Mycobacterium interjectum

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

Name

Etymology: Phylogenetic position between (Latin: interjectum) rapidly and slowly growing mycobacteria.

Description

Mycobacterium interjectum is Gram-positive, nonmotile and acid-fast rods (0.6-1.0 µm x 0.7-2.0 µm). Filaments (up to 6.0 µm) possible.

Colony characteristics

Dysgonic, smooth and scotochromogenic colonies (1–2 mm in diameter).

Physiology

• Slow growth on Löwenstein-Jensen medium at temperatures between 31°C and 37 °C within 3–4 weeks.
• Susceptible to rifampicin.
• Resistant to isoniazid and ethambutol.

Differential characteristics

• Most closely related to M. simiae.
• Phylogenetic position between rapidly and slowly growing mycobacteria.

Pathogenesis

• Chronic lymphadenitis
• Biosafety level 2

Type strain

• First isolated from a lymph node of a child with chronic lymphadenitis in Germany.

Strain 4185/92 = ATCC 51457 = CCUG 37514 = DSM 44064

References

• Springer et al. 1993. Mycobacterium interjectum, a new species isolated from a patient with chronic lymphadenitis. J. Clin. Microbiol., 31, 3083–3089.