Which bacterium causes anthrax, the disease historically linked to infected animal hides and wool?

Bacillus anthracis causes anthrax, a disease historically linked to infected animal hides and wool.

This Gram-positive, rod-shaped bacterium forms durable endospores that can persist in soil for years. Grazing animals may ingest spores while feeding, and people can become infected through skin contact, inhalation, or eating contaminated meat. The cutaneous form, which begins through broken skin, is the most common human form.

Anthrax is associated with three major virulence factors: a capsule and two toxin components called protective antigen and edema factor or lethal factor. The bacterium was also central to the history of microbiology: Robert Koch demonstrated its role in disease in 1876, helping establish the germ theory of disease.

Anthrax is not the same as infection by Bacillus cereus, a related species that can cause food poisoning. The name anthrax comes from a Greek word associated with coal, referring to the dark center of a characteristic skin lesion.