RESUMO
In this study, the possibility that dogs could eventually be carriers of infectious bursal disease virus (IBDV) after having eaten (voluntarily or accidentally) IBDV-infected chicks has been evaluated. A single Beagle dog was fed chicks infected by a very virulent IBDV strain (vvIBDV). Afterwards, the presence and viability of IBDV in the faeces was assessed. Viable vvIBDV was detected in the dog's faeces for 2 days after the initial ingestion, which indicates excretion of vvIBDV. Comparison by molecular techniques of the administered and excreted virus using reverse transcription-polymerase Chain reaction and enzymatic digestion confirmed that the initial virus maintained the same characteristics after being excreted. We believe that this study could be of great interest for a better understanding of the epidemiology of IBD disease on farms where dogs live close to avian facilities.
Assuntos
Infecções por Birnaviridae/veterinária , Portador Sadio/veterinária , Cães/virologia , Vírus da Doença Infecciosa da Bursa/isolamento & purificação , Doenças das Aves Domésticas/transmissão , Ração Animal/virologia , Animais , Infecções por Birnaviridae/epidemiologia , Infecções por Birnaviridae/transmissão , Infecções por Birnaviridae/virologia , Portador Sadio/transmissão , Portador Sadio/virologia , Galinhas/virologia , Fezes/virologia , Feminino , Vírus da Doença Infecciosa da Bursa/patogenicidade , Carne/virologia , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/virologia , Organismos Livres de Patógenos Específicos , VirulênciaRESUMO
The immunogenicity and protective capability of several baculovirus-expressed infectious bursal disease virus (IBDV)-derived assemblies as VP2 capsids, VPX tubules and polyprotein (PP)-derived mixed structures, were tested. Four-week-old chickens were immunised subcutaneously with one dose of each particulate antigen. VP2 icosahedral capsids induced the highest neutralising response, followed by PP-derived structures and then VPX tubules. All vaccinated animals were protected when challenged with a very virulent IBDV (vvIBDV) isolate, however the degree of protection is directly correlated with the levels of neutralising antibodies. VP2 capsids elicited stronger protective immunity than tubular structures and 3 micrograms of them were sufficient to confer a total protection comparable to that induced by an inactivated vaccine. Therefore, VP2 capsids represent a suitable candidate recombinant vaccine instead of virus-like particles (VLPs) for IBDV infections. Our results also provide clear evidence that the recombinant IBDV-derived antigens are structure-dependent in order to be efficient as vaccine components.
Assuntos
Galinhas/imunologia , Vírus da Doença Infecciosa da Bursa/imunologia , Vacinas Virais/imunologia , Animais , Infecções por Birnaviridae/imunologia , Infecções por Birnaviridae/prevenção & controle , Capsídeo/imunologia , Células Cultivadas , Relação Dose-Resposta Imunológica , Imunização , Vírus da Doença Infecciosa da Bursa/química , Controle de Qualidade , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Spodoptera , Relação Estrutura-Atividade , Vacinas Sintéticas/química , Vacinas Sintéticas/imunologia , Proteínas Virais/biossíntese , Vacinas Virais/químicaRESUMO
The immunogenicity and protective capability of several baculovirus-expressed infectious bursal disease virus (IBDV)-derived assemblies as VP2 capsids, VPX tubules and polyprotein (PP)-derived mixed structures, were tested. Four-week-old chickens were immunised subcutaneously with one dose of each particulate antigen. VP2 icosahedral capsids induced the highest neutralising response, followed by PP-derived structures and then VPX tubules. All vaccinated animals were protected when challenged with a very virulent IBDV (vvIBDV) isolate, however the degree of protection is directly correlated with the levels of neutralising antibodies. VP2 capsids elicited stronger protective immunity than tubular structures and 3& mgr;g of them were sufficient to confer a total protection comparable to that induced by an inactivated vaccine. Therefore, VP2 capsids represent a suitable candidate recombinant vaccine instead of virus-like particles (VLPs) for IBDV infections. Our results also provide clear evidence that the recombinant IBDV-derived antigens are structure-dependent in order to be efficient as vaccine components.
