Mycobacterium bovis

Mycobacterium bovis (M. bovis) is a slow-growing aerobic bacterium and the causative agent of tuberculosis in cattle (known as bovine TB). It is related to Mycobacterium tuberculosis, the bacterium which causes tuberculosis in humans. M. bovis can jump the species barrier, usually from infected mammals to humans, leading to zoonotic TB.

Characteristics

M. bovis is a small, aerobic, nonmotile bacillus. It is characterized by its slow growth rate, taking up to six weeks to form visible colonies. The bacterium is a facultative intracellular parasite, usually of macrophages, with a slow replication time, between 15–20 hours.

Pathogenesis

M. bovis causes TB and can affect all mammals, including humans. The disease is spread in the air when people who are sick with pulmonary TB expel bacteria, such as through coughing. Infection is established in the lungs and the regional lymph nodes.

Diagnosis

Diagnosis of M. bovis involves isolating the bacterium from a clinical specimen. The use of PCR technology has also been developed to detect and identify mycobacteria.

Treatment

Treatment of M. bovis infection in humans is difficult and requires long courses of multiple antibiotics. Active disease due to M. bovis is resistant to pyrazinamide, one of the first-line drugs for TB.

Prevention

Prevention of M. bovis is achieved by a combination of a test and slaughter policy in cattle, and by pasteurization of milk.

See also

• Mycobacterium
• Tuberculosis
• Zoonosis

• 
  Mycobacterium bovis BCG under Ziehl-Neelsen stain
• 
  Bovine tuberculosis in a boar
• 
  USDA Bovine TB Free logo