Evaluation of dot-blot test for serological diagnosis of bovine brucellosis

Abstract

The objective of this study was to standardize and validate the dot-blot test for the serological diagnosis of bovine brucellosis, compare the results with those found in the 2-mercaptoethanol (2-ME) and complement fixation test (CF), and estimate the relative sensitivity and specificity of the dot-blot compared to these tests. Fifty bovine blood serum samples were used for the test standardization, and 1315 samples were used for evaluation and comparison between the tests; the results were compared using the Kappa indicator. At the end of standardization, it was established as optimal for the antigen obtained from Brucella abortus B19 after passing through a microorganism rupture process, the blood serum samples diluted at 1:100, and the conjugate at 1:30,000. The comparison of the dot-blot results with 2-ME showed Kappa index of 0.9939, sensitivity of 99.48%, and specificity 99.91%, with CF, Kappa index of 0.8226, sensitivity 100% and specificity 95.32%. Using the combination of the test results 2-ME and CF to establish the true condition of the animal, the dot-blot showed relative sensitivity of 100%, and relative specificity of 99.91%. The evaluated test proved to be effective and reliable, besides being easy to handle and interpret the results.

Development and standardization of the Dot Blot test for serological diagnosis of bovine leptospirosis

“…culture allowed to perform 600 tests, the antigen's ability to sensitize the NM and induce satisfactory answer, indicate that the Dot Blot test is feasible. Similar results were found by Dewes et al (2020a) As reported in recent research this technique had proving suitable for the serological diagnosis other diseases, with the bovine brucellosis, the antigen adheres to the center of the nitrocellulose membrane, which ensures the use of an established antigen concentration, and its simplicity, precision and speed demonstrated that the assay can be used in the field for large scale diagnosis (Bastos et al, 2018).…”

An Overview of Brucellosis in Cattle and Humans, and its Serological and Molecular Diagnosis in Control Strategies

“…Acomparative analysis of three tests (RBT, SAT, and Coombs’ test (CT)) recommended Coombs gel test regarding specificity and sensitivity [ 78 ]. Several other serological tests are also used for diagnosis including the standard tube agglutination test (STAT), enzyme-linked immunosorbent assay (ELISA), milk ring test (MRT), and fluorescence polarization assay (FPA) [ 79 ]. Among them the SAT remained the most popular and used test for routine diagnostic practice worldwide [ 49 ].…”

Comparative Surface Interaction Study to Detect Brucella melitensis 16M Using Biosensor Transducer Modifications with 4-MBA, ZnONPs/AuNPs, ZnONPs/AuNPs/4-MBA

“…Other methods for diagnosis and rapid testing employs antibody agglutination assays like Serum Agglutination Test (SAT) but it mostly lacks agglutination at higher antibody titers and results in false negative interpretation due to high prozone effects [14,15]. Serological tests like Rose Bengal Agglutination Test, Direct and Indirect Fluorescent Polarization Antibody Test, Complement Fixation Test, 2-β Mercaptoethanol, Indirect Coomb's Test, Brucellacapt, Dipstick, Micro agglutination and Dot Blot Assays are often used for its rapid detection [16,17]. But, they are also known to present false positive results due to non-specific and non-agglutinating 'blocking antibodies' in severe chronic infection [18,19].…”