Taxonomy
Family: Bacillaceae

Bacillus cereus group: B. anthracis, B. cereus, B. mycoides, B. thuringiensis

Natural habitats
Soil inhabitant in sporulated form. Anthrax spores in soil can remain infectious for decades.

They are obligate pathogens.

Isolated from blood of animals and human with anthrax, animal carcasses and products and soil contaminated with spores

Clinical significance / ANTHRAX

- cutaneous anthrax
Infection occurs through a break in the skin. Following the incubation period of usually 2 to 3 days, a small papule appears, progressing over the next 24h to a ring of vesicles, with subsequent ulceration and formation of a characteristic blackened eschar.
Subsequent eschar formation may become thick and surrounded by extensive edema.
Fever and pus and pain at the side are normally absent; their presence probably indicate a secondary bacterial infection.

- gastrointestinal anthrax
The symptoms are the result of ulcerations developing primarily in the cecal and terminal ileal mucosae: vomiting, nausea and abdominal pain, accompanied by fever.

This can rapidly progress to bloody diarrhea and systemic infection

- inhalation anthrax / bioterrorism
The inhaled spores are ingested by macrophages and carried from the lungs to the lymphatic system, where the infection progresses.
During transit to lymph nodes, spores germinate into vegetative cells, begin to replicate and produce the capsule and toxins that lead to bacteremia and associated hemorrhage and necrosis.

Anthrax is high on the list of agents that could be used in biological warfare or bioterrorism.