Marek's disease in roosters in the Potiguar semi-arid region

Background: Marek's disease (MD) is a transmissible disease in chickens caused by Gallid alphaherpesvirus 2 (GaHV-2). The infection is characterized by lymphocyte cellular infiltrates in peripheral nerves and other organs and tissues, including the skin; which can lead to dysfunction causing progressive asymmetric paresis and complete spastic paralysis of body extremities. Dermatitis and cardiac myositis caused by GaHV-2 in free-range chickens has rarely been described in Brazil. This reports the occurrence of the disease with a confirmatory molecular diagnosis in free-range poultry showing signs of dermatitis, poor performance, and cachexia and no mortality in the semi-arid Potiguar region. Cases: Twenty roosters of the Shamo lineage, among a brood of 42 birds, had a history of progressive weight loss and skin lesions. Two birds with poor body condition, erythema, and scaling of the skin in the head and cervical regions were sent for clinical care. All birds were between 12 and 18 months of age and were vaccinated against Newcastle disease and Fowlpox with only a few receiving vaccines against MD and Gumboro disease. According to the owner's report, some birds were previously kept outdoors, and when they were transferred to a small shed with little air circulation, they began to develop clinical signs after approximately 15 days. The first signs of the disease were also reported to have appeared 2.5 months before clinical care and, in the meantime, several treatments were instituted without success. Owing to the general condition of the animals and inconclusive clinical suspicion, the birds were subjected to euthanasia and necropsy. Tissue samples were collected for histopathological and polymerase chain reaction analyses to search for the GaHV-2 DNA meq gene. The main clinicopathological findings were erythema (47%, 20/42) and desquamation of skin and mild, prominent white multifocal areas in the heart. Histopathology revealed infiltration of pleomorphic lymphoblastic cells in the skin, heart, and sciatic nerve. The amplification of the L-meq and meq oncoprotein genes in these organs and in the liver, confirmed the infection by GaHV-2, consistent with that of a field strain. Discussion: MD was confirmed based on the macroscopic and histological lesions, and with the detection of GaHV-2 DNA in the affected tissues. The unusual clinical presentation represented an initial challenge for diagnosis. The clinical history was important to lead to the suspicion of MD, as roosters initiated clinical signs 15 days after they were transferred to a small shed with poor air circulation. This probably favored the high viral concentration and disease transmission among susceptible birds in the brood because the feather follicle is the primary site of viral replication for transmission; and desquamation of infected epithelial cells favor airborne horizontal transmission to susceptible chickens. The roosters had not been vaccinated against MD, which probably favored the infection, as vaccination is known to be a fundamental approach for MD control for effective growth of the poultry industry. Clinical findings and lesions, together with viral molecular detection, were fundamental for the diagnosis, a premise for the application of adequate prevention and control measures for the disease in breeding. This is the first report of MD with a confirmatory molecular diagnosis in northeastern Brazil.

Fatores de risco associados com a presença de infecções virais em aves domésticas na região Sul do Rio Grande do Sul, Brasil / Risk factors associated with the presence of viral diseases in domestic poultry in the Southern region of Rio Grande do Sul, Brazil

Background: The introduction of any infectious agent into an industrial or subsistence farm worries agribusiness owners in Brazilbecause it reduces product quality and increases treatment costs, although most diseases are untreatable, thus causing economic losseswith morbidity and mortality. Therefore, an epidemiological survey of viral diseases associated with poultry was developed by performing a detailed description of the risk factors that may be related to existing diseases using domestic poultry sample data recordedin the Regional Diagnostic Laboratory (LRD) of College of Veterinary Medicine of the Federal University of Pelotas (UFPel), RioGrande do Sul, Brazil, from 2000 to 2016.Materials, Methods & Results: Epidemiological and clinical-pathological data were collected and then compared with disease databy multivariate analysis using statistical EpiInfo version 6.04 and Microsoft Office Excel 2010 software. The frequencies and 95%confidence intervals (CI), association measures (odds ratio=OR and relative risk=RR), Chi-square test, and the results consideredsignificant with a value of P ≤ 0.05 were described. A total of 410 samples of domestic poultry were tested, and the results showed66 (16.1%) viral diseases. The following conditions were the most commonly found diseases in this study: Mareks disease (42.4%),Infectious bursal disease (31.8%), Avian leukosis (16.6%), Avian pox (7.5%) and Avian infectious bronchitis (1.5%). In this articlewe discuss the most frequent viral diseases: Mareks disease (DM) and Gumboro disease. It was also possible to conclude that birdswith Mareks disease presented higher odds of developing nerve, tegumentary and locomotors signs (P ≤ 0.05). As well as, morelikely to present tumoriform lesions in the liver, spleen, kidneys and heart P ≤ 0.05, as well as lesions in the proventriculus, musclelesions and in the sciatic nerve P ≤ 0.05. Laying poultry...(AU)

