Immunogenicity and safety of a live Riemerella anatipestifer vaccine and the contribution of IgA to protective efficacy in Pekin ducks.
Vet Microbiol
; 222: 132-138, 2018 Aug.
Article
en En
| MEDLINE
| ID: mdl-30037633
ABSTRACT
Riemerella anatipestifer (RA) infections cause major economic losses in the duck industry. In this study, we developed an RA vaccine to control virulent serotype 1 and 2 RA, which predominate in worldwide prevalence. We established a strategy for vaccine candidate screening, and selected strains D15-RDA-92 (serotype 1) and D14-RDA-8 (serotype 2). These strains were characterized by ≤50% embryo mortality and <3.0 serum resistance assay values in in vitro screening. We evaluated the protective efficacy of live bivalent RA vaccines against virulent homologous serotype RA. Ducklings received two oral immunizations with the bivalent vaccine and showed significant protection against two virulent strains (serotypes 1 and 2) at 21â¯days post-immunization. No death or clinical signs of diarrhea, tremors, or limb swelling were observed in the immunized ducks. In a safety evaluation, ducks immunized with 100 times higher doses showed no clinical signs, mortality, gross lesions, or histological lesions, and body weight of the ducks showed no significant difference compared to that of negative controls. In addition, IgA analysis showed a significant increase in secretory IgA antibodies generated in the trachea and duodenum of orally immunized ducks at 28â¯days of age. The IgA might be involved in one of the major immune responses to RA and contributes to protecting against virulent RA. In this study, we developed monovalent and bivalent RA vaccines that were safe in ducks and provided significant protective efficacy against virulent homologous RA strains.
Palabras clave
Texto completo:
1
Bases de datos:
MEDLINE
Asunto principal:
Enfermedades de las Aves de Corral
/
Inmunoglobulina A
/
Vacunas Bacterianas
/
Infecciones por Flavobacteriaceae
/
Riemerella
Tipo de estudio:
Risk_factors_studies
Límite:
Animals
Idioma:
En
Revista:
Vet Microbiol
Año:
2018
Tipo del documento:
Article