Microbiology Study Tool by Alexandra Levy https://padlet.com/alevy241/3y75b1zvfwxz1os7 en-us 2022-09-13 12:46:13 UTC 2022-09-13 17:39:43 UTC hello@padlet.com Microbiology alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294212295 Review of Cells
  • Cells are the simplest unit of living matter
Cell theory
1) All living organisms are composed of cells. They may be unicellular or multicellular
2) The cell is the basic unit of life
3) Cells arise from pre-existing cells

Prokaryotes vs. Eukaryotes
Prokaryotes
  • Simple, no nucleus or membrane-bound organelles
  • Bacteria and Archaebacteria
  • Grow and reproduce commonly through asexual reproduction - binary fission
  • Typically rod, spherical, or corkscrew shape
Eukaryotes
  • Complex, membrane-bound organelles
  • Protists, plants, fungi, animals
  • Grow and reproduce via mitosis or meiosis

Prokaryotic Metabolism
Autotroph
  • Carbon is obtained directly from CO2
  • Photoautotroph- Light
  • Chemoautotroph - inorganic oxidation (of water, minerals, nitrogen gas) 
  Heterotroph
  • Carbon is obtained from other things (not directly CO2)
  • Photoheterotroph - Energy from light
  • Chemoheterotroph - depend on organisms for carbon
 
Prokaryotes Reproduction
  • Genetic Transfer/Bacterial Conjugation
    • Prokaryotes can grab stray DNA from environment
    • Plasmid transfer***
  • This is how prokaryotes get variation!
    • Antibiotic resistance, new virulence factors, diversity
  • Binary Fission
    • Rapid reproduction of 2 identical daughter cells

Eukaryotes Reproduction
Cell Cycle
  • Mitosis
    • Somatic/Body cells
  • Meiosis
    • Gametes
    • Egg/Sperm
  • Variations & Diversity come from mutations

Fermentation
  • Fermentation: A natural metabolic process in which microorganisms convert carbohydrates into byproducts such as alcohol, Carbon Dioxide, or acid.
    • It is an anaerobic process (aka - without oxygen)
    • Can be prokaryotic or eukaryotic cells!
    • Lactobacillus - breaks down lactose into lactic acid
    • Saccharomyces (a fermentative yeast) - helpful for bread and alcohol
    • Penicillium (a fermentative mold) - preserves shelf life of dairy and meat products
]]> 2022-09-13 12:51:48 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294212295 Prokaryotic Metabolism alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294241409 2022-09-13 13:07:19 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294241409 Binary Fission alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294266668 2022-09-13 13:17:54 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294266668 The Cell Cycle alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294268385 2022-09-13 13:18:49 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294268385 Microbial Taxonomy alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294280338 Microbial Taxonomy - The Prokaryotes
Bacteria
  • Unicellular
  • May possess a flagella for movement
  • Aerobic (live in O2)
  • Anaerobic (can’t live in O2)
  • Facultative (An)aerobe (lives in either environment)
  • Gram + or Gram - (depends on peptidoglycan in cell wall)
Archaea
  • Unicellular
  • Live in extreme environments
  • Thermophiles (extreme hot temps)
  • Halophiles (salty environment)
  • Methanogens (methane-producing)
  • Psychrophiles (extreme cold)
Microbial Taxonomy - The Eukaryotes
Protozoa
  • Aerobic eukaryotes
  • Cellulose in cell wall
  • Many ways of locomotion (movement)
    • Cilia (hair-like)
    • Flagellates (whip-like)
    • Pseudopodia (fake feet)
Algae
  • Unicellular or multicellular
  • Cyanobacteria or blue-green algae
    • Photosynthetic
  • Live in damp soil, water, and on rocks
Microbial Taxonomy - Fungi
Fungi
  • Mushroom, molds, yeast
  • Cell wall contains chitin
  • Reproduce by releasing spores
  • Decomposers
Microbial Taxonomy - Viruses
Viruses
  • Non-living, non-cellular entities
  • Consist of: 
    • DNA or RNA (nucleic acid)
    • Surrounded by a protein coat
  • Require a host to reproduce
Microbial Taxonomy - The Helminths
Helminths
  • Not technically microorganisms, but part of their life cycle is microscopic
  • Flatworms
  • Lung Fluke Disease (Paragonimiasis)
  • Roundworms
  • Ascariasis (infection of small intestine)
  • Their parasitic tendencies are important for clinical reference