Fatores de risco associados com a presença de infecções virais em aves domésticas na região Sul do Rio Grande do Sul, Brasil / Risk factors associated with the presence of viral diseases in domestic poultry in the Southern region of Rio Grande do Sul, Brazil

Background: The introduction of any infectious agent into an industrial or subsistence farm worries agribusiness owners in Brazilbecause it reduces product quality and increases treatment costs, although most diseases are untreatable, thus causing economic losseswith morbidity and mortality. Therefore, an epidemiological survey of viral diseases associated with poultry was developed by performing a detailed description of the risk factors that may be related to existing diseases using domestic poultry sample data recordedin the Regional Diagnostic Laboratory (LRD) of College of Veterinary Medicine of the Federal University of Pelotas (UFPel), RioGrande do Sul, Brazil, from 2000 to 2016.Materials, Methods & Results: Epidemiological and clinical-pathological data were collected and then compared with disease databy multivariate analysis using statistical EpiInfo version 6.04 and Microsoft Office Excel 2010 software. The frequencies and 95%confidence intervals (CI), association measures (odds ratio=OR and relative risk=RR), Chi-square test, and the results consideredsignificant with a value of P ≤ 0.05 were described. A total of 410 samples of domestic poultry were tested, and the results showed66 (16.1%) viral diseases. The following conditions were the most commonly found diseases in this study: Marek’s disease (42.4%),Infectious bursal disease (31.8%), Avian leukosis (16.6%), Avian pox (7.5%) and Avian infectious bronchitis (1.5%). In this articlewe discuss the most frequent viral diseases: Marek’s disease (DM) and Gumboro disease. It was also possible to conclude that birdswith Marek’s disease presented higher odds of developing nerve, tegumentary and locomotors signs (P ≤ 0.05). As well as, morelikely to present tumoriform lesions in the liver, spleen, kidneys and heart P ≤ 0.05, as well as lesions in the proventriculus, musclelesions and in the sciatic nerve P ≤ 0.05. Laying poultry...

Histopathology and serology reaction to an immune complex infectious bursal disease vaccine (V877 strain) in SPF and commercial birds / Reação histopatológica e sorológica a uma vacina de imunocomplexo contra gumboro (cepa V877) em aves SPF e comerciais

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.

Histopathology and serology reaction to an immune complex infectious bursal disease vaccine (V877 strain) in SPF and commercial birds / Reação histopatológica e sorológica a uma vacina de imunocomplexo contra gumboro (cepa V877) em aves SPF e comerciais

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)

Relationship between virus replication and apoptosis events in IgM + cells from chicken spleen and bursa of Fabricius infected with Malaysia strain of very virulent infectious bursal disease virus

Background: Infection of IBDV was reported to be endemic in worldwide including Malaysia and can be spread orally thru polluted fodder and water source, thus causing economic losses especially in commercial poultry industry. The infection resulted in depletion of B lymphocytes and subsequently destruction of the bursa which leaded to immunosuppression of the bird and it was postulated that the depletion of cells in the bursa was due to induction of apoptosis. In the current study, the infection of Malaysia isolated very virulent IBDV UPM0081 on IgM bearing B lymphocytes (IgM+ cells) from chicken spleen and bursa was compared. Materials, Methods & Results: A total of sixty eggs were obtained and raised until the age of 3 weeks old. The birds were divided into two groups (n = 30), which one of them served as control while IBDV strain UPM0081 was used to infect another group of birds at the concentration of 103 ELD50. The birds were observed and sacrificed at day 2, 4 and 5 post infections. Spleen and bursa of Fabricius were harvested and subjected to IgM+ cell enrichment using microbeads. The cell viability of enriched cells was assayed using MTT and cell cycle was analyzed using propidium iodide. Annexin V FITC and acridine orange/propidium iodide double stain assays were used to determine the event of apoptosis in the enriched IgM+ cells. Also, the IBDV viral load was also [...](AU)

Relationship between virus replication and apoptosis events in IgM + cells from chicken spleen and bursa of Fabricius infected with Malaysia strain of very virulent infectious bursal disease virus

Background: Infection of IBDV was reported to be endemic in worldwide including Malaysia and can be spread orally thru polluted fodder and water source, thus causing economic losses especially in commercial poultry industry. The infection resulted in depletion of B lymphocytes and subsequently destruction of the bursa which leaded to immunosuppression of the bird and it was postulated that the depletion of cells in the bursa was due to induction of apoptosis. In the current study, the infection of Malaysia isolated very virulent IBDV UPM0081 on IgM bearing B lymphocytes (IgM+ cells) from chicken spleen and bursa was compared. Materials, Methods & Results: A total of sixty eggs were obtained and raised until the age of 3 weeks old. The birds were divided into two groups (n = 30), which one of them served as control while IBDV strain UPM0081 was used to infect another group of birds at the concentration of 103 ELD50. The birds were observed and sacrificed at day 2, 4 and 5 post infections. Spleen and bursa of Fabricius were harvested and subjected to IgM+ cell enrichment using microbeads. The cell viability of enriched cells was assayed using MTT and cell cycle was analyzed using propidium iodide. Annexin V FITC and acridine orange/propidium iodide double stain assays were used to determine the event of apoptosis in the enriched IgM+ cells. Also, the IBDV viral load was also [...]

