Category:Mycobacterium species
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Overview
- Mycobacterial infections are caused by bacteria belonging to the family Mycobacteriaceae, order Actinomycetales
- Includes obligate pathogens, opportunistic pathogens and saprophytes
- Cause chronic, progressive, granulomatous infections
- Cause tuberculosis, Johne's disease and feline leprosy
- M. bovis, M. tuberculosis and M. avium cause tuberculosis of cattle, tuberculosis of pigs and tuberculosis of dogs respectively
- The 'classical' tuberculosis lesions are caused by the Mycobacterium tuberculosis complex
- The Johne's type lesions are caused by the Mycobacterium avium complex
- Environmental species are found in soil, vegetation and water
- Mycobacterium leprae and M.lepraemurium cause human, feline/murine leprosy respectively
- Atypical mycobacteriosis is a localized opportunistic skin and subcutaneous infection caused by saprophytic and rapidly growing atypical mycobacteria
- Granulomatous lesions in muscle and skin
- Skin tuberculosis of cattle causes nodules along the lymphatics of the limbs
- Bovine farcy is thought to be caused by M. senegalense and M. farcinogenes
- Saprophytic mycobacteria cause granulomatous lesions
Characteristics
- Aerobic, weakly Gram-positive acid-fast rods
- Non-motile, non-spore forming
- Cell walls contain mycolic acid
- Require egg-based media for growth
- Slow-growing colonies
- Resistant to disinfectants and environmental conditions; susceptible to pasteurisation
- Mycobacteria stain with carbol dyes and resist subsequent decolorization with inorganic acids; this characteristic which is due to the spatial arrangement of mycolic acids within the cell wall makes them acid fast
Identification
- Identified by Ziehl-Neelson staining
- Differentiated by culture, biochemical tests, chromatography and molecular techniques
- Pathogenic species require at least three weeks for growth on egg-based media
<ncl style=bullet maxdepth=2 headings=bullet headstart=2 showcats=1 showarts=1>Category:Mycobacterium species</ncl>
Pages in category "Mycobacterium species"
The following 4 pages are in this category, out of 4 total.