Mycobacterium spp

Classification

Taxonomy

• Family: Mycobacteriaceae.
• Genus: Mycobacterium.

Etymology

• Mycobacterium – small fungus-like rod:
  • Gr: myces – a fungus;  bakterion – a small rod.
• Tuberculum – a small swelling; bovis – of the ox; avium – of birds.

Distribution

• Worldwide.

Significance

• M. tuberculosis causes tuberculosis in non-human primates, dogs and birds but is mainly a disease of humans.
• M. avium subsp avium is a disease of birds.
• Spontaneous mycobacteriosis is rare in rabbits with the exception of the pygmy rabbit (Brachylagus idahoensis) where a subpopulation of Columbia Basin pygmy rabbits kept in captivity were diagnosed with disseminated mycobacteriosis due to Mycobacterium avium complex.
• M. avium subsp paratuberculosis causes paratuberculosis (Johne’s disease) in ruminants.  The first suspected case report of M. avium subsp paratuberculosis in a European brown hare (Lepus europaeus) was reported in England in 1977.  Three surveys of rabbits (Oryctolagus cuniculus) from farms in Eastern Scotland confirmed paratuberculosis by post mortem observations (lymphadenopathy and thickened intestines), histology and culture. The rabbit is thought to pose a high risk in disease transmission to cattle via rabbit droppings. A high concentration of mycobacterium (10⁶ CFU/g feces) has been found in rabbit feces. Cattle consume these droppings whilst grazing.
• M. bovis causes significant disease and economic loss in cattle. The potential of rabbits as a reservoir for Mycobacterium spp has not been fully evaluated.
• M. genavense has been described in a single case report causing a granulomatous pneumonia in a rabbit Pneumonia.