AVALIAÇÃO DE PROBIÓTICO E GLUTAMINA IN OVO EM FRANGOS DE CORTE DESAFIADOS COM SALMONELLA HEIDELBERG

A Salmonella Heidelberg (SH) é uma bactéria que resulta em grande prejuízo econômico à produção avícola brasileira e, uso não racional de antibióticos na criação das aves pode induzir a seleção de cepas resistentes. Desta forma, produtos naturais são alternativas para substituição de antibióticos, contribuindo também para a manutenção da saúde intestinal das aves. O objetivo do estudo foi avaliar a eclodibilidade e o efeito profilático de um probiótico com cinco cepas de Lactobacillus reuteri e da glutamina in ovo em frangos de corte desafiados com SH. O delineamento experimental foi inteiramente casualizado com sete tratamentos. Os ovos foram vacinados in ovo com os aditivos avaliados (probiótico, glutamina e antibiótico) misturados à vacina para a doença de Marek e Gumboro. O desafio com SH ocorreu 24 horas após o alojamento e cada ave recebeu 0,5 mL do inóculo com SH contendo 4 x 106 UFC/mL. Os parâmetros avaliados foram: quantificação molecular de bactérias totais e de Lactobacillus spp, eclodibilidade, quantificação das colônias de SH, análise biométrica do intestino e análise morfológica da mucosa intestinal. Os dados foram submetidos a análise de variância, teste de Tukey e Dunn com nível de significância de 5%. Todos os tratamentos que receberam glutamina in ovo apresentaram melhor eclodibilidade que o grupo controle. Os embriões que receberam o tratamento com probiótico + glutamina obtiveram maior quantidade de bactérias totais no trato digestório do que aqueles que receberam antibiótico. O tratamento com o probiótico, associado ou não com a glutamina, apresentou menor quantidade de SH quando comparado com os demais tratamentos. Após três dias do desafio o tratamento que recebeu o probiótico apresentou maior altura de vilo e maior profundidade de cripta no duodeno jejuno e íleo comparado ao tratamento que recebeu o antibiótico. Portanto, a glutamina in ovo melhora a eclodibilidade e, o probiótico in ovo reduz a quantidade de SH, além de aumentar a altura de vilo e a profundidade de cripta em frangos de corte.

Salmonella Heidelberg (SH) is a bacterium that causes great economic damage to Brazilian poultry production and, the indiscriminate use of antibiotics in poultry farming may induce the selection of resistant strains. In this way, natural products are alternatives for replacing antibiotics, also contributing to the maintenance of the intestinal health of birds. Thus, the objective of the experiment was to evaluate the effect of probiotic and glutamine in ovo in broiler chickens exposed to SH. The experimental design was completely randomized with seven treatments. The in ovo treatments evaluated (probiotic, glutamine, and an antibiotic) were mixed with the vaccine against Marek and Gumboro disease. The exposure to SH occurred 24 hours after chick placement and each chick received 0.5 mL of the inoculum with SH containing 4 x 106 UFC/mL. The parameters evaluated were: molecular quantification of total bactéria and Lactobacillus spp., hatchability, quantification of SH colonies, biometric analysis of the intestine and morphological analysis of the intestinal mucosa. Data was subjected to analysis of variance, Tukey, and Dunn test, with a significance level of 5%. All treatments that received glutamine in ovo showed better ability to hatch. Embryos that received the treatment with probiotic + glutamine had a greater number of total bacteria in the digestive tract than those that received antibiotics. The treatment with the probiotic, associated or not, with glutamine, showed a lower amount of SH when compared to the other treatments. Three days after exposure, the treatment that received the probiotic showed greater villus height and greater crypt depth in the duodenum, jejunum, and ileum compared to the treatment that received the antibiotic. Therefore, glutamine in ovo improves the hatchability and probiotic in ovo reduces the amount of SH, in addition to increasing the villus height and crypt depth in broilers

