Mycobacterium fallax

Mycobacterium fallax
Scientific classification
Kingdom:	Bacteria
Phylum:	Actinobacteria
Order:	Actinomycetales
Suborder:	Corynebacterineae
Family:	Mycobacteriaceae
Genus:	Mycobacterium
Species:	M. fallax
Binomial name
Mycobacterium fallax Lévy-Frébault et al. 1983, ATCC 35219

Mycobacterium fallax is a species of the phylum actinobacteria (Gram-positive bacteria with high guanine and cytosine content, one of the dominant phyla of all bacteria), belonging to the genus mycobacterium.

Description

Gram-positive, nonmotile and acid-fast rods (0.5 – 1 µm long) except for a small number (less than 20%) of cyanophil forms.

Colony characteristics

• Large, eugonic, buff coloured and rough colonies (Löwenstein-Jensen medium at 30°C).
• Cauliflower-like morphology, resembling M. tuberculosis colonies. Cord formation at the edges of colonies (Middlebrook 7H10 agar at 30°C).

Physiology

• Rapid growth on Löwenstein-Jensen or Middlebrook 7H10 media.
• Susceptible to ethambutol, rifampin and kanamycin.
• Resistant to isoniazid, pyrazinamide and streptomycin.

Differential characteristics

• Similarities to M. tuberculosis include colony morphology, thermolabile catalase, positive nitrate reductase; differences are negative reactions for niacin production and rapid growth at 30°C.

Pathogenesis

• Not known. Biosafety level 1.

Type strain

• Isolated from environmental sources in France and the former Czechoslovakia. Strain ATCC 35219 = CCUG 37584 = CIP 81.39 = DSM 44179 = JCM 6405.

References

• Lévy-Frébault et al. 1983. Mycobacterium fallax sp. nov. Int. J. Syst. Bacteriol., 1983, 33, 336-343.