]]> 2022-09-13 13:24:48 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294280338 Bacterial Identification alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294543947 2022-09-13 15:24:39 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294543947 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294547791 2022-09-13 15:26:30 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294547791 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294550697 2022-09-13 15:28:01 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294550697 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294552079 2022-09-13 15:28:41 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294552079 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294553962 2022-09-13 15:29:39 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294553962 Bacteria Tests alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294567829 Gram Staining
  1. Add crystal violet stain
  2. Add Iodine
  3. Rinse gently with ethyl alcohol 
  4. Counterstain with safranin
  5. Gram + will be violet/blue (+ Thick peptidoglycan layer)
  6. Gram - will be pink/red (- Thin/no peptidoglycan layer)
Identifying Aerobic Bacteria - Catalase Test
  • Catalase: Enzyme produced by bacteria that uses OXYGEN
  • A positive catalase test will have bubbles present
  • A negative catalase test will have no reaction
Identifying Aerobic Bacteria - Thioglycolate Test
  1. Obligate Aerobic: Love O2
  2. Obligate anaerobic: Avoid O2
  3. Facultative: Prefer O2, but not hurt by the lack of O2
  4. Microaerophiles: Low O2 levels
  5. Aerotolerant: They do not care
  6. Aerobic: Love O2
  7. Obligate anaerobic: Avoid O2
  8. Facultative: Prefer O2, but not hurt by the lack of O2
  9. Microaerophiles: Low O2 levels
  10. Aerotolerant: They do not care










]]> 2022-09-13 15:36:25 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294567829 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294574253 2022-09-13 15:39:36 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294574253 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294574536 2022-09-13 15:39:44 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294574536 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294574706 2022-09-13 15:39:50 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294574706 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294574927 2022-09-13 15:39:56 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294574927 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294575456 2022-09-13 15:40:02 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294575456 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294575822 2022-09-13 15:40:12 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294575822 Viruses alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294587459 Viruses - Structure
  • Consists of a nucleic acid
    • DNA or RNA
    • This is its genetic material
    • Single or double stranded
  • Outer layer is the... 
    • Cospid: rigid structure to withstand harsh environments.
    • Envelope: can only survive in aqueous solutions (usually transmitted via fluids)
Viruses - Shape
  • Complex, 
    • Bacteriophage: A virus that infects bacteria)
  • Helical/Filamentous 
    • Tobacco mosaic virus, Ebola
  • Spherical
    • COVID-19, Influenza, Hepatitis B and C
    • Enveloped
  • Polyhedral
    • Poliovirus, adenovirus, rhinovirus





]]> 2022-09-13 15:45:36 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294587459 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294589028 2022-09-13 15:46:25 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294589028 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294589295 2022-09-13 15:46:33 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294589295 Pathogens alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294598057 Chain of Infection
Organism → Reservoir → 
Portal of Exit → Transmission → Portal of Entry → Susceptible Host
Spread of Infection
  •  Airborne
    • Long distance, remain suspended in air up to 6ft - Measles, TB, Chickenpox
  • Vector-borne
    • Transfer from host (carrier) → victim - Malaria (mosquitoes)
  • Common Vehicle
    • Transfer by contaminated source - Salmonella
  • Droplet
    • Close proximity, coughing, sneezing, talking - Pertussis, Flu, TB
  • Direct Contact
    • Person/Person, Animal/Person, Pregnancy -     Rabies, HIV, Ebola, Lice, STDs
Virulence Factors
  • Invade the host
  • Cause disease
  • Evade host defenses
What Medication Would We Use?
 Antibiotics
  • Used for a bacterial infection
  • Common Bacterial Infections: Bronchitis, ear infections, UTIs
  • Common Antibiotics: Doxycycline, Penicillin, Amoxicillin
Antivirals
  • Used for a VIRAL infection
  • Common Viral Infections: Influenza, HIV, Herpes
  • Common Antivirals: Tamiflu, Retrovir, Zovirax













]]> 2022-09-13 15:50:27 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294598057 Microbiology alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294614373 2022-09-13 15:57:39 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294614373 Bacterial Tests alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294618493 2022-09-13 15:59:47 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294618493 Viruses alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294619821 2022-09-13 16:00:31 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294619821 Pathogens alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294632904 2022-09-13 16:07:26 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294632904 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294637407 2022-09-13 16:09:47 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294637407 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294637619 2022-09-13 16:09:55 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294637619 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294637819 2022-09-13 16:10:03 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294637819 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294638045 2022-09-13 16:10:10 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294638045 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294638370 2022-09-13 16:10:21 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294638370 Growing Bacteria alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294795939 2022-09-13 17:15:04 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294795939 Growing Bacteria alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294818163 How Do We Grow Bacteria?
  1. First, we need to make sure we practice aseptic technique.
  2. Second, we need a media to grow them on.
  3. Third, we’ll need to wipe surfaces with a sterile applicator (looks like a really long Q-Tip or cotton swab).
  4. Fourth, we would inoculate the agar plate using a spreading technique.
  5. Fifth, wrap plates in parafilm and incubate 48-72 hours!
What's a Media?
Nutrients for Microbes
  • Different media can have different nutrients that grow specific bacteria
Different Kinds
  •  LB Agar
  • YMA
  • Potato Dextrose
  • MacConkey Agar
  • Sheep’s Blood
Identification
  •  Narrowing down growth allows microbiologists to identity their cultures
Types of Agar
 LB Agar
  • Common
  • Not very selective
Potato Dextrose
  • Grows both bacteria and fungi
Yeast Mannitol
  • Used for soil microbiology
Sheep's Blood
  • Determines type of hemolysis (breaking down blood)
MacConkey
  • Selects for Gram (-) bacteria and lactose fermentation