Doença infecciosa bursal

A doença infecciosa bursal (DIB),também conhecida como doença de Gumboro, em referência à cidade dos Estados Unidos (no estado de Delaware) onde foi descrita pela primeira vez, é uma das principais doenças a comprometer a imuno competência em aves. A doença atinge principalmente abolsa cloacal (BC), outro nome para a bolsa de Fabricius, destruindo oslinfoblastos B, precursores dos plasmócitos,estes responsáveis pela síntese de anticorpos.A doença é importante pela alta morbidade, alta a moderada mortalidade,imunodepressão por perda na diversidade de linhagens de linfócitos B e redução da viabilidade das aves industriais, com aumento da condenação por oportunismo infeccioso. A DIB está em muitos casos naturais, em infecção associada à anemia infecciosa das galinhas, causada por um circovírus que atinge linfócitos T(timo). As coinfecções,inclusive com outros vírus, como adenovírus e reovírus, e bactérias,como Escherichia coli e Clostridium, resultam em maior comprometimento das funções sistêmicas e do sistema imune, com maior morbidade,maior mortalidade e maior perda da imunocompetência.

Doença infecciosa bursal

A doença infecciosa bursal (DIB),também conhecida como doença de Gumboro, em referência à cidade dos Estados Unidos (no estado de Delaware) onde foi descrita pela primeira vez, é uma das principais doenças a comprometer a imuno competência em aves. A doença atinge principalmente abolsa cloacal (BC), outro nome para a bolsa de Fabricius, destruindo oslinfoblastos B, precursores dos plasmócitos,estes responsáveis pela síntese de anticorpos.A doença é importante pela alta morbidade, alta a moderada mortalidade,imunodepressão por perda na diversidade de linhagens de linfócitos B e redução da viabilidade das aves industriais, com aumento da condenação por oportunismo infeccioso. A DIB está em muitos casos naturais, em infecção associada à anemia infecciosa das galinhas, causada por um circovírus que atinge linfócitos T(timo). As coinfecções,inclusive com outros vírus, como adenovírus e reovírus, e bactérias,como Escherichia coli e Clostridium, resultam em maior comprometimento das funções sistêmicas e do sistema imune, com maior morbidade,maior mortalidade e maior perda da imunocompetência.

Avaliação do sistema de desinfecção de substrato (maravalha) de cama de aviários por processo Fotohidroionização

Os procedimentos implementados na avicultura, como o cuidado intensivo da limpeza e desinfecção das instalações e de todos os materiais que terão contato com os planteis, são imprescindíveis para prevenção das enfermidades. Portanto, o objetivo do estudo foi avaliar a eficiência da Fotohidroionização (PHI) sobre a desinfecção de maravalha nova, utilizada como substrato para camas utilizadas em aviários comerciais. O experimento foi conduzido utilizando-se maravalha nova, esterilizada por autoclavagem e desafiada com inóculos pré- estabelecidos: bacteriano, fúngico e viral. Os agentes bacterianos selecionados foram cepas de Escherichia coli, Staphylococcus aureus e Salmonella enterica sorovar Abony. O agente fúngico de eleição foi Saccharomyces cerevisiae e o agente viral utilizado foi uma estirpe de campo do vírus da doença de Gumboro (VDG). Foram utilizados 250 g de maravalha para cada repetição, desafiadas com 32 ml de inóculo bacteriano e fúngico e 10 ml de inóculo viral, sendo realizadas 6 repetições em quatro tempos distintos expostos à Fotohidroionização: 0, 1, 5 e 10 minutos. O processo de desinfecção foi realizado em um Fotohidroionização de bancada equipado com 4 lâmpadas ultravioletas. Os agentes inoculados na maravalha foram recuperados após o processo de desinfeção por meio das análises de bactérias totais e enterobactérias, cultura fúngica e título viral. Os dados foram submetidos ao teste de normalidade e as análises de regressão (REG) e regressão broken line (NLIN) utilizando o SAS. Foram observados valores médios de 4,48; 1,73; 1 e 0,66 UFC/g de enterobactérias; 3,48; 2,56; 1,70 e 1,77 UFC/g de bactérias totais; 3,80; 3,65; 3,51 e 3,38 UFC/g de fungos e 2,84; 2,38, 0 e 0 de título viral/100 g de maravalha nos tempos 0, 1, 5 e 10 minutos, respectivamente. As contagens de enterobactérias e bactérias totais apresentaram efeito quadrático, enquanto as contagens de fungos e vírus apresentaram efeito linear negativo com aumento no tempo do processo de Fotohidroionização. Foram observados para enterobactérias efeito platô de resposta linear (LRP, P < 0,0147), com ponto de tempo mínimo de 5,46 (R) minutos na contaminação mínima de 0,66 UFC/g (L) com redução de 82,27% do inóculo pré-estabelecido, enquanto para bactérias totais efeito LRP (P < 0,0001), com ponto de tempo mínimo 1,90 (R) minutos na contaminação mínima de 1,74 UFC/g (L) com redução de 50,00% do inóculo pré-estabelecido. Para fungos foi encontrado efeito LRP (P < 0,0002), com ponto de tempo mínimo de 7,93 (R) minutos na contaminação mínima de 3,38 UFC/g (L) com redução de 11,00% do inóculo pré-estabelecido. Para vírus foi observado efeito LRP (P < 0,0001), com ponto de tempo mínimo de 5,01 (R) minutos na contaminação mínima de 0 título viral/100 g de maravalha (L) com redução de 64,78% do inóculo pré- estabelecido. Portanto, a Fotohidroionização foi efetiva em eliminar completamente o agente viral e reduzir os agentes bacterianos e fúngico da maravalha nova, utilizada como substrato para camas utilizadas em aviários comerciais.

