
You
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Microorganisms are ubiquitous
They are present virtually everywhere in the environment, as well as in
and on our bodies.
Microorganisms exist in virtually all environmental extremes
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Why study microorganisms?
Microorganisms can be both beneficial and harmful.
Beneficial examples:
food preservation
flavor
food production (vinegar, yogurt, alcohol, sauerkraut…)
biogeochemical recycling (such as cleanup of oil spills)
vitamins (enteric bacteria produce some vitamins for you)
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Why study microorganisms?
Microorganisms can be both beneficial and harmful.
Harmful examples:
disease
food blights
spoilage
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History of Microbiology
Origins of Microscopy: Early use of compound (2 lens) microscope
1665 - Robert Hooke (England)
Looking in his microscope at cork, Hooke described "little boxes" or
"cells”
Why is this important?
This was the beginning of the Cell Theory of life…
all living things are composed of cells
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1673 - Antoni van Leeuwenhoek
(Holland)
First to observe live microorganisms
Leeuwenhoek called his discoveries "animalcules“ (tiny animals)
In fact, what Leeuwenhoek observed are now recognized to be…
bacteria
protozoa
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The Origins of Life?
The next major hurdle for early biologists was
To determine precisely how new living things appeared
One early idea with much support
(now thought rather odd)
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Spontaneous Generation ?
During this period (1600’s) there was a common belief that
new organisms arose spontaneously from certain substances.
Manure
Mud
toads
Rotting Meat
maggots
This view persisted into the 1800’s
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Experimenters begin to examine
Spontaneous Generation
1668 - Francesco Redi (Italy)
(before microscopic observations of Leeuwenhoek),
Redi placed meat in jars some sealed, some jars unsealed.
He showed maggots did not arise “from” decaying meat.
EVIDENCE - No maggots grew on meat which was sealed in jars
while they did appear on the meat in open jars
Problems with this…
Opponents claimed that AIR was necessary for life
some still believed that simple organisms could arise spontaneously
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Evidence In Support of
Spontaneous Generation
1745 - John Needham (England) boiled meat broths and poured them into
covered containers
microbes still grew after heated nutrient fluids were poured into covered
containers. (He said this was spontaneous)
WHY did bacteria still grow?
The answer will DIRECTLY affect YOU in lab this semester!
POOR TECHNIQUE
Organisms could have fallen in the solutions after boiling &
before being transferred into the sealed containers
Organisms might have traveled into the solution from fingers or other
contaminated objects
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Evidence Against
Spontaneous Generation
1765 - Lazzaro Spallanzani (Italy)
Spalanzani proposed that microorganisms came from air getting
into Needham's samples
found none in broth after heating in sealed containers
Needham countered by saying…
A ‘vital force’ needed for spontaneous generation was killed by the
heating and could not enter the sealed flask
let’s leave this argument for now…
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Biogenesis
Life from life…
First major challenge to Spontaneous Generation
1858 - Rudolf Virchow (Germany)
Biogenesis states that
‘All life can arise only from preexisting, living cells’
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Spontaneous Generation Disproved
1861 - Louis Pasteur (France)
Pasteur heated broth in open flasks with s-shaped necks
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FIRST
Broth poured into
open neck of flask
THEN
neck heated
and bent but
remains open
at tip of neck
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FINALLY
contents heated
to kill organisms
Pasteur & Others
The discoveries by Pasteur and others lead to the development
of aseptic techniques…
…the most important techniques that all microbiologists use methods
for preventing contamination by unwanted micro-organisms.
Asceptic Techniques – Laboratory techniques used to minimize
contamination of a sample, culture, work area or individuals.
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Pasteurization
A process developed by Pasteur to kill particular organisms
heating which kills pathogens (disease-causing) organisms, but
does not damage the food (milk or other).
Classic Pasteurization: Heat to 63oC for 30 minutes
Modern Pasteurization: Heat to 72oC for 15 seconds
NOTE: Pasteurization is NOT sterilization
Kills pathogens and most other organisms (not all organisms killed)
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Further Work of Pasteur
Important business problem:
French businessmen asked Pasteur to help discover why
their wine and beer soured. They hoped to prevent spoilage
Common misconception:
• air caused sugars to convert to alcohol
Pasteur discovered instead that yeast are the vital part of
this process. Further that bacterial probably caused the
spoilage after the process was complete.
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Pasteur continued…
Pasteurization developed in order to save the beer/wine industry!
(and you thought it was to protect your milk…)
This major link between microorganisms and spoiled foods
lays the groundwork for the next step of relating diseases
to microorganisms
This idea that ‘germs’ or microorganisms might be involved in diseases
is referred to as the
Germ Theory of Disease
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Lending Support to Germ Theory
Ignaz Semmelweis (1840's, Hungary)
Joseph Lister (1860, England)
don’t shudder when you see these…
Semmelweis showed that simply washing hands by doctors between
obstetrical patients reduced the incident of childbirth fever
Lister applied germ theory to other medical procedures,
using phenol (an organic acid) to treat wounds (found less incident
of infections, many other doctors applied this technique).
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Germ Theory of Disease
Robert Koch (1876, German physician)
First direct proof of bacteria causing disease
What did Koch do???
Linked a bacterium, Bacillus anthracis, to anthrax.
Developed steps to experimentally determine if a microorganism
is involved in a disease – Koch’s Postulates
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Koch’s Postulates
1. The same pathogen must be present in every case of the disease
2. The pathogen must be isolated from the diseased host and
then grown in pure culture
3. The pathogen from the pure culture must cause the disease
when it is inoculated into a healthy, susceptible animal
4. The pathogen must be isolated from the inoculated animal
and must be shown to be the original organism.
