Module 4 Testas

Question 1

• Used to detect indole production by
  the organism.
• They produce indole from tryptophan
  present in peptone water.

Positive indole test – pink ring
– Negative indole test - yellow ring

E coli positive

Answer 1

Indole Test

Question 2

Triple Sugar Iron Agar, Lactose or reduce sulfur and ferment carbs

Answer 2

RED RED N/A

RED/YELLOW GLUCOSE ONLY

YELLOW/YELLOW LACTOSE

BLACK H2S

Question 3

BLACK - ferrous sulfide
Colorless - no production

RED - change into indole, tryptophanase
Colorless - no production

M - only in line - non.motile

Answer 3

SIM Medium results

Question 4

BLACK - ferrous sulfide
Colorless - no production

RED - change into indole, tryptophanase
Colorless - no production

M - only in line - non.motile

Answer 4

SIM Medium results

Question 5

• To detect the ability of certain
  bacteria to utilize citrate as the
  sole source of carbon.
• Contains Sodium citrate and
  bromothymol blue as the indicator.
• If citrate is utilized, alkali is
  produced which turns the medium to
  blue.

– Citrate positive – blue color
– Citrate negative – green color

E coli neg

Answer 5

CITRATE UTILIZATION TEST

Question 6

• Done in Christensen’s urease
  medium.
• This test is used to detect
  organisms that produce urease.
• Urease produced by the
  organisms split urea into ammonia
  and CO2.
  – Urease positive – pink color
  – Urease negative – yellow color

E coli neg

Answer 6

UREASE TEST