Bacillus anthracis is a Gram-positive bacteria which is spore forming and produces endotoxins as well as lethal factors.
It is classically associated with anthrax in cattle worldwide and has a preference for regions with neutral or alkaline, calcareous soils.
After the bacterium penetrates wounds or is inhaled or ingested, spores infect macrophages and proliferate. In cutaneous and GI infection, proliferation can occur at the site of infection and the lymph nodes draining the site of infection.
Lethal toxin and edema toxin are produced by B. anthracis and respectively cause local necrosis and extensive edema, which is a frequent characteristic of the disease. As the bacteria multiply in the lymph nodes, toxemia progresses and bacteremia may ensue.