Mycobacterium genavense is a slow-growing species of the phylum

Actinomycetota The ''Actinomycetota'' (or ''Actinobacteria'') are a phylum of all gram-positive bacteria. They can be terrestrial or aquatic. They are of great economic importance to humans because agriculture and forests depend on their contributions to soi ...

(

Gram-positive In bacteriology, gram-positive bacteria are bacteria that give a positive result in the Gram stain test, which is traditionally used to quickly classify bacteria into two broad categories according to their type of cell wall. Gram-positive bacte ...

bacteria Bacteria (; singular: bacterium) are ubiquitous, mostly free-living organisms often consisting of one biological cell. They constitute a large domain of prokaryotic microorganisms. Typically a few micrometres in length, bacteria were among ...

with high guanine and cytosine content, one of the dominant phyla of all bacteria), belonging to the genus ''

Mycobacterium ''Mycobacterium'' is a genus of over 190 species in the phylum Actinomycetota, assigned its own family, Mycobacteriaceae. This genus includes pathogens known to cause serious diseases in mammals, including tuberculosis ('' M. tuberculosis'') and ...

''.

Description

Nonmotile,

acid-fast Acid-fastness is a physical property of certain bacterial and eukaryotic cells, as well as some sub-cellular structures, specifically their resistance to decolorization by acids during laboratory staining procedures. Once stained as part of a sam ...

coccobacilli (1.0 µm x 2.0 µm). No formation of

spores In biology, a spore is a unit of sexual or asexual reproduction that may be adapted for dispersal and for survival, often for extended periods of time, in unfavourable conditions. Spores form part of the life cycles of many plants, algae, f ...

, capsules or aerial

hyphae A hypha (; ) is a long, branching, filamentous structure of a fungus, oomycete, or actinobacterium. In most fungi, hyphae are the main mode of vegetative growth, and are collectively called a mycelium. Structure A hypha consists of one or ...

. Colony characteristics *Tiny, transparent, nonphotochromogenic and dysgonic

colonies In modern parlance, a colony is a territory subject to a form of foreign rule. Though dominated by the foreign colonizers, colonies remain separate from the administration of the original country of the colonizers, the '' metropolitan state'' ...

(on solid Middlebrook 7H11 medium MJ (Allied Laboratories).

Physiology Physiology (; ) is the scientific study of functions and mechanisms in a living system. As a sub-discipline of biology, physiology focuses on how organisms, organ systems, individual organs, cells, and biomolecules carry out the chemical ...

*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 Streptomycin is an antibiotic medication used to treat a number of bacterial infections, including tuberculosis, ''Mycobacterium avium'' complex, endocarditis, brucellosis, ''Burkholderia'' infection, plague, tularemia, and rat bite fever. Fo ...

and

rifampicin Rifampicin, also known as rifampin, is an ansamycin antibiotic used to treat several types of bacterial infections, including tuberculosis (TB), mycobacterium avium complex, ''Mycobacterium avium'' complex, leprosy, and Legionnaires’ disease. ...

*Resistant to

isoniazid Isoniazid, also known as isonicotinic acid hydrazide (INH), is an antibiotic used for the treatment of tuberculosis. For active tuberculosis it is often used together with rifampicin, pyrazinamide, and either streptomycin or ethambutol. For l ...

Differential characteristics *Differentiation from other slowly growing mycobacteria by its fastidious growth. *Closely related to ''M. simiae'' by evaluation of

16S rDNA 16 S ribosomal RNA (or 16 S rRNA) is the RNA component of the 30S subunit of a prokaryotic ribosome (SSU rRNA). It binds to the Shine-Dalgarno sequence and provides most of the SSU structure. The genes coding for it are referred to as 16S rR ...

sequences.

Pathogenesis

*Opportunistic

pathogen In biology, a pathogen ( el, πάθος, "suffering", "passion" and , "producer of") in the oldest and broadest sense, is any organism or agent that can produce disease. A pathogen may also be referred to as an infectious agent, or simply a germ ...

. Clinically indistinguishable from generalised infections in patients with

AIDS Human immunodeficiency virus infection and acquired immunodeficiency syndrome (HIV/AIDS) is a spectrum of conditions caused by infection with the human immunodeficiency virus (HIV), a retrovirus. Following initial infection an individual m ...

due to M. avium complex strains, but more related to gastro-intestinal disorders. *Most common cause of mycobacterial disease in

parrots Parrots, also known as psittacines (), are birds of the roughly 398 species in 92 genus (biology), genera comprising the order (biology), order Psittaciformes (), found mostly in tropics, tropical and subtropics, subtropical regions. The order ...

and

parakeets A parakeet is any one of many small to medium-sized species of parrot, in multiple genera, that generally has long tail feathers. Etymology and naming The name ''parakeet'' is derived from the French wor''perroquet'' which is reflected in ...

Type strain

Strain 2289 = ATCC 51234

References

*Böttger et al. 1993. Mycobacterium genavense sp. nov. Int. J. Syst. Bacteriol., 43, 841–843. Acid-fast bacilli genavense Bacteria described in 1993 {{Mycobacterium-stub