title: Serologic cross-reactivity between Anaplasma marginale and Anaplasma phagocytophilum.
abstract: In the context of a serosurvey conducted on the Anaplasma marginale prevalence in Swiss cattle, we suspected that a serological cross-reactivity between A. marginale and A. phagocytophilum might exist. In the present study we demonstrate that cattle, sheep and horses experimentally infected with A. phagocytophilum not only develop antibodies to A. phagocytophilum (detected by immunofluorescent-antibody assay) but also to A. marginale (detected by a competitive enzyme-linked immunosorbent assay). Conversely, calves experimentally infected with A. marginale also developed antibodies to A. phagocytophilum using the same serological tests. The identity of 63% determined in silico within a 209-amino-acid sequence of major surface protein 5 of an isolate of A. marginale and one of A. phagocytophilum supported the observed immunological cross-reactivity. These observations have important consequences for the serotesting of both, A. marginale and A. phagocytophilum infection of several animal species. In view of these new findings, tests that have been considered specific for either infection must be interpreted carefully.
authors.affiliation: Clinical Laboratory, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland.
authors.forename: U M
authors.initials: UM
authors.lastname: Dreher
authors.forename: J
authors.initials: J
authors.lastname: de la Fuente
authors.forename: R
authors.initials: R
authors.lastname: Hofmann-Lehmann
authors.forename: M L
authors.initials: ML
authors.lastname: Meli
authors.forename: N
authors.initials: N
authors.lastname: Pusterla
authors.forename: K M
authors.initials: KM
authors.lastname: Kocan
authors.forename: Z
authors.initials: Z
authors.lastname: Woldehiwet
authors.forename: U
authors.initials: U
authors.lastname: Braun
authors.forename: G
authors.initials: G
authors.lastname: Regula
authors.forename: K D C
authors.initials: KD
authors.lastname: Staerk
authors.forename: H
authors.initials: H
authors.lastname: Lutz
mesh_terms: D042322:Anaplasma marginale / Q000276:immunology*; D041081:Anaplasma phagocytophilum / Q000276:immunology*; D000712:Anaplasmosis / Q000175:diagnosis*; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood / Q000276:immunology; D002417:Cattle; D003429:Cross Reactions / Q000276:immunology*; D004797:Enzyme-Linked Immunosorbent Assay; D006736:Horses; D012680:Sensitivity and Specificity; D012698:Serologic Tests / Q000592:standards; D012756:Sheep
chemical_list: D000907:Antibodies, Bacterial