Diagnostic performance of Rose Bengal, competitive ELISA, and Native Hapten (NH) assays in S19 mass-vaccinated cattle in endem brucellosis environment.ic
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| Autores: | , , , , , , , , , , |
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| Formato: | artículo preliminar |
| Fecha de Publicación: | 2024 |
| Descripción: | Vaccination with S19 is the best alternative to control bovine brucellosis, but depending on the immunization protocol, it may induce long-lasting antibodies interfering with diagnostic tests. Conjunctival vaccinated brucellosis-free heifers (Farm 1) produced antibodies detected in RBT and cELISA that disappeared <50 days after immunization. In contrast, heifers of Farm 1 subcutaneously vaccinated with S19 reduced dose produced antibodies detected in 10% of the bovines for up to one year. Sera of brucellosis-free vaccinated heifers did not immunoprecipitate native hapten polysaccharide (NH). In contrast, sera of Brucella-infected bovines readily immunoprecipitated NH. A Brucella abortus infected herd (Farm 2), previously vaccinated with RB51 and subjected to regular tests and slaughter until reaching negative serology, was mass vaccinated with S19 through either the conjunctival or subcutaneous routes with reduced and complete doses. Bovines of Farm 2 displayed sustained and increasing RBT and cELISA positive reactions for a protracted period, with ~5% bovines reacting against NH, indicating an anamnestic response upon contact with field Brucella. After an abortion and isolation of field B. abortus at day 225 in one cow of Farm 2, a significantly higher ratio of cELISA/RBT reactors was detected (2.5±1.6%) than in preceding days (0.9±0.2). Previous vaccination with RB51 did not modify the herd brucellosis situation or the serological results of S19-vaccinated bovines. We conclude that serial testing of RBT-positive animals with cELISA is not an adequate diagnostic strategy and that the NH immunoprecipitation test helps identify actively infected cows in herds submitted to mass vaccination with S19. |
| País: | Repositorio UNA |
| Institución: | Universidad Nacional de Costa Rica |
| Repositorio: | Repositorio UNA |
| Lenguaje: | Inglés |
| OAI Identifier: | oai:null:11056/28597 |
| Acceso en línea: | http://hdl.handle.net/11056/28597 |
| Palabra clave: | BRUCELLA BRUCELOSIS BRUCELLOSIS BOVINOS BOVINE VACUNACIÓN VACCINATION ELISA |