RESUMO
Infectious bursal disease (IBD) is an acute, highly contagious immunosuppressive disease that affects young birds causing important economic losses in the poultry industry worldwide. Strict hygiene management together with effective vaccination programs are the most important strategies to prevent Infectious bursal disease virus entry in poultry production facilities. Hyperimmunisation of dams with inactivated vaccines just before the laying period provides passive immunity to the progeny that protects them during the critical first few weeks after hatching before vaccination with live attenuated virus takes place. In the present study, a safe and economic plant-based vaccine candidate against IBD intended for breeder hens was evaluated. We demonstrated that the recombinant immunogen is effective as booster for previously primed hens since it increases specific antibodies against VP2 that are transmitted to the offspring with titres and decay rate similar to those achieved by inactivated vaccine. Moreover, these maternally derived antibodies have virus neutralising activity and are able to confer protection against challenge in progeny, as evidenced by absence of bursal damage and low viral titres in this organ. Taking into account the disadvantages of inactivated vaccines as well as the benefits of plants as expression systems, such as time and cost efficiency, lower risk of contamination from animal pathogens and nearly unlimited scalability, a plant-based subunit IBD vaccine represents a viable alternative in the veterinary field.
Assuntos
Infecções por Birnaviridae/prevenção & controle , Plantas/metabolismo , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/prevenção & controle , Vacinas Atenuadas/uso terapêutico , Vacinas de Produtos Inativados/uso terapêutico , Vacinas Virais/uso terapêutico , Animais , Anticorpos Antivirais/imunologia , Anticorpos Antivirais/metabolismo , Infecções por Birnaviridae/imunologia , Galinhas , Vírus da Doença Infecciosa da Bursa/imunologia , Vírus da Doença Infecciosa da Bursa/patogenicidade , Vacinas de Produtos Inativados/imunologiaRESUMO
Infectious bursal disease virus (IBDV) is a very important pathogen to poultry production and it is classified into three main groups: classical virulent (cvIBDV), very virulent (vvIBDV) and antigenic variants (avIBDV). This last group is composed by five different genetic lineages (recently classified in genogroups G2, G4, G5, G6, and G7) distributed in specific regions around the world. Brazil is one of the biggest poultry producers in the world and the present study aimed to investigate the evolutionary history of avIBDVs of the genogroup G4 in Brazil. A total of 5331 IBDV positive bursa samples, from different Brazilian poultry flocks, were genotyped in a period of ten years (2005 to 2014) and 1888 (35.42%) were identified as local avIBDVs. The highly variable region of the viral protein 2 (hvvp2) gene of 28 avIBDVs was sequenced and used in phylogenetic analyses and evaluation of local amino acid signatures. In addition, all complete and partial IBDV vp2 gene sequences, with local and year of collection information available on GenBank, were retrieved. Phylogenetic analyses were carried out based on a maximum likelihood method for the classification of genogroups occurring in Brazil. Based on a Maximum Likelihood (ML) phylogenetic tree, all Brazilian avIBDVs grouped into the genogroup 4. Bayesian phylodynamics analysis demonstrated the ancestor virus of this group was probably introduced in South America in 1968 (1960 to 1974, 95% HPD) and in Brazil in 1974 (1968 to 1977, 95% HPD) and the most likely source was East Europe (Hungary or Poland). All Brazilian avIBDV sequences, as well as the other genogroup 4 sequences, showed a specific pattern of amino acid: S222, T272, P289, I290, and F296. This report brings new insights about the IBDV epidemiology in Brazil and South America.
Assuntos
Infecções por Birnaviridae/veterinária , Variação Genética , Genótipo , Vírus da Doença Infecciosa da Bursa/genética , Epidemiologia Molecular , Filogenia , Aminoácidos , Animais , Variação Antigênica , Teorema de Bayes , Infecções por Birnaviridae/epidemiologia , Infecções por Birnaviridae/virologia , Brasil/epidemiologia , Galinhas , Vírus da Doença Infecciosa da Bursa/imunologia , Funções Verossimilhança , Doenças das Aves Domésticas/epidemiologia , Doenças das Aves Domésticas/virologiaRESUMO
Fowl adenovirus (FAdV), which causes the high-impact diseases such as inclusion body hepatitis and hepatitis-hydropericardium syndrome, is of major concern to the poultry industry internationally. This study was carried out in direct response to mortality rates of up to 75% in commercial broiler flocks in Trinidad, West Indies. Symptoms in 3- to 8-week-old broilers and 13- to 18-week-old pullets pointed to infection with an immunosuppressive viral pathogen. The objectives of the study were to determine whether the infectious agent FAdV, along with other viral pathogens, was responsible for the clinical disease, and to obtain information on the serotypes of FAdV that were infecting the birds. Tissue samples from clinically affected birds from eight different farms were tested for chicken infectious anaemia virus (CIAV) and infectious bursal disease virus (IBDV) by real-time reverse transcription polymerase chain reaction (PCR) and for FAdV by conventional PCR. The birds tested positive for FAdV and CIAV, but negative for IBDV. The gene corresponding to the L1 loop of the hexon protein for FAdV was amplified and sequenced. Phylogenetic analysis of seven FAdV strains inferred that four serotypes were likely to be circulating in the chickens. Well supported genetic relatedness was observed for serotype 8a (97.8%), 8b (97.8%), 9 (95.8%) and 11 (98.8%-99.5%). This is the first published report from Trinidad and Tobago on the presence and circulation of pathogenic FAdV strains, in combination with CIAV, in poultry. The data demonstrate a possible need for the introduction of serotype-specific vaccines against FAdV, as well as vaccines against CIAV, in broilers in the region and emphasize the importance of maintaining high levels of biosecurity on farms to prevent the spread of these potentially devastating viruses between farms.
