| Bacillus anthracis | |
|---|---|
 |
|
| Photomicrograph of Bacillus anthracis (fuchsin-methylene blue spore stain). | |
| Scientific classification | |
| Kingdom: | Bacteria |
| Phylum: | Firmicutes |
| Class: | Bacilli |
| Order: | Bacillales |
| Family: | Bacillaceae |
| Genus: | Bacillus |
| Species: | B. anthracis |
| Binomial name | |
| Bacillus anthracis Cohn 1872 |
|
Bacillus anthracis is a Gram-positive spore-forming, rod-shaped bacterium, with a width of 1-1.2µm and a length of 3-5µm. It can be grown in an ordinary nutrient medium under aerobic or anaerobic conditions[citation needed]. It is the only bacterium with a protein capsule (D-glutamate), and the only pathogenic bacteria to carry its own adenylyl cyclase virulence factor (edema factor). It bears close genotypical and phenotypical resemblance to Bacillus cereus and Bacillus thuringiensis. All three species share cellular dimensions and morphology. All form oval spores located centrally in a non-swollen sporangium. Bacillus anthracis spores in particular are highly resilient, surviving extremes of temperature, low-nutrient environments, and harsh chemical treatment over decades or centuries.
Contents |
Casimir Davaine first isolated this bacterium from the blood of sheep suffering from anthrax.[1] 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.
Three forms of anthrax disease are recognized based on their form of inoculation.
Infections with B. anthracis can be treated with β-lactam antibiotics such as penicillin, and others which are active against Gram-positive bacteria.[3]
Components of tea, such as polyphenols, have the ability to inhibit the activity both of bacillus anthracis and its toxin considerably; spores, however, are not affected. The addition of milk to the tea completely inhibits its antibacterial activity against anthrax[4]. Activity against the anthrax bacillum in the laboratory does not prove that drinking tea affects the course of an infection, since it is unknown how these polyphenols are absorbed and distributed within the body.
As with other pathogenic bacteria, B. anthracis must acquire iron in order to grow and proliferate in its host environment. The most readily available iron sources for pathogenic bacteria are the heme groups used by the host in the transport of oxygen. In order to scavenge heme from host hemoglobin and myoglobin, B. anthracis uses two secretory proteins, IsdX1 and IsdX2. These proteins can separate heme from hemoglobin, allowing surface proteins of B. anthracis to transport it into the cell.[5]
Main Page
Superregnum: Bacteria
Regnum: Bacteria
Phylum: Firmicutes
Classis: Bacilli
Ordo: Bacillales
Familia: Bacillaceae
Genus: Bacillus
Species: Bacillus
anthracis
Strain: Bacillus anthracis
str. 'Ames Ancestor' - Bacillus anthracis str.
Ames - Bacillus anthracis str.
Sterne -
Bacillus anthracis Cohn, 1872
| Bacillus anthracis | |||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Scientific classification | |||||||||||||||
| |||||||||||||||
| Binomial name | |||||||||||||||
| Bacillus anthracis Cohn 1872 | |||||||||||||||
Bacillus anthracis is a Gram-positive rod-shaped bacterium, 1 - 1.2µm in width and 3 - 5µm in length.
It lives in soils worldwide at mesophilic temperatures. It can be grown in aerobic or anaerobic conditons (facultative anaerobe) in a medium with essential nutrients, including carbon and nitrogen sources. In 1877, this organism was the first to be shown to cause disease by Dr. Robert Koch and verified by Dr. Louis Pasteur.
|
|
Wikis
Quiz
Facts
Search
