Mycobacterium intermedium

Mycobacterium intermedium

Etymology:Latin, intermedium, meaning between, rapidly and slowly-growing mycobacteria.

Description
Gram-positive, and nonmotile acid-fast coccobacilli (2.0µm x 2.6 µm).

Colony characteristics
 * Eugonic, smooth and photochromogenic colonies (3–5mm in diameter) on Löwenstein-Jensen medium.

Physiology
 * Growth on Löwenstein-Jensen medium at 22°C, 31°C, 37°C and 41°C, (optimal temperature between 31°C and 37°C), within 2-3 weeks.
 * Susceptible to ethambutol and rifampin.
 * Resistant to isoniazid and streptomycin.

Differential characteristics
 * Phylogenetic position between rapidly and slowly-growing mycobacteria.
 * M. asiaticum is phenotypically very similar, but can be distinguished by its growth at 22°C, and by its dysgonic growth.

Pathogenesis

 * Pulmonary disease
 * Biosafety level 2

Type Strain
Strain 1669/91 = ATCC 51848 = CCUG 37583 = CIP 104542 = DSM 44049 = JCM 13572
 * Repeatedly isolated from sputum from a patient with pulmonary disease.