Assuntos
Infecções por Adenoviridae/veterinária , Adenoviridae/isolamento & purificação , Vírus da Anemia da Galinha/isolamento & purificação , Galinhas/virologia , Infecções por Circoviridae/veterinária , Doenças das Aves Domésticas/virologia , Adenoviridae/genética , Adenoviridae/imunologia , Infecções por Adenoviridae/epidemiologia , Infecções por Adenoviridae/virologia , Animais , Infecções por Birnaviridae/epidemiologia , Infecções por Birnaviridae/veterinária , Infecções por Birnaviridae/virologia , Vírus da Anemia da Galinha/genética , Vírus da Anemia da Galinha/imunologia , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/virologia , Coinfecção/veterinária , Feminino , Vírus da Doença Infecciosa da Bursa/genética , Vírus da Doença Infecciosa da Bursa/imunologia , Vírus da Doença Infecciosa da Bursa/isolamento & purificação , Filogenia , Doenças das Aves Domésticas/epidemiologia , Sorogrupo , Trinidad e Tobago/epidemiologiaRESUMO
Infectious bursal disease virus (IBDV) is the causative agent of a highly contagious immunosuppressive disease affecting young chickens. The recently described "distinct IBDV" (dIBDV) genetic lineage encompasses a group of worldwide distributed strains that share conserved genetic characteristics in both genome segments making them unique within IBDV strains. Phenotypic characterization of these strains is scarce and limited to Asiatic and European strains collected more than 15 years ago. The present study aimed to assess the complete and comprehensive phenotypic characterization of a recently collected South American dIBDV strain (1/chicken/URY/1302/16). Genetic analyses of both partial genome segments confirmed that this strain belongs to the dIBDV genetic lineage and that it is not a reassortant. Antigenic analysis with monoclonal antibodies indicated that this strain has a particular antigenic profile, similar to that obtained in a dIBDV strain from Europe (80/GA), which differs from those previously found in the traditional classic, variant and very virulent strains. Chickens infected with the South American dIBDV strain showed subclinical infections but had a marked bursal atrophy. Further analysis using Newcastle disease virus-immunized chickens, previously infected with the South American and European dIBDV strains, demonstrated their severe immunosuppressive effect. These results indicate that dIBDV strains currently circulating in South America can severely impair the immune system of chickens, consequently affecting the local poultry industry. Our study provides new insights into the characteristics and variability of this global genetic lineage and is valuable to determine whether specific control measures are required for the dIBDV lineage. Research Highlights A South American strain of the dIBDV lineage was phenotypically characterized. The strain produced subclinical infections with a marked bursal atrophy. Infected chickens were severely immunosuppressed. The dIBDV strains are antigenically divergent from other IBDV lineages.
Assuntos
Infecções por Birnaviridae/veterinária , Galinhas/virologia , Vírus da Doença Infecciosa da Bursa/genética , Vírus da Doença Infecciosa da Bursa/imunologia , Doenças das Aves Domésticas/virologia , Animais , Infecções por Birnaviridae/imunologia , Infecções por Birnaviridae/virologia , Galinhas/imunologia , Genótipo , Imunogenicidade da Vacina , Terapia de Imunossupressão/veterinária , Vírus da Doença Infecciosa da Bursa/isolamento & purificação , Vírus da Doença Infecciosa da Bursa/patogenicidade , Fenótipo , Doenças das Aves Domésticas/imunologia , VirulênciaRESUMO
In a previous paper we showed that the yeast Pichia pastoris X-33 grown in parboiled rice effluent supplemented with glycerol byproduct from the biodiesel industry improved the quality of the effluent. In this paper we show the validation of this yeast (PPE) as probiotic for broilers. Its effect on feed efficiency and immunomodulation was compared with the same yeast grown in yeast peptone dextrose medium (PPY), with Saccharomyces boulardii (SBY) and with the controls fed unsupplemented feed (CON). One-day-old female chicks were vaccinated against infectious bursal disease (IBD) and the titers of anti-IBD antibodies were measured by ELISA. PPE group had the highest mean titres on days 14 and 28 (p<0,05), and at 28 days, 64% of the animals showed seroconvertion. The PPE group also showed the best weight gains at 42 days of age, that, on days 7, 14 and 21 were 19%, 15%, and 8.7% higher, respectively, than the control group. The best feed conversion, 8.2% higher than the control group, was obtained by PPY at 42 days. Histopathological studies did not detect any undesirable effects in the supplemented animals. We concluded that Pichia pastoris X-33 when grown in effluents of the rice parboiling industry supplemented with glycerol byproduct from the biodiesel has probiotic properties for poultry.
