# data[].attributes.body
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).

# data[].attributes.body
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 a slide using a flame (wave it over the flame, never HOLD it over).

4. Add a drop of crystal violet onto the sample and let sit for 20 seconds.

5. GENTLY rinse the 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 the slide with distilled water or you’ll lose your sample.

8. Add a few drops of decolorizer (acetone/ethanol) and let it run off the slide. Rinse with water after 5 seconds.

9. Counterstain with fuchsin for 40-60 seconds then rinse off with water.

10. Gently shake of excess water and let air dry.

11. Look under microscope

12. Blue stain: Gram-positive

13. Red stain: Gram-negative

# data[].attributes.body
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.

# data[].attributes.body
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!

Why???

# data[].attributes.body
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

# data[].attributes.body
Used to count the 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)

(Average Viable Cells) x 10,000 x DF

Q1: 20 white, 3 blue

Q2: 20 white, 2 blue

Q3: 20 white, 2 blue

Q4: 21 white, 3 blue

DF = 5

((20+20+20+21)/4) x 10,000 x 5 20.25 x 10,000 x 5 = 1,012,500 viable cells

# data[].attributes.body
LB Agar- Common, Not very selective
Potato Dextrose- Grows both bacteria and fungi
Yeast-Mennitol- Used for soil microbiology
Sheep's Blood-  Determines type of hemolysis (breaking down blood)
MacConkey- Selects for Gram (-) bacteria and lactose fermentation

# data[].attributes.body
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 identify their cultures

# data[].attributes.body
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!

# data[].attributes.body
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

# data[].attributes.body
Invade the host

Cause disease

Evade host defenses

Adherence Factors- Bacteria use pili to stick to cells
Invasion Factors- Allow easier invasion of host cell - coded in plasma

Capsules- Protection - resistant to phagocytosis
Endotoxins- On Gram Negative bacteria - released when cell dies
Exotoxins- Secreted - neurotoxins, cytotoxins, enterotoxins
Siderophores- Iron binding factor - competes host for iron, Hemoglobin uses iron to carry O2

# data[].attributes.body
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

# data[].attributes.body
Organism → Reservoir→

Portal of Exit→ Transmission → Portal of Entry→ Susceptible Host

# data[].attributes.body
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

# data[].attributes.body
COVID...

Envelope

No capsid

Transmits via fluids

Single stranded RNA

Spherical

# data[].attributes.body
Consists of a nucleic acid

DNA or RNA

This is its genetic material

Single or double stranded

Outer layer is the...

Capsid: rigid structure to withstand harsh environments.

Envelope: can only survive in aqueous solutions (usually transmitted via fluids)

# data[].attributes.body
Space, Waste

Nutrients, Temp

pH & gas concertation

Water

# data[].attributes.headline
Identifying AEROBIC Bacteria- Thioglycolate Test

# data[].attributes.subject
Identifying AEROBIC Bacteria- Thioglycolate Test

# data[].attributes.body
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

# data[].attributes.headline
Identifying AEROBIC Bacteria- Catalase Test

# data[].attributes.subject
Identifying AEROBIC Bacteria- Catalase Test

# data[].attributes.body
Catalase: Enzyme produced by bacteria that uses oxygen

A positive catalase test will have bubbles present

A negative catalase test will have no reaction

# data[].attributes.body
1. Add crystal violet stain

2. Add iodine

3. Rinse gently with ethyl alcohol

4. Counterstain with safranin

5. Gram + will be violet/blue

6. Gram - will be pink/red

Gram  +:
Thick, peptidoglycan layer

Gram -:
Thin/no, peptidoglycan layer

# data[].attributes.body
Spirilla- Rigid spiral-shaped bacteria
Filamentous- Thread-like, cells elongate but don’t divide

# data[].attributes.body
Bacilli-Rod-shaped, Important Examples: Streptobacillus, Bacillus

Cocci-Round, spherical, Important Examples: Staphylococci, Streptococci

# data[].attributes.body
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

# data[].attributes.body
Viruses-

Non-living, non-cellular entities

Consist of:

DNA or RNA (nucleic acid)

Surrounded by a protein coat

Require a host to reproduce

# data[].attributes.body
Fungi-

Mushroom, molds, yeast

Cell wall contains chitin

Reproduce by releasing spores

Decomposers

# data[].attributes.body
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

# data[].attributes.body
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)

# data[].attributes.body
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

# data[].attributes.body
Cell Cycle

Mitosis

Somatic/Body cells

Meiosis

Gametes

Egg/Sperm

Variations & Diversity come from mutations

# data[].attributes.body
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

# data[].attributes.body
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

# data[].attributes.body
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

# data[].attributes.body
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.