]]> 2022-09-13 17:27:27 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294818163 Counting Bacteria alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294818878 2022-09-13 17:27:38 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294818878 Counting Bacteria alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294825068 Hemocytometer
  • Used to count number of cells in a sample under the microscope
  • Trypan Blue: A dye that exclusively labels dead cells to differentiate them from live cells
  • Cells that are white (not filled in with blue) are live cells!
  • Solid blue cells are dead cells.
  • Equation for Total Viable Cells:
  • (Average Viable Cells) x 10,000 x DF (DF = Dilution Factor)



]]> 2022-09-13 17:30:43 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294825068 alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294827754 2022-09-13 17:32:12 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294827754 How to Plate Cells alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294828833 2022-09-13 17:32:40 UTC https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294828833 How to Plate Cells alevy241 https://padlet.com/alevy241/3y75b1zvfwxz1os7/wish/2294841669 Preparing the Petri Dish
  • Always read directions on how to prepare the agar!
  • On the petri dish, write this on the agar side:
    • Your Name
    • Date
    • Time
    • Sample (Example: Ms. Fusco’s door handle)
  • DO NOT WRITE ON THE lid
Plating Techniques
METHOD 1: Triple-Z - This should give you isolated colonies. 
  1. Draw T on bottom of plate.
  2. Flame sterilize inoculating loop, let cool 10 seconds
  3. Pick up culture with loop.
  4. Streak like a z-method back and forth in quadrant 1. DO NOT CROSS your T.
  5. Flame sterilize and let cool
  6. Drag inoculating loop through the end of quadrant 1 into quadrant 2.
  7. Keep streaking in quadrant 2 with a z pattern. DO NOT CROSS ANY T again. 
  8. Flame sterilize, let cool
  9. Drag inoculating loop through the end of quadrant 2 into quadrant 3.
  10. Keep streaking in quadrant 3 with a z pattern. DO NOT CROSS the T again. 
Method 3: 4-Quadrant Streak
  1. Sterilize loop, let cool for 10 seconds
  2. Pick up desired colony and spread horizontally in Quadrant 1.
  3. Sterilize loop, let cool for 10 seconds.
  4. Overlap Quadrant 1 and spread horizontally in Quadrant 2.
  5. Repeat steps 3&4 for Quadrants 3 and 4.
Incubation
  1. Wrap parafilm around the edges of the petri dish.
  2. Place dish into incubator (can stack dishes to save time).
  3. Make sure plates are turned upside down due to condensation 
Plating Viruses
  • Can be cultured, but it looks a little different
  • Viruses can be grown in vivo(inside a whole living organism) or in vitro (in a test tube, agar plate, cell culture flask)
  • On agar plates: bacteriophages need a bacterial lawn first! They will not grow without any cells to infect.
How to do a Gram Stain
  1. Add one drop of distilled water onto a slide.
  2. Put a loopful of the desired bacteria colony into that drop (you do not need the entire colony - too much will crowd your stain).
  3. Fix culture onto slide using a flame (wave it over flame, never HOLD it over).
  4. Add a drop of crystal violet onto sample and let sit for 20 seconds.
  5. GENTLY rinse slide with distilled water or you’ll lose your sample.
  6. Add a drop of iodine and let sit for 20 seconds.
  7. GENTLY rinse slide with distilled water or you’ll lose your sample.
How to do a Gram Stain (continued)
  1. Add a few drops of decolorizer (acetone/ethanol) and let it run off the slide. Rinse with water after 5 seconds.
  2. Counterstain with fuchsin for 40-60 seconds then rinse off with water.
  3. Gently shake of excess water and let air dry. 
  4. Look under microscope
  5. Blue stain: Gram positive
  6. Red stain: Gram negative
How to do a Catalase Test
  1. Put a sample colony onto the slide using an inoculating loop.
  2. Add one drop of hydrogen peroxide and look for bubbles.
  3. Bubbles = catalase positive (catalase is present).
  4. No bubbles = catalase negative (no catalase is present)

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