Transcript No Slide Title

Title
Dr. Gary Andersen
USD 500
Kansas City Kansas Public Schools
913-279-2211
[email protected]
Two Truths and a Lie
• I have wrestled and alligator.
• I have knocked down an elk.
• I have chased off a bear with a frying pan.
I. Key Terms
A. Microbiology - the logic of small
living things.
B. Microbiologist - specialist in the field.
There are 3 general branches:
1. Virologist- study viruses
2. Bacteriologist – study bacteria
3. Immunologist - study immune
system
C. Microscopy - observing minute
objects with a microscope
• How small?
http://www.cellsalive.com/howbig.htm
D. Cell - the most basic microscopic unit of structure
E.
F.
G.
H.
I.
and function of all living things. Robert Hooke Micrographia (1665) British natural philosopher
coined the term “cella” which means small room.
Note: a cell contains DNA and RNA!
Organism - any individual living thing composed of
one cell or more.
Microorganism - any microscopic living organism
Microbe - a microscopic medically significant
organism
Pathogen – any disease causing organism includes,
parasites, fungi, bacteria and viruses.
Germ – (colloquial) disease causing organism.
J. Etiological agent - disease causing microbe
usually in reference to a virus.
K. Etiology - the microbial cause or origin of any
disease
L. Virulence - the degree of pathogenicity which
varies depending on the strain of microbe.
M. Parasite - any organism that lives upon or
within another organism at whose
expense it gains some advantage.
N. Virus - Latin term for “poison” refers to a
non-living infectious agent. Contains either
DNA or RNA, never both! Obligate
Intracellular Molecular Parasites
O. strains (see pg. 234) - microbes that belong to the
same species but are further subdivided based on
unique chemicals found either on the cell surface, or
being secreted as exotoxins. For example, there is a
difference between the type of toxin produced by the
strain of E.coli in the U.S., and the strain found in
water in Mexico!
The Importance of Microbes 1
• Maintain fertility
and texture of the
soil
The Importance of Microbes 2
• Clean up dead
organic material.
The Importance of Microbes 3
• Absorb heat and
light in the oceans
influencing life
and the weather.
Also absorb
carbon modifying
greenhouse gas
effects.
GAsp08
The Importance of Microbes 4
• Form the basis for
the oceanic
food/energy chain.
The Importance of Microbes 5
• Fix atmospheric
gaseous nitrogen
into the soil in
forms that can be
used. (NH3 NO2,
NO3)
The Importance of Microbes 6
• Modify the
atmosphere with
various gas
production. (ex.
Methane)
The Importance of Microbes 7
• Can extract minerals
from ore.
I. Five Kingdoms of Life (note: viruses are not
included!) See chart on page 237.
A. Taxonomy - system of classification which forms
the basis for studying evolutionary relationships.
B. Carolus Linneaus – (Swedish botanist) developed
system called BINOMIAL NOMENCLATURE
for naming organisms (1735). K,P C, O, F, G, S
Plant and Animal Kingdoms only at first. Used Latin
names.
Ex. Homo sapiens
(genus) (species).
Eventually the microscopic world was classified in
the late 1800’s.
Ex. Escherichia coli (E.coli) (Genus) (Species).
Discovered in 1890 by Dr. Theodor Escherich.
coli - found in the colon of animals..
C. Five Kingdom System (1959 Whitaker).
1. Kingdom Prokaryotae (or Monera)
a.k.a. BACTERIA!
a. “false-nucleus” - no membrane
around the DNA. No cell organelles.
b. Average 1.0 micrometer in size
c. Rigid cell wall made of peptidoglycan
d. Reproduce by binary fission.
e. 3.9 – 4.0 billion years old
GA f 05
Note: THE EUKARYOTIC KINGDOMS: ALL
HAVE A TRUE NUCLEUS!! (see pg 95)
2. Kingdom Protista - (protozoans)
a. Contains a true nucleus, membranous organelles, ex.
mitochondria, endoplasmic reticulum, Golgi
apparatus, vacuoles etc. Compartmentalized
processes. The only single celled euk’s! (See the
virtual cell at the web address below)
http://www-class.unl.edu/bios201a/spring97/group6/
b. Reproduce by mitosis.
c. Ex. Amoeba, paramecium, algae, etc.
