Microbiology

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Microbiology

• Life as a Single Cell
• Where does disease come from?
• Microbes and Mankind

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Some Key Terms

• Disease
• a condition of the living animal or plant body or
  of one of its parts that impairs normal
  functioning and is typically manifested by
  distinguishing signs and symptoms
• Infectious Disease
• A disease capable of spreading rapidly to others
• Pathogen
• a specific living causative agent of disease
• Parasite
• an organism living in, with, or on another
  organism as a source of nutrition / energy

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There are 5 basic forms of infectious disease.

• Viruses
• Bacteria
• Protozoans (animal-like protists)
• Fungi
• Invertebrate parasites

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The Micro Scale 10-6m

• Single celled or unicellular life exists in four
  Kingdoms of life.
• Kingdom Monera the bacteria
• Kingdom Fungi yeast mold
• Kingdom Protista the Protozoans
• Kingdom Archaea archaeans
• Microbial life exists in five Kingdoms
• Kingdom Animalia various invertebrates
• Requirements for micro-life

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Characteristics of Living Things

• Reproduce (make more of its kind)
• Obtain energy (heterotrophs/autotrophs)
• Metabolize (breaking down and building up)
• Eliminate waste
• Made of cells (Eukarya/Prokarya/Archaea)
• Genetic information (DNA)
• Part of a food chain (producer / consumer)
• All have to die (have a life cycle)
• Adapt to environment (individuals group)
• Grow (size) and develop (complexity)

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Where does disease come from?
Microbes/Parasites - Genetics - Environment

• What happens to us on the macro-scale depends on
  what is happening to us on the micro-scale.
• Microbes/Parasites need to feed to get raw
  materials and to get energy.
• We are food.

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The Virus Questions

• Are Viruses classified as living things or not?
• Currently NO.
• A Taxonomy has been built

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The Virus Questions

• Why is there a debate?
• Viruses meet some but not all criteria of living
  things

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NO

• Respond to the environment ?
• Move under their own power ?
• Influence / change host they live in ?
• Mimic living infections ?
• Have ability to replicate ?
• Age or die under optimal conditions ?
• Have a metabolism ?
• Grow or develop ?
• Contain organic molecules (carbon) ?
• Have genetic information - DNA or RNA ?
• Adapt as a group over time ?
• Eat ?
• Produce by-products / waste products ?
• Reproduce outside of host assistance ?
• Can be killed / inactivated ?
• Produce and consume energy ?
• Made of cells ?

NO
YES
YES
YES
NO
NO
NO
YES
YES
YES
NO
NO
NO
YES
NO
NO
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Virus Questions

• If they are not alive, then what else would they
  be?
• Viruses are ultramicroscopic non-cellular genetic
  elements (nucleic acids DNA/RNA) surrounded by
  a protein coat, which are of biological
  significance.
• Renegade / parasitic DNA RNA

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Visualizing Viruses

• Seeing the ultramicroscopic is only possible
  using the electron microscope
• The probe is the electron not light
• The images are in black and white because there
  is no visible light involved.

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Helical Symmetry - Coiled spiral
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The helical structure of the rigid tobacco mosaic
virus rod
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Icosahedral Symmetry

• 20 equilateral triangle faces

SPIKES
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Sugarcane Fiji disease virus
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Polyhedral Virus
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Bacteriophages

• Icosahedral head, helical tail, fibers pins

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Phage Transmission Electron Microscope
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Envelope enclosed - Icosahedral Symmetry
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Virus Vocab
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• Viral Envelope membrane structure - from host
• Spikes-projections from the envelope, attachment
• Unique viral proteins - in lipid bi-layer. Used
  to complete attachment and invade host cell

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Viral Infection/Replication

• Transmission Airborne / respiratory,
• blood-borne / body fluids
• Attachment host and viral receptors unite
• Viral - protein coat, glycoproteins,
  envelope,
• spikes
• Host - pili, cilia, flagella, membrane
  proteins
• Penetration of the cell membrane phagocytosis
  - active transport by host cell blending -
  envelope with cell membrane inject -
  bacteriophage tail sheath uses enzymes to open
  a hole in the cell wall/membrane

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The End
and a new beginning
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Genome
Icosahedral
Transmission Attachment Penetration
Capsid
Phagocytosis
Nucleus
Ribosome
Genomes
Capsids
Golgi body
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Release

• Biological exhaustion of the cell -
  disintegration
• Cell lysis - cell is physically overloaded with
  viruses and the cell membrane bursts
• Cell to cell passage virus moves from one cell
  to the next without passing through the
  environment
• Budding (see next slide)

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Release

• Budding - nucleocapsid moves to cell membrane
  where it forces itself out of the cell taking a
  portion of the cell with it.

