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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).


References in periodicals archive ?
Factors influencing numbers of Mycobacterium avium, Mycobacterium intracellulare, and other mycobacteria in drinking water distribution systems.
Rapid detection methods for viable Mycobacterium avium subspecies paratuberculosis in milk and cheese.
Characteristics of pulmonary Mycobacterium avium complex disease diagnosed later in follow-up after negative mycobacterial study including bronchoscopy.
Genetic polimorphisim identification from Mycobacterium avium subspecies paratuberculosis in goats in central Mexico.
Hypercalcaemia: a clue to Mycobacterium avium intracellulare infection in a patient with AIDS.
Infeccion pulmonar por Mycobacterium avium complex en el huesped inmunocompetente.
Since there have been no studies to date on the role of mycobacteria in the pathogenesis of human allergies, we evaluated the allergenicity of Mycobacterium avium subspecies paratuberculosis (MAP) and its possible contribution to the pathogenesis of these diseases.
SGM comprise some common species, such as the Mycobacterium avium complex (Mycobacterium avium, Mycobacterium intracellulare, and Mycobacterium chimaera), Mycobacterium kansasii, Mycobacterium haemophilum, Mycobacterium marinum, and Mycobacterium ulcerans, in addition to some less common pathogens, such as Mycobacterium scrofulaceum, Mycobacterium simiae, Mycobacterium malmoense and Mycobacterium xenopi.

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