(average 10 micrometers in size)
d. ~ 2.7-3.5 billion years old. The first euk’s!
e. The mitochondria in eukaryotes is very similar to a
bacteria in size and function. Theory of
Endosymbiosis.
f. People who study protists are called protozoologists.
Protozoa photos
Euglena
Paramecium
Amoeba
g. Medically significant protozoans:
1. Giardia lamblia – chronic diarrhea
2. Plasmodium vivax – malaria
3. Trichomonas vaginalis – vaginosis in
females and urethritis in males.
http://www.molecularmovies.com/movies/berry_malariaV4
.mov
http://www.biosci.ohio-state.edu/~parasite/plasmodium.html
3. Kindgom Fungi
a. People who study fungi are
called mycologists
b. Multicellular eukaryotes
c. Note: the prefix myco = fungi
d. Ex. Yeast: Candida albicans
microscopic fungi causes
vaginosis, or thrus
e. Ex. Mushrooms - often edible
macroscopic fungi.
f. Molds – such as Aspergillis flavus
Fungi Photos
Slime mold
Yeast
Fungi Photos
4. Kingdom Plantae - (botany/botanist)
a. Photosynthetic – the only non-disease
causing euk’s!
b. Cells with cell walls
c. Primarily multicellular eukaryotes
d. Provide oxygen and glucose to us via
photosynthesis! Ex. Green algae
5. Kingdom Animalia - (zoology/zoologist)
a. Life stages: eggs, larvae and adult.
b. all multicellular euk’s with no cell
wall.
c. organ systems
d. Flatworms, hookworms,
roundworms, and tapeworms studied
in Parasitiology.
III. Major Groups of Bacteria - DNA
sequencing will change prokaryotic
taxonomy. Pgs 242-243 show the latest
systems of taxonomic classification. A
simpler version consists of 8 groups.
A. Eubacteria - “true bacteria”. There
are roughly 2000 genera of bacteria,
1600 are eubacteria. Most have
peptidoglycan in their cell wall, stain
easily and feed on dead cells. Ex. E.coli
Streptococcus
GA F 08
B. Spirochetes –
1. Flexible cell walls
2. Spring and coil locomotion
3. Ex. Treponema pallidum – syphilis
4. Ex. Borelia burgdorferi – Lymes disease
C. Actinomycetes – “ray or beam – fungus” funguslike bacteria filamentous appearance
microscopically. Mycobacteria tuberculosis
causes tuberculosis, and Mycobacteria
leprae - leprosy. Streptomyces – soil
bacteria used to make antibiotics
Spirochetes
Spirochetes – Flexible and coil-springlike.
Actinomycetes
Actinomycetes – filimentous with fungus like characteristics
D. Rickettsia - Virus-like bacteria Infect cells
lining the capillaries (intracellular).
Transmitted by insects (arthropods).
Defective bacteria - leaky plasma
membranes, very small 0.3-1.0 micrometers.
Ex. Rocky Mountain Spotted Fever, typhus,
Q fever.
E. Chlamydia - “virus-like” (intracellular)
Spread from one human to the next. Very
small: 0.2-0.7 micrometers. Defective
bacteria - can’t make their own ATP.
Complicated reproductive cycle. Diseases:
blindness, urethritis, and pneumonia.
sp08
Rickettsia
Chlamydia
F. Mycoplasma Sometimes form long strands
that resemble fungi in microscopic
appearance.
• No cell walls - instead contains
sterols.
• Ameboid locomotion - disease:
“walking” pneumonia
• The smallest bacteria - 0.2
micrometers
Mycoplasma “fungus-form”
G. Cyanobacteria,
Photosynthetic, formerly “bluegreen algae”.
2 H2O + CO2 + sunlight  CH2O + H2O + O2
Formed O2 in the earth’s
atmosphere. Important nitrogenfixers. 3.9 billion year old fossils
in Australia.
