Mycobacterium genavense

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Mycobacterium genavense
Scientific classification
Kingdom: Bacteria
Phylum: Actinobacteria
Order: Actinomycetales
Suborder: Corynebacterineae
Family: Mycobacteriaceae
Genus: Mycobacterium
Species: M. genavense
Binomial name
Mycobacterium genavense
Böttger et al. 1993, ATCC 51234

Mycobacterium genavense is a slow-growing 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[edit]

Nonmotile, acid-fast coccobacilli (1.0 µm x 2.0 µm). No formation of spores, capsules or aerial hyphae.

Colony characteristics

Physiology

  • Slow, fastidious growth in liquid media within 3–12 weeks at 31°C, 37°C and 42°C, with slightly better growth at 45°C.
  • Primary cultures for isolation require liquid broth media such as BACTEC 12B medium, Middlebrook 7H9 medium.
  • Acid broth media such as, BACTEC pyrazinamidase test medium, may facilitate primary isolation.
  • No growth on standard solid media like Löwenstein-Jensen, unsupplemented Middlebrook 7H11 or Middlebrook 7H10 media.
  • Visible growth on solid Middlebrook 7H11 medium supplemented with MJ after inoculation with a broth culture within 3–9 weeks.
  • Susceptible to streptomycin and rifampicin
  • Resistant to isoniazid and ethambutol

Differential characteristics

  • Differentiation from other slowly growing mycobacteria by its fastidious growth.
  • Closely related to M. simiae by evaluation of 16S rDNA sequences.

Pathogenesis[edit]

  • Opportunistic pathogen. Clinically indistinguishable from generalised infections in patients with AIDS due to M. avium complex strains, but more related to gastro-intestinal disorders.
  • Most common cause of mycobacterial disease in parrots and parakeets.

Type strain[edit]

Strain 2289 = ATCC 51234

References[edit]

  • Böttger et al. 1993. Mycobacterium genavense sp. nov. Int. J. Syst. Bacteriol., 43, 841-843.