unknown test Flashcards
what does Indole do?
Some bacteria can hydrolyze a tryptophan, making indole as a byproduct.
what are indole’s results
(+) red oily
(-) green, beige, green
Indole procedure
add 6 drops of Kovac’s reagent
What does methyl red do?
Some bacteria can ferment glucose, making acids as the byproduct.
What are methyl red procedure
inoculate in MR/VP, add 3 drops of methyl red
methyl red results
(+) pale-ish pink red
(-) no color change
what does VP do?
some bacteria can ferment glucose, making 2,3 butanediol as byproduct.
What are VP procedure
inoculate in MR?VP then add 8 drops of Barritt’s A and B reagent each.
what are the results of VP
(+) red band
(-) no color change
what does citrate do?
some bacteria only use citrate as their sole carbon source, creating alkaline(basic) conditions as a byproduct.
What is the citrate procedure
streak isolation on agar
what are the results for citrate
(+) color change from green to blue
(-) color stays green
what does PR Glucose do?(similar process with the rest of the carbohydrate
some bacteria can ferment glucose with acid and gas, using a durham
what is the PR Glucose procedure
inoculate
what are the PR Glucose results?
(+) bubbles and yellow
(-) no bubbles
what does Urea Hydrolysis do?
if bacteria can hydrolyze urea where ammonia is produced as a byproduct
What is Urea procedure
inoculate in urea broth
What are Urea results
(+) bright pink
(-) no bright pink
what does SIM-Sulfur do?
if bacteria can reduce sulfur to Hs2 and forms ferrous salts to amke ferric sulfide
what does SIM- Motility do?
if bacteria can swim
what is the procedure for SIM-Sulfur and motility
inoculate by stabbing into sim agar, then add 6 drops of kovac reagents
What is the results of SIM-Sulfur
insoluble black precipitate
What is the result of SIM- Motility
visible turbidity that extend outwards from the stab line
what does Nitrate reduction do?
Shows if bacteria can partially or fully reduce nitrates.
what are Nitrate reduction prodcedures?
inoculate in broth and then add 5 drops of Nitrate reagent IF no bubbles are present
what are Nitrate reduction results?
(+) tube turns red
(+) bubbles present =full reduction
What does Blood agar do?
asking if bacteria can hemolysis partially or fully destroy red blood cells
What are the blood agar procedure?
inoculate only , ayay!
Blood agar results
alpha hemolysis (+)= partial clearing of the red color of red agar, sometimes a green color present
beta hemolysis(+)= full destruction of red blood cells, complete clearing
gamma hemolysis(-)= no clearing stays red
What does CNA agar do?
its selective for gram positive( kills gram negative), and differential for hemolysis
What is the CNA procedure
streak-inoculate
What are the CNA agar results
(+) = will have gram-positive
(+) = alpha or beta hemolysis
(-)= will have gram-negative
(-)= gamma hemolysis
what does MacConkey agar
selective for gram-negative (kills gram-positive) and differential for lactose fermentation aka is it able to ferment?
what is the procedure for MacConkey agar
Streak-inoculate
What are the results for MacConkey
(+)= will be gram-negative
(+)= colonies are red or pink
(-)= will have gram-positive
(-)= no color change
what are the results for catalase?
(+)= bubbles = has catalase
(-)= no bubbles
what does Catalase do?
if bacteria have the enzyme catalase, they can neutralize hydrogen peroxide. Which is necessary for aerobic metabolism.
what is the procedure for catalase?
On a slide, place bacteria on one side and add 2-3 drops of hydrogen peroxide
What does Oxidase do?
tells us if bacteria have cytochrome C oxidase enzyme, which is used to transfer electrons from Cytochrome C in the ETC to oxygen. This is important for aerobic respiration
what is the procedure for oxidase
place bacteria on one side of the strip and the other side place P. aeruginosa. Add 2-3 drops of water on each side.
what is the result of oxidase
(+)= purple within 30 seconds
(-)= no purple at all or in 30 seconds
