Mycobacterium avium complex: Difference between revisions

Revision as of 13:50, 13 October 2019

Revision as of 13:54, 29 March 2020

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{{Distinguish|Mycobacterium tuberculosis complex}}{{italic title|string=Mycobacterium avium}}

{{Taxobox

| name = ''Mycobacterium avium'' complex

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}}

'''''Mycobacterium avium ''complex''' is a group of [[mycobacteria]] comprising '''''Mycobacterium intracellulare''''' and '''''Mycobacterium avium''''' (No mention of ''M. chimera'' in ref) that are commonly grouped together because they infect humans together; this group, in turn, is part of the group of [[nontuberculous mycobacteria]]. These bacteria cause disease in humans called [[Mycobacterium avium-intracellulare infection|''Mycobacterium avium-intracellulare'' infection]] or ''Mycobacterium avium'' complex infection.<ref>{{cite web|title=Mycobacterium Avium Complex. MAI; MAC Information|url=https://patient.info/doctor/mycobacterium-avium-complex|publisher=Patient Info|date=29 August 2014}}</ref> ThisThese groupbacteria shouldare notcommon beand confusedare withfound in fresh and salt water, in household [[Mycobacteriumdust]] tuberculosisand in soil.<ref name=":0">{{Cite web|url=https://rarediseases.info.nih.gov/diseases/7123/mycobacterium-avium-complex-infections|title=Mycobacterium Avium Complex infections {{!}} Genetic and Rare Diseases Information Center (GARD) – an NCATS Program|website=rarediseases.info.nih.gov|language=en|access-date=2020-03-29}}</ref> MAC bacteria only cause infection in those who are [[immunocompromised]] or those with severe [[lung disease]].

==Description==

In the [[Runyon classification]], allboth threebacteria are nonchromogens. They can be differentiated from ''M. tuberculosis'' and each other by commercially available [[DNA probes]].<ref name=Tropical>{{cite book|last1=Jones-Lopez|first1=Edward C.|last2=Ellner|first2=Jerrold J.|editor1-last=Guerrant|editor1-first=Richard L.|editor2-last=Walker|editor2-first=David H.|editor3-last=Weller|editor3-first=Peter F.|title=Tropical infectious diseases : principles, pathogens, & practice|date=2011|publisher=Saunders|___location=Edinburgh|isbn=9780702039355|edition=3rd|chapter=Chapter 35: Tuberculosis and Atypical Mycobacterial Infections}}</ref>{{rp|245}}

They are characterized as [[Gram-positive]], nonmotile, [[acid-fast]], short to long rods.

'''Colony characteristics'''

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'''Physiology'''

*Growth on [[Löwenstein-Jensen]] medium and [[Middlebrook 7H10 Agar|Middlebrook 7H10 agar]] occurs at 37°C after 7seven or more days.

*The complex can be (but is not often) resistant to [[isoniazid]], [[ethambutol]], [[rifampin]], and [[streptomycin]].<ref name="pmid29054853">{{cite journal | vauthors = Haworth CS, Banks J, Capstick T, Fisher AJ, Gorsuch T, Laurenson IF, Leitch A, Loebinger MR, Milburn HJ, Nightingale M, Ormerod P, Shingadia D, Smith D, Whitehead N, Wilson R, Floto RA | title = British Thoracic Society guidelines for the management of non-tuberculous mycobacterial pulmonary disease (NTM-PD) | journal = Thorax | volume = 72 | issue = Suppl 2 | pages = ii1–ii64 | date = November 2017 | pmid = 29054853 | doi = 10.1136/thoraxjnl-2017-210927 }}</ref>

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==Human health==

MAC bacteria enter most people's body when inhaled into the lungs or swallowed, but only cause infection in those who are [[immunocompromised]] or who have severe [[lung disease]] such as those with [[cystic fibrosis]] or [[chronic obstructive lung disease]] (COPD).<ref name=":0" /> [[Mycobacterium avium-intracellulare infection|MAC infection]] can cause chronic pulmonary diseaseCOPD and [[lymphadenitis]], and can cause disseminated disease, especially in people with [[immunodeficiency]].<ref name=Tropical/>{{rp|245}}

==History==