Mycobacterium

a genus of bacteria, related to actinomycetes; it differs from true bacteria in a number of ways. The young vegetative cells are rodlike (0.5–0.8 × 2.2 microns); they are capable of branching and acquiring V or Y shapes. In old cultures spherical cells predominate. Mycobacteria, which do not form endospores, are nonmotile, gram-positive, and strictly aerobic. They reproduce mainly by dividing and budding. Mycobacteria contain carotenoids, and, as a result, their colonies are often pigmented (yellow, orange, or red). Owing to their cell composition (including lipides and wax), some myco-bacteria, in contrast to other bacteria, are acid-fast.

Mycobacteria are widely distributed in soils and are active in the mineralization of plant remains. Some species of Mycobacterium are nitrogen-fixing microorganisms; others are capable of metabolizing the carbohydrates of petroleum and natural gas and, when cultured, accumulate protein, which is used for fodder and other purposes. Some species of Mycobacterium are pathogenic to humans (for example, mycobacteria are the causative agents of tuberculosis and leprosy).

A. A. IMSHENETSKII

Mycobacterium

[mi″ko-bak-tēr´e-um] a genus of gram-positive, aerobic, acid-fast bacteria, occurring as slightly curved or straight rods. It contains many species, including the highly pathogenic organisms that cause tuberculosis (M. tuberculo´sis) and leprosy (M. lep´rae). M. a´vium causes tuberculosis in birds and pigs and pulmonary disease in humans. M. bo´vis is the bovine tubercle bacillus and can cause tuberculosis in humans who drink infected milk (strict testing of cattle makes this uncommon in developed countries); an attenuated strain is used to prepare BCG vaccine. M. chelo´nae is an opportunistic pathogen that causes synovial lesions, gluteal abscesses, and gross lesions in various organs. M. fortu´itum causes lesions of the lung, bone, or soft tissue following trauma. M. haemo´philum causes skin lesions. M. ho´minis is a common inhabitant of the vagina and cervix and causes infections of the male and female reproductive tracts, as well as respiratory disease and pharyngitis. M. intracellula´re occasionally causes chronic pulmonary disease in adults and lymph node infection in children. M. kansa´sii causes a tuberculosis-like disease. M. mari´num (also known as M. bal´nei) is the agent of granuloma" >swimming pool granuloma.

mycobacterium

[mi″ko-bak-tē″re-um] (L.) 1. an individual organism of the genus Mycobacterium.2. a slender, acid-fast microorganism resembling the bacillus that causes tuberculosis.nontuberculous mycobacteria mycobacteria other than M. tuberculosis or M. bovis, consisting of nonpathogens and pathogens causing opportunistic infections in immunocompromised patients and infections in otherwise normal individuals.

Mycobacterium

(mī'kō-bak-tē'rē-ŭm), A genus of aerobic, nonmotile bacteria (family Mycobacteriaceae) containing gram-positive, acid-fast, slender, straight or slightly curved rods; slender filaments occasionally occur, but branched forms rarely are produced. Parasitic and saprophytic species occur. Several of species are associated with infections in immunocompromised people, especially those with AIDS. The type species is Mycobacterium tuberculosis. It is the type genus of the family Mycobacteriaceae. [myco- + bacterium]

mycobacterium

(mī′kō-băk-tîr′ē-əm)n. pl. mycobac·teria (-tîr′ē-ə) Any of various rod-shaped, aerobic, often pathogenic bacteria of the genus Mycobacterium, including the causative agents of tuberculosis and leprosy.

my′co·bac·ter′i·al adj.

Mycobacterium

A genus of obligate aerobic bacteria, family Mycobacteriaceae, order Actinomycetales. All myobacteria are capable of producing the typical chronic inflammation, Langhans’ giant cells and caseating necrosis, and are indistinguishable by acid-fast staining (due to the high lipid concentration in the outer cell wall). Skin is the usual portal of entry for non-tuberculous mycobacteria.

