Bacillus anthracis is a rod-shaped
Gram-positive bacterium of size about 1 by 6
microns, and is the cause of the disease known as
anthrax.
B. anthracis was the first bacterium ever to be shown to cause disease, by
Robert Koch in
1877. The name
anthracis originates from the
Greek word
anthrax meaning
coal, and is used because victims develop black skin lesions. The bacteria normally rest in
spore form in the soil, and can survive for decades in this state. Once taken in by a
herbivore, the bacteria start multiplying inside the animal and eventually kill it, then continue to reproduce in the carcass. Once they run out of nutrients there, they revert back to the dormant spore state.
See also: Bacillus