The procedures implemented in the farms, such as the intensive care of cleaning and disinfection of the facilities and all materials that will have contact with the animals are essential for disease prevention. Therefore, the aim of this study was to test the disinfection of shavings, used as substrate for litter used in commercial poultry houses, through Photohydroionization (PHI). The experiment was carried out with 15 kg of new shaving, sterilized by autoclaving and challenged with pre-established bacterial, fungal and viral inoculum. The bacterial agents selected were Escherichia coli strain, Staphylococcus aureus and Salmonella enterica serovar Abony. The fungal agent used was Saccharomyces cerevisiae, the viral agent was the Gumboro disease virus (IBDv) isolated from the field. For each batch, 250 g of shavings challenged with 32 ml of bacterial and fungal inoculum and 10 ml of viral inoculum were used, being performed 6 repetitions at four different times: 0, 1, 5 and 10 minutes. The disinfection process was performed in a benchtop Photohydroionization equipped with 4 ultraviolet lamps. The agents inoculated in the shavings were recovered after the disinfection process through the analysis of total bacterial and enterobacterial, fungal cultures and viral titer. The data were submitted to the normality test and the regression (REG) and broken line regression (NLIN) analyzes using the SAS. Mean values of reduction were observed, such as, 4,48, 1,73, 1,00 and 0,66 CFU/g of enterobacterial, 3,48; 2,56; 1,70 and 1,77 CFU/g of total bacterial, 3,80; 3,65; 3,51 and 3,38 CFU/g of fungal and 2,84; 2,38, 0 e 0 of viral title per 100 g of shavings at times 0, 1, 5 and 10 minutes, respectively. Enterobacterial and total bacterial counting showed a quadratic effect, while the fungal counting and viral titer showed a negative linear effect with an increase in the time of the Photohydroionization process. The linear response plateau (LRP) effect for enterobacterial (P <0,0147) was observed, with a minimum time point of 5,46 (R) minutes at minimum contamination of 0,66 CFU/g (L) with a reduction of 82,27% in the pre- established inoculum. For the total bacterial LRP effect (P <0,0001) was observed, with a minimum time point of 1,90 (R) minutes in the minimum contamination of 1,74 CFU/g (L) with a reduction of 50,00% in the pre-established inoculum. For the fungal was found LRP effect (P <0,0002), with a minimum time point of 7,93 (R) minutes in the minimum contamination of 3,38 CFU/g (L) with a reduction of 11,00% in the pre-established inoculum. For the viral LRP effect (P <0,0001) was observed, with a minimum time point of 5,01 (R) minutes in the minimum contamination of 0% viral title per 100 g of shavings (L) with a reduction of 64,78% in the pre-established inoculum. Therefore, Photohydroionization process was effective in completely eliminating the viral agent and reducing the bacterial and fungal agents of the new poultry litter, used as a substrate for poultry houses.

Canarypox virus expressing infectious bursal disease VP2 protein as immunogen for chickens

Canarypox viruses (CNPV) carrying the coding sequence of VP2 protein from infectious bursal disease virus (IBDV) were obtained. These viruses were able to express VP2 protein in vitro and to induce IBDV-neutralizing antibodies when inoculated in specific pathogen-free chickens demonstrating that CNPV platform is usefulness to develop immunogens for chickens.

Canarypox virus expressing infectious bursal disease VP2 protein as immunogen for chickens

Canarypox viruses (CNPV) carrying the coding sequence of VP2 protein from infectious bursal disease virus (IBDV) were obtained. These viruses were able to express VP2 protein in vitro and to induce IBDV-neutralizing antibodies when inoculated in specific pathogen-free chickens demonstrating that CNPV platform is usefulness to develop immunogens for chickens.(AU)

Efficient assembly of full-length infectious clone of Brazilian IBDV isolate by homologous recombination in yeast

The Infectious Bursal Disease Virus (IBDV) causes immunosuppression in young chickens. Advances in molecular virology and vaccines for IBDV have been achieved by viral reverse genetics (VRG). VRG for IBDV has undergone changes over time, however all strategies used to generate particles of IBDV involves multiple rounds of amplification and need of in vitro ligation and restriction sites. The aim of this research was to build the world's first VRG for IBDV by yeast-based homologous recombination; a more efficient, robust and simple process than cloning by in vitro ligation. The wild type IBDV (Wt-IBDV-Br) was isolated in Brazil and had its genome cloned in pJG-CMV-HDR vector by yeast-based homologous recombination. The clones were transfected into chicken embryo fibroblasts and the recovered virus (IC-IBDV-Br) showed genetic stability and similar phenotype to Wt-IBDV-Br, which were observed by nucleotide sequence, focus size/morphology and replication kinetics, respectively. Thus, IBDV reverse genetics by yeast-based homologous recombination provides tools to IBDV understanding and vaccines/viral vectors development.

