title: Serological evidence for antigenic relationships between Ehrlichia canis and Cowdria ruminantium.
abstract: The sera from dogs experimentally infected with Ehrlichia canis reacted at very similar titres in indirect fluorescent antibody (IFA) tests with E canis and Cowdria ruminantium antigen. In Western blots these sera reacted strongly with the immunodominant antigens of E canis (27 kDa) and C ruminantium (25 and 32 kDa). The dogs experimentally infected with C ruminantium showed no clinical evidence of infection, though the presence of organisms in the blood was demonstrable, for up to two weeks after inoculation, by a polymerase chain reaction. The sera from these dogs were also reactive with both organisms in the IFA tests, but the antibody titres were four- to fivefold higher with C ruminantium than with E canis antigen. In Western blots, these sera reacted strongly with the 25 and 32 kDa antigens of C ruminantium but weakly with the 27 kDa antigen of E canis. These results provide strong evidence that the immunodominant antigens of E canis and C ruminantium contain cross-reacting epitopes.
authors.affiliation: Faculty of Veterinary Science, University of Zimbabwe, Mount Pleasant, Harare.
authors.forename: P J
authors.initials: PJ
authors.lastname: Kelly
authors.forename: L A
authors.initials: LA
authors.lastname: Matthewman
authors.forename: S M
authors.initials: SM
authors.lastname: Mahan
authors.forename: S
authors.initials: S
authors.lastname: Semu
authors.forename: T
authors.initials: T
authors.lastname: Peter
authors.forename: P R
authors.initials: PR
authors.lastname: Mason
authors.forename: P
authors.initials: P
authors.lastname: Brouqui
authors.forename: D
authors.initials: D
authors.lastname: Raoult
mesh_terms: D000818:Animals; D000942:Antigens, Bacterial / Q000276:immunology / Q000302:isolation & purification; D001483:Base Sequence; D015153:Blotting, Western / Q000662:veterinary; D003429:Cross Reactions; D004283:Dog Diseases / Q000276:immunology*; D004285:Dogs; D004536:Ehrlichia / Q000276:immunology*; D016995:Ehrlichia ruminantium / Q000276:immunology*; D016873:Ehrlichiosis / Q000276:immunology / Q000662:veterinary*; D005455:Fluorescent Antibody Technique / Q000662:veterinary; D006357:Heartwater Disease / Q000276:immunology*; D008969:Molecular Sequence Data
chemical_list: D000942:Antigens, Bacterial