Development and evaluation of a double-antigen sandwich ELISA to identify Anaplasma marginale–infected and A. centrale–vaccinated cattle
| Autor: | B. S. Valentini, Macarena Sarli, Mariano Mastropaolo, Carolina S. Thompson, I.E. Echaide, Susana T de Echaide, María Evangelina Primo, María B. Novoa |
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| Rok vydání: | 2019 |
| Předmět: |
0301 basic medicine
Attenuated vaccine General Veterinary biology 040301 veterinary sciences Immunogenicity 04 agricultural and veterinary sciences medicine.disease biology.organism_classification Virology 0403 veterinary science 03 medical and health sciences 030104 developmental biology parasitic diseases medicine Enzootic Anaplasma Anaplasmosis Seroconversion Nested polymerase chain reaction Bovinae |
| Zdroj: | Journal of Veterinary Diagnostic Investigation. 32:70-76 |
| ISSN: | 1943-4936 1040-6387 |
| Popis: | Bovine anaplasmosis is a worldwide infectious disease caused by the intraerythrocytic bacterium Anaplasma marginale, which is transmitted by ticks and fomites. A. centrale is a less virulent subspecies used as a live vaccine in cohorts of 8- to 10-mo-old calves that did not naturally reach enzootic stability. We developed 3 variants of a double-antigen sandwich ELISA (dasELISA) using a recombinant major surface protein 5 (MSP5) from A. marginale (dasELISAm) or from A. centrale (dasELISAc) or using MSP5 from both organisms (dasELISAmc). Each dasELISA was tested for the detection of antibodies against A. marginale and A. centrale. The tests were validated using serum samples from cattle not infected with Anaplasma spp. ( n = 388), infected with A. marginale ( n = 436), and vaccinated with A. centrale ( n = 358), confirmed by nested PCR. A total of 462 samples were compared with a commercial competitive ELISA (cELISA). For dasELISAm, dasELISAc, and dasELISAmc, specificities were 98.7%, 98.7%, and 97.4%, and overall sensitivities were 92.6%, 85.7%, and 97.4%, respectively. For A. marginale–infected and A. centrale–vaccinated cattle, sensitivities were 97.7% and 86.3% for dasELISAm, and 77.7% and 95.5% for dasELISAc, respectively. Sensitivity of dasELISAmc was similar for both groups (>96%). The agreement rate between dasELISAmc and cELISA was 96.3% (κ = 0.92); the former test allowed earlier detection of seroconversion of vaccinated cattle than did cELISA. Based on these results, the test could be used to 1) determine the enzootic stability or instability of anaplasmosis in calves, 2) conduct epidemiologic studies, and 3) evaluate the immunogenicity of A. centrale live vaccine. |
| Databáze: | OpenAIRE |
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