Anaplasma phagocytophilumandEhrlichia chaffeensiscause the emerging zoonoses human granulocytic anaplasmosis and human monocytic ehrlichiosis, respectively, which are among the most prevalent life-threatening tick-borne zoonoses in the United States. Yasuko Rikihisa reviews the adaptations of these obligate intracellular bacteria that allow them to subvert and manipulate host cells.
