Animation of Bacillus anthracis bacteria, which cause the disease anthrax in humans and some animals, including livestock. Anthrax bacteria are long rod-shaped bacteria that can survive many years in soil in a dormant spore state. The bacteria contain endospores (brown). When ingested by a grazing animal they can cause disease, which can be passed to humans when processing the animal. The disease can take different forms depending on the route of entry, with a skin (cutaneous) form being most common and least lethal. Intestinal and pulmonary anthrax are less common but much more dangerous. The disease can be treated with antibiotics, but untreated pulmonary anthrax is almost always fatal, and intestinal anthrax is fatal in a majority of cases. The virulence is due to the bacteria producing anthrax toxin, an cytotoxin mix of proteins.