Modelo de protocolo experimental para induzir, classificar e avaliar as enterites inespecíficas em frangos de corte / Experimental protocol model to induce, classified and evaluate non specific enteritis in broilers

Vários fatores negativos podem afetar a saúde intestinal de frangos de corte e reduzir o seu desempenho. Aditivos para alimentação animal, chamados melhoradores de crescimento são utilizados na produção de frangos para controlar os problemas intestinais. Entretanto, a dificuldade de se induzir enterites em condições experimentais torna difícil a avaliação destes produtos. O objetivo deste estudo foi avaliar o melhor modelo experimental para induzir enterite em frangos de corte. Foram utilizados 192 pintinhos de corte, machos (Cobb 500®), divididos em esquema fatorial 2x4 (com boa ou baixa qualidade do óleo na dieta e com ou sem vacina contra coccidiose e doença de Gumboro), com oito tratamentos. As aves foram alojadas em cama de maravalha, com água e ração à vontade, e foram pesadas semanalmente. Nos dias 14, 21, 28 e 35, seis aves por tratamento foram abatidas para avaliação de lesões macroscópicas e microscópicas mediante a implementação de um sistema padrão de classificação de severidade das lesões que considerou infiltração linfocítica, morfologia dos enterócitos, edema intersticial e dilatação dos vasos linfáticos na mucosa do intestino. Foi observado que frangos alimentados com gordura de baixa qualidade na ração apresentaram menor ganho de peso e maior severidade de lesões histológicas em todos os segmentos intestinais. Estas lesões foram mais severas em aves desafiadas com coccidiose e doença de Gumboro. Estes resultados sugerem que a inclusão de gordura de baixa qualidade na ração, associada ao desafio com cocciciose no primeiro dia de vida e contra doença de Gumboro no 16º dia, é o melhor protocolo para induzir enterite em frangos de corte em condições experimentais, e ainda que o sistema padrão de classificação de severidade de lesões intestinais foi adequado para avaliar as enterites em frangos de corte.(AU)

Several negative conditions affect broilers intestinal health and reduce their performance. Feed additives, called growth promoters, are used in broilers production to control enteric problems, but is very difficult to evaluate these products in experimental conditions. The aim of this study was to evaluate the best experimental model to induce enteritis in broilers. A 192 one-day-old male broilers (Cobb 500®) were divided into 2x4 a factorial design (with good or poor quality oil in diet and with or without coccidiosis and Gumboro disease vaccine), with eight treatments. The birds were housed on litter, with water and feed ad libitum and were weighed weekly. At days 14, 21, 28 and 35, six birds per treatment were euthanized and gut gross lesions evaluated. Samples of duodenum, jejunum and ileum were taken for histopathological evaluation. A standard lesion score considering lymphocytic infiltration, enterocytes morphology, interstitial edema, and lymph vessel dilation was used. It was observed that broilers fed with poor quality of oil in the diet showed lower body weight and more severe macroscopic and histopathologic lesions on all intestinal segments. These lesions were more severe in birds challenged with coccidiosis and Gumboro disease. The results suggest that an inclusion of poor quality of oil in diet, associated with challenge with coccidiosis at first day and Gumboro virus vaccine at 16 day is the best protocol to promote enteritis in broilers at experimental conditions, and that use of standard lesion score was useful to evaluate enteritis.(AU)

Immune response elicited by the oral administration of an intermediate strain of IBDV in chickens

The immune response elicited by the oral inoculation of an intermediate strain of infectious bursal disease virus was studied in chickens. A strong over expression of IL-6, IL-8, IFNα and IFNγ was observed in bursa at 3 days post inoculation together with an increase in splenic NO2 release. An influx of T-lymphocytes was also detected.

