title: A sensitive ELISA technique for the diagnosis of Anaplasma marginale infections.
abstract: A sensitive enzyme-linked immunosorbent assay (ELISA) technique using a horse radish peroxidase conjugate is described for measuring Anaplasma marginale antibodies in bovine serum. This technique utilizes two antigen preparations, a 'negative' antigen derived from an animal prior to infection and a 'positive' antigen derived from A. marginale-infected red cells from the same animal following infection. This markedly reduces cross-reactions which are a result of isoantigens. Absorbance values obtained using the 'negative' antigen are subtracted from those obtained using the 'positive' antigen to give a net figure. Of 100 A. marginale-positive sera tested no false negative results were obtained. All 11 animals maintained tick-free after initial diagnosis of naturally transmitted anaplasmosis were positive 3 years later, 15 A. marginale-infected animals maintained with ticks were positive 27 months after initial infection and a further 26 animals infected with A. marginale by blood inoculation were positive 3 months later. Three per cent of negative sera, 2% of B. bovis and 4% of B. bigemina-positive sera gave positive reactions.
authors.affiliation: Lalahan Nuclear Research Centre in Animal Health, Lalahan-Ankara, Turkey.
authors.forename: A
authors.initials: A
authors.lastname: Duzgun
authors.forename: C A
authors.initials: CA
authors.lastname: Schuntner
authors.forename: I G
authors.initials: IG
authors.lastname: Wright
authors.forename: G
authors.initials: G
authors.lastname: Leatch
authors.forename: D J
authors.initials: DJ
authors.lastname: Waltisbuhl
mesh_terms: D000709:Anaplasma / Q000276:immunology*; D000712:Anaplasmosis / Q000175:diagnosis*; D000818:Animals; D000907:Antibodies, Bacterial / Q000032:analysis*; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis*; D004797:Enzyme-Linked Immunosorbent Assay
chemical_list: D000907:Antibodies, Bacterial