title: Human endothelial cells as an alternative to DH82 cells for isolation of Ehrlichia chaffeensis, E. canis, and Rickettsia rickettsii.
abstract: Ehrlichia chaffeensis, etiologic agent of human ehrlichiosis, and Rickettsia rickettsii, etiologic agent of Rocky Mountain spotted fever (RMSF), are both tick-borne agents that cause nonspecific symptoms that may be indistinguishable from each other early in the course of infection. E. canis is a canine pathogen closely related to E. chaffeensis and was initially suspected of being the causative agent of human ehrlichiosis. If a febrile illness is reported, after tick exposure, neither ehrlichiosis nor RMSF can be immediately ruled out. When attempts are made to isolate the agent from blood, a very limited amount of blood is often available; we, therefore, sought a tissue-culture cell line that would support the growth of both R. rickettsii and E. chaffeensis. A newly established human microvascular endothelial immortal cell line (CDC/EU.HMEC-1) was evaluated for supporting the growth of both agents. Our results demonstrate that HMEC-1 supports the growth of R. rickettsii, E. chaffeensis, and E. canis and may be a useful tool for the isolation of these agents.
authors.affiliation: Viral and Rickettsial Zoonoses Branch, Centers for Disease Control and Prevention, Atlanta, Ga 30333.
authors.forename: J E
authors.initials: JE
authors.lastname: Dawson
authors.forename: F J
authors.initials: FJ
authors.lastname: Candal
authors.forename: V G
authors.initials: VG
authors.lastname: George
authors.forename: E W
authors.initials: EW
authors.lastname: Ades
mesh_terms: D000818:Animals; D002460:Cell Line; D004285:Dogs; D004536:Ehrlichia / Q000302:isolation & purification*; D016873:Ehrlichiosis / Q000175:diagnosis; D004730:Endothelium, Vascular / Q000166:cytology* / Q000382:microbiology*; D006801:Humans; D008264:Macrophages / Q000166:cytology* / Q000382:microbiology*; D008722:Methods; D012284:Rickettsia rickettsii / Q000302:isolation & purification*; D012373:Rocky Mountain Spotted Fever / Q000175:diagnosis