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Antiviral Agents

• Antibiotics do not work against viruses because
  they do not have the cellular functions
  antibiotics target
• Nucleotide analogs - bind to viral DNA / RNA
• Acyclovir - prevent viral replication of herpes
• Azidothymidine (AZT) - prevent viral replication
  of HIV
• Gamciclovir - cytomegalovirus
• Amantadine - influenza
• Interferon - proteins, produced naturally by an
  infected host cell. Do not help infected cell,
  but protects neighboring cells

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Viral Vaccines

• Preventive measure - not treatment
• Injection / oral dose to prime the immune
  system antigen - host makes antibody
• inactivated virus - dead from physical/chemical
  treatment
• attenuated virus - live, weakened virus - slow
  replication, no symptoms of the disease
• synthetic antigens - genetically engineered
  antigens
• examples polio, yellow fever,
• measles, rubella, hepatitis,
• smallpox

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Kingdom Monera

• Formerly know as Prokaryotae,
  all Monerans are prokaryotic bacteria
• Heterotrophs - parasitic saprobphitic
• Autotrophs - photosynthetic chemosynthetic
• All are microscopic - some are ultramicroscopic
• Most are motile - flagella, cilia, slimy gliders
• Some are useful or harmless to humans, some cause
  infection/disease

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Morphology - Basic shapes

• Cocci (coccus) spherical
• Bacilli (bacillus) rod-like
• Vibrio comma
• Spirochete flexible wavy shape
• Spirochetes have a worm-like, spiral-shaped form,
  and wiggle vigorously when viewed under a
  microscope
• Spirillum corkscrew
• Anywhere from less than one to five helical
  turns.
• They have rigid helical cell structure as opposed
  to the flexible cell structure of spirochetes.
• diplococcus pair of cocci
• streptococcus chain of cocci
• streptobacilli chain of bacilli
• tetracoccus four cocci in a cube
• staphylococcus grapelike cluster

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Im Wavy
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Tetrads
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Phylum Eubacteria

• the true bacteria
• mostly heterotrophs
• Decomposers, saprobes, parasites, symbionts
• all have a complex carbohydrate cell walls made
  of peptidoglycan and at least one inner membrane
• common causes of disease
• example Streptococcus aureus

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Other Moneran Phyla

• Prochlorobacteria small, photosynthetic
• Cyanobacteria formerly blue-green algae
• Archaebacteria now Kingdom Archaea, live in
  extreme environments

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Kingdom Archaea

•   The archaea very much resemble bacteria, so
  much so that they were once thought to be a weird
  group of bacteria. However, by studying archaeal
  cells on a molecular level, scientists have now
  come to think that these "weird bacteria"
  actually are a separate category of life
  altogether. In fact, in some ways, archaea are
  more like you than they are like bacteria!

•   The archaea very much resemble bacteria, so
  much so that they were once thought to be a weird
  group of bacteria. However, by studying archaeal
  cells on a molecular level, scientists have now
  come to think that these "weird bacteria"
  actually are a separate category of life
  altogether. In fact, in some ways, archaea are
  more like you than they are like bacteria!

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Archeaens Distinctives -Extremophiles

• Many archaeans thrive in conditions that would
  kill other creatures boiling water, super-salty
  pools, sulfur-spewing volcanic vents, acidic
  water and deep in Antarctic ice. These types of
  archaea are often labeled "extremophiles,"
  meaning creatures that love extreme conditions.

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Kingdom Profiles - Archaea
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Archaean Distinctives
Biochemistry of the cell membrane
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Archaean Distinctives
Structure of the ribosomes
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Archaean Distinctives
Alternate Sources of nutrition Hydrogen,
Sulfur, Carbon Dioxide
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Moneran Parts

• Most have a cell wall - some just a defective
  layer
• Prevents cell from exploding in a hypotonic
  solution
• Provides some protection against viruses, other
  bacteria, antibiotics, host immune system,
  environment, dehydration, disinfection
• adhere to surfaces
• Cell walls are classified as Gram or Gram -
• Gram variable capsule, thick peptidoglycan,
  membrane
• Gram - variable capsule, outer lippoprotein
  membrane, sheet of peptidoglycan, periplasam,
  inner membrane

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Bacterial Growth

• Very short generation time (doubling time)
• 20 min for the fastest
• Average time is 30 min to 3 hours
• Lag phase - bacteria become accustomed to new
  environment, new cells replace dying cells, slope
  up
• Logarithmic (log) phase - optimal level of
  growth, population doubles rapidly, straight
  ascending line.
• Stationary phase - reproduction offsets death
  (from accumulation of waste, lack of nutrients,
  unfavorable environment and host immune response.
  
• Death phase - decline in population

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Antibiotic Resistance

• Resistance is being able to defeat the antibiotic
  by, making an enzyme that destroys the antibiotic
  (penicillinase) -or- making a molecule that binds
  to the active site of the antibiotic.
• When exposed to antibiotics, the susceptible
  cells in the population die - the resistant cells
  multiply rapidly when competition is gone.
• Resistant strains become widespread.
• Sometimes even non-resistant bacteria living near
  resistant ones can survive
• drug resistant genes can be transferred during
  conjugation

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Controlling Bacterial Disease

• Alxandar Flemming - discovered 1st antibiotic in
  1929
• discovered penicillin growing on a moldy petri
  dish - isolated antibacterial agent

• Lister - listerine is named for him
• pioneered hygiene sanitation
• heating to 60 C for 30 min destroys exotoxins and
  kills most bacteria.

