BIOCHEMICAL TESTING

Question 1

Heat Stable Catalase (+):

Answer 1

M. szulgai
M. xenopi
M. malmoense
MAC

Question 2

Heat Stable Catalase (-):

Answer 2

M. gastri
M. marinum
M. haemophilum

Question 3

Reagent of Heat Stable Catalase Test

Answer 3

30% H202

Question 4

Reagent of Pyrazinamide Test

Answer 4

1% Ferrous ammonium sulfate

Question 5

Media of Pyrazinamide Test

Answer 5

Pyrazinamidase agar

Question 6

Media of Heat Stable Catalase Test

Answer 6

Tween 80

Question 7

(+) Pyrazinamide Test

Answer 7

PINK TO RED

Question 8

(+) Pyrazinamide Test after 4 days

Answer 8

tuberculosis and Mannirum

Question 9

(-) Pyrazinamide Test

Answer 9

no pigment
M. kansasii / M. bovis

Question 10

For Rapid Growers

Answer 10

Arylsulfatase Test

Question 11

Rgt used in Arylsulfatase Test

Answer 11

sodium bicarbonate

Question 12

Media used in Arylsulfatase Test

Answer 12

tripotassium phenolphthalein disulfide

Question 13

Distinguish M. chelonae from other rapid growers
Reagent: Ammonium ferric citrate
Media: LJ

Answer 13

Iron Uptake Test

Question 14

Differentiates M. flavescens from M. szulgai
Reagent: 5% NaCl
Media: Egg-based media
(+) result: with growth

Answer 14

NaCl Tolerance Test

Question 15

pH indicator: neutral red
(+) result: pink/red
ID of M. kansasii (+) in 6 days and
M. tuberculosis (+) in 10-20 days

Answer 15

Tween 80 Hydrolysis Test

Question 16

Ability to reduce tellurite in 3-4 days
Distinguishes members of MAC
(+) result: BLACK METALLIC

Answer 16

Tellurite Reduction Test

Question 17

MAC

Answer 17

Mycobacterium Avium complex

Question 18

Distinguish M. bovis from M. tuberculosis
TUBERCULOSIS : RESISTANCE
BOVIS : SENSITIVE

Answer 18

TCH/T2H (thiopene-2- carboxylic acid hydrazide)
Susceptibility Test

Question 19

Suitable for M. fortuitum and M. chelonae

Answer 19

Growth on MacConkey agar

Question 20

Reagent: cyanogen bromide and aniline dye
Media: LJ
(+) result: yelllow (Indication of MTB)
no color : Mycobacterium bovis

Answer 20

Niacin Test

Question 21

Reagent: after incubation, add the following:
Diluted HCl
0.2% sulfanilamide
0.1% N-naphthylethylene-diamine
(+) result: pink/red
For NEGATIVE – add small amount of powdered

Answer 21

Nitrate Reduction

Question 22

Distinguish M. scrofulaceum from M. gordonae
(+) result: pink to red
M. scro (+) , while M gonor (-)

Answer 22

Urease Test

Question 23

Skin Test

Answer 23

Mantoux test
Von Pirquet
Vollmer Patch
Moro Percutaneous

Question 24

Quantiferon Test (measures interferon gamma)
Uses heparinized whole blood
Measures interferon gamma

Answer 24

IGRA (Interferon Gamma Release Assay)