Comparison of Fluorescence Polarization Assay with Rose Bengal Plate Agglutination test and Competitive Enzyme-Linked Immunosorbent assay for bovine brucellosis in Tanzania

Abstract

Brucella are Gram-negative, facultative, intracellular bacterial species with B. abortus, B. melitensis, and B. suis carrying the smooth-lipopolysaccharide antigen. Accurate diagnostic results of brucellosis are needed for its control and eradication, however, they are primarily based on the serological testing of brucellosis in animals. The Rose Bengal Plate Agglutination Test (RBPT) and competitive Enzyme-Linked Immunosorbent Assay (c-ELISA) are the most commonly used tests for making such diagnosis. The use of Fluorescence Polarization Assay (FPA) in Tanzania is still in nascent stage. The purpose of this study was to compare RBPT, c- ELISA, and FPA in the diagnosis of bovine brucellosis. A total of 75 serum samples from cattle that were infected with Brucella in Kagera region were obtained. The FPA showed 90% (68 samples) prevalence, RBPT revealed 93% (70 samples) prevalence, and c-ELISA revealed 81% (61 samples) prevalence of brucellosis in the farm. The RBPT test has shown an inability to distinguish antibodies from cross-reacting organisms compared to the FPA test, while the c- ELISA was unable to pick a positive sample compared to the FPA test. FPA is very quick (5 min per sample), does not require specialized staff, and may be performed under field conditions. Therefore, FPA has a potential to overcome limitations in the detection of bovine brucellosis and can be used as a confirmatory test.