Mycobacterium

A genus of obligate aerobic bacteria, family Mycobacteriaceae, order Actinomycetales; all are capable of producing the typical chronic inflammation, Langhans' giant cells and caseating necrosis, and are indistinguishable by acid-fast staining–due to the high lipid concentration in the outer cell wall; skin is the usual portal of entry for non-TB mycobacteria. See Acid-fast stain, Atypical mycobacteria, Buruli ulcer, Langhans' giant cells, MOTT, Nontuberculous mycobacteria, Prosector's wart, Runyon classification, Scrofula, Tuberculosis.

My·co·bac·te·ri·um

(mī'kō-bak-tēr'ē-ŭm) A genus of aerobic, nonmotile bacteria (family Mycobacteriaceae) containing gram-positive, acid-fast, slender, straight or slightly curved rods; slender filaments occasionally occur, but branched forms rarely are produced. Parasitic and saprophytic species occur. Some species are associated with infections in immunocompromised people, especially those with AIDS. The type species is M. tuberculosis. It is the type genus of the family Mycobacteriaceae. [myco- + bacterium]

Mycobacterium

(mi?ko-bak-tir'e-um) [ myco- + bacterium] A genus of acid-fast, nonmotile, non–spore-forming bacilli of the family Mycobacteriaceae, which includes the causative agents of tuberculosis and leprosy. The organisms are slender, nonmotile, gram-positive rods and do not produce spores or capsules.

Species include M. africanum, M. avium intracellulare, M. bovis, M. chelonei, M. fortuitum, M. gastri, M. gordonae, M. kansasii, M. marinum, M. scrofulaceum, M. terrae, M. triviale, M. smegmatis, and M. xenopi.

Mycobacterium bovis

The causative species of tuberculosis in cows and, less commonly, in humans.

Mycobacterium kansasii

A causative species of tuberculosis-like pulmonary disease in humans.

Mycobacterium leprae

The causative species of leprosy.

Mycobacterium marinum

An atypical mycobacterium that thrives in water and produces skin infection resembling sporotrichosis. It is the cause of swimming pool granuloma.

nontuberculous Mycobacterium

Abbreviation: NTM
Any mycobacterium that does not cause tuberculosis. There are four main classes. Three of these groups grow more slowly than M. tuberculosis and one group grows more rapidly. These organisms may cause various skin, lung, or other conditions or they may be harmless.

Mycobacterium triplex

An emerging but still uncommon acid-fast bacillus that grows slowly. It differs from M. avium in having distinct mycolic acids and ribosomal RNA.

MYCOBACTERIUM TUBERCULOSIS: Acid-fast bacillus in sputum (orig. mag. ×500)

Mycobacterium tuberculosis

The causative agent of tuberculosis in humans. See: tuberculosis; illustrationillustration

Mycobacterium ulcerans

A causative agent of infections of the skin and the underlying soft tissues. It is a common cause of illness in tropical and subtropical Africa and South America, where it is responsible for Buruli ulcer. It is thought to be the third most common disease-causing mycobacterium (after M. tuberculosis and M. leprae) in humans.

Mycobacterium

A genus of ACID FAST bacteria that contains a number of species causing TUBERCULOSIS in humans and other animals and HANSEN'S DISEASE in humans. Species of medical importance include Mycobacterium tuberculosis , Mycobacterium leprae and Mycobacterium ulcerans .

My·co·bac·te·ri·um

(mī'kō-bak-tēr'ē-ŭm) A genus of aerobic, nonmotile bacteria. Some species are associated with infections in immunocompromised people, especially those with AIDS. The type species is M. tuberculosis. [myco- + bacterium]

mycobacterium

my·co·bac·te·ri·um

mycobacterium

my•co•bac•te•ri•um

Mycobacterium

Mycobacterium

Mycobacterium

Mycobacterium

mycobacterium

Mycobacterium

mycobacterium

Mycobacterium

Mycobacterium

My·co·bac·te·ri·um

Mycobacterium

Mycobacterium bovis

Mycobacterium kansasii

Mycobacterium leprae

Mycobacterium marinum

nontuberculous Mycobacterium

Mycobacterium triplex

Mycobacterium tuberculosis

Mycobacterium ulcerans

Mycobacterium

My·co·bac·te·ri·um

mycobacterium

Synonyms for mycobacterium

noun rod-shaped bacteria some saprophytic or causing diseases

Synonyms

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