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The microbe that causes anthrax is rather complex– it is interesting how this little microbe has such big effects!
Bacillus anthracis is a rod-shaped, single cellular, gram-positive bacterium. Due to its gram-positive nature, this microbe has a thick layer of peptidoglycan. Typically the size ranges from 1-1.5 μm by 3-10 μm. Bacillus species do not move, their method of spreading the anthrax disease derives from their endospores. These spores can get in the body from contamination of food or water, inhalation, or entry through open cuts on the skin.
This image displays a gram stain of the Bacillus anthracis bacterium. https://microbewiki.kenyon.edu/index.php/Bacillus_anthracis_as_a_Bioterrorism_Agent
The Bacillus anthracis has a species-specific protein capsule, specifically a poly-D-glutamate peptide, that aids with the infection process. More importantly, this capsule helps the microbe avoid consumption and attack from the immune system so that it can attach effectively to the host. Attachment is a critical step to pathogenesis, and the bacterium is greatly benefited by the capsule preserving it.
The genome of the Bacillus anthracis is considerably large.
https://www.nature.com/articles/nature01586
The visual above shows the various genes making up the genome of the Bacillus Anthracis.
There are nearly 6,000 genes derived from the chromosome, pXO1, and pXO2. pXO1 and pXO2 are plasmids specific to the Bacillus anthracis species, and both of these plasmids have a significantly smaller larger number of genes compared to the chromosome. Scientists are aware of the function of a large amount of these genes, but there are exactly 670 that have unknown functions. This is important because these genes could potentially be playing additional roles in pathogenesis that we are unaware of concerning anthrax.
Below is a “Draw my life” about the Bacillus Anthracis to give a little more information about the microbe (0:00-0:57) . Enjoy!
Citations-
https://www.ncbi.nlm.nih.gov/pmc/articles/PMC1769905/
http://web.uconn.edu/mcbstaff/graf/Student%20presentations/Banthracis/Banthracis.html