Detection of Mycoplasma Synoviae and Other Pathogens in Laying Hens with Respiratory Signs in the Rearing and Production Phases

The present study aimed to investigate the occurrence of Mycoplasma synoviae (MS), M. gallisepticum (MG), Ornitobacterium rhinotracheale (OR), Avibacterium paragallinarum (AP), Pasteurella multocida (PM) and Infectious Bronchitis Virus (IBV) in laying hens with respiratory clinical signs in two phases of production. 140 tracheal swabs and 140 blood samples were collected from laying hens in the rearing and production phases, the chickens belonged to six farms (A-F) located in the state of São Paulo, Brazil. The samples were analyzed by PCR for MG, MS, OR, AP, PM and IBV and by ELISA for MG and MS. The highest frequencies observed by PCR were for MS at farms B and C with 95 and 100% positivity, followed by MG at farms D and E with 35% and 65%, IBV with 35% at farm F and ORT with 15% at farm A. All flocks were positive for MG and MS in serology. Although MG and IBV have been detected, this can be explained by the vaccination protocols, since live attenuated vaccines are widely used for immunization against these pathogens. It was also possible to detect OR and AP thorugh PCR in some flocks. The occurrence of several etiological agents that cause respiratory diseases in laying hens was confirmed by PCR and serology, with MS being the most prevalent and being present in all farms studied.(AU)

Detection of Mycoplasma Synoviae and Other Pathogens in Laying Hens with Respiratory Signs in the Rearing and Production Phases

The present study aimed to investigate the occurrence of Mycoplasma synoviae (MS), M. gallisepticum (MG), Ornitobacterium rhinotracheale (OR), Avibacterium paragallinarum (AP), Pasteurella multocida (PM) and Infectious Bronchitis Virus (IBV) in laying hens with respiratory clinical signs in two phases of production. 140 tracheal swabs and 140 blood samples were collected from laying hens in the rearing and production phases, the chickens belonged to six farms (A-F) located in the state of São Paulo, Brazil. The samples were analyzed by PCR for MG, MS, OR, AP, PM and IBV and by ELISA for MG and MS. The highest frequencies observed by PCR were for MS at farms B and C with 95 and 100% positivity, followed by MG at farms D and E with 35% and 65%, IBV with 35% at farm F and ORT with 15% at farm A. All flocks were positive for MG and MS in serology. Although MG and IBV have been detected, this can be explained by the vaccination protocols, since live attenuated vaccines are widely used for immunization against these pathogens. It was also possible to detect OR and AP thorugh PCR in some flocks. The occurrence of several etiological agents that cause respiratory diseases in laying hens was confirmed by PCR and serology, with MS being the most prevalent and being present in all farms studied.

Circulation of Major Respiratory Pathogens in Backyard Poultry and their Association with Clinical Disease and Biosecurity

Raising backyard birds is a common practice in Brazil, mainly in the countryside or suburban areas. However, the level of respiratory pathogens in these animals is unknown. We sampled two hundred chickens from 19 backyard flocks near commercial poultry farms and performed ELISA to Infectious Bronchitis Virus, avian Metapneumovirus, Mycoplasma synoviae and Mycoplasma gallisepticum. We evaluated the association between the predictive ability of ELISA and Hemagglutination-inhibition (HI)by comparing results from eight flocks positive to Mycoplasma gallisepticum on ELISA. Besides, we assessed essential biosecurity measures in the properties (multiple species birds, rodent control, hygienic conditions, and water quality for the bird`s consumption). We could access the vaccination program only on four properties; in three of them, the birds were supposedly vaccinated for IBV. Overall the properties had a poor score for the biosecurity measures, and the seroprevalence in backyard poultry flocks for IBV, a MPV, MS, and MG were respectively 87.5% (14/16), 89.5% (17/19), 100 (19/19) and MG 84.21% (16/19). We found low specificity and predictive value between ELISA and HI in MG analysis and a positive correlation between the presence of clinical symptoms and mean MG titers. Backyard chicken are pathogens reservoirs and pose a risk for the commercial poultry farms in the region, and further efforts of the governmental entities and private sector of poultry production should consider these information to avoid future economic losses.(AU)

Circulation of Major Respiratory Pathogens in Backyard Poultry and their Association with Clinical Disease and Biosecurity

Raising backyard birds is a common practice in Brazil, mainly in the countryside or suburban areas. However, the level of respiratory pathogens in these animals is unknown. We sampled two hundred chickens from 19 backyard flocks near commercial poultry farms and performed ELISA to Infectious Bronchitis Virus, avian Metapneumovirus, Mycoplasma synoviae and Mycoplasma gallisepticum. We evaluated the association between the predictive ability of ELISA and Hemagglutination-inhibition (HI)by comparing results from eight flocks positive to Mycoplasma gallisepticum on ELISA. Besides, we assessed essential biosecurity measures in the properties (multiple species birds, rodent control, hygienic conditions, and water quality for the bird`s consumption). We could access the vaccination program only on four properties; in three of them, the birds were supposedly vaccinated for IBV. Overall the properties had a poor score for the biosecurity measures, and the seroprevalence in backyard poultry flocks for IBV, a MPV, MS, and MG were respectively 87.5% (14/16), 89.5% (17/19), 100 (19/19) and MG 84.21% (16/19). We found low specificity and predictive value between ELISA and HI in MG analysis and a positive correlation between the presence of clinical symptoms and mean MG titers. Backyard chicken are pathogens reservoirs and pose a risk for the commercial poultry farms in the region, and further efforts of the governmental entities and private sector of poultry production should consider these information to avoid future economic losses.

