Phylum Actinobacteria, Class Actinobacteria, Order Actinomycetales, Suborder Corynebacterineae, Family Mycobacteriaceae, Genus
Mycobacterium, Mycobacterium malmoense Schroder and Juhlin 1977.
Acid-alcohol-fast, coccoid to short rods. When grown on Middlebrook 7H10 agar, rods
are longer than on Lowenstein-Jensen. No cording or cross-barring.
Gram-stain-positive. Noncapsulate. Asporogenous.
Colonies are smooth, grayish white, non-pigmented, usually domed, and circular.
Some umbonate colonies occur with compact, raised centers and flattened irregular
edges on Middlebrook and cornmeal agars. Incubation time varies from 1 to 6 weeks.
It appears in primary cultures only after 8-12 weeks, therefore the laboratory should
extend the incubation period more than 8 weeks Temperature range for growth is
22-37 ºC; growth does not occur at 42 or 45 ºC. Strains are micro-aerophilic and grow
beneath the surface of semisolid agar medium after deep inoculation. No growth on
MacConkey agar or in meia supplemented with 5% NaCl. Nonphotochromogenic.
Isolated from sputum and biopsy specimens from patients with pulmonary disease.
Susceptible to ethambutol (2 µg/ml), cycloserine (16 µg/ml) and kanamycin (8 µg/ml). Resistant to TCH (1 µg/ml), isoniazid (1 µg/ml),
rifampin (32 µg/ml) and streptomycin (8 µg/ml).
Can produce pulmonary disease in humans.
Experimental infection: subcutaneous inoculation of guinea pigs with 0.1 mg bacilli produces local, but not generalized, lesions.
Intravenous inoculation of chickens with 0.1 mg bacilli caused macroscopic lesions in the liver and spleen in about half of the birds,
some of which died. Intravenous inoculation of rabbits with 0.1 mg bacilli caused rare minimal lesions that contained rare viable
- 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.
- 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.
- Schroder KH, Juhlin I. Mycobacterium malmoense sp. nov. International Journal of Systematic Bacteriology 1977; 27:241-246.
- Springer B, Wu WK, Bodmer T, Haase G, Pfyffer GE, Kroppenstedt RM, Schroder KH, Emler S, Kilburn JO, Kirschner P, et al.
Isolation and characterization of a unique group of slowly growing mycobacteria: description of Mycobacterium lentiflavum sp. nov.
J Clin Microbiol 1996; 34:1100-1107.
- Rastogi N, Legrand E, Sola C. The mycobacteria: an introduction to nomenclature and pathogenesis. Rev Sci Tech. 2001;20(1):21‐
- Tsukamura M. Numerical identification of slowly growing mycobacteria. Microbiol Immunol. 1985;29(11):1039‐1050. doi:10.1111/j.
Positive results for nicotinamidase, pyrazinamidase, alpha- and beta-esterase (weak reaction), tellurite reduction (9 days), and
Tween 80 hydrolysis.
Negative results for arylsulfatase (3, 7 and 10 days), acid phosphatase, catalase (semi-quantitative), beta-galactosidase, iron uptake,
nitrate reduction and niacin production.
No utilization as sole carbon source of acetate, citrate, succinate, malate, pyruvate, benzoate, fumarate, glucose, fructose, sucrose
ethanol, and propanol.
Variable results for catalase (inactivated at 68 ºC) and urea hydrolysis.
(c) Costin Stoica