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*Includes obligate pathogens, opportunistic pathogens and saprophytes
*Includes obligate pathogens, opportunistic pathogens and saprophytes
*Cause chronic, progressive, granulomatous infections
*Cause chronic, progressive, granulomatous infections
*Cause tuberculosis, Johne's disease and feline leprosy
*Cause tuberculosis, [[Intestines Proliferative Enteritis - Pathology#Paratuberculosis (Johnes disease)|Johne's disease]] and feline leprosy
*''M. bovis'', ''M. tuberculosis'' and ''M. avium'' cause [[Respiratory Bacterial Infections - Pathology#Tuberculosis|tuberculosis of cattle]], [[Respiratory Bacterial Infections - Pathology#Tuberculosis in pigs|tuberculosis of pigs]] and [[Respiratory Bacterial Infections - Pathology#Tuberculosis in dogs|tuberculosis of dogs]] respectively
*''M. bovis'', ''M. tuberculosis'' and ''M. avium'' cause [[Respiratory Bacterial Infections - Pathology#Tuberculosis|tuberculosis of cattle]], [[Respiratory Bacterial Infections - Pathology#Tuberculosis in pigs|tuberculosis of pigs]] and [[Respiratory Bacterial Infections - Pathology#Tuberculosis in dogs|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 found in soil, vegetation and water
*Environmental species found in soil, vegetation and water
*[[''Mycobacterium leprae'' and ''M.lepraemurium'']] cause human, feline and murine leprosy
*Atypical mycobacteriosis is a localized opportunistic skin and subcutaneous infection caused by saprophytic and rapidly growing [[Atypical Mycobacterium]]
*Granulomatous lesions in [[Muscles Inflammatory - Pathology#Tuberculosis|muscle]] and[[Bacterial skin infections - Pathology#Bacterial granulomatous dermatitis|skin]]
**Mycobacteria utilize several virulence factors including cord factor or trehalose dimycolate, surface glycolipid, sulfatides, lipoarabinomannan, heteropolysaccharide, heat shock protein, complement, and tubuloprotein
**Mycobacteria utilize several virulence factors including cord factor or trehalose dimycolate, surface glycolipid, sulfatides, lipoarabinomannan, heteropolysaccharide, heat shock protein, complement, and tubuloprotein
**The types of immune responses that are critical in responding to mycobacterial infection are cell-mediated immunity and the delayed hypersensitivity response
**The types of immune responses that are critical in responding to mycobacterial infection are cell-mediated immunity and the delayed hypersensitivity response
**Pathogenicity of mycobacteria depends on their ability to escape phagocytic killing
**Pathogenicity of mycobacteria depends on their ability to escape phagocytic killing, mostly imparted by the cell wall consitiutents:
***Cord factor (trehalose dimycolate) – surface glycolipid responsible for serpentine growth in vitro
***Cord factor (trehalose dimycolate) – surface glycolipid responsible for serpentine growth in vitro
***Suphatides – surface glycolipid containing sulphur which prevents fusion of phagosome with lysosome. cAMP secreted by the bacteria may also facilitate this. Also something about the cholesterol content of the phagosome….. nature article
***Suphatides – surface glycolipid containing sulphur which prevents fusion of phagosome with lysosome. cAMP secreted by the bacteria may also facilitate this.
***LAM – heteropolysaccharide which inhibits macrophage activation by IFNγ and induces macrophages to secrete TNFα -induces fever, etc and IL-10 which suppresses mycobacteria-induced T cell proliferation
***LAM – heteropolysaccharide which inhibits macrophage activation by IFNγ and induces macrophages to secrete TNFα which induces fever and IL-10 which suppresses mycobacteria-induced T cell proliferation
***The wax of the cell wall, peptidoglycans and other glycolipids are responsible for the adjuvant activity – attracts APCs
***The wax of the cell wall, peptidoglycans and other glycolipids are responsible for the adjuvant activity – attracts antigen presenting cells
***Tubuloprotein – important Ag, purified tubuloprotein is the basis of the tuberculin test
***Tubuloprotein – important antigen; purified tubuloprotein is the basis of the tuberculin test
**Mycobacteria are released from macrophages and also migrate within macrophages around the body
**Mycobacteria are released from macrophages and also migrate within macrophages around the body
**Waxy cell wall contributes to the host immune response to the mycobacteria and the development of lesions
**Waxy cell wall contributes to the host immune response to the mycobacteria and the development of lesions
===Johne's disease (paratuberculosis)===
===[[Intestines Proliferative Enteritis - Pathology#Paratuberculosis (Johnes disease)|Johne's Disease (paratuberculosis)]]===
*Chronic, contagious enteritis of ruminants
*[[Intestines Proliferative Enteritis - Pathology#Paratuberculosis (Johnes disease)|Johne's Disease]] is a chronic, contagious enteritis of ruminants
*Caused by ''M avium'' subsp. ''paratuberculosis''
*Caused by ''M avium'' subsp. ''paratuberculosis''
**Separation and isolation of calves from affected dams
**Separation and isolation of calves from affected dams
**Inactivated adjuvanted vaccines are available and reduce shedding of mycobacteria but do not eliminate infection
**Inactivated adjuvanted vaccines are available and reduce shedding of mycobacteria but do not eliminate infection