title: Serological reactions of leptospirosis-positive (MAR and CFT) bovine sera in ELISA.
abstract: The collection of test sera for measuring ELISA results was composed of bovine sera with MAT titres of greater than or equal to 1:200 in the leptospirosis MAT and of greater than or equal to 1:5 in the CFT together with sera from a serologically negative and clinically non-suspicious cattle herd. To establish cut-off ODs, the geometric mean net-extinction of the negative serum collection plus 1, 2, and 3 standard deviations were calculated. By comparison of 3 different conjugates from rabbits, it was demonstrated that results from anti-total bovine Ig were superior to anti-IgG and anti-IgM conjugates. Considerations regarding sensitivity and specificity led to the recommendation to use a test serum dilution of 1:160, to apply anti-total bovine Ig conjugates, and to establish the cut-off OD at the geometric mean net-extinction of negative sera plus 3 standard deviations. Under such conditions, agreement between leptospirosis MAT/CFT positivity on the one side and ELISA positivity on the other was reached in 74%. This recommendation is made for cross-sectional studies but not for examinations of clinically suspicious cattle herds.
authors.affiliation: Institut für Veterinärmedizin des Bundesgesundheitsamtes, Berlin.
authors.forename: C
authors.initials: C
authors.lastname: Staak
authors.forename: M
authors.initials: M
authors.lastname: Mekaprateep
authors.forename: U
authors.initials: U
authors.lastname: Kämpe
authors.forename: A
authors.initials: A
authors.lastname: Schönberg
mesh_terms: D000372:Agglutination Tests; D000818:Animals; D000907:Antibodies, Bacterial / Q000097:blood*; D002417:Cattle; D002418:Cattle Diseases / Q000175:diagnosis*; D003168:Complement Fixation Tests; D004797:Enzyme-Linked Immunosorbent Assay; D007919:Leptospira / Q000276:immunology*; D007922:Leptospirosis / Q000175:diagnosis / Q000662:veterinary*
chemical_list: D000907:Antibodies, Bacterial