Trisha Shetty (Editor)

Mycobacterium genavense

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Kingdom
  
Bacteria

Order
  
Actinomycetales

Family
  
Mycobacteriaceae

Scientific name
  
Mycobacterium genavense

Phylum
  
Actinobacteria

Suborder
  
Corynebacterineae

Genus
  
Mycobacterium

Rank
  
Species

Similar
  
Mycobacterium, Mycobacterium celatum, Bacteria, Mycobacterium malmoense, Mycobacterium haemophilum

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.

Contents

Description

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

Colony characteristics

  • Tiny, transparent, nonphotochromogenic and dysgonic colonies (on solid Middlebrook 7H11 medium MJ (Allied Laboratories).

    • 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

  • 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

    Strain 2289 = ATCC 51234

    References

    Mycobacterium genavense Wikipedia
    (Text) CC BY-SA