Bacillus anthracis
You don't need to be Editor-In-Chief to add or edit content to WikiDoc. You can begin to add to or edit text on this WikiDoc page by clicking on the edit button at the top of this page. Next enter or edit the information that you would like to appear here. Once you are done editing, scroll down and click the Save page button at the bottom of the page.
| Bacillus anthracis | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Image:Bacillus anthracis 01.png Photomicrograph of Bacillus anthracis (fuchsin-methylene blue spore stain).
| ||||||||||||||
| Scientific classification | ||||||||||||||
| ||||||||||||||
| Binomial name | ||||||||||||||
| Bacillus anthracis Cohn 1872 |
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.[1]
Each cell is about 1 by 6 μm in size.
Historical background
B. anthracis was the first bacterium conclusively demonstrated to cause disease, by Robert Koch in 1877.[2] 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.[3]
B. anthracis has at 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.[4]
The bacterium can be cultivated in ordinary nutrient medium under aerobic or anaerobic conditions.
Treatment
Infections with B. anthracis can be treated with β-lactam antibiotics such as penicillin, and others which are active against Gram-positive bacteria.[5]
References
- ↑ Ryan KJ, Ray CG (editors) (2004). Sherris Medical Microbiology, 4th ed., McGraw Hill. ISBN 0-8385-8529-9.
- ↑ Madigan M, Martinko J (editors). (2005). Brock Biology of Microorganisms, 11th ed., Prentice Hall. ISBN 0-13-144329-1.
- ↑ Turnbull PCB (1996). Bacillus. In: Barron's Medical Microbiology (Baron S et al, eds.), 4th ed., Univ of Texas Medical Branch. ISBN 0-9631172-1-1.
- ↑ Dixon TC, Meselson M, Guillemin J, Hanna PC (1999). "Anthrax". N. Engl. J. Med. 341 (11): 815-26. PMID 10477781.
- ↑ Barnes JM (1947). "Penicillin and B. anthracis.". J Path Bacteriol 194: 113.
External links
he:Bacillus anthracis nl:Bacillus anthracisuk:Bacillus anthracis
Acknowledgement and Attribution Regarding Sources of Content
Some of the initial content on this page may be incorporated in part from copyleft sources in the public domain including wikis such as Wikipedia and AskDrWiki. Drug information for patients came from the The National Library of Medicine. Infectious disease information may have come from the Centers for Disease Control (CDC). Differential Diagnoses are drawn from clinicians as well as an amalgamation of 3 sources: 1.The Disease Database; 2. Kahan, Scott, Smith, Ellen G. In A Page: Signs and Symptoms. Malden, Massachusetts: Blackwell Publishing, 2004:3; 3. Sailer, Christian, Wasner, Susanne. Differential Diagnosis Pocket. Hermosa Beach, CA: Borm Bruckmeir Publishing LLC, 2002:7 .
