BACILLUS ANTHRACIS

'''Bacillus anthracis''' is a Gram-positive, facultatively anaerobic, rod-shaped bacterium of the genus ''Bacillus''. An endospore forming bacterium, ''B. anthracis'' is a natural soil-dwelling organism, as well as the causative agent of anthrax. Sherris Medical Microbiology, Ryan KJ, Ray CG (editors), , , McGraw Hill, 2004,
Each cell is about 1 by 6 μm in size.

Contents

Historical background

Pathogenicity

Treatment

References

External links

Historical background

''B. anthracis'' was the first bacterium conclusively demonstrated to cause disease, by Robert Koch in 1877. Brock Biology of Microorganisms, Madigan M, Martinko J (editors)., , , Prentice Hall, 2005, The species name ''anthracis'' is from the Greek ''anthrakis'' (ἄνθραξ), meaning ''coal'' and referring to the most common form of the disease, cutaneous anthrax, in which large black skin lesions are formed.

Pathogenicity

Under conditions of environmental stress, ''B. anthracis'' bacteria naturally produce endospores which rest in the soil and can survive for decades in this state. When ingested by a cattle, sheep, or other herbivores, the bacteria begin to reproduce inside the animal and eventually kill it, then continue to reproduce in its carcass. Once the nutrients are exhausted, new endospores are produced and the cycle repeats. Bacillus. ''In:'' Barron's Medical Microbiology ''(Baron S ''et al'', eds.), Turnbull PCB, , , Univ of Texas Medical Branch, 1996,
''B. anthracis'' has as least 89 known strains, ranging from highly virulent strains with biological warfare and bioterrorism applications (Ames and ''Vollum'') to benign strains used for inoculations (''Sterne''). The strains differ in presence and activity of various genes, determining their virulence and production of antigens and toxins. The form associated with the 2001 anthrax attacks produced both toxin (consisting of three proteins: the protective antigen, the edema factor and the lethal factor) and a capsule (consisting of a polymer of glutamic acid). Infection with anthrax requires the presence of all three of these exotoxins^[1].
The bacterium can be cultivated in ordinary nutrient medium under aerobic or anaerobic conditions.

Treatment

Main articles: Anthrax

Infections with ''B. anthracis'' can be treated with β-lactam antibiotics such as penicillin, and others which are active against Gram-positive bacteria^[2].

References

1. Anthrax, Dixon TC, Meselson M, Guillemin J, Hanna PC, , , N. Engl. J. Med., 1999
2. Penicillin and ''B. anthracis''., Barnes JM, , , J Path Bacteriol, 1947

External links

★ Bacillus anthracis Genome Projects