The properties that allow a microbe to cause disease are called virulence factors. B. anthracis has four know virulence factors. B. anthracis causes disease because the cells have a capsule that is not digested by the body's white blood cells. The capsule is made of the amino acid, glutamic acid, but the unusual form, called D-glutamic acid.

B. anthracis secretes a toxin made up of three proteins: protective antigen (PA), edema factor (OF) and lethal factor (LF). PA binds to cell-surface receptors on the host's cell membranes. After being cleaved by a protease, PA binds to the two toxic enzymes, OF and LA, and mediates their transportation into the cytosol where they exert their pathogenic effects.