| Journal: | Revista brasileira de ciencia avicola |
| Database: | PERIÓDICA |
| System number: | 000279320 |
| ISSN: | 1516-635X |
| Authors: | Nascimento, Elmiro Rosendo do1 Polo, P. de A Pereira, V.L. de A Barreto, Maria Lucia Nascimento, Maria da Graca Fichel do Zuanaze, Marcelo Alexandre Fagnani Correa, A.R.A Silva, R. de C.F2 |
| Institutions: | 1Universidade Federal Fluminense, Faculdade de Veterinaria, Niteroi, Rio de Janeiro. Brasil 2Empresa de Pesquisa Agropecuaria do Estado do Rio de Janeiro, Niteroi, Rio de Janeiro. Brasil |
| Year: | 2006 |
| Season: | Ene-Mar |
| Volumen: | 8 |
| Number: | 1 |
| Pages: | 45-50 |
| Country: | Brasil |
| Language: | Inglés |
| Document type: | Nota breve o noticia |
| Approach: | Experimental |
| English abstract | False positive serologic reactions and difficulties in the diagnosis of Mycoplasma gallisepticum (MG) in chickens have increased lately as a result of infection by low virulent MG strains and the use of live MG vaccines in poultry. The objective of this study was to evaluate the serologic responses of SPF chickens exposed to the three commercially available live MG vaccines, and one low virulent MG strain (MG-70), contributing to the diagnosis and monitoring of MG infection in birds. Six groups of SPF chickens were used. The control group was not infected nor challenged; one group was infected with the low virulent strain MG-70 (MG-70); three groups were immunized and named after the MG vaccine used, i.e., MG-6/85, MG-ts11, and MG-F; and finally one group was infected with the virulent MG standard strain, MGR. Random Amplification of Polymorphic DNA (RAPDPCR) was used to compare the strains to each other, to the standard MG-A5969, and to MGR. All strains were found to be genetically distinguishable from each other. Birds in the control group showed negative results throughout the experiment and showed no cross-reaction with M. synoviae in any serologic test. ELISA tests at 21 days post first exposure (P1E) and seven days after the second exposure (P2E), evidenced that 25% of the MG70 birds were positive, whereas vaccine groups yielded higher positivity rate, i.e., 57%, 43% and 29% for MG-6/85, MG-ts11 and MG-F, respectively. Serum plate agglutination (SPA) evidenced the first positive results at 35 days P1E on birds in the MG-F group at the rate of 100%; followed by 40% of birds in the MG-70 group at 63 days P1E. Chickens in MG-ts11 and MG 6/85 groups had identical behavior and yielded 100% positive SPA at 77 days P1E. In regard to hemagglutination inhibition (HI), 14 % of the birds in MG-F and MG-ts11 reacted at 42 days P1E, while MG-70 and MG-6/85 groups yielded positive results only after challenge; MG-70 birds r |
| Disciplines: | Medicina veterinaria y zootecnia |
| Keyword: | Aves de corral, Medicina veterinaria, Mycoplasma gallisepticum, Tratamiento, Vacunas, Serología |
| Keyword: | Veterinary medicine and animal husbandry, Poultry, Veterinary medicine, Mycoplasma gallisepticum, Treatment, Vaccines, Serology |
| Full text: | Texto completo (Ver HTML) |
