Rickettsiales

Rickettsiales
"Rickettsia rickettsii" (red dots) in the cell of a deer tick
Rickettsia rickettsii (red dots) in the cell of a deer tick
Scientific classification Edit this classification
Domain: Bacteria
Phylum: Pseudomonadota
Class: Alphaproteobacteria
Order: Rickettsiales
Gieszczykiewicz 1939 (Approved Lists 1980)
Families
  • "Candidatus Deianiraeaceae" Castelli et al. 2019
  • Ehrlichiaceae Moshkovski 1945 (Approved Lists 1980)
  • "Candidatus Midichloriaceae" Montagna et al. 2013
  • Rickettsiaceae Pinkerton 1936 (Approved Lists 1980)
  • "Candidatus Tenuibacteraceae" Kroer et al. 2016
  • Genera incertae sedis
    • "Candidatus Anadelfobacter veles" Vannini et al. 2010
    • "Candidatus Repentibacter" corrig. Prokopchuk et al. 2019
    • "Sinorickettsia" Li et al. 2021[1]

The Rickettsiales, informally called rickettsias, are an order of small Alphaproteobacteria. They are obligate intracellular parasites, and some are notable pathogens, including Rickettsia, which causes a variety of diseases in humans, and Ehrlichia, which causes diseases in livestock. Another genus of well-known Rickettsiales is the Wolbachia, which infect about two-thirds of all arthropods and nearly all filarial nematodes.[2] Genetic studies support the endosymbiotic theory according to which mitochondria and related organelles developed from members of this group.[3]

The Rickettsiales are difficult to culture, as they rely on living eukaryotic host cells for their survival.

  1. ^ Li D, Fang J, Wen B, Wua X (2021). "Molecular identification of a novel intracellular proteobacteria from scallop Chlamys farreri". Aquaculture. 539: 736565. Bibcode:2021Aquac.53936565L. doi:10.1016/j.aquaculture.2021.736565. S2CID 233921822.
  2. ^ Werren JH, Baldo L, Clark ME (2008). "Wolbachia: master manipulators of invertebrate biology". Nat. Rev. Microbiol. 6 (10): 741–51. doi:10.1038/nrmicro1969. PMID 18794912. S2CID 12816914.
  3. ^ Thomas S. (2016). Rickettsiales:Biology, Molecular Biology, Epidemiology, and Vaccine Development. pp.529. Springer•ISBN 978-3-319-46857-0