Mycobacterium kansasii
Cultural characteristics
Biochemical characters
Phylum Actinobacteria, Class Actinobacteria, Order Actinomycetales, Suborder Corynebacterineae, Family Mycobacteriaceae, Genus
Mycobacterium kansasii Hauduroy 1955.

Seven subtypes have been reported, subtypes I–VI being elevated to species rank:
Subtype I -
Mycobacterium kansasii,
Subtype II -
Mycobacterium persicum,
Subtype III -
Mycobacterium pseudokansasii,
Subtype IV -
Mycobacterium ostraviense,
Subtype V -
Mycobacterium innocens,
Subtype VI -
Mycobacterium attenuatum.
Acid-fast, moderately long or long rods. Broaden and exhibit cross-barring when
grown in the presence of fatty acids. Few strains may produce cords.
Colonies usually appear somewhat rough microscopically, but are readily emulsified in water; some strains resist emulsification.
Photochromogenic; grown in the dark are non-pigmented; when grown in light, or when exposed briefly to light young colonies
become brilliant yellow. Sometimes may produce a deep orange pigment when grown in the dark or may not form pigments. Most
strains, when grown in a lighted incubator, form dark red crystals of beta-carotene on the surface and inside colonies. Grows at  
22-42 ºC, but not at 45 ºC. Growth time 10-21 days. No growth on 5% (w/v) NaCl. No growth on MacConkey agar.
Isolated from human pulmonary lesions. Rarely isolated from lungs or lymph nodes of cattle, deer, and swine. Also isolated from water
sources. Susceptible to hydroxylamine (500 µg/ml), ethambutol (2 µg/ml) and rifampin (32 µg/ml). Resistant to TCH (1 µg/ml), isoniazid
(1 µg/ml) and streptomycin.
Causes chronic human pulmonary disease resembling tuberculosis although not normally considered contagious from man to man.
May cause nosocomial infections.
Pathogenicity may be related to catalase activity; isolates with strong catalase activity are thought to be more virulent.
Closely related to
Mycobacterium gastri but cross-reactivity does not occur between the surface antigens of Mycobacterium kansasii,
Mycobacterium gastri, and Mycobacterium marinum.
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    Mikołaj, Pennings Lian, van Ingen Jakko, Zolnir-Dovc Manca, Strapagiel Dominik.Genomic Insights Into the Mycobacterium
    kansasii Complex: An Update. Front. Microbiol., 15 January 2020,
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Positive results for arylsulfatase (10 days; only few strains positive at 3 days), thermostable catalase (68 ºC), catalase
(semi-quantitative), nitrate reduction, neutral red, nicotinamidase, Tween 80 hydrolysis, and urea hydrolysis (variable). Most strains are
strongly catalase-positive, but some are weakly positive and inactivated at 68 ºC. Can utilize glucose, propionate and pyruvate.

Negative results for acid phosphatase, alpha-esterase, beta-galactosidase, niacin production (biotypes 12 and 13 are positive),
pyrazinamidase, and tellurite reduction.
No utilization of benzoate, citrate, fumarate, malate, succinate, fructose, sucrose, ethanol, and propanol. No iron uptake.

Subtype IV does not reduce nitrates and does no produce thermostable catalase  (68 ºC).
Subtypes I, II, III, V and VI cannot be biochemically differentiated. Some subtype II and III strains may reduce tellurite; some subtype V
strains may be nonchromogenic; some subtype VI strains may be positive for niacin test.
(c) Costin Stoica
Culture media
Biochemical tests
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