''Mycobacterium avium'' is a 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 ...

''. The

type strain The International Code of Nomenclature of Prokaryotes (ICNP) formerly the International Code of Nomenclature of Bacteria (ICNB) or Bacteriological Code (BC) governs the scientific names for Bacteria and Archaea.P. H. A. Sneath, 2003. A short histor ...

is ATCC 25291 = CCUG 20992 = CIP 104244 = DSM 44156 = NCTC 13034. The subspecies name ''Mycobacterium avium ''subsp.'' avium'' Chester 1901 is automatically created by the valid publication of ''Mycobacterium avium ''subsp.'' paratuberculosis'' (Bergey et al. 1923) and the valid publication of ''Mycobacterium avium ''subsp.'' silvaticum'' Thorel et al. 1990. Based on differences in IS1245 RFLP, 16S-23S rDNA ITS and growth temperature, Mijs et al. 2002MIJS (W.), de HAAS (P.), ROSSAU (R.), VAN DER LAAN (T.), RIGOUTS (L.), PORTAELS (F.) and van SOOLINGEN (D.): Molecular evidence to support a proposal to reserve the designation Mycobacterium avium subsp. avium for bird-type isolates and 'M. avium subsp. hominissuis' for the human/porcine type of M. avium. Int. J. Syst. Evol. Microbiol., 2002, 52, 1505-1518. propose to reserve the designation ''Mycobacterium avium ''subsp.'' avium'' for

bird Birds are a group of warm-blooded vertebrates constituting the class Aves (), characterised by feathers, toothless beaked jaws, the laying of hard-shelled eggs, a high metabolic rate, a four-chambered heart, and a strong yet lightweigh ...

-type isolates. These authors suggest, but do not formally propose, the designation "''Mycobacterium avium ''subsp.'' hominissuis''" for the isolates from

human Humans (''Homo sapiens'') are the most abundant and widespread species of primate, characterized by bipedalism and exceptional cognitive skills due to a large and complex brain. This has enabled the development of advanced tools, culture, ...

s and

pig The pig (''Sus domesticus''), often called swine, hog, or domestic pig when distinguishing from other members of the genus '' Sus'', is an omnivorous, domesticated, even-toed, hoofed mammal. It is variously considered a subspecies of ''Sus s ...

Epidemiology

Present mainly in

cattle Cattle (''Bos taurus'') are large, domesticated, cloven-hooved, herbivores. They are a prominent modern member of the subfamily Bovinae and the most widespread species of the genus ''Bos''. Adult females are referred to as cows and adult mal ...

and humans with an immunocompromised disorder, e.g.

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 ...

, it is transmitted to man by drinking unpasteurized cow

milk Milk is a white liquid food produced by the mammary glands of mammals. It is the primary source of nutrition for young mammals (including breastfed human infants) before they are able to digestion, digest solid food. Immune factors and immune ...

. Pigs are susceptible to ''M. avium avium '', ''M. bovis'', and ''M. tuberculosis'', with ''M. avium'' being most common. Lesions are typically lymphoid, gastrointestinal, or rapidly progressive disseminated forms. Intradermal testing is the diagnostic test of choice. Isolation of purified protein derivatives is useful for ''M. bovis'' and ''M. tuberculosis''. However, cross-reaction between ''M. avium avium, M. tuberculosis,'' or ''M. avium paratuberculosis'' is a disadvantage. Dogs, cats, deer, mink, cattle, birds (serotypes 1, 2, and 3) and some cold-blooded animals are all also susceptible to ''M. avium''. False-negative tuberculin tests are common in dogs. Radiographs and a thorough history are useful in diagnosis. Affected dogs should be euthanized because of public health concerns.

References

J.P. Euzéby: List of Prokaryotic Names with Standing in Nomenclature - genus ''Mycobacterium''

External links

Type strain of ''Mycobacterium avium avium'' at Bac''Dive'' - the Bacterial Diversity Metadatabase
{{Taxonbar, from=Q310728 Acid-fast bacilli avium avium Bacteria described in 1901