Anaplasma phagocytophilum (formerly
Ehrlichia phagocytophilum) is a gram-negative bacterium that is unusual in its tropism to
neutrophils. It causes
anaplasmosis in sheep and cattle, also known as
tick-borne fever and
pasture fever, and also causes the
zoonotic disease
human granulocytic anaplasmosis.
Anaplasma phagocytophilum is a
Gram-negative, obligate bacterium of neutrophils. It causes human granulocytic anaplasmosis, which is a tick-borne rickettsial disease. Because this bacterium invades neutrophils, it has a unique adaptation and pathogenetic mechanism.