Lab Practical 1

Question 1

What is a colony derived from?

Answer 1

A single cell

Question 2

What is a cfu?

Answer 2

Colony forming unit

Question 3

Describe a bacterial colony that would be indicative of coming from the surfact of people

Answer 3

• Small to medium in size
• white, off-white, or yellow in color

Question 4

Describe bacterial colonies that originate from water

Answer 4

glistening/shiny in appearance

Question 5

Describe bacterial colonies that originate from soil

Answer 5

rough appearance, not shiny

Question 6

Which of the treatments would be considered the most effective at sanitizing hand?

Answer 6

Soap and water followed byb hand sanitizer

Question 7

What are the 3 components of ACC’s Hazard communication system?

Answer 7

1. communication from your instructor
2. material safety data sheets (MSDS)
3. Hazard labels

Question 8

What are the required PPE for lab?

Answer 8

• Z87 approved safety eyewear
• gloves
• shoes that cover all of foot
• lab apron
• tie back long hair

Question 9

What type of information does a typical chemical hazard label portray?

Answer 9

1. category of the hazard (Health - blue, flammability - red, reactivity - yellow, personal protection -white)
2. Level of Hazard (0 = no hazard, 4 = extremely hazardous)

Question 10

Know the difference between a biohazard and radioactive materials label image

Question 11

What are 4 tools used for aseptic technique?

Answer 11

1. incenerator
2. bunsen burner
3. inoculating loop
4. inoculating needle

Question 12

What is a term that described cloudy growth in a broth?

Answer 12

Turbidity

Question 13

What is a semisolid media?

Answer 13

• also referred to as motility media
• assessed whether an organism is mobile or not based on where growth occurs - growth only at site of inoculation is immobile while growth outside of that is considered mobile
• uses stick and poke method

Question 14

What is a solid slant media and what is it used for?

Answer 14

• solid medium that provies larger surface area to grow microorganisms

Question 15

What is a media solid plate?

Answer 15

• Used as an agar plate, and provides the largest surface area for microbial growth

Question 16

What is aseptic technique?

Answer 16

• uses practices and procedures to prevent contamination from microorganisms
• minimizes risk of exogenous contamination that may lead to infection in a healthcare setting

Question 17

What are the different growth patterns that can occur in broth?

Answer 17

1. control - no growth
2. turbid - general cloudyness throughout
3. pellicle - bacteria floating on top of the broth
4. sediment - bacteria that sinks to bottom
5. flecculent growth - bacteria that grows in clumps

Question 18

What is the purpose of streaking a plate for isolation?

Answer 18

• to produce isolated colonies of an organism on an agar plate
• can be used to seperate organisms in a mixed culture of when you need to study colony morphology of an organism

Question 19

What are the 5 conditions that fluid thioglycolate broth/medium (FTM) provides?

Answer 19

1. aerobic
2. anaerobic
3. facultative
4. microaerophil
5. aerotolerant

Question 20

What does fluid thioglycollate medium test for?

Answer 20

• it tests the aerotolerance of bacteria
• uses methylene blue indicator which shows color in the presence of oxygen

Question 21

What is the purpose of an anaerobic jar?

Answer 21

• creates an enviornment where there is no molecular oxygen available for cellular respiration
• a catalyzed reaction creates water in the form of condensation on the inside of the jar
• methylene blue is used as an indicator - turns blue in presence of oxygen but is colorless in an anaerobic enviornment

Question 22

What are the different types of flagellar arrangements?

Answer 22

1. atrichous - no flagella
2. monotrichous - one flagella
3. amphitrichous - flagella on either end
4. peritrichous - all over surface
5. lophotrichous - tuft of flagella (like a tail)

Question 23

What are the 3 different ways that can determine is a bacterium is motile?

Answer 23

1. wet mount
2. motility media
3. flagellar stain

Question 24

How does the flagella stain work?

Answer 24

• provides a method for viewing bacterial flagella by employing crystal violet in an alcoholic solution as a primary stain
• Alchol evaporates leaving the stain around the flagella

Question 25

What is the mortant used for flagella?

Answer 25

Tannic acid

Question 26

What is the primary purpose of simple stains?

Answer 26

The simple stain is used to discern morphology - cell shape, size, and arrangement

Question 27

What are the stains typically used for simple stains?

Answer 27

* methylene blue * safranin * crystal violet

Question 28

Are simple stains basic or acidic?

Answer 28

* basic - the cell wall of bacteria are acidic so they react and accept the basic stain * can cause some distortion from the reaction

Question 29

Are negative stains basic or acidic?

Answer 29

* Acidic - the dye is repelled by the cell wall of bacteria, but it stains the background instead * bacteria show up more clearly, no distortion * takes longer to dry

Question 30

What is the primary dye used for negative stains?

Answer 30

nigrosin

Question 31

What is the catalase test?

Answer 31

* used to differentiate staphylococci (catalase-positve) from steptococci (catalase-negative) * catalase is an enzyme produced by bacteria that respire using oxygen, and it protects them from the toxic by products of oxygen metabolism

Question 32

What is the gram stain?

Answer 32

a staining method that differentiates bacterial species into two groups: gram-positive and gram-negative

Question 33

What is the primary stain used for the gram stain?

Answer 33

crystal violet

Question 34

what is the secondary stain used in the gram stain?

Answer 34

Safranin

Question 35

What is the mortant used in the gram stain?

Answer 35

Iodine

Question 36

What is the decolorizer used in the gram stain?

Answer 36

Ethanol or acetone

Question 37

What is an endospore stain?

Answer 37

it will display the presence or absence of endospores which can be used to identify specifc gram-positive bacteria in Bacillus of Clostridium

Question 38

What stains are used in the endospore stain?

Answer 38

* Mahcalite green - colors the endospores * safranin - acts as counterstain, stains vegetative cells * water - used as decolorizer

Question 39

What us an acid fast stain?

Answer 39

A differential stain used to identify acid-fast organisms

Question 40

How are acid-fast organisms characterized?

Answer 40

by their wax-like nearly impermeable cell walls that contain ***mycolic acid***

Question 41

What stains are used in an acid-fast stain?

Answer 41

* carbol fuchsin - stains acid fast as pink * acid-alcohol - used as decolorizer * methylene blue - counterstain which stains non acid-fast organisms blue

Question 42

What is an example of a diagnostic test that uses acid-fast?

Answer 42

Mycobacterium tuberculosis

Question 43

What is a capsule stain?

Answer 43

* method devised to observe bacterial capsules * mixes india ink which stains the background providing a negative background to view cells and capsules * utilizes an acidic dye for background and basic dye to stain the cell purple

Question 44

What types of stains are used in the capsule stain?

Answer 44

A mixture of india ink (acidic background) and crystal violet (basic cell wall)