Cyanobacteria
Cyanobacteria bloom
H. Archaeobacteria - Discovered in 1977 by Carl
Woese. “Primitive bacteria”, Grow in range of
environmental conditions. Eukaryotic-like cell wall
and reproductive enzymes.
• Thermoacidophiles - live at 105C, low pH, found
in geysers, vents in the ocean floor and Antartica.
• Halophiles - live in extreme salinity (high salt
concentration above 10%).
• Methanogens - convert waste water into
methane. Used in waste water management
• Related to oldest protocells found in fossils of
Greenland? ~3.9 billion yrs. old. Many
bacteriologists consider them a separate kingdom
due to an unusual RNA sequences.
GA
Archaeobacteria
Thermophiles growing in Yellowstone hot springs.
Life on Mars?
Magnified view of objects in Martian meteorite found in
Antarctica. (Archaeobacteria like?)
IV. The Scope of Microbiology
A. Medical micro - infectious disease diagnosis
and treatment. There are roughly 2000
species of bacteria. Only ~ 200 are
pathogenic.
B. Ecological - most bacteria live in soil and
water. They form the basis of our food
chain. Bacteria recycle:
• 1. Nitrogen - found in DNA, RNA and the
plasma membrane of animals and protein
• 2. Sulfur - found in 2 of 20 amino acids. (Amino
acids are the building blocks for proteins).
• 3. Carbon - found in all living things.
• 4. Oxygen - found in the atmosphere and
vital for making ATP.
C. Evolutionary - bacteria are
considered the first living things on our
planet. Their role has been to regulate
the number of all species on the planet.
The oldest bacteria are thought to be
~3.9 billion years old. The earth’s
crust is thought to be ~4.0 billion years
old.
D. FOOD MICRO
Bacteria and/or yeast are
fermented for:
1.
2.
3.
4.
5.
Alcohol - beer and wine industry
Bread
Vinegar, pickles and sauerkraut
Cheese
Yogurt
E. BIOTECHNOLOGY
Agriculture - used to control crop insects.
2. Bioremediation - a field of
environmental biotechnology where
bacteria are used to clean up toxic wastes.
Ex. Oil spills.
3. Pharmacology - developing antimicrobics (antibiotics and other
chemotherapeutic substances) to destroy
pathogens.
4. Vaccines - developing weakened strains
of pathogenic bacteria or viruses in order
to protect (immunize) against infection.
5. Snow for ski resorts (artificial)
1.
6. Forensics - analyzing DNA left as
evidence in criminal investigations (PCR
test).
7. Genetic engineering - transfer of genes
(DNA) from one organism to another
8. Bioinformatics - the application of
computer information science to complex
biological problems (genomics,
proteomics, glycomics) ex. at Stowers
Institute in K.C.!
V. History of Microbiology
A. Antony van Leeuwenhoek – 1632-1723,
Dutch, The father of microbiology. The
first to draw bacterial morphology (shapes)
as seen with a microscope in 1600.
– Robert Hooke 1635-1703, - Devised the compound
microscope. Published micrographia which included
drawings of cork undermagnification. He coined term
“cells”.
– Louis Pasteur 1822-1895, (French), helped to disprove
spontaneous generation and developed vaccines for
anthrax and rabies, 1880. The father of modern
microbiology.
–
Robert Joseph Lister 1827-1912, (British), famous
surgeon who used carbolic acid to sterilize surgical tools
and dressings. 1880
Carbolic Acid Sprayer in Surgery
E. Robert Koch (German) proved the germ
theory of disease by developing “Koch’s
Postulates”. Discovered the etiology of
anthrax, cholera and tuberculosis. 1880
F. Theobald Smith (American) 1880’s
originated the “insect vector” concept
(Texas Cattle Fever), invented the
fermentation tube, diphtheriae vaccine
(serum sickness, toxin-antitoxin
combination), & discovered the
Salmonella. Father of American
microbiology.
F. Koch’s Postulates - p. 13
1. Isolate - bacteria from diseased host fluids.
Streak Plate (p 160) technique to observe
bacterial colonies on nutrient agar, and cell
shape under the microscope. In vitro.
2. Propagate - growth large amounts of
isolated microbe in nutrient media. In
vitro.
