Bacillus anthracis: Dose Response Models
Bacillus anthracis is a rod shaped gram negative bacterium which is the causative agent of the disease anthrax. Anthrax can be subdivided into three main categories generically named for the route of exposure or affected terminal organs, and are cutaneous, inhalational and gastrointestinal anthrax (CDC, 2003) . Cutaneous anthrax is the most common form of naturally occurring anthrax. Although this type of the disease may be debilitating or scarring to the host, it is not typically fatal especially where modern healthcare is available. Inhalational anthrax is the most lethal form of the disease and the preferred form of anthrax in bioterror scenarios. Inhalation of the spores introduces them to the lower regions of the lungs (alveoli, or air sacs) where oxygen and carbon dioxide are exchanged with the blood. At this location the pathogenesis of B. anthracis occurs where eventually after intracellular transport can result in septicemia and death . Gastrointestinal anthrax is a very rare form of the disease. This form of anthrax is typically observed with immune-compromised individuals or with those exposed to an overwhelming load of pathogens. This form of the disease is potentially lethal due to the development of a systemic infection from the internal infection.
There are three main strains of B. anthracis. The Ames strain garnered wide public attention during the 2001 anthrax postal attacks. The Vollum strain is a weaponized form that is comparatively more infectious than the Ames strain. There is also an attenuated vaccine strain, known as the Sterne strain. The main datasets gathered for B. anthracis are for the Vollum strain.
- Centers for Disease Control and Prevention (CDC) (2003) Emergency Preparedness and Response: Anthrax Q&A Signs and Symptoms 
- Guidi-Rontani, C., Weber-Levy, M. Labruyere, E., Mock, M. (1999) Germination of Bacillus anthracis Spores Within Alveolar Macrophages. Molecular Microbiology 31(1):9-17