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Protozoans

• The animal-like, heterotrophic, unicellular,
  Protists

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ectoplasm
endoplasm
Hyalin cap
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Giardia - common beaver parasite
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Giardia Scanning Electron microscope
Compound light microscope
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Plasmodium, causes malaria - 1 infectious human
disease
Do you know anyone with malaria?
Why not?
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Toxoplasma gondii - 1/2 of all Americans have had
this sporazoa at one time - found in cats
pork.Not serious for healthy adults, but very
dangerous to newborns, fetus AIDS patients.
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This diagram shows the possible steps in the
complicated life-cycle of Toxoplasma
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6 General Characteristics
Kingdom Fungi

• 1) Eukaryotic
• 2) Non-photosynthetic, heterotrophic absorptive
• 3) Lack tissue differentiation, composed of
  similar cells hyphae
• 4) Have cell walls made of chitin
  polysaccharide, strength molecule
• 5) Propagate by spores may be produced sexually
  or asexually
• 6) Non-motile

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Hyphae a Fungus original
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Hyphae a closer look
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Hyphae a microsopic view
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Fungi Feeding

• Parasites - specialized hyphae called haustoria
  pierce the cell membranes of host cells and feed
  directly from them

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Typical Deuteromycota Mycelium
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Thursh - Angular cheilitis
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Thrush - Atrophic candidiasis
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Thrush - Atrophic candidiasis
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Thrush - Atrophic candidiasis
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Babies with Thrush
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Athletes Foot - Moccasin Pattern
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Athletes Foot - Craks Fissures
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Onychomycosis Toenails fingernails
submitted by Stephanie Johnson class 04
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What can you do ?
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Athletes Foot - Advanced Spread
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Ringworm - Basic Lesion Pattern
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Ringworm - Ankle
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Ringworm - Back
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Ringworm Face Head
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Ringworm - Legs
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Ringworm - Feet
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Ringworm - Feet 77 year old woman
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Ringworm - More Nappy Old Toes
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Kingdom Anamalia - Phylum Platyhelminthes
Three Classes Turbellaria - free living
flatworms Trematoda - parasitic
flukes Cestoda - tapeworms
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Class Trematoda Sheep Liver Fluke
Pharynx
Oral Sucker
Two Part Digestive Tract
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Class Trematoda Chinese Liver Fluke
Ventral Sucker
Oral Sucker
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Kingdom Anamalia - Phylum Platyhelminthes -
Class Cestoda
Young Progottid
Scolex
Old Progottid
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can grow up to 30 feet length of whole intestine
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Kingdom Anamalia - Phylum Platyhelminthes -
Class Cestoda
Hooks
Suckers
Scolex
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A tapeworms fancy attachment equipment
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Kingdom Anamalia - Phylum Platyhelminthes -
Class Cestoda
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Suckers
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how do you get a tape worm?
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Urban Myths

• A young woman had tried all kinds of diets that
  didn't work, and finally she decided to try diet
  pills. They made her lose so much weight all at
  once that she was really happy. Then one night,
  when she was lying in bed with her husband, a
  tapeworm crawled right out of her nose. It had
  made her sick and caused her to lose so much
  weight all of a sudden.

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Urban Myths
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Kingdom Anamalia Phylum Nematoda
Examples Round worms, pinworms, filarial worms
(elephantiosis), trichinella (trichinosis) hookwor
m
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Hookworm
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Are round worms dangerous? There have been cases
of human illness caused by the ingestion of live
Phocanema or Anisakis larvae in countries where
raw or lightly cured fish is commonly eaten. By
1980, there had been only one reported case of
illness in the United Kingdom caused by larval
round worms from fish this is because in the UK
fish products are normally cooked before
consumption.
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• Toxocara canis is the predominant cause of a
  serious condition called Visceral Larva Migrans
  in humans. Most victims are children. They are
  infected by inadvertantly consuming worm eggs in
  soil (typically by getting dirty fingers in their
  mouths).  The worm is not present in its correct
  host but tries to complete its life cycle anyway.
  The worm gets lost in the human body (classically
  in the eye), dies, and generates an extreme
  inflammatory reaction. If the worm dies within
  the human eye, blindness usually results.
• For this reason, it is important for parents to
  be aware of this hazard.  Proper hand-washing
  will prevent infection. Monthly pet deworming
  will reduce environmental contamination. Public
  leash laws and restriction of dog walking are
  meant to reduce fecal contamination of public
  areas. Stray cats should be kept away from
  childrens sandboxes.