3. Inoculate - suitable healthy animal host
with isolated suspected pathogen.
Reproduce the original disease symptoms.
In vivo.
4. Reisolate – repeat step 1. In vitro.
Ga f 08
5. Koch discovered the etiology of:
a) Cholera; Vibrio cholerae
b) Tuberculosis; Mycobacteria
tuberculosis
c) Anthrax; Bacillus anthracis
VI. Anatomy of Prokaryotes Chap. 4
I. Morphology - the study of cell shape and structure.
3 types of basic bacterial cell morphology. p. 79
A. Coccus - sphere shape. (common types of cocci
arrangements.) all non-motile
1. Diplococci - ex. Streptococcus
pneumoniae. #1 killer in U.S. by bacteria.
2. Tetrads – packets of 4
3. Sarcina – cube shaped
4. Streptococci – chains (Streptococcus
pyogenes - strep throat) (Streptococcus
mutans – cavities)
5. Staphylococci – irregular clusters or clumps,
ex. Staphylococcus aureus (skin
infxn./bedsores)
Morphology and plane of cell division
Merisopedia (100X)
Sarcinia lutea (16,000X)
B. Bacillus - rod shape (3
arrangements) usually motile.
1. Streptobacilli – chains, ex.
Bacillus anthracis
2. Palisade – hinged, ex.
Corynebacterium
diphtheriae
3. Filamentous – Mycobacteria
tuberculosis.
C. Curved Forms - (3 types)
always motile (see pg136-137)
1. Vibros - Comma shape - ex. Vibrio
cholerae (cholera)
2. Spirilla- Rigid spiral - ex. Spirillum
minus (rat bite fever)
3. Spirochetes -Flexible spiral - spring
and coil ex. Treponema pallidum the
cause of syphilis.
Generalized Bacterial Cell
Nucleoid
Flagella
Capsule
Plasma Cytoplasm
Ribosome
membrane
Fimbriae (on some)
(small granular)
Or Pili
Cell Wall
TYPICAL PROKARYOTIC CELL
Typical Prokaryotic Cell
II. STRUCTURE OF PROKARYOTES
A. Flagella (java applet of euk. motion) ,(motion
of prok. Flagella) , (types of prok. Motion)
1. Structure - composed of a protein
called flagelin. Has 3 parts, the basal
body, hook and filament. P 91
2. Function: MOTILITY (2 varieties)
a. Chemotaxis - chemical attraction
and movement to nutrients
b. Phototaxis - attraction to light.
Brownian Motion – Random motion of microscopic objects
due to the random collisions of molecules in the
environment. java applet
Polar, monotrichous flagellum
Pseudomonas (3,300X)
Peritrichous flagella
Salmonella (1200X)
Structure of Two Different Bacterial Flagella
Gram-negative bacterium
Gram-positive bacterium
3. Flagella in bacteria rotate like a
propeller. Flagella in eukaryotic cells
(found in Kingdom’s Protista,
Plantae, Fungi and Animalia)
undulate.
B. Fimbriae - (or Pili)
1. Smaller than flagella, used for
specific attachment to host tissues.
Not for motility.
2. Sex Pili – p. 93 number fewer than 10
per cell. They elongate during
conjugation and function as genetic
transfer mechanisms.
C. CAPSULE
1. An outer thick polysaccharide coating
that prevents phagocytosis.
2. Forms only when plenty of nutrients are
available. Very few bacteria have
capsules.
3. Pathogenic ex. Streptococcus
pneumoniae, Strep. mutans, Neisseria
meningitidis, Bordetella pertussis.
4. Bacillus anthracis forms a rare protein
(D-glutamic acid) capsule.
D. CELL WALL
1. Provides shape and prevents lysis. 2 general
types of cell walls.
a. Gram + (pg 83-84)
1. Violet in Gram Stain
2. Chemical composition: NAcetylmurmamic acid (NAM)
and N-acetylglucosamine (NAG) sugar
backbone.
3. L-lys & D-ala. amino acids (polypeptide
glycine bridge).
