Phylum Actinobacteria, Class Actinobacteria, Order Actinomycetales, Suborder Corynebacterineae, Family Mycobacteriaceae, Genus
Mycobacterium, Mycobacterium tusciae Tortoli et al. 1999.
Acid-alcohol-fast rods. Nonmotile. Non-spore forming.
Colonies are rough and strongly yellow-pigmented. Their early microscopic
morphology on Middlebrook 7H11 agar is characterized by a very elevated centre
surrounded by an uneven flat fringe. At temperatures between 25 and 32 ºC,
scotochromogenic colonies grow in about 4 weeks on Lowenstein-Jensen medium.
Growth at 37 ºC is inconsistent and requires a longer incubation, while no growth
occurs at 42 ºC. No growth in media supplemented with 5% (w/v) NaCl or on
Isolated from a lymph node of an immunocompromised child, from tap water and from a respiratory sample from apatient with
Resistant to ethambutol (2 µg/ml), thiophene-2-carboxylic acid and thiacetazone. Susceptible to rifampin (32 µg/ml), streptomycin (8
µg/ml), ciprofloxacin, clarithromycin, rifabutin, and sparfloxacin.
Not considered to be pathogenic.
- 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.
- Tortoli E, Kroppenstedt RM, Bartoloni A, Caroli G, Jan I, Pawlowski J, Emler S. Mycobacterium tusciae sp. nov. Int J Syst Bacteriol
Positive results for acid phosphatase, heat-stable catalase (68 ºC), nitrate reductase, Tween 80 hydrolysis after 10 days incubation,
arylsulfatase after 14 days, but not after 3 days incubation, and urease.
Negative results for niacin accumulation, beta-galactosidase, and semi-quantitative catalase test.
Variable results for Tellurite reduction (9 days).
(c) Costin Stoica