5.19: Triple Sugar Iron Agar Flashcards
Which carbohydrate(s) are typically present in TSI agar?
-glucose, lactose, and sucrose
If an organism is capable of reducing sulfur and producing hydrogen sulfide, the result that is expected in a TSI agar slant is:
-black precipitate
What does a TSI tube with a cracked or lifted agar surface indicate?
-The bacteria produced gas (CO2 and H2).
What is the primary purpose of using TSI agar in microbiology?
-To test for carbohydrate fermentation and sulfur reduction
In TSI agar, what does a pink color throughout the medium indicate?
-Alkaline conditions
Which of the following describes a bacterial strain that ferments glucose but not lactose and sucrose in the TSI test?
-K/A
Which of the following statements is true about TSI agar?
-It helps differentiate bacteria based on carbohydrate fermentation and sulfur reduction.
What is the role of phenol red in the TSI test?
-it serves as a pH indicator
What does the “TSI” in TSI agar stand for?
-triple iron sugar
Which of the following describes a bacterial strain that does not ferment glucose but catabolizes aerobically and anaerobically the peptone in the TSI test?
-K/NC
If an organism that is incubated on a TSI agar slant produces a red slant and red butt, this indicates that the organism
-Does not ferment either glucose or lactose.
What is the purpose of the slant and butt portions in TSI agar?
-To provide different nutrient sources
If an organism that is incubated on a TSI agar slant produces a yellow slant and yellow butt, this indicates that the organism
-Ferments both glucose and lactose.
In TSI agar, what does a yellow color throughout the medium indicate?
-acidic conditions
In TSI agar, what does a red slant and yellow butt indicate?
-The bacteria can ferment glucose but not lactose.
the TSI tests for:
-sulfur reduction
-glucose, lactose, and sucrose fermentation
The medium is an agar slant with a deep butt, to prove ?? and ?? growth environments
-aerobic
-anaerobic
A glucose-only fermenter - lower the pH (acid
products) and turn the entire medium ??
-yellow
As the glucose diminishes, ammonia produced
from the deamination of amino acids by organisms
located in the aerobic region (slant) will begin to
raise the pH and turn it ??
-red
A TSI with a red slant and yellow butt after a 24-
hour incubation period indicates that the organism
ferments:
–glucose but not lactose and/or sucrose
K/A:
K/NC:
K/A,H2S:
A/A:
-alkaline slant/acid butt
-alkaline slant/no change in butt
-alkaline slant/acid butt, hydrogen sulfide present
-acid slant/acid butt
