Mycobacterium szulgai
Cultural characteristics
Biochemical characters
Phylum Actinobacteria, Class Actinobacteria, Order Actinomycetales, Suborder Corynebacterineae, Family Mycobacteriaceae, Genus
Mycobacterium szulgai Marks et al. 1972.
Acid-alcohol-fast, moderately long rods with some patchy staining or cross-barring.
No cording.
Colonies on egg medium after 2 weeks incubation at 37 ºC, are usually smooth and
easily emulsified. Rough forms may appear after prolonged subculture. The
production of an orange pigment is enhanced by growth in continuous light. Shows
temperature-dependent photochromogenicity: it is scotochromogenic when grown at
37 ºC, but at 25 ºC it tends to be photochromogenic. Growth is slower at 25 ºC and
absent at 42 ºC. No growth in media supplemented with 5% (w/v) NaCl or on
MacConkey agar without crystal violet.
Isolated from human clinical samples. One strain was isolated from a crocodile in South Africa without any obvious lesions. The
natural habitat is not known. Resistant to tiophene-2-carboxylic acid hydrazide (1 µg/ml) and isoniazid. Susceptible to hydroxylamine  
(500 µg/ml), ethambutol (5 µg/ml), and rifampin (25 µg/ml).
Involved in cervical adenitis, olecranon bursitis, and pulmonary disease in humans.
  1. John G. Magee and Alan C. Ward 2012. Family III. Mycobacteriaceae Chester 1897, 63AL in Bergey’s Manual of Systematic
    Bacteriology, Volume Five The Actinobacteria, Part A, Michael Goodfellow & al. (editors), 312-375.
  2. Loredana Gabriela Popa, Mircea Ioan Popa 2009. Identificarea bacililor acido-rezistenti in: Tratat de microbiologie clinica, Dumitru
    Buiuc, Marian Negut, ed. a III-a, Editura Medicala, 881-890, ISBN (13) 978-973-39-0593-6.
  3. Marks J, Jenkins PA, Tsukamura M. Mycobacterium szulgai - a new pathogen. Tubercle 1972; 53:210-214.
  4. Tsukamura M. Numerical identification of slowly growing mycobacteria. Microbiol Immunol. 1985;29(11):1039‐1050. doi:10.1111/j.
  5. Tsukamura M. Numerical Classification of Slowly Growing Mycobacteria. International Journal of Systematic Bacteriology, Oct. 1976,
    p. 409-420.
  6. Bhalla, G. S., Sarao, M. S., Kalra, D., Bandyopadhyay, K., & John, A. R. (2018). Methods of phenotypic identification of non-
    tuberculous mycobacteria. Practical Laboratory Medicine, 12, e00107.
  7. Attorri S, Dunbar S, Clarridge JE 3rd. Assessment of morphology for rapid presumptive identification of Mycobacterium tuberculosis
    and Mycobacterium kansasii. J Clin Microbiol. 2000;38(4):1426‐1429.
  8. Gcebe, N., Michel, A.L. & Hlokwe, T.M. Non-tuberculous Mycobacterium species causing mycobacteriosis in farmed aquatic animals
    of South Africa. BMC Microbiol 18, 32 (2018).
Positive results for acid phosphatase, catalase (68 ºC), catalase (semiquantitative), nitrate reduction, and pyrazinamidase (negative
in Tsukamura's paper.
Can utilize pyruvate as sole carbon source in the presence of ammonia. Can utilize acetate as sole carbon source.

Negative results for arylsufatase (3 days), niacin production and beta-galactosidase. No acid production from glucose, mannitol, or  
sorbitol. No utilization of benzoate, citrate, glucose, fructose, ethanol, n-propanol, succinate, malate and fumarate.

Variable results for arylsulfatase (10 d), alpha-esterase, tellurite reduction, Tween 80 hydrolysis, and urea hydrolysis.
(c) Costin Stoica
Culture media
Biochemical tests
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