Nitrate Reductase/Bacitracin/Novobiocin/Coagulase test

Question 1

Purpose of Nitrate Reductase test

Answer 1

detect enzyme reductase

Question 2

Media/Inoculation/Incubation for nitrate reductase

Answer 2

Nitrate broth (beef extract, peptone, potassium nitrate, durham tube), loopful, 37C for 48 hours

Question 3

Theory of Nitrate Reductase TEST

Answer 3

Nitrate reductase turns nitrate into nitrite

Question 4

Results of nitrate reductase test

Answer 4

Red tube: positive for nitrate reductase (done)
None-red tubes: add powdered zinc (if turns red detects nitrate) if red, (-) for nitrate reductase. If not red positive for nitrate reductase

Question 5

Novobiocin Susceptibility test (purpose, application, media, inoculation, results)

Answer 5

Purpose: to determine if your organism is susceptible or resistant to novobiocin
Application: used to differentiate coagulase (-) Staphylococcus and identify Novobiocin resistant Staph. sapprophyticus
Media: TSA
Inoculation: streak 1/2 plate w/ lawn and place novobiocin disc on surface
Incubation: 37C for 48 hours
Result: S: ZOI > 16mm
R: ZOI < 16mm (saprophyticus)

Question 6

Bacitracin Susceptibility Test (Purpose, Application, Media, Inoculation guide, Incubation, Results)

Answer 6

Purpose: To determine if your organism is susceptible or resistant to bacitracin
Application: used to differentiate resistant staphylococcus from susceptible micrococcus
Media: TSA
Inoculation guide: streak 1/2 lawn, place bacitracin disc on surface
Incubation: 37C for 48 hours
Results: S: ZOI > 10mm (micrococcus)
R: ZOI < 10mm

Question 7

Coagulase test (Purpose, Application, Media, Inoculation, Incubation, theory, Results)

Answer 7

Purpose: to detect the presence of coagulase
Application: differentiate coagulase (+) staph. aureus from outer gram (+) cocci
Media: Rabbit Plasma
Inoculation guide: Loopful
Incubation: 37C for 48 hours
Theory: Coagulase turns fibrinogen to fibrin
Results:
(+) gelatinous clump (Staph. aureus)
(-) liquid