Anaplasma belongs to the family Anaplasmataceae, in the order Rickettsiales and the class α-proteobacteria
The Anaplasmataceae family includes six genera, Ehrlichia, Anaplasma, Aegyptianella, Wolbachia, Neorickettsia and “Candidatus Neoehrlichia”
Vector-borne obligatory intracellular pathogen
Bacteria from the Anaplasmataceae family develop within a cytoplasmic vacuole in the host cell cytoplasm, whereas other members of Rickettsiales order escape from the phagosome after entering the host cell and multiply in the cytoplasm before being released in the extracellular environment
Anaplasmataceae that infects granulocytes, bone marrow progenitor cells, and endothelial cells of various mammalian species, including humans
A. phagocytophilum is responsible for anaplasmosis and infects deer, dogs, cat, horses, ruminants, rodents, and humans, inducing human granulocytic anaplasmosis (HGA), an emerging infectious disease first detected in 1994
E. chaffeensis infects deer, dogs, and humans, inducing canine ehrlichiosis and human monocytic ehrlichiosis
A. marginale and E. ruminantium infect only domestic and wild ruminants
Genomes (comparative pathogenomics):
A. centrale str. Israel, 1206806 bp, NC_013532
A. marginale str. Florida, 1202435 bp, NC_012026
A. marginale str. St. Maries, 1197687 bp, NC_004842
A. phagocytophilum HZ, 1471282 bp, NC_007797
A. phagocytophilum str. Dog2, 1473302 bp, NC_021881
A. phagocytophilum str. HZ2, 1477581 bp, NC_021879
A. phagocytophilum str. JM, 1481598 bp, NC_021880
Herndon DR, et al., 2010. Complete genome sequence of Anaplasma marginale subsp. centrale. J Bacteriol 192(1):379-80.
Dark MJ, et al., 2009. Conservation in the face of diversity: multistrain analysis of an intracellular bacterium. BMC Genomics 10:16.
Brayton KA, et al., 2005. Complete genome sequencing of Anaplasma marginale reveals that the surface is skewed to two superfamilies of outer membrane proteins. Proc Natl Acad Sci U S A 102(3):844-9.
Lin M, et al., 2011. Global proteomic analysis of two tick-borne emerging zoonotic agents: anaplasma phagocytophilum and ehrlichia chaffeensis. Front Microbiol 2:24.
The intracellular niches of A. phagocytophilum and E.
chaffeensis in human cells. (From: Rikihisa Y, 2010. Anaplasma phagocytophilum and Ehrlichia chaffeensis: subversive manipulators of host cells. Nat Rev Microbiol 8(5):328-39.)
Major virulence factors in Anaplasma:
Location of virulence-associated genes in A. phagocytophilum: