Mycobacterium interjectum

Mycobacterium interjectum

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

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

Colony characteristics Dysgonic, smooth and scotochromogenic colonies (1-2mm 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.