Lab #14 Flashcards
Indole Production Test
Add Kovac’s reagent, gently shake, but keep reagent on top of broth
Pink ring indicates
a) Positive
b) Negative
a) Positive
Indole Production Test
Add Kovac’s reagent, gently shake, but keep reagent on top of broth
Yellow ring indicates
a) Positive
b) Negative
b) Negative
Indole Production Test
Pink ring in broth
= positive
= has Trp-ase
- E. coli vs. other enteric bacteria
- Proteus mirabilis vs. other Proteus spp.
Indole Production Test
Yellow ring in broth
= negative
= does not have Trp-ase
- E. coli vs. other enteric bacteria
- Proteus mirabilis vs. other Proteus spp.
Methyl Red Test
Add methyl red growth culture; gently shake
Red indicates
a) Positive
b) Negative
a) Positive
Methyl Red Test
Add methyl red growth culture; gently shake
Yellow indicates
a) Positive
b) Negative
b) Negative
Methyl Red Test
Red
= positive
= pH < 5
= presence of acids
= has FHase
Klebsiella spp./Enterobacter aerogenes (-) vs. E. coli (+)
Methyl Red Test
Yellow
= negative
= pH > 6
= no acids produces
= lacks FHase
Klebsiella spp./Enterobacter aerogenes (-) vs. E. coli (+)
Carbohydrate Fermentation Test
Medium
Bromocresol purple (BCP) “carbohydrate” broth
(BCP = color pH indicator)
Carbohydrate Fermentation Tests
purple → yellow
a) positive
b) negative
a) positive
Carbohydrate Fermentation Tests
still purple…
a) Positive
b) Negative
b) Negative
Carbohydrate Fermentation Tests
Inoculate BCP lactose broth
purple → yellow
= positive
= pH change (acidic)
= ferments lactose
All Enterobacteriaceae ferment lactose!
Carbohydrate Fermentation Tests
Inoculate BCP lactose broth
still purple…
= negative
= no pH change
= does not ferment lactose
All Enterobacteriaceae ferment lactose!
Motility Test
Growth away from stab =
a) motile
b) non-motile
a) motile
Motility Test
Growth at stab =
a) motile
b) non-motile
b) non-motile
Urease Test
Yellow =
a) Urease( - )
b) Urease( + )
a) Urease( - )
Urease Test
Pink =
a) Urease( - )
b) Urease( + )
b) Urease( + )
Control of Microbial Growth
_____ _____ are used for control of microbial growth
Chemical agents