Serologic Cross-Reactivity between Anaplasma marginale and Anaplasma phagocytophilum
Dreher, U. M.Clinical Laboratory, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland
de la Fuente, J.Instituto de Investigación en Recursos Cinegéticos IREC (CSIC-UCLM-JCCM), Ronda de Toledo s/n, 13005 Ciudad Real, Spain
Hofmann-Lehmann, R.Clinical Laboratory, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland
Meli, M. L.Clinical Laboratory, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland
Pusterla, N.Department of Medicine and Epidemiology, School of Veterinary Medicine, University of California, Davis, California 95616
Kocan, K. M.Department of Veterinary Pathobiology, Center for Veterinary Health Sciences College of Veterinary Medicine, Oklahoma State University, Stillwater, Oklahoma 74078
Woldehiwet, Z.Department of Veterinary Pathology, Veterinary Teaching Hospital, University of Liverpool, Leahurst, Neston Wirral, CH64 7TE, United Kingdom
Braun, U.Department of Farm Animals, Vetsuisse Faculty, University of Zurich, Winterthurerstrasse 260, 8057 Zurich, Switzerland
EnglishABSTRACT 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.