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Species of bacterium
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 .
Description
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
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
Böttger et al. 1993. Mycobacterium genavense sp. nov. Int. J. Syst. Bacteriol., 43, 841–843.