Deck 7: Traditional Cultivation and Identification

Question 1

Increased concentrations of CO₂ (5% to 10%) and approximately 15% O₂ is the environmental condition that best suits which type of organism?

A)Aerobes
B)Anaerobes
C)Capnophiles
D)Microaerophiles

Answer 1

C
Various types of microorganisms require different atmospheric conditions. Capnophiles grow best in the presence of increased levels of carbon dioxide.

Question 2

Which category of media would MacConkey agar best fit?

A)Selective
B)Differential
C)Selective and differential
D)Supportive only

Answer 2

C
MacConkey agar contains crystal violet to inhibit gram-positive bacteria and fungi, allowing gram-negative bacilli to grow.

Question 3

Which medium can be described as containing crystal violet dye to inhibit the growth of gram-positive bacteria and fungi, and allows many types of gram-negative bacilli to grow?

A)Thayer-Martin
B)MacConkey
C)PEA (phenylethyl alcohol)
D)Hektoen

Answer 3

B
MacConkey contains crystal violet dye to inhibit the growth of gram-positive bacteria and fungi, and allows many types of gram-negative bacilli to grow.

Question 4

The role of the agar ingredient in culture medium is to

A)provide a nutritional base for bacterial metabolism.
B)solidify the medium and provide a stable culture surface.
C)sterilize the medium and prevent contamination.
D)All of the above are correct.

Question 5

Organisms that have nutritional needs that are relatively complex and require extra media components to be used for growth are called

A)fastidious.
B)capnophiles.
C)neutrophiles.
D)halophiles.

Question 6

Which medium can be described as suppressing the growth of most gram-negative organisms while allowing gram-positive bacteria to grow?

A)Chocolate
B)CNA (colistin, nalidixic acid) blood
C)BHI (brain heart infusion)
D)Thioglycollate

Question 7

Which medium can be described as a nutritionally rich medium used to grow various microorganisms, either as a broth or as an agar, with or without added blood?

A)Chocolate
B)CNA (colistin, nalidixic acid) blood
C)BHI (brain heart infusion)
D)Thioglycollate

Question 8

Which category of media can be described as containing specific nutrients required for the growth of particular bacterial pathogens in a patient specimen?

A)Enrichment
B)Supportive
C)Selective
D)Differential

Question 9

Which category of media can be described as containing nutrients that support growth of most nonfastidious organisms without giving any particular organism a growth advantage?

A)Enrichment
B)Supportive
C)Selective
D)Differential

Question 10

What name is given to the type of hemolysis that produces incomplete hemolysis and a greening discoloration of the medium?

A)Beta hemolysis
B)Gamma hemolysis
C)Alpha hemolysis
D)Kappa hemolysis

Question 11

To read the hemolytic reaction on a blood agar plate accurately, the technologist must

A)hold the plate up to the light and observe the plate with the light coming from behind.
B)hold the plate under the light and observe the plate with the light coming from the top.
C)hold the plate over a white background.
D)examine the plate using reflected and transmitted light.

Question 12

Which category of media would blood agar best fit?

A)Selective
B)Differential
C)Selective and differential
D)Supportive only

Question 13

Which category of media would Löwenstein-Jensen best fit?

A)Selective
B)Differential
C)Selective and differential
D)Supportive only

Question 14

Ambient air, which contains 21% oxygen (O₂) and a small amount (0.03%) of carbon dioxide (CO₂), is the environmental condition that best suits which type of organism?

A)Aerobes
B)Anaerobes
C)Capnophiles
D)Microaerophiles

Question 15

What name is given to the type of hemolysis that produces complete hemolysis and a clearing of the medium?

A)Beta hemolysis
B)Gamma hemolysis
C)Alpha hemolysis
D)Kappa hemolysis

Question 16

Which category of media can be described as containing one or more agents that are inhibitory to all organisms except those being sought?

A)Enrichment
B)Supportive
C)Selective
D)Differential

Question 17

A bacterial colony can be described as

A)sufficiently large numbers of a bacterium that can be observable with the unaided eye.
B)derived from a single bacterial cell.
C)belonging to the same genus and species.
D)having identical genetic and phenotypic characteristics.
E)All of the above are correct.

Question 18

Which category of media can be described as containing some factor (or factors) that allows colonies of one bacterial species or type to exhibit certain metabolic or culture characteristics that can be used to distinguish them from other bacteria growing on the same agar plate?

A)Enrichment
B)Supportive
C)Selective
D)Differential

Question 19

Which medium can be described as containing hemoglobin, hemin ("X" factor), and the coenzyme nicotinamide adenine dinucleotide (NAD or "V" factor)?

