IMViC Reactions

Question 0

What are IMViC reactions?

Answer 0

Biochemical tests.

Question 1

What type of metabolic activity is happening in IMViC reactions?

Answer 1

Fermentation

Question 2

What does IMViC stand for?

Answer 2

Represents the order of the four tests…

Indole, Methyl red, Voges-Proskauer, and Citrate.

Question 3

What are IMViC tests designed to determine?

Answer 3

Specific physiological properties of microorganisms.

Question 4

What types of bacteria are these tests useful for?

Answer 4

Coilform such as E. Coli and Enterobacter-Klebsiella groups as well as Enterobacteriaceae. Any gram (-) bacterium.

Question 5

What is indole?

Answer 5

A breakdown product of the amino acid tryptophan.

Question 6

What group of bacteria typically have a positive indole test?

Answer 6

Typical strains of E. Coli. Enterobacter-Klebsiella does not.

Question 7

What bacteria was used for the indole test?

Answer 7

E. Coli and Enterobacter aerogenes.

Question 8

What is the incubation requirements for the indole test?

Answer 8

35 degrees C for 24hrs.

Question 9

What media and inculcating process was used for the indole test?

Answer 9

SIM was used and a single stab was administered.

Question 10

What reagent was used in the indole test?

Answer 10

Kovac’s indole reagent was used.

Question 11

Describe a positive indole test.

Answer 11

After the reagent is added the amyl alcohol of the reagent will separate and turn a BRIGHT RED color if indole is present.

Question 12

Describe a negative indole test.

Answer 12

There will be no color change.

Question 13

What media is used in the methyl red test?

Answer 13

MR-VP broth.

Question 14

What does MR-VP broth contain?

Answer 14

Peptone, glucose, and a phosphate buffer.

Question 15

What does the methyl red test depend on?

Answer 15

Depends on the ability if the organism to produce acid from glucose.

Question 16

What are the incubation requirement for the methyl red test?

Answer 16

Incubate at 35 degree C for 5days.

Question 17

What reagent is added the the media after 5days of incubation in the methyl red test?

Answer 17

Methyl red

Question 18

Describe a positive test for Methyl Red.

Answer 18

There will be a red color that indicates acid below a pH of 4.4.

Question 19

Describe a negative test for methyl red.

Answer 19

A yellow color.

Question 20

What is the citrate test designed to determine?

Answer 20

Whether or not a bacterium has a cell membrane transport protein to carry citrate to the cell. If protein is present it grows, if not it doesn’t grow.

Question 22

What type of bacteria typically utilizes the citrate?

Answer 22

Enterobacter-Kelbsiella

Question 23

What media and process was used in this lab?

Answer 23

Simmons citrate agar (green) and we used the stab and streak method.

Question 24

What are the intermediates of the IMViC tests?

Answer 24

Organisms not typical with E. Coli (++–) or E. Aerogenes (–++) are considered intermediates.

Question 25

Describe a positive citrate test (organism was able to transport citrate in the cell and grow)

Answer 25

Growth on the slant and change in color from green to a deep blue.

Question 26

Describe a negative citrate test (organism unable to transport citrate into the cell)

Answer 26

No growth, and green color.

Question 27

What type of bacteria typically does NOT utilize citrate?

Answer 27

E. Coli.