Ch. 41: Culture Techniques

Question 1

How long should a routine culture sample be incubated for?

Answer 1

48 hours (examined after 18-24)

Question 2

What bacteria is blood agar able to grow?

Answer 2

Negative & positive

Question 3

What bacteria is MacConkey agar able to grow?

Answer 3

Negative (Positive usually don’t grow)

Question 4

What is the preferred method of streaking an agar plate?

Answer 4

Quadrant streak

Question 5

Bacterial colonies may be described on the basis of their ______, _________, and ________.

Answer 5

Form, elevation, and margins

Question 6

Isolated colonies typically grow in what area of the plate?

Answer 6

Quadrant D, the last quadrant made

Question 7

What two areas of a slant agar can be inoculated?

Answer 7

The slant surface or the butt

Question 8

How is the slant surface of a tube medium inoculated?

Answer 8

Starting at the bottom of the slant, a needle is used to streak the slant in an S-shape up the slant

Question 9

How is the butt of a tube medium inoculated?

Answer 9

A bacteriologic needle is stabbed in the center of and to the bottom of the agar containing a bacterial colony from the plate and is injected through the same path when lifted out of the tube

Question 10

What is the optimal growth temperature for incubation?

Answer 10

37 degrees celcius

Question 11

Optimal growth temperature of 37 C may be lower when dealing with what pathogens?

Answer 11

Fish, skin, and environmental organisms

Question 12

Incubation time depends on what?

Answer 12

The generation time of individual bacterial species and the type of medium on which they are growing

Question 13

What species of bacteria may take 72 hours to incubate before colonies are visible?

Answer 13

Nocardia

Question 14

If the plate isn’t placed in the incubator properly, mositure could collect on the surface of the agar and cause what?

Answer 14

Clumping of colonies

Question 15

A candle jar is used for pathogens that require _________ for growth.

Answer 15

Carbon dioxide

Question 16

A candle jar creates an anaerobic condition.

True or False?

Answer 16

False

Question 17

When using a candle jar, how long are plates incubated for?

Answer 17

18-24 hours (If no growth occurs, they are incubated for another 18-24 hours)

Question 18

What factors help you to identify specific bacteria?

Answer 18

Size, pigment, density, elevation, form, texture, odor, and any hemolysis

Question 19

What are the different form classifications of bacteria?

Answer 19

Punctiform, circular, filamentous, irregular, rhizoid, and spindle

Question 20

What are the different elevation classifications of bacteria?

Answer 20

Flat, raised, convex, pulvinate, and umbonate

Question 21

What are the different margin classifications of bacteria?

Answer 21

Entire (even), undulate (wavy), filamentous, lobate (lobes), erose (serrated), and curled

Question 22

Most anaerobes can’t survive exposure to air longer than how many minutes?

Answer 22

20 minutes

Question 23

Swabs are an acceptable collection method for culture of anaerobes.

True or False?

Answer 23

False

Blocks of tissue in a sealed, sterile container and any pus or exudate collected in a sterile syringe with air expelled are the proper collection methods

Question 24

What medias are used for anaerobic culture?

Answer 24

Blood agar and thioglycollate broth