Rickettsiales
Rickettsia rickettsii
The Rickettsiales make an order smaller bacteria within the Alphaproteobacteria. Most species of this group are obligate intracellular, they can only survive as endosymbionts within foreign cells. Rickettsiales are difficult to cultivate in the laboratory. Many genera, such as Rickettsia, contain pathogenic agents.
Of particular interest for the endosymbiont theory of mitochondria, the species of Rickettsia prowazekii is. The genome has been completely sequenced and has very strong similarity to the mitochondrial DNA on. This suggests that occurring in Eukrayotenzellen mitochondria and Rickettsia prowazekii had a common ancestor.
- 2.1 Older, classic systematics
Pathogenic species and pests (selection)
Family Rickettsiaceae
- (Also known as epidemic typhus ) Classical typhus: Rickettsia prowazekii
- Rickettsia rickettsii: Rocky Mountain spotted fever
- Orientia tsutsugamushi: tsutsugamushi disease ( scrub typhus )
Family Anaplasmataceae
- Anaplasma phagocytophilum: Human granulocytic anaplasmosis ( HGA ), because of the synonym Ehrlichia equi, the disease also known as Human granulocytic ehrlichiosis ( HGE ) is known.
- Anaplasma platys (Canine Cyclic Thrombocytopenia )
- Ehrlichia chaffensis: Human monocytic ehrlichiosis (HME )
- Ehrlichia ruminantium: heartwater disease in ruminants
- Ehrlichia canis: ehrlichiosis in dogs ( canine ehrlichiosis )
- Neorickettsia sennetsu: sennetsu fever
Family Holosporaceae
- A not yet identified in detail, but on the basis of 16S rRNA analysis probably -tory in this family bacterium causes Necrotizing Hepatopancreatitis ( NHP ) in shrimp. The type is called therefore often referred to as the NHP bacterium ( NHPB ). In shrimp farms, the spread of this species cause major economic damage.
System
The systematics of this order was subjected in recent years due to 16S rRNA analysis of a large change. The former is divided into this order Bartonellaceae family was placed in a different order, Rhizobiales. But even within the family, many changes have been made. Among other things, dividing the Rickettsiaceae was placed in three tribes.
Families of this order and unclear positions:
- Rickettsiaceae
- Anaplasmataceae
- Holosporaceae
Branches with unclear or controversial position within this order:
- Caedibacter
- Odyssella
- Midichloria
- Hepatincola
- Nicolleia
- Pelagibacter
Older, classic systematics
An older classification which is still often found in the literature:
Rickettsiaceae: ( This family is here in three groups ( tribes ) divided )
- Tribus Rickettsieae with the genera Rickettsia, Rochalimaea, Coxiella
- Tribus Ehrlicheae with the genera: Ehrlichia, Cowdria, Neorickettsia
- Tribus Wolbachieae with the genera Wolbachia, Rickettsiella
Bartonellaceae:
- Genera Bartonella and Graham Ella
Anaplasmataceae:
- Genera: Anaplasma, Aegyptianella, Haemobartonella and Eperythrozoon