| Species/Subspecies: | Rickettsia rickettsii | ||||||||
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| Category: | Motile | ||||||||
| Etymology: | Genus namn: Named after Howard T. Ricketts, who showed which organism caused Rocky Mountain spotted fever, which resulted in his death Species epithet: see Genus namn. | ||||||||
| Significance: | [Of minor importance] | ||||||||
| Taxonomy: | Class Alphaproteobacteria Order Rickettsiales Family Rickettsiaceae Genus Rickettsia |
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| Type Strain: | Smith = ATCC VR-149. | ||||||||
| Macromorphology (smell): | Cannot be cultivated on cell free substrates (for instance agar plates). | ||||||||
| Micromorphology: | Short (paired) motile rods (0.2-0.3 x 0.3-2 µm).R. rickettsia exhibits actin-based motility (see references 154 and 155 below). | ||||||||
| Gram +/Gram -: | G- | ||||||||
| Metabolism: | Aerobic | ||||||||
| Catalase/Oxidase: | |||||||||
| Fermentation of carbohydrates: | Is not used for identification of Rickettsia spp. | ||||||||
| Spec. Char.: | Is obligate intracellular because the plasma membrane is leaky and the bacteria require correct osmolarity and constant supply of nutrients. | ||||||||
| Special Media: | |||||||||
| Vector: | American dog tick or wood tick (Dermacentor variabilis) and Rocky Mountain wood tick (Dermacentor andersoni). | ||||||||
| Disease: | Rocky Mountain spotted fever |
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| Hosts: | Dog, man | ||||||||
| Clinical Picture: | |||||||||
| Genome Sequence: |
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| 16S rRNA Seq.: |
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| Taxonomy/phylogeny:
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About 30 species have been described within the genus Ricketsia. This genus is relatively closely related to other genera within the orderRickettsialas (Anaplasma, Ehrlichia and Neorickettsia). | ||||||||
| Legislation: | R. rickettsia belongs to category C as a potential bioterrorism agent according to NIAID | ||||||||
| Comment: | Intracellular in endothelial cells where it is primarely growing freely in the cytoplasm. An evolutionary interesting bacterium, because its ancestors invaded cells and formed the mitochondria by endosymbiosis. Can use ATP from the hostcell, but also synthesize ATP by oxidative phosphorylation. | ||||||||
| Reference(s): | No. 154, 155 | ||||||||
| Updated: | 2023-03-22 |