Edema factor is a calmodulin-dependent adenylate cyclase, which, as the name implies, causes the intense edema observed with the disease. These pathways are critical to proper cell cycle regulation, cellular proliferation, and defense against cellular stresses. Lethal factor cleaves the N-terminus of these proteins, disrupting the ERK1/2, JNK/SAPK, and p38 signaling pathways in host cells. Lethal factor is a zinc-dependent metalloprotease that targets the mitogen-activated kinase kinases (MAPKKs, or Meks). The anthrax toxin is composed of three proteins: lethal factor, edema factor, and protective antigen. The anthrax toxin genes are located on virulence plasmid pXO1, and the capsule biosynthetic operon is located on pXO2 ( 17). Recently, a fourth form, injectional anthrax, has been recognized in heroin addicts whose drug supply was likely contaminated by contact with infected animal material ( 15, 16). Spores are inhaled and deposited into the lung tissue, where they proceed to germinate and spread through lymph nodes, rapidly causing systemic disease, massive tissue damage, shock and death ( 14). The other systemic form, inhalational anthrax, is the most deadly form, in part because of its ambiguous set of symptoms and rapid onset. One of these, gastrointestinal anthrax, is the result of ingesting spores, which may occur in grass-fed mammals that consume the spores in the soil, or in humans through the consumption of contaminated food products. This disease is distinguished by the presence of a characteristic, black eschar on the skin, and typically remains a localized infection.
Spore dark injection questions skin#
Entry of spores via a preexisting lesion in the skin can result in cutaneous anthrax. anthracis infection can manifest as a cutaneous or systemic disease.
cereus sensu lato group are only occasionally cited as disease causing in mammals but their potential virulence factors are not known.ī.
thuringiensis are lethal for invertebrates and are used as insecticides ( 12, 13). cereus can cause food poisoning in humans, while some strains of B. Human disease is generally acquired accidentally during outbreaks of anthrax in domestic livestock and wildlife, but has also been associated with bioterrorism ( 11).
anthracis is the causative agent of anthrax in mammals, an often-lethal disease. Of these, the most well-studied species are B. anthracis, Bacillus thuringiensis, Bacillus mycoides, Bacillus pseudomycoides, Bacillus weihenstephanensis, and Bacillus cytotoxicus ( 2– 10). Member species of the Bacillus cereus sensu lato group include B. In addition to DNA sequence similarities and gene synteny, horizontal transfer of closely related plasmids is apparent among these ubiquitous soil bacteria ( 1). The Bacillus cereus sensu lato clade of this well-studied genus contains pathogens and nonpathogens, with a complex taxonomy that in recent years has been continuously modified to reflect DNA sequence data. The Bacillus species are Gram-positive, spore-forming, facultative aerobes that are commonly found in the soil, sometimes associated with plants and nematodes. Bacillus anthracis and Other Pathogenic Bacillus Species