Assuntos
Ração Animal , Galinhas , Suplementos Nutricionais , Pichia , Probióticos/administração & dosagem , Ração Animal/microbiologia , Fenômenos Fisiológicos da Nutrição Animal , Animais , Anticorpos Antivirais/sangue , Biocombustíveis , Infecções por Birnaviridae/prevenção & controle , Infecções por Birnaviridae/veterinária , Galinhas/imunologia , Feminino , Vírus da Doença Infecciosa da Bursa/imunologia , Oryza , Doenças das Aves Domésticas/prevenção & controle , Distribuição Aleatória , Saccharomyces boulardii , Vacinação , Vacinas Virais/imunologia , ResíduosRESUMO
The purpose of this study was to investigate the effect of a new infectious bursal disease (IBD) immune complex vaccine on immune system response in both specific pathogen-free (SPF) and commercial birds. Evaluation of response to the vaccination in the two experiments was done by histopathological examination and serology. The results of this study have shown that immune complex vaccine with the V877 strain is quite safe in White Leghorn SPF birds in which there has been no participation of maternal antibodies. In commercial birds was also observed that the immune complex vaccine with the V877 strain acted synergistically with different levels of passive antibodies and the vaccine virus began to replicate as passive immunity decreased to provide the animal active immunological response.
O objetivo desse estudo foi investigar o efeito de uma nova vacina de imunocomplexo contra a doença de Gumboro sobre o sistema imune de aves SPF e comerciais. A avaliação da resposta à vacinação foi realizada por meio de exame histopatológico e sorologia. Os resultados desse estudo demonstraram que a vacina de imunocomplexo com cepa V877 contra Gumboro é muito segura mesmo em aves SPF da linhagem White Leghorn nas quais não existia a participação de imunidade materna. Em aves comerciais também foi demonstrado que a vacina de imunocomplexo com a cepa V877 atuou sinergicamente com diferentes níveis de anticorpos passivos maternais, iniciando a replicação do vírus vacinal a partir do momento que a imunidade passiva diminui, para promover uma resposta imunológica ativa.
Assuntos
Animais , Aves/imunologia , ISCOMs/análise , ISCOMs/efeitos adversos , Vírus da Doença Infecciosa da Bursa/imunologia , Medicamentos de Referência , Sorologia , VacinasRESUMO
The purpose of this study was to investigate the effect of a new infectious bursal disease (IBD) immune complex vaccine on immune system response in both specific pathogen-free (SPF) and commercial birds. Evaluation of response to the vaccination in the two experiments was done by histopathological examination and serology. The results of this study have shown that immune complex vaccine with the V877 strain is quite safe in White Leghorn SPF birds in which there has been no participation of maternal antibodies. In commercial birds was also observed that the immune complex vaccine with the V877 strain acted synergistically with different levels of passive antibodies and the vaccine virus began to replicate as passive immunity decreased to provide the animal active immunological response.(AU)
O objetivo desse estudo foi investigar o efeito de uma nova vacina de imunocomplexo contra a doença de Gumboro sobre o sistema imune de aves SPF e comerciais. A avaliação da resposta à vacinação foi realizada por meio de exame histopatológico e sorologia. Os resultados desse estudo demonstraram que a vacina de imunocomplexo com cepa V877 contra Gumboro é muito segura mesmo em aves SPF da linhagem White Leghorn nas quais não existia a participação de imunidade materna. Em aves comerciais também foi demonstrado que a vacina de imunocomplexo com a cepa V877 atuou sinergicamente com diferentes níveis de anticorpos passivos maternais, iniciando a replicação do vírus vacinal a partir do momento que a imunidade passiva diminui, para promover uma resposta imunológica ativa.(AU)
Assuntos
Animais , Aves/imunologia , Vírus da Doença Infecciosa da Bursa/imunologia , ISCOMs/efeitos adversos , ISCOMs/análise , Sorologia , Vacinas , Medicamentos de ReferênciaRESUMO
A stable cell-line was established that expressed the recombinant avian antibody (rAb) against the infectious bursal disease virus (IBDV). rAb exhibited neutralization activity to IBDV-B87 strain in DF1 cells. The minimum rAb concentration required for inhibition of the cytopathic effect (CPE) was 1.563µg/mL. To test the efficacy of rAb, a 168-h cohabitation challenge experiment was performed to transmit the disease from the chickens challenged with vvIBDV (HLJ0504 strain) to three test groups of chickens, i.e. (1) chickens treated with rAb, (2) chickens treated with yolk antibody, and (3) non-treatment chickens. The survival rates of chickens treated with rAb, yolk antibody and without treatment were 73%, 67% and 20%, respectively. Another batch of chickens was challenged with IBDV (BC6/85 strain) and then injected with rAb (1.0mg/kg) 6, 24 and 36h post-challenge. Non-treatment chickens had 100% morbidity, whereas those administered with rAb exhibited only 20% morbidity. Morbidity was evaluated using clinical indicators and bursal histopathological section. This study provides a new approach to treating IBDV and the rAb represents a promising candidate for this IBDV therapy.
