Verification of Sera from Cattle and Pigs for Brucellosis with Fluorescence Polarisation Assay

Fluorescence polarisation assay (FPA) was evaluated as a potential tool improving specificity of serological diagnosis of brucellosis in cattle and pigs. The evaluation was performed by comparing the results of FPA with the results of rose Bengal test (RBT), serum agglutination test (SAT), complement fixation test, and indirect ELISA when problematic sera, regarded as false positive, were tested. Four hundred and seventy-five sera, including 201 porcine and 274 bovine samples, reacting positively in at least one classical serological assay were used. Only six bovine sera were FPA positive (two positive in SAT and RBT and four positive in SAT only). Different situation was observed when porcine sera were examined. Out of 201 sera, 109 were also positive in FPA. The studies confirmed that in cattle FPA enables to reduce highly the number of false positive reactions for brucellosis. On the other hand, in pigs, the method is a little more specific in comparison to other methods applied.