Species of bacterium
Mycobacterium genavense is a slow-growing species of the phylumActinomycetota (Gram-positive bacteria with highguanine and cytosine content , one of the dominant phyla of all bacteria), belonging to the genusMycobacterium
Nonmotile,acid-fast coccobacilli (1.0μm x 2.0 μm). No formation ofspores ,capsules or aerialhyphae .
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 asBACTEC 12B medium,Middlebrook 7H9 medium. Acid broth media such as,BACTEC pyrazinamidase test medium , may facilitate primary isolation. No growth on standard solid media likeLöwenstein-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 tostreptomycin andrifampicin Resistant toisoniazid Differential characteristics
Differentiation from other slowly growing mycobacteria by its fastidious growth. Closely related toM. simiae by evaluation of16S rDNA sequences. Opportunisticpathogen . Clinically indistinguishable from generalised infections in patients withAIDS due toM. avium complex strains, but more related to gastro-intestinal disorders. Most common cause of mycobacterial disease inparrots andparakeets . Strain 2289 =ATCC 51234
Böttger et al. 1993. Mycobacterium genavense sp. nov. Int. J. Syst. Bacteriol., 43, 841–843.