Immunomodulatory and growth-promoting effect of a probiotic supplemented in the feed of broiler chicks vaccinated against infectious bursal disease

This study was designed to investigate the effects of a probiotic plus an immunomodulatory product on the growth performance, immune response and net economic returns of broiler chicks vaccinated against Infectious bursal diseases virus (IBDV). A flock of 350 day-old chicks were equally and randomly distributed in seven groups, each comprising 50 birds. A mixture of microorganisms (¹Probiotic) or Cyclophosphamide (immune suppressor) was offered through feed supplementation to different groups. The Probiotic, consisting of Lactobacillus species, Bifidobacterium, Streptococcus salivarius and Enterococcus faecium, in addition to Aspergillus oryza and Candida pintolopessii. Compared with control treatment group, the probiotic-supplemented chicks had better feed conversion ratio (FCR) (1.938 and 1.959), with significantly heavier live body weight 2141.0±34.2 and 2120.3±33.2, respectively. Similarly, their antibody titers against IBDV were significantly higher (941 and 832) on day 35. No morbidity and mortality were observed in these groups. This study suggests that a product composed of a probiotic and cyclophosphamide enhanced the growth rate as well as the immunity against infectious bursal disease virus of broilers chicks.(AU)

Assessment of arginine diet on the immune response of broilers immunized against Gumboro disease - doi: 10.4025/actascianimsci.v33i2.9738 / Avaliação da arginina dietética sobre a resposta imunológica de frangos de corte imunizados contra a Doença de Gumboro - doi: 10.4025/actascianimsci.v33i2.9738

The study was conducted to evaluate the effect of supplemental Arginine (Arg) on the humoral immune response and development of lymphoid organs of broiler chickens vaccinated against Gumboro disease. Six hundred and forty broilers were reared in a complete randomized design with four treatments (1. Control, 2. Immunization, 3. Immunization and supplementation of L-Arg, and 4. Supplemental L-Arg.) and eight replications of 20 birds each. Birds in treatments 3 and 4 were vaccinated at 16 days against Gumboro disease (intermediate plus strain). Serum samples from birds at 14, 21, 28 and 35 days old were analyzed by ELISA for detection of antibody titers against Gumboro disease, and at these same ages, lymphoid organ weight was determined and the height of the primary folds of lymphoid tissue in the cloacal bursa was measured. There was no significant difference (p > 0.05) among treatments. Arg supplementation did not improve the immune response of broilers immunized against Gumboro Disease. The lack of response to immunization may be attributed to the low virulence of the vaccine strain used and the presence of environmental virus.

O estudo foi realizado com o objetivo de avaliar o efeito da suplementação de Arginina (Arg) sobre a resposta imune humoral e o desenvolvimento dos órgãos linfoides de frangos de corte imunizados contra a Doença de Gumboro. Foram utilizados 640 pintos de corte, distribuídos aleatoriamente em um delineamento inteiramente casualizado com quatro tratamentos (1. Controle, 2. Imunização, 3. Imunização + suplementação de L-Arg e 4. Suplementação de L-Arg.) e oito repetições de 20 aves cada. As aves dos tratamentos 3 e 4 foram imunizadas no 16 dia, contra a Doença de Gumboro (cepa intermediária plus). Amostras de soro das aves com 14, 21, 28 e 35 dias de idade foram analisadas por ELISA para detecção de título de anticorpos contra a Doença de Gumboro e nestas mesmas idades foi determinado o peso dos órgãos linfoides e a altura de pregas primárias do tecido linfoide da bolsa cloacal. Não houve diferença significativa (p > 0,05) entre os tratamentos. A suplementação de Arg não contribuiu com a resposta imune dos frangos de corte imunizados contra a Doença de Gumboro. A falta de resposta à imunização pode ser atribuída à baixa virulência da cepa vacinal utilizada e à presença de vírus de campo.

Avaliação da arginina dietética sobre a resposta imunológica de frangos de corte imunizados contra a Doença de Gumboro / Assessment of arginine diet on the immune response of broilers immunized against Gumboro disease

O estudo foi realizado com o objetivo de avaliar o efeito da suplementação de Arginina (Arg) sobre a resposta imune humoral e o desenvolvimento dos órgãos linfoides de frangos de corte imunizados contra a Doença de Gumboro. Foram utilizados 640 pintos de corte, distribuídos aleatoriamente em um delineamento inteiramente casualizado com quatro tratamentos (1. Controle, 2. Imunização, 3. Imunização + suplementação de L-Arg e 4. Suplementação de L-Arg.) e oito repetições de 20 aves cada. As aves dos tratamentos 3 e 4 foram imunizadas no 16º dia, contra a Doença de Gumboro (cepa intermediária plus). Amostras de soro das aves com 14, 21, 28 e 35 dias de idade foram analisadas por ELISA para detecção de título de anticorpos contra a Doença de Gumboro e nestas mesmas idades foi determinado o peso dos órgãos linfoides e a altura de pregas primárias do tecido linfoide da bolsa cloacal. Não houve diferença significativa (p > 0,05) entre os tratamentos. A suplementação de Arg não contribuiu com a resposta imune dos frangos de corte imunizados contra a Doença de Gumboro. A falta de resposta à imunização pode ser atribuída à baixa virulência da cepa vacinal utilizada e à presença de vírus de campo.

