Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
11 Cards in this Set
- Front
- Back
|
IMVIC
|
-Indol
-Methyl red -Voges-Proskauer -Citrate |
|
|
Indol Production test
|
1. Principle: to show fermentation can take place with products other than carbohydrates
2. Some organisms can degrade tryptophane to Indol. Presence of Indol indicates E. Coli 3. Reagents: tryptone broth and Kovac's Reagent 4. Interpretation: upon adding Kovac's Reagent, a red ring formation means positive and no red color means negative. |
|
|
Ideal incubation time for the IMViC reactions
|
24 - 48 hours
|
|
|
Methyl-Red / Voges-Proskauer test
|
1. Both MR and VP tests use the same medium, MRVP broth
2. Methyl Red test depends on ability of organism to produce acid from glucose, causing Methyl Red indicator to change to Red. 3. VP test results from a red colored complex, acetoin, formed from glucose fermentation. 4. There is an inverse relationship between the MR and VP tests. bacteria that are MR positive are VP negative and vice versa. 5. Reagents: VP uses alpha-napththol and 40% KOH. MR uses Methyl Red indicator. 6. Biochemistry: Glucose --> Pyruvate --> Acetoin 6. |
|
|
Simmons Citrate Test
|
1. Principle: Tests the organism's ability to metabolize citrate. If it metabolizes citrate, the pH of the medium will go up.
2. Interpretation: Citrate metabolization --> Higher pH --> Blue color. Positive is Blue color. |
|
|
Which bacteria produce a positive VP test?
|
Klebsiella, Enterobacter, and Serratia
|
|
|
What medium is shared by two tests?
|
MRVP broth, for Methyl Red and VP test
|
|
|
Group A Strep
|
GAS are pus forming, produce toxins, and cause pharyngitis, scarlet fever, bacteremia, skin infections.
|
|
|
Taxo A disk
|
Bacitracin inhibits GAS. Taxo A disks have bacitracin
|
|
|
Taxo P disk
|
Optochin inhibits Pneumococci. Taxo P disks have Optochin.
|
|
|
Interpreting Taxo A and Taxo P disk results
|
For Taxo A, any zone of inhibition is positive. For Taxo P, a zone of inhibition > 14mm is positive.
|
