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| __NOTOC__
| | #REDIRECT [[Bacillus anthracis]] |
| {{Anthrax}}
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| {{CMG}}; {{AE}} {{JS}}
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| ==Overview==
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| ==Taxonomy==
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| [[Bacterium|Bacteria]]; [[Archaebacteria]]; [[Firmicutes]]; [[Bacilli]]; [[Bacillales]]; [[Bacillaceae]]; [[Bacillus]]; anthracis; Bacillus anthracis
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| ==Biology==
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| {| style="float: right;"
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| | [[File:AnthraxCauses2.png|200px|thumb|none| Photomicrograph depicting a number of Gram-positive, endospore-forming Bacillus anthracis bacteria<SMALL>Courtesy: ''[http://phil.cdc.gov/phil/home.asp Public Health Image Library (PHIL), Centers for Disease Control and Prevention (CDC)]''<ref>{{Cite web | title = http://phil.cdc.gov/phil/details.asp | url = http://phil.cdc.gov/phil/details.asp}}</ref></SMALL>]]
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| | [[File:AnthraxCauses1.jpg|200px|thumb|none| Scanning electron micrograph (SEM) depicted spores from the Sterne strain of Bacillus anthracis bacteria<SMALL>Courtesy: ''[http://phil.cdc.gov/phil/home.asp Public Health Image Library (PHIL), Centers for Disease Control and Prevention (CDC)]''<ref>{{Cite web | title = http://phil.cdc.gov/phil/details.asp | url = http://phil.cdc.gov/phil/details.asp}}</ref></SMALL>]]
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| |}
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| [[B. anthracis]], the causative agent of anthrax, is a is a nonmotile, [[Gram-positive]], [[aerobic]] or facultatively anaerobic, [[endospore]]-forming, [[rod]]-shaped [[bacterium]] approximately 4 μm by 1 μm, although under the microscope it frequently appears in chains of [[cells]]. In [[blood smear]]s, smears of tissues or lesion fluid from diagnostic specimens, these chains are two to a few cells in length; in smears made from [[in vitro]] cultures, they can appear as endless strings of [[cells]] - responsible for the characteristic tackiness of the colonies and for the flocculating nature of broth cultures. Also characteristic is the square-ended appearance traditionally associated with [[B. anthracis]] vegetative cells, although this may not always be very clear. In the presence of [[oxygen]], and towards the end of the exponential phase of growth, one ellipsoidal [[spore]] (approximately 2 μm by 1 μm in size) is formed in each [[cell]]; this does not swell the [[sporangium]] and is generally situated centrally, sometimes sub terminally.<ref name=WHO>{{cite web | title = Anthrax in Humans and Animals | url = http://www.who.int/csr/resources/publications/anthrax_web.pdf }}</ref> The [[spores]] of [[B. anthracis]], which can remain dormant in the environment for decades, are the [[infectious]] form, but vegetative [[B. anthracis]] rarely causes disease.<ref>{{Cite journal | author = [[Sean V. Shadomy]] & [[Theresa L. Smith]] | title = Zoonosis update. Anthrax | journal = [[Journal of the American Veterinary Medical Association]] | volume = 233 | issue = 1 | pages = 63–72 | year = 2008 | month = July | doi = 10.2460/javma.233.1.63 | pmid = 18593313}}</ref>
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| In the absence of [[oxygen]] and under a high partial pressure of Co2 in the presence of [[bicarbonate]], the vegetative [[cell]] secretes its [[polypeptide]] [[capsule]] and it is one of the two established [[in vivo]] [[virulence factor]]s of [[B. anthracis]]. The [[capsule]] is also a primary [[diagnostic]] aid.<ref name=WHO>{{cite web | title = Anthrax in Humans and Animals | url = http://www.who.int/csr/resources/publications/anthrax_web.pdf }}</ref>
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| B. anthracis begins producing toxins within hours of germination (7). Protective antigen (PA) and edema factor (EF) combine to form edema toxin (ET) and PA and lethal factor (LF) combine to form lethal toxin (LT)
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| ==Origin==
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| [[Anthrax]] is thought to have originated in Egypt and Mesopotamia. Many scholars think that in Moses’ time, during the 10 plagues of Egypt, [[anthrax]] may have caused what was known as the fifth [[plague]], described as a sickness affecting horses, cattle, sheep, camels and oxen.
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| ==Tropism==
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| ==Natural Reservoir==
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| [[Natural reservoir]]s of [[Bacillus anthracis]] includes:
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| * Humans
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| * Mammals
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| * Herbivores
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| * Reptiles
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| * Birds
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| ==References==
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| {{reflist|2}}
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