Mycobacterium genavense is a slow-growing 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.
Mycobacterium genavense | |
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Scientific classification | |
Domain: | Bacteria |
Phylum: | Actinomycetota |
Class: | Actinomycetia |
Order: | Mycobacteriales |
Family: | Mycobacteriaceae |
Genus: | Mycobacterium |
Species: | M. genavense
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Binomial name | |
Mycobacterium genavense Böttger et al. 1993, ATCC 51234
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Description
editNonmotile, 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).
- 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
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
editStrain 2289 = ATCC 51234
References
edit- Böttger et al. 1993. Mycobacterium genavense sp. nov. Int. J. Syst. Bacteriol., 43, 841–843.