A species of gram-negative bacteria in the genus ANAPLASMA, family ANAPLASMATACEAE, formerly called Ehrlichia phagocytophila or Ehrlichia equi. This organism is tick-borne (IXODES) and causes disease in horses and sheep. In humans, it causes human granulocytic EHRLICHIOSIS.

Synonyms: Anaplasma phagocytophilum, txid948, Cytoecetes phagocytophila, Ehrlichia phagocytophila, Ehrlichia equi, HGE Agent