Assuntos
Anticorpos Antivirais/imunologia , Infecções por Birnaviridae/veterinária , Galinhas , Vírus da Doença Infecciosa da Bursa/imunologia , Doenças das Aves Domésticas/prevenção & controle , Proteínas Estruturais Virais/imunologia , Animais , Infecções por Birnaviridae/prevenção & controle , Linhagem Celular , Doenças das Aves Domésticas/imunologia , Doenças das Aves Domésticas/virologia , Proteínas Recombinantes , Vacinas Virais/imunologiaRESUMO
Infectious bursal disease is a severe acute viral disease of young chickens, affecting mainly the B-lymphocytes in the bursa of Fabricius, leading to severe immunosuppression as a result of the death of lymphoid cells. In the bursa infected with infectious bursal disease virus, viral replication is associated with apoptosis of lymphoid cells, inflammatory change and atrophy. Vaccination has appeared to be a crucial factor for control, with live attenuated vaccines being the most used. However, the apoptotic effect of these vaccines on the bursa has not been tested. We determined the apoptotic effect caused by the most used vaccines in local production on the bursa of Fabricius cells and the correlation with histological changes. In this study, it was demonstrated that apoptosis levels in the vaccinated groups were higher than those observed in the non-vaccinated birds leading to the conclusion that the action of the live virus vaccine strains modifies the boundary of the bursa and shapes processes of cell death by apoptosis. In contrast to other studies, the vaccine strains used did not show the phenomenon of bursal atrophy during the experimental period.
Assuntos
Infecções por Birnaviridae/veterinária , Bolsa de Fabricius , Galinhas , Vírus da Doença Infecciosa da Bursa/imunologia , Animais , Infecções por Birnaviridae/virologia , Caspase 3/genética , Caspase 3/metabolismo , Feminino , Regulação da Expressão Gênica/imunologia , Masculino , Proteínas Proto-Oncogênicas c-bcl-2/genética , Proteínas Proto-Oncogênicas c-bcl-2/metabolismo , Proteína X Associada a bcl-2/genética , Proteína X Associada a bcl-2/metabolismoRESUMO
In this study, the immune response induced by a mixture of polysaccharide and nucleic acid extracted from Bacillus Calmette-Guerin (BCG) was evaluated in chickens inoculated with infectious bursal disease virus (IBDV) vaccine. After the mixture was injected intramuscularly at a dose of 0.075, 0.15 or 0.3 mg·kg(-1)·day(-1) for 3 days, the 14-day-old chickens were inoculated with the attenuated IBDV vaccine via intranasal and ocular routes. The relative weight of bursa of Fabricius (BF) and thymus, the serum IBD antibody titer, the CD4+/CD8+ ratio, and the concentrations of IFN-γ, IL-2 and IL-6 in peripheral blood were investigated on days 5, 15 and 25. The IBD antibody titer in BCG-treated groups was higher than in the negative control and only IBD-vaccinated chickens, indicating that the mixture of BCG can significantly enhance chicken humoral response. CD4+/CD8+ and the secretions of IFN-γ, IL-2 and IL-6 were also clearly increased compared with that in the negative control and IBD-vaccinated chickens, indicating that the mixture can also enhance the cell-mediated immune response. The results also showed that the relative weights of BF and thymus increased after chickens were inoculated with BCG, indicating that the BCG mixture can clearly enhance the immunity of IBD-vaccine and can be expected to be viewed as a candidate for a new type of immune adjuvant.