The study was conducted to evaluate the effect of supplemental Arginine (Arg) on the humoral immune response and development of lymphoid organs of broiler chickens vaccinated against Gumboro disease. Six hundred and forty broilers were reared in a complete randomized design with four treatments (1. Control, 2. Immunization, 3. Immunization and supplementation of L-Arg, and 4. Supplemental L-Arg.) and eight replications of 20 birds each. Birds in treatments 3 and 4 were vaccinated at 16 days against Gumboro disease (intermediate plus strain). Serum samples from birds at 14, 21, 28 and 35 days old were analyzed by ELISA for detection of antibody titers against Gumboro disease, and at these same ages, lymphoid organ weight was determined and the height of the primary folds of lymphoid tissue in the cloacal bursa was measured. There was no significant difference (p > 0.05) among treatments. Arg supplementation did not improve the immune response of broilers immunized against Gumboro Disease. The lack of response to immunization may be attributed to the low virulence of the vaccine strain used and the presence of environmental virus.

Caracterização molecular da região hipervariável do gene vp2 do vírus da doença da Bursa de Fabrícius (IBVD) em frangos de corte do Estado do Rio de Janeiro

A Doença Infecciosa da Bursa de Fabrícius (DIB), também chamada de doença de Gumboro, é uma doença aguda que leva à imunossupressão em aves jovens. A cepa viral pode ser altamente patogênica e tem grande importância econômica para granjas comerciais do Brasil e do mundo. A proteína externa da capsídeo viral (vp2) do vírus da doença Infecciosa da Bursa de Fabrícius (IBDV) tem uma região hipervariável que é usada para a caracterização viral. Atualmente, estirpes virais do IBD são classificados como clássico (cvIBDV), variante atenuada (atIBDV), altamente virulenta (vvIBDV) e distinta (diIBDV). O objetivo deste estudo foi estudar a caracterização molecular da região hipervariável do gene vp2 a partir de amostras de aves brasileiras do estado do Rio de Janeiro. A detecção e genotipagem de estirpes de IBDV foram realizadas por real time RT-PCR. A partir de 65 de amostras avaliadas, 49 foram positivas para IBDV e 45 foram classificados como não muito virulenta (clássico, atenuado ou variantes distintas) e quatro como muito virulenta. As mesmas amostras foram submetidas a RT-PCR com iniciadores específicos para amplificar um fragmento de 642 pb que codifica a região hipervariável do gene VP2. Subsequentemente, as amostras positivas foram seqüenciadas e comparadas com outras seqüências disponíveis no GenBank para o estudo da diversidade genética de estirpes virais. A análise filogenética mostrou que a amostra RJ esta agrupada em um clado de estirpes muito virulentas e as amostras 1, 2, 3, 4 e 5 estão agrupadas em outro clado com cepas classificadas como distintas. Além disso, diferenças na região hipervariável do gene de vp2 foram encontrados neste estudo, quando comparado com outras estirpes virais disponíveis no GenBank. Este fato mostra que eles podem ser genótipos virais ainda não identificados que estão em circulação em granjas comerciais no Estado do Rio de Janeiro.

The InfectiousBursal Disease (IBD), also called Gumboro disease, is an acute disease that leads to immunosuppression in young birds. The viral strain can be highly pathogenic and has great economic importance to the Brazilian and global commercial poultry. The external protein of the viral capsid (vp2) of Infectious Bursal Disease Virus (IBDV) has a hypervariable region which is used for viral characterization. Currently, viral strains of the IBD are classified as classic (cvIBDV), attenuated (atIBDV) variant (avIBDV), highly virulent (vvIBDV) and different (diIBDV). The aim of this study was to study the molecular characterization of the hypervariable region of the vp2 gene of Brazilian samples from fowl runs in the state of Rio de Janeiro. The detection and genotyping of IBDV strains were performed by real-time RT-PCR. From 65 of evaluated samples, 49 were positives for IBDV and, 45 were classified as not very virulent (classical, attenuated, or different variants) and four as very virulent. The same samples were subjected to RT-PCR with specific primers to amplify a fragment of 642 bp encoding the hypervariable region of the vp2 gene. Subsequently, the positive samples were sequenced and compared with other sequences available in GenBank for the study of genetic diversity of viral strains. Phylogenetic analysis showed that the sample RJ are grouped in a very virulent strains cluster and samples 1, 2, 3, 4 and 5 are clustered in another clade with strains classified as distinct. In addition, differences in the hypervariable region of the vp2 gene were found in this study, when compared to other viral strains available in GenBank. This fact shows that they can be a viral genotypes not identified yet that are in circulation in commercial farms in the state of Rio de Janeiro.