lab tests

Question 1

what type pH test is able to hydrolyze urea?

Answer 1

urease test

Question 2

what is urea?

Answer 2

a product of the carboxylation of several amino acids

Question 3

when you hydrolyze urea you get two products, what are they?

Answer 3

ammonia and CO2

Question 4

what is used for the detection of urease-producing bacteria?

Answer 4

pH indicator (phenol red)

Question 5

in a urease test, if the bacteria has a high pH this means it is_______ and the broth will turn______.

Answer 5

basic, hot pink

Question 6

RAPID urease producers

Answer 6

media that have two buffers to resist alkalization

Question 7

T/F you have to read the urease test within 24hrs.

Answer 7

True

Question 8

why do you have to read the urease test within 24 hours?

Answer 8

So it doesn’t make a burst of ammonia to take over the system in a very lange concentration

Question 9

Is the urease test able to be autoclaved?

Answer 9

No

Question 10

How do you sterilize the urease test?

Answer 10

use filter sterilization (need to have pores of 0.2 uL)

Question 11

DNAase test

Answer 11

Excoenzyme, Depolimerizes DNA

Question 12

After the DNA is polimerized, can DNA associate with methyl green?

Answer 12

no

Question 13

what kind of organism is the IMViC test mostly used for?

Answer 13

gram negative enteric organisms

Question 14

what does IMViC stand for?

Answer 14

Indole, Methyl red, Voges-pros-Kaver, citrate

Question 15

what does the Indole test look for?

Answer 15

looks for the expression of tryptophanase

Question 16

what does tryptophanase do?

Answer 16

breaks down tryptophan

Question 17

what 3 products are produced if tryptophanase is produced?

Answer 17

indole, pyruvate, ammonia

Question 18

In the indole test, what is the only product that sticks around?

Answer 18

indole (its the key target)

Question 19

what type of broth do you use during the indole test? what do you add to see the results?

Answer 19

1% tryptone broth, add kovacs reagent

Question 20

what does the kovacs reagent do?

Answer 20

adds a red ring on top of the media

Question 21

what does SIM media stand for?

Answer 21

sulfer reduction, indole, motility

Question 22

Both methyl red and voges pros kaver use________

Answer 22

MR-VP broth

Question 23

what is methyl red looking for?

Answer 23

looks for evidence of mixed acid fermentation (lactase succinate, formate, acetate)

Question 24

in the IMViC test does methyl red use a pH indicator?

Answer 24

yes, if red its an acidic pH which is a positive test

Question 25

what is the voges pros kaver test looking for?

Answer 25

looking for evidence of butandiol fermentation, acetoin

Question 26

what is acetoin?

Answer 26

precurser to butandiol

Question 27

what two reagents do you add to the voges pros kaver test?

Answer 27

Barritts reagent A( alpha napthol) and Barritts reagent B (KOH)

Question 28

Are you able to get an organism that is positive for mixed acid and butandiol fermentation?

Answer 28

No

Question 29

what type of agar does the citrate test use?

Answer 29

simmons citrate agar (synthetic media)

Question 30

all ______ ________ ________ bacteria can use citrate as an energy source

Answer 30

gram negative enteric

Question 31

what does the citrate test look for?

Answer 31

looking for the expression of citrate permease

Question 32

what is in simmons citrate agar?

Answer 32

mineral salts, sodium citrate, and ammonium ions

Question 33

T/F if bacteria can grow in the simmons citrate agar they have citrate permease

Answer 33

true

Question 34

in citrate test, if the broth uses _______ _____ and increase pH, this can be used as a definitive answer. (look for pH change)

Answer 34

ammonium ions

Question 35

what is the pH indicator in the citrate test?

Answer 35

Bromthymol blue

Question 36

if the pH _____ then the tube turns _____. green means _______

Answer 36

increases, blue, neutral

Question 37

T/F Methyl green attaches to fragmented DNA to signify a positive DNase result

Answer 37

False

Question 38

why are there two buffers that resist alkilization in the urease test?

Answer 38

so you can distinguish the RAPID urease producers

Question 39

what three characteristics can be determied by inoculating SIM media?

Answer 39

sulfer reduction
indole
motility

Question 40

the ___________________ test determines whether a bacteria can undergo butandiol fermentation by looking for the production of the butandiol precursor, _________, after incubation after the the addition of _____________.

Answer 40

voges pros kaver, acetoin, barritts reagents