4. Polypeptides and sugar make up 70% of
the Gram + cell wall (peptidoglycan)
5. Resistant to Ethyl Alcohol, sensitive to
penicillin and lysozyme.
b. Gram -
1. Red in Gram Stains.
2. More complicated than Gram +
3. Chemical composition: Outer
lipopolysaccharide surface contains
various “O” polysaccharide antigens
4. Outer membrane mostly
phospholipids.
5. Thin Peptidoglycan 20%.
6. Sensitive to ethyl alcohol,
resistant to penicillin and
lysozyme.
7. Lipid A is a toxic chemical for
humans.
Phospholipid Structure
glycerol
Porin (channel for small molecule passage).
Antigenic O polysaccharide chains
Lipid A
Phospholipids
E. Plasma (Cytoplasmic) Membrane p. 86
http://personal.tmlp.com/Jimr57/textbook/chapter3/cms.htm
Functions:
a. Encloses cytoplasm
b. Point of attachment for the DNA helps
ensure binary fission.
c. Place where ATP is made.
d. Provides selective permeability for
nutrients transported into the cell. Ex.
Glucose, amino acids and triglycerides.
2. Composition: phospholipid bilayer.
a. Hydrophillic head: glycerol +
Phosphorus, polar
b. Hydrophobic tails: fatty acids, nonpolar.
1.
The Fluid-Mosaic Model of the Membrane Structure
F. Cytoplasm - the internal matrix of The cell
consisting of dissolved solutes: nucleic acids,
amino acids, glycerol, fatty acids and simple
sugars like glucose. Place where metabolism
occurs.
G. Nucleoid – (in bacteria only) a single
circular macromolecule of double stranded
DNA. Contains the genetic information
necessary to express all the enzymes used to
reproduce and maintain cell functions.
GA
H. Plasmid - a separate small piece of DNA
found only in bacteria that have
conjugated. The genes are non-essential
on the plasmid. It replicates separate
from the nucleoid. Sometimes plasmids
carry genes for antibiotic resistance.
I. Ribosomes - small granular structures in
the cytoplasm that can only be seen with
an electron microscope. This is where
protein synthesis takes place. Contains
RNA.
J. Inclusions – large granular structures in
the cytoplasm used for storage of sugar or
phosphate.
K. Endospores -“dormant or
resting cells” p 159
1. Function - allows 2 genus of
gram + bacteria (Bacillus and
Clostridium) a means of survival
under extremely harsh
environmental conditions. Not
the same as “spores” found in
plants or fungi.
2. ENDOSPORE RESISTANCE
a. Desiccation – drying out
b. Toxic chemicals except hydrogen
peroxide and ethylene oxide
c. Antibiotics
d. Most forms of radiation
e. Boiling in water for one hour.
3. STERILIZATION Problems with
endospores
A. All surgical instruments must be
sterilized due to possible endospore
contamination.
B. Autoclave is steam heat at 120 degrees
Celsius for 20 minutes. 15 lbs pressure
C. Chemiclave is with ethylene oxide used
to sterilize pacemakers and other heat
sensitive materials.
4. ENDOSPORE CHEMICAL
COMPOSITION
a. Calcium dipicolinate coats and seals the
peptidoglycan.
5. ENDOSPORE LIFE CYCLE
a. Sporogenesis – the process of generating an
endospore inside Clostridium or Bacillus.
b. Sporulation – the release of the endospore
from Clostridium or Bacillus bacterium.
c. Germination – the return to the active
vegetative state of bacteria when “normal”
conditions exist. Oldest germinating spore
was claimed to be 250 million years.
6. TWO MEDICALLY SIGNIFICANT
SPORE PRODUCING GENERA
a. Clostridium – an anaerobic bacteria.
Germinates only in absence of oxygen as in
necrotic tissue. 3 major diseases causing
species: C. tetani (tetanus), C. perfringens
(gas gangrene), and C. botulinum (botulism).
b. Bacillus is an aerobic endospore forming
bacteria. B. cereus – gastroenteritis, and B.
anthracis – anthrax in sheep and cattle.
End of Slides
You guessed correctly. This is
not true. I did knock down an
antelope, though.
Back