Phylum Actinobacteria, Class Actinobacteria, Order Actinomycetales, Suborder Corynebacterineae, Family Mycobacteriaceae, Genus
Mycobacterium, Mycobacterium conspicuum Springer et al. 1996.
Acid-alcohol-fast coccobacilli. Does not form aerial hyphae, capsules, or spores.
Colonies are dysgonic, smooth, yellowish, and non-photochromogenic. Visible
growth occurs in 2-3 weeks from dilute inocula on Lowenstein-Jensen medium.
Temperature range for growth is 22-31 ºC; does not grow at 37 ºC under routine
conditions, but growth at 37 ºC was achieved in BACTEC 12B medium. Does not
grow on media supplemented with 5% (w/v) NaCl or on MacConkey agar (without
Isolated from blood, sputum, and skin biopsy of patients with immune deficiency and disseminated mycobacterial infection.
Resistant to isoniazid (1 μg/ml), hydroxylamine (500 μg/ml), and thiophene-2-carboxylic acid hydrazide (TCH). Susceptible to
ethambutol (2 μg/ml), rifampin (32 μg/ml), and streptomycin (8 μg/ml).
May cause disseminated infection in immunocompromised persons.
- 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.
- Springer B, Tortoli E, Richter I, Grunewald R, Rusch-Gerdes S, Uschmann K, Suter F, Collins MD, Kroppenstedt RM, Bottger EC.
Mycobacterium conspicuum sp. nov., a new species isolated from patients with disseminated infections. J Clin Microbiol 1995; 33:
- Rastogi N, Legrand E, Sola C. The mycobacteria: an introduction to nomenclature and pathogenesis. Rev Sci Tech. 2001;20(1):21‐
Positive results for arylsulfatase (3 and 10 days), heat-stable catalase (68 ºC), and Tween 80 hydrolysis.
Negative results for acetamidase, benzamidase, semiquantitative catalase test, beta-galactosidase, niacin accumulation, nitrate
reductase, nicotinamidase, pyrazinamidase, tellurite reduction, and urease.
Variable results for acid phosphatase.
(c) Costin Stoica