Which of the following is an obligate intracellular parasite?

Ans: C. Ehrlichia chaffeensis (Ref: Ananthanarayan 10/e p416, 8/e p409; Jawetz 27/e p346, 347; Harrison 19/e p1159, 1162)Though both Coxiella and Ehrlichia are obligate intracellular pathogens, in 2009 scientists repoed a technique allowing the Q-fever pathogen Coxiella burnetii to grow in an axenic culture and suggested the technique may be useful for study of other pathogens.Hence, Ehrlichia is a better answer in this case.