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 (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
Differential characteristics
 * 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.
 * Most closely related to M. simiae.
 * Phylogenetic position between rapidly and slowly growing mycobacteria.

Pathogenesis

 * Chronic lymphadenitis
 * Biosafety level 2

Type strain
Strain 4185/92 = ATCC 51457 = CCUG 37514 = DSM 44064
 * First isolated from a lymph node of a child with chronic lymphadenitis in Germany.