Biochemical Test for Mycobacterium Flashcards
Reagents/materials for Semi-Quantitative Catalase test (SQC)
30% H2O2 and 10% Tween 80
Positive QC organism for SQC (>45 mm column of bubbles)
M. flavescens
Negative QC organism for SQC (<45 mm column of bubbles)
M. tuberculosis
Mycobacteria positive for SQC
M. terrae, Scotochromogens, Rapid growers, Photochromogens except M. marinum
Reagents/materials for 68°C Heat-stable Catalase test
30% H2O2, 10% Tween 80, Water bath
Positive QC organism for 68°C Heat-stable Catalase test (Bubble formation)
M. flavescens
Negative QC organism for 68°C Heat-stable Catalase test (No change)
M. tuberculosis
Mycobacteria positive for 68°C Heat-stable Catalase test
M. terrae, Scotochromogens, M. fortuitum, S. smegmatis, M. xenopi, M. ulcerans, Photochromogens except M. marinum
Reagents/materials for Niacin accumulation
Lowenstein-Jensen with ≥50 colonies
Positive QC organism for Niacin accumulation (Yellow)
M. tuberculosis
Negative QC organism for Niacin accumulation (No color change)
M. fortuitum
Mycobacterium lacking niacin enzyme
M. tuberculosis”Reagents/Materials for Arylsulfatase test
Positive QC organism for Arylsulfatase test (Pink in 3 or 14 days)
M. fortuitum
Negative QC organism for Arylsulfatase test (No color change)
M. tuberculosis
Mycobacteria positive for Arylsulfatase test (3 and 14 days)
M. fortuitum, M. chelonae, M. xenopi
Mycobacteria positive for Arylsulfatase test (14 days only)
M. marinum
Reagents/Materials for Tween 80 hydrolysis
Indicator: Phenol red
Positive QC organism for Tween 80 hydrolysis (Pink color in 10 days)
M. kansasii
Negative QC organism for Tween 80 hydrolysis (No color change)
M. intracellulare
Mycobacteria positive for Tween 80 hydrolysis
M. flavescens, M. gordonae, M. terrae, M. smegmatis, M. kansasii, M. marinum
End products of Tween 80 hydrolysis
Oleic acid and Sorbitol
Reagents/Materials for Tellurite reduction
Potassium tellurite
Positive QC organism for Tellurite reduction (Black metallic ppt)
M. intracellulare
Negative QC organism for Tellurite reduction (No color change)
M. kansasii
Mycobacteria positive for Tellurite reduction
M. avium complex (MAC), M. simiae
Reagents/Materials for T2H inhibition
Culture media with T2H
Positive QC organism for T2H inhibition (No growth, Sensitive)
M. bovis
Negative QC organism for T2H inhibition (Growth, Resistant)
M. tuberculosis
Remarks for T2H inhibition
Use along with nitrate and niacin tests
Reagents/Materials for Pyrazinamidase test
Ferric ammonium sulfate and Pyrazinoic acid
Positive QC organism for Pyrazinamidase test (Red/Pink band in 4 days)
M. intracellulare
Negative QC organism for Pyrazinamidase test (Colorless/Gray)
M. bovis
Mycobacteria positive for Pyrazinamidase test
M. tuberculosis, M. avium, M. marinum
End products of Pyrazinamidase test
Pyrazinoic acid and Ammonia
Reagents/materials for Nitrate reduction
Nutrient broth with 1% Potassium nitrate; Indicator: Sulfanilic acid
Positive QC organism for Nitrate reduction (Red)
M. tuberculosis
Negative QC organism for Nitrate reduction (No color change)
M. marinum
Mycobacteria positive for Nitrate reduction
M. tuberculosis, M. kansasii, M. szulgai, M. flavescens, M. terrae, M. fortuitum
Reagents/Materials for Iron-uptake test
20% ferric ammonium citrate
Positive QC organism for Iron-uptake test (Rusty brown colonies in egg-based media)
M. smegmatis, M. fortuitum
Negative QC organism for Iron-uptake test (No color change)
The rest of Mycobacteria
Remarks for Iron-uptake test
M. smegmatis and M. fortuitum are rapid growers
Reagents/Materials for Urease test
Urea broth
Positive QC organism for Urease test (Pink/Red in 3 days)
M. tuberculosis
Negative QC organism for Urease test (No color change)
M. gordonae
Mycobacteria positive for Urease test
M. tuberculosis, M. kansasii, M. marinum
Reagents/Materials for Salt tolerance test
5% NaCl added to egg-based media
Positive QC organism for Salt tolerance test (Substantial growth)
M. fortuitum
Negative QC organism for Salt tolerance test (No growth)
M. gordonae
Mycobacteria positive for Salt tolerance test
M. fortuitum, M. flavescens