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Organism Infromation
Bacillus anthracis has a long history of interest to microbiologists. It was the first organism used to prove Robert Koch's postulate: that an organism could be isolated from a diseased animal, grown in the laboratory and then used to infect a healthy animal, resulting in disease transmission. Since Dr. Louis Pasteur performed these experiments in 1877, B. anthracis has remained at the forefront of studies on pathogenic bacteria. The anthrax bioterror attacks in the fall of 2001 that resulted in 5 deaths highlighted the importance of the B. anthracis bacteria in bioterrorism.

Photo: Frederick C. Michel, ASM MicrobeLibrary
The virulence of the organism is due to the presence of two virulence plasmids, one of which (pXO1) encodes a tripartite toxin which forms binary products of lethal factor (LF) and protective antigen (PA) or edema factor (EF) and protective antigen (PA). Collectively these binary toxins (LF/PA and EF/PA) target multiple host functions, resulting in suppression of the immune responses and eventually in death of the organism from a variety of disrupted systems. The capsular polysaccharide (CPS) provides additional protection against the host immune responses and genes for its production are carried on the pXO2 plasmid. Ongoing studies are aimed at both identifying the molecular mechanisms responsible for virulence and potentially nullifying them or in producing a vaccine capable of providing protection against the organism. Genomic comparison studies can identify both the source of isolates used in the bioterror attacks as well as understanding the evolution of the pathogen.

Assembly viewer
Genome sequencing
TIGR, who was done the bulk of genome sequencing for the B. anthracis and B. cereus organisms, was the first to publish a B. anthracis genome in 2003 ( Nature. 2003 May 1;423(6935):81-6). This was for the non-virulent Ames strain that lacks the two virulence plasmids. TIGR has sequenced a fully virulent strain, Ames 0581, that contains both plasmids and is considered the type strain for B. anthracis and the "gold standard" against which all comparisons should be made. A number of other B. anthracis strains have been sequenced by TIGR for comparison and have recently been released.
Assembly Archive recently created at NCBI links together trace data and finished sequence providing complete information about a genome assembly. The Assembly Archive's first entries are a set of closely related strains of Bacillus anthracis. The assemblies are avalaible at /projects/assembly.
Comarative genomics
A final remarkable find with regards to the related organism, Bacillus cereus, has recently been published. B. anthracis is considered to be a member of the same phylogenetic cluster as B. cereus, although B. cereus causes a much less severe disease than B. anthracis. This difference is mainly attributable to the two toxin plasmids in B. anthracis. The WGS sequencing of a new B. cereus strain G9241, was undertaken since this organism was found to cause an anthrax-like disease in a patient ( Proc Natl Acad Sci USA. 2004 Jun 1; 101(22):8449-54). Two virulence plasmids, one almost identical to pXO1 which contains the same toxin genes, and an analogous plasmid to pXO2, pBC218, that presumably contains a polysaccharide capsule biosynthetic cluster that could produce a extracellular polysaccharide capable of providing the same protection as the capsule encoded on pXO2 from B. anthracis. This finding proves the close relationship of B. anthracis and B. cereus as well as showing that the anthrax disease can be caused by an organism other than B. anthracis, an important discovery that will be of vast interest to not only the micriobiological and medical communities, but also the general public.

Global genome comparison of Bacillus anthracis strains

Genome sequencing projects:
Genome sequence
Trace Assembly
Bacillus anthracis Ames complete sequence AE016879NC_003997
Nature. 2003 May 1;423(6935):81-6 The Bacillus anthracis Porton Ames isolate which is non-virulent due to the lack of the two virulence plasmids.
Bacillus anthracis strain 'Ames Ancestor' complete sequence
NC_007530 - chromosome
NC_007322 - pXO1
NC_007323 - pXO2
Virulent Bacillus anthracis Ames ancestor.
Bacillus anthracis strain A2012 AAAC01000001NC_003995
Science. 2002 Jun 14;296(5575):2028-33 This strain was isolated from one of the patients in the bioterror attacks in Florida in 2001.
Bacillus anthracis strain Kruger B AAEQ00000000NZ_AAEQ00000000 ContigID:602-665
This virulent strain is phylogenetically diverse as compared to the Ames strain and is found in South Africa.
Bacillus anthracis strain Western North America USA6153 AAER00000000NZ_AAER00000000 ContigID:787-830
This is the most commonly found strain found in France and Western North America.
Bacillus anthracis strain Australia 94 AAES00000000NZ_AAER00000000 ContigID:738-786
This virulent strain is found in Australia.
Bacillus anthracis strain CNEVA-9066 AAEN00000000NZ_AAEN00000000 ContigID:666-695
This phylogenetically diverse strain is found in France.
Bacillus anthracis strain A1055 AAEO00000000NZ_AAEO00000000 ContigID:696-737
This strain comes from the laboratory of Paul Keims.
Bacillus anthracis strain Vollum AAEP00000000NZ_AAEP00000000 ContigID:831-882
This low virulence strain is used in research studies and is found in the UK, Spain, and Zimbabwe.
Bacillus cereus strain ATCC 10987 complete sequence AE017194 NC_003909
Nucleic Acid Res.2004 Feb 11;32(3):977-88 This nonlethal strain was isolated from a study on cheese spoilage in Canada.
Bacillus cereus strain ATCC 14579 complete sequence AE016877NC_004722
Nature. 2003 May 1; 423(6935):87-91. This is the type strain for B. cereus.
Bacillus cereus strain G9241 AAEK00000000NZ_AAEK00000000
Proc Natl Acad Sci USA. 2004 Jun 1; 101(22):8449-54 This is a virulent organism that causes a disease very similar to anthrax due to the presence of two virulence plasmids.
Revised September 20, 2004