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Waging war - advances in combating
microbial diseases:
VACCINES - 1796 (before Koch) Edward Jenner (British physician)
Developed first vaccine –
Jenner was told by a young milkmaid that she couldn’t get smallpox
because she had already been sick from cowpox (milder disease)
He decided to test her tale… collected scrapings from cowpox blisters
and inoculated a healthy 8-yr old volunteer with these scrapings.
Scratched arm with contaminated needle. On later exposure to
smallpox this volunteer did not contract smallpox
WHY doesn’t this bright milkmaid get credit for her observations?
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Immunology
Jenner’s efforts with smallpox/cowpox inoculations were the:
Origins of immunology – Jenner’s use of body's own
defense mechanisms to fight disease
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Antimicrobials & Antibiotics
Paul Ehrlich (Germany), early 1900's. Speculated about a “magic
bullet”
"Magic Bullet" - medicine for particular diseases that would ‘hunt/kill’
disease organisms without harming the patient.
Ehrlich tested hundreds of chemical agents before finding Salvarsan
(an arsenic derivative) which was effective against syphilis.
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First Modern Antibiotic
Alexander Fleming (Scotland), 1928)
Fleming tossed out some cultures that were contaminated by mold ...
When taking out the garbage later, taking a second look noticed a
clear around the mold where no bacteria were growing.
he had accidentally discovered a mold which inhibited bacterial growth
Mold was Penicillium notatum – A.F. named the compound Penicillin
Serendipity = the faculty or phenomenon of finding valuable or
agreeable things not sought for.
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Virology
1892, Dmitri Iwanowski speculated about tobacco mosaic virus.
Attempted to isolate the agent responsible for this
economically disastrous plant disease
Tried to isolate by using filtration (common technique at the time)
He reported that the factor causing the disease was so small that it was
not filtered out by filters small enough to stop all known bacteria.
‘this is something smaller than any know bacterium
IMPORTANT: He did NOT understand the organism as a virus
as we now understand the concept
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Next Major Steps In Virology
1935, Wendel Stanley crystallized TMV – in doing so, he showed
that it was something different than cellular life.
1940's - electron microscope allowed direct visualization of virus
particles. These things looked like nothing we had seen before!
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Naming and Classification
Our system of naming = Binomial nomenclature
Binomial - bi = two & nomial = names TWO NAMES
1735, Carolus Lennaeus: Names usually based on Latin and
consists of: Genus species
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Classification
Kingdom
Phylum
Class
Order
Family
Genus
Species
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Classification
5 Kingdoms: as defined by Whittaker
Monera - archae (‘blue-green bacteria’) and true bacteria
Protista – protozoans (Paramecium, Amoeba etc.)
Fungi – fungi and molds
Plantae - plants
Animalia - animals
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Classification
3 Domains: 1978, Carl Woese
(Domain = a level of classification above Kingdoms)
Archaea – ancient ‘bacteria-like’ organisms (more on this subject in a
moment)
Eubacteria – ‘true bacteria’
Eukarya – organisms whose cells have a nucleus
(the previous two DO NOT have nuclei)
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Two Main Groups of
Microorganisms
The difference? Some have a nucleus, some don’t
Prokaryotes – HAVE NO NUCLEUS
Examples = Bacteria and Archaea
Eukaryotes – DNA enclosed in membrane called the nucleus.
Examples = Fungi, Protozoa, Algae, Multicellular animal parasites
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Microorganisms include:
Bacteria
•single celled
•no nucleus,
•cell walls contain peptidoglycan (structural molecule of sugar &
amino acid combination)
•Reproduce by binary fission
•Some derive nutrients from organic materials, which can come from
living or dead organisms.
•Some make food via photosynthesis
•Some can use inorganic compounds as a food source
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Microorganisms include:
Archae Similar to bacterial (no nucleus).
Cell walls lack peptidoglycan.
Often found in extreme environments (Great Salt Lake, Dead Sea, hot
springs, thermal vents)
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Three major groups of Archae
methanogens – produce methane as a waste product
-gen = ‘producing’
extreme halophiles – thrive in high salt environments
-phile = ‘loving’
extreme thermophiles – thrive in hot waters
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Fungi
Fungi– are eukaryotes. HAVE NUCLEI..
Unicellular or multicellular
Cell wall of chitin.
Reproduce sexually or asexually (eg. budding)
Yeast is a unicellular fungi larger than bacteria.
Other fungi include molds which form visible mycelia. Obtain
nutrients from organic material in their environment.
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Protozoa
Protozoa – unicellular, eukaryotic microbes. Remember, eukaryote
means that these HAVE a nucleus.
Includes organisms like Amoeba, Paramecium etc.
Reproduce sexually or asexually, many shapes, some are parasites,
derive nutrients from environment.
Many are mobile moving by flagella, cilia, or pseudopods (flowing),
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Algae
Algae – photosynthetic eukaryotes
many have cell wall made of cellulose (like plants) present in soil,
water (fresh & salt)..
Unicellular or multicelluar/colonial
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Multicellular Animal Parasites
These are not strictly microorganisms, but are medically important
‘small things’ so they will be mentioned in this class.
Includes flatworms and roundworms
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Viruses
Viruses are vastly different from other life forms. They are NOT
cellular life forms
Contain a core of nucleic acid (RNA or DNA) genetic material. This
core is often surrounded by protein coat.
Viruses can not reproduce on their own. They must use the cellular
machinery of other organisms to reproduce.
All viruses are parasites
& can’t reproduce outside host cells
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Prions
Infections protein particles
These odd agents have only been partially understood in the past
decade.
Responsible for such diseases as: (nine identified)
Mad-Cow Disease
Creutchfeld-Jakob
Spongiform Encephalopathys
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