Anaplasma phagocytophilum and Ehrlichia chaffeensis: subversive manipulators of host cells

Nat Rev Microbiol. 2010 May;8(5):328-39. doi: 10.1038/nrmicro2318. Epub 2010 Apr 7.


Anaplasma spp. and Ehrlichia spp. cause several emerging human infectious diseases. Anaplasma phagocytophilum and Ehrlichia chaffeensis are transmitted between mammals by blood-sucking ticks and replicate inside mammalian white blood cells and tick salivary-gland and midgut cells. Adaptation to a life in eukaryotic cells and transmission between hosts has been assisted by the deletion of many genes that are present in the genomes of free-living bacteria (including genes required for the biosynthesis of lipopolysaccharide and peptidoglycan), by the acquisition of a cholesterol uptake pathway and by the expansion of the repertoire of genes encoding the outer-membrane porins and type IV secretion system. Here, I review the specialized properties and other adaptations of these intracellular bacteria.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Anaplasma phagocytophilum / genetics
  • Anaplasma phagocytophilum / growth & development
  • Anaplasma phagocytophilum / pathogenicity*
  • Anaplasma phagocytophilum / physiology
  • Animals
  • Apoptosis
  • Autophagy
  • Bacterial Proteins / genetics
  • Bacterial Proteins / physiology
  • Cholesterol / metabolism
  • Ehrlichia chaffeensis / genetics
  • Ehrlichia chaffeensis / growth & development
  • Ehrlichia chaffeensis / pathogenicity*
  • Ehrlichia chaffeensis / physiology
  • Ehrlichiosis / metabolism
  • Ehrlichiosis / microbiology*
  • Ehrlichiosis / pathology
  • Ehrlichiosis / transmission
  • Genome, Bacterial
  • Host-Pathogen Interactions
  • Humans
  • Phylogeny


  • Bacterial Proteins
  • Cholesterol