Microbiology

Question 1

General purpose, shows true hemolysis and satellitism

Answer 1

BAP

Question 2

Selects for Gram = rods, fermentors are colorful

Answer 2

MAC

Question 3

Selects for Gram + cocci, encourages Staph and Strep, inhibits Gram = rods

Answer 3

PEA

Question 4

Grows fastidious organisms; plate has X and V factor; used especially for Haemophilus and gonnorhea

Answer 4

CHOC

Question 5

Selective for N. gonnorhea; contains nystatin, vancomycin, and colistin

Answer 5

MTM

Question 6

What is nystatin used for in MTM?

Answer 6

inhibit yeast

Question 7

What is vancomycin used for in MTM?

Answer 7

inhibits all Gram +

Question 8

What is colistin used for in MTM?

Answer 8

inhibits aerobic Gram =

Question 9

Shows H2S which should make you think Salmonella; lactose fermenters appear orange/yellow

Answer 9

HE

Question 10

How does Shigella appear on HE?

Answer 10

clear because non-lactose fermenter

Question 11

Selects for E. coli O157:H7 which appears clear

Answer 11

MAC/SOR

Question 12

Selects for oxidase +, Gram = rods; incubated at 42C for two days

Answer 12

CAMPY

Question 13

If alpha colonies are seen on CAMPY, what should you look for?

Answer 13

VRE

Question 14

Used for stools; enteric Gram = rods; recovers Salmonella and Shigella

Answer 14

GN broth

Question 15

Identifies shigatoxin

Answer 15

MAC broth

Question 16

Can grow aerobic; used for anaerobic Gram + rods such as C. perfringens

Answer 16

CDC ANA

Question 17

Contains kanamycin and vancomycin; grows anaerobic Gram = rods

Answer 17

CDC ANA w/ KV

Question 18

What are some examples of organisms that grow on CDC ANA w/ KV

Answer 18

Fusobacterium and Bacteroides

Question 19

General purpose that supports the growth of aerobic, anaerobic, and microaerophilic pathogens and nonpathogens

Answer 19

THIO broth

Question 20

Contains vitamin K and hemin; helps grow anaerobes

Answer 20

ET broth

Question 21

Only grows Beta Strep A, C, and G colonies

Answer 21

SSA

Question 22

Only grows Group B Strep

Answer 22

LIM broth

Question 23

Shows mauve colonies if positive for MRSA

Answer 23

CHROMagar

Question 24

What is the measurement of the green loop?

Answer 24

0.001 mL (1 µL)

Question 25

What is the measurement of the blue loop?

Answer 25

0.01 mL (10 µL)

Question 26

What are some of the etiologic agents frequently isolated from UTI patients? (7)

Answer 26

Escherichia coli, Enterococcus spp., Klebsiella-Enterobacter spp., Proteus spp., Pseudomonas spp., and Staphylococcus saprophyticus

Question 27

What should be done if growth is obtained for a suprapubic aspiration or cytoscopy specimen?

Answer 27

Any growth should be worked up

Question 28

When <10,000 colonies are counted, what should be done?

Answer 28

Report only colony count, unless Staphylococcus aureus, Group B β streptococci, yeast, a catheterized specimen containing a possible pathogen, known chronic problem, or if the specimen was received from Dr. Hammock

Question 29

What type of chronic problems are indicated when <10,000 colonies that should be always worked up?

Answer 29

VRE, MRSA, or recurrent UTI

Question 30

If yeast is observed under wet mount, what should be performed next?

Answer 30

germ tube test using pooled serum, positive and negative controls with the patient specimen

Question 31

What is the positive control for germ tube?

Answer 31

Candida albicans

Question 32

What is the negative control used in the germ tube test?

Answer 32

Candida glabrata

Question 33

How many potential pathogens are worked up when the colony count is greater than or equal to 10,000?

Answer 33

Up to two potential pathogens