A)Chocolate
B)CNA (colistin, nalidixic acid) blood
C)BHI (brain heart infusion)
D)Thioglycollate

Question 20

Which medium can be described as containing bile salts and dyes (bromthymol blue and acid fuchsin) to selectively slow the growth of most nonpathogenic gram-negative bacilli found in the gastrointestinal tract and allow Salmonella spp.and Shigella spp.to grow?

A)Thayer-Martin
B)MacConkey
C)PEA (phenylethyl alcohol)
D)Hektoen

Question 21

Capnophiles grow best in

A)ambient air, which contains 21% oxygen (O₂) and a small amount (0.03%) of carbon dioxide.
B)increased concentrations of CO₂ (5% to 10%) and approximately 15% O₂.
C)5% to 10% hydrogen (H₂), 5% to 10% CO₂, 80% to 90% nitrogen (N₂), and 0% O₂.
D)reduced O₂ (5% to 10%) and increased CO₂ (8% to 10%).

Question 22

Microaerophiles grow best in

A)ambient air, which contains 21% oxygen (O₂) and a small amount (0.03%) of carbon dioxide.
B)increased concentrations of CO₂ (5% to 10%) and approximately 15% O₂.
C)5% to 10% hydrogen (H₂), 5% to 10% CO₂, 80% to 90% nitrogen (N₂), and 0% O₂.
D)reduced O₂ (5% to 10%) and increased CO₂ (8% to 10%).

Question 23

Which type of media is designed to support the growth of one group of organisms, but not another, by containing antimicrobials, dyes, or alcohol?

A)Selective
B)Nutritive
C)Differential
D)Definitive

Question 24

A differential medium is designed especially to

A)support the growth of a wide range of microorganisms.
B)distinguish microorganisms on the basis of certain growth characteristics.
C)support the growth of one group of organisms, but not another, by containing antimicrobials, dyes, or alcohol.
D)enhance the growth of pathogens and discourage the growth of commensals.

Question 25

Anaerobes grow best in

A)ambient air, which contains 21% oxygen (O₂) and a small amount (0.03%) of carbon dioxide.
B)increased concentrations of CO₂ (5% to 10%) and approximately 15% O₂.
C)5% to 10% hydrogen (H₂), 5% to 10% CO₂, 80% to 90% nitrogen (N₂), and 0% O₂.
D)reduced O₂ (5% to 10%) and increased CO₂ (8% to 10%).

Question 26

A supportive medium is designed especially to

A)support the growth of a wide range of microorganisms.
B)distinguish microorganisms on the basis of certain growth characteristics.
C)support the growth of one group of organisms, but not another, by containing antimicrobials, dyes, or alcohol.
D)enhance the growth of pathogens and discourage the growth of commensals.

Question 27

Cultivation of most medically important bacteria sought in the medical laboratory is done using incubators with temperatures maintained in what range?

A)35° to 37° C
B)30° to 35° C
C)37° to 39° C
D)25° to 35° C

Question 28

Reduced O₂ (5% to 10%) and increased CO₂ (8% to 10%) is the environmental condition that best suits which type of organism?

A)Aerobes
B)Anaerobes
C)Capnophiles
D)Microaerophiles

Question 29

A selective medium is designed especially to

A)support the growth of a wide range of microorganisms.
B)distinguish microorganisms based on certain growth characteristics.
C)support the growth of one group of organisms, but not another, by containing antimicrobials, dyes, or alcohol.
D)enhance the growth of pathogens and discourage the growth of commensals.

Question 30

Aerobes grow best in

A)ambient air, which contains 21% oxygen (O₂) and a small amount (0.03%) of carbon dioxide.
B)increased concentrations of CO₂ (5% to 10%) and approximately 15% O₂.
C)5% to 10% hydrogen (H₂), 5% to 10% CO₂, 80% to 90% nitrogen (N₂), and 0% O₂.
D)reduced O₂ (5% to 10%) and increased CO₂ (8% to 10%).

Question 31

A candle jar is used to cultivate which type of bacteria?

A)Aerobes
B)Anaerobes
C)Capnophiles
D)Microaerophiles

Question 32

Which type of media is designed to support the growth of a wide range of microorganisms?

A)Selective
B)Supportive
C)Differential
D)Definitive

Question 33

Which type of media is designed to distinguish microorganisms on the basis of certain growth characteristics?

A)Selective
B)Nutritive
C)Differential
D)Definitive

Question 34

Selection of media to inoculate for any given specimen is usually based on

A)the characteristics of the organisms most likely to be involved in the disease process.
B)the likelihood and types of normal flora present at the site.
C)the most likely pathogens of the suspected disease.
D)All of the above are true.