Use of the Brucella melitensis Native Hapten To Diagnose Brucellosis in Goats by a Rapid, Simple, and Specific Fluorescence Polarization Assay

Abstract

The performance of the fluorescence polarization assay (FPA) using the recently described Brucella melitensis native hapten and the Brucella abortus O-polysaccharide tracer was evaluated and compared with those of The World Organization for Animal Health tests related to indirect and competitive enzyme-linked immunosorbent assays as classification variables for goat sera obtained from a high-prevalence area where vaccination was performed; test series were also evaluated to increase the final specificity of the tests. Our results showed that the respective relative sensitivity and specificity were 99.7% and 32.5% for the rose Bengal test with a 3% cell concentration (RBT3), 92.8% and 68.8% for the rose Bengal test with 8% cell concentration (RBT8), 98.4% and 84.9% for the Canadian complement fixation test (CFT), 83.7% and 65.5% for the Mexican CFT, 98.4% and 81.0% for the buffered plate agglutination test (BPAT), and 78.1% and 89.3% for the fluorescence polarization assay (FPA). The use of the FPA as the secondary test significantly increased the final specificities of test combinations; the screening tests BPAT, RBT3, and RBT8 plus FPA resulted in 90%, 91.2%, and 91.3% final specificities, respectively, whereas for the combinations RBT3 plus Mexican CFT, RBT8 plus Mexican CFT, and BPAT plus Canadian CFT, the specificities were 65.5%, 63.2%, and 91.7%, respectively. The results suggested that the FPA may be routinely applied as an adaptable screening test for diagnosis of goat brucellosis, since its cutoff can be adjusted to improve its sensitivity or specificity, it is a rapid and simple test, it can be the test of choice when specificity is relevant or when an alternative confirmatory test is not available, and it is not affected by vaccination, thus reducing the number of goats wrongly slaughtered due to misdiagnosis.

Bayesian estimation of true prevalence, sensitivity and specificity of indirect ELISA, Rose Bengal Test and Slow Agglutination Test for the diagnosis of brucellosis in sheep and goats in Bangladesh

“…The sensitivity of RBT in goats and sheep were 80.2% and 82.8% respectively even though the specificity of RBT in both goats and sheep was more than 98%. The estimated sensitivity and specificity of RBT were coherent with findings from previous studies (Nielsen et al, 2004;Ramirez-Pfeiffer et al, 2008). The sensitivity and specificity of SAT in goats and sheep were 57.1%, 99.3% and 72.0%, 98.6% respectively.…”

A survey of zoonotic diseases in trade cattle slaughtered at Tanga city abattoir: a cause of public health concern

“…The sample was classified positive if any agglutination was observed and negative if no agglutination. The RBPT, when compared with blood culture and complement fixation test (CFT), has shown a sensitivity of 94.2% and a specificity of 62% on field sera and has been described by other researchers [18,19] . Confirmation of positive samples with tests of higher sensitivities and specificities such as a CFT or enzyme linked immunosorbent assay (ELISA) was not done due to the lack of resources (funds) to buy the required kits.…”

Diagnosis of Brucellosis

“…The rate of reduction is proportional to the amount of antibody present. The fluorescence polarization assay was developed in 1996 [194] but has since been validated [195][196][197][198][199][200][201][202][203][204][205][206][207][208][209][210][211][212][213].…”