Mycobacterium bovis

Mycobacterium bovis, is a slow-growing (16- to 20-hour generation time), aerobic bacterium and the causative agent of tuberculosis in cattle (known as Bovine TB). Related to M. tuberculosis—the bacterium which causes tuberculosis in humans—M. bovis can also jump the species barrier and cause tuberculosis in humans and other mammals.

Pathogenesis

During the first half of the 20th century, M. bovis is estimated to have been responsible for more losses among farm animals than all other infectious diseases combined. Infection occurs if the bacterium is ingested.

M. bovis is usually transmitted to humans by infected milk, although it can also spread via aerosol droplets. Actual infections in humans are nowadays rare in developed countries, mainly because pasteurisation kills most bacteria in infected milk; also, cattle are randomly tested for the disease and immediately culled if infected, but can still be used for human consumption. However, in areas of the developing world where pasteurisation is not routine, M. bovis is a relatively common cause of human tuberculosis.