Mycobacterium bovis

Mycobacterium bovis is a member of the Mycobacterium tuberculosis complex and an obligate aerobe bacterium that is the cause of tuberculosis in cattle. M. bovis can also cause tuberculosis in other mammals including humans.

Epidemiology

In the United States, M. bovis accounts for ~ 2% of all new tuberculosis cases, with similar figures in The Netherlands (1.4%).

Pathology

As a zoonosis, human infection with M. bovis usually occurs by way of infected milk, although droplet infection is possible.

Infections in humans are rare because of pasteurisation of milk and dairy, and because infected cattle are normally culled immediately. In countries where pasteurisation is not routinely undertaken, M. bovis is a relatively common cause of tuberculosis.

Rarely, human-to-cattle and human-to-human infection can occur as during a 2004 outbreak in Birmingham (United Kingdom) amongst nightclub patrons, the index case having drunk unpasteurised milk.

Bacillus Calmette-Guérin (BCG) is a live attenuated strain of Mycobacterium bovis.

Treatment and prognosis

M. bovis is inherently resistant to pyrazinamide. The standard treatment consists of combination isoniazid and rifampin.