Experimental inoculation with human granulocytic Ehrlichia agent derived from high- and low-passage cell culture in horses

We report the successful infection throughout intravenous inoculation with low and high passage of in vitro-grown human granulocytic ehrlichiosis (HGE ) agent in horses. Differences in disease severity but not in incubation ti me, hematological changes, PCR detection, ehrlichial load, seroconversion t ime, and titer range were noted between horses infected with a low and a hi gh passage of in vitro-grown HGE agent.