Construction and characterization of a recombinant vaccine encoding the nucleocapsid protein gene of avian infectious bronchitis virus / Construção e caracterização de uma vacina recombinante codificando o gene da proteina do nucleocapsideo do virus da bronquite infecciosa das galinhas

A vacinação é a forma mais utilizada para prevenir a bronquite infecciosa causada pelo vírus da bronquite infecciosa das galinhas (IBV). Contudo, as vacinas convencionais são incapazes de diferenciar aves infectadas de vacinadas. No presente trabalho foi construído, caracterizado, e avaliado como candidato vacinal, um adenovírus recombinante expressando o gene N do IBV. O gene N foi clonado em um adenovírus humano tipo 5 defectivo e transfectado para as células HEK-293A para gerar rAd5_N. Após o vetor ser obtido como esperado e a confirmação da expressão da proteína N em HEK-293ª, foi realizada inoculação pela via oculo-nasal na dose de 10 7 TCID 50 /0,1mL para imunização de galinhas livres de patógenos específicos (SPF). A resposta imunológica do Ad5_N e a proteção contra o desafio ao IBV foram avaliadas e comparadas com uma vacina viva comercial. Não foram detectados anticorpos anti-IBV em aves vacinadas com o Ad5_N. A vacina comercial induziu anticorpos detectáveis a partir do 7º dia pós-vacinal. Em aves vacinadas com o Ad5_N não houve aumento na expressão de IFNγ. Neste estudo, o rAd5_N obtido não conferiu proteção contra desafio com IBV-M41. Os resultados indicam a necessidade de avaliar adenovírus recombinantes expressando outros genes do IBV.(AU)

Construction and characterization of a recombinant vaccine encoding the nucleocapsid protein gene of avian infectious bronchitis virus / Construção e caracterização de uma vacina recombinante codificando o gene da proteina do nucleocapsideo do virus da bronquite infecciosa das galinhas

A vacinação é a forma mais utilizada para prevenir a bronquite infecciosa causada pelo vírus da bronquite infecciosa das galinhas (IBV). Contudo, as vacinas convencionais são incapazes de diferenciar aves infectadas de vacinadas. No presente trabalho foi construído, caracterizado, e avaliado como candidato vacinal, um adenovírus recombinante expressando o gene N do IBV. O gene N foi clonado em um adenovírus humano tipo 5 defectivo e transfectado para as células HEK-293A para gerar rAd5_N. Após o vetor ser obtido como esperado e a confirmação da expressão da proteína N em HEK-293ª, foi realizada inoculação pela via oculo-nasal na dose de 10 7 TCID 50 /0,1mL para imunização de galinhas livres de patógenos específicos (SPF). A resposta imunológica do Ad5_N e a proteção contra o desafio ao IBV foram avaliadas e comparadas com uma vacina viva comercial. Não foram detectados anticorpos anti-IBV em aves vacinadas com o Ad5_N. A vacina comercial induziu anticorpos detectáveis a partir do 7º dia pós-vacinal. Em aves vacinadas com o Ad5_N não houve aumento na expressão de IFNγ. Neste estudo, o rAd5_N obtido não conferiu proteção contra desafio com IBV-M41. Os resultados indicam a necessidade de avaliar adenovírus recombinantes expressando outros genes do IBV.(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: 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...

Isolation and genetic stability of an infectious bronchitis virus strain (IBV) / Isolamento e estabilidade genética de uma cepa do vírus da bronquite infecciosa (IBV)

O vírus da bronquite infecciosa (IBV) é um importante patógeno respiratório presente na avicultura comercial e tem provocado grandes perdas econômicas em todo o mundo. A vacinação é realizada pela indústria produtora de aves, mas continuam surgindo novos sorotipos e variações antigênicas, dificultando o controle de IBV. Nós realizamos uma caracterização molecular de uma cepa de IBV obtida diretamente de tecidos e comparamos com a mesma cepa que havia sido passada três vezes em ovo embrionado. Nós mostramos uma variação significante na sequência viral depois de ter sido isolada em ovo embrionado.(AU)

Isolation and genetic stability of an infectious bronchitis virus strain (IBV) / Isolamento e estabilidade genética de uma cepa do vírus da bronquite infecciosa (IBV)

O vírus da bronquite infecciosa (IBV) é um importante patógeno respiratório presente na avicultura comercial e tem provocado grandes perdas econômicas em todo o mundo. A vacinação é realizada pela indústria produtora de aves, mas continuam surgindo novos sorotipos e variações antigênicas, dificultando o controle de IBV. Nós realizamos uma caracterização molecular de uma cepa de IBV obtida diretamente de tecidos e comparamos com a mesma cepa que havia sido passada três vezes em ovo embrionado. Nós mostramos uma variação significante na sequência viral depois de ter sido isolada em ovo embrionado.(AU)

Effect of stocking density on the performance and immunity of 1- to 14-d- old broiler chicks / 10.1590/1806-9061-2016-0289

The current experiment was conducted to evaluate the effect of stocking density (SD) on the performance and immunity of 1- to 14-d-old broilers. A total of 1836 one-day-old Cobb 500 broilers were housed at four different SD (30, 60, 90 and 120 chicks/m2). Body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) were estimated on d 2, 5, 8, 11 and 14. Relative lymphoid organ weights, maternal antibody titers against IBV, IBD and NDV, and stress indicators were estimated on d 3, 6, 9 and 12.The results indicated that age significantly (p 0.001) affected the performance and immunity of broiler chicks. Stocking density significantly (p 0.001) affected the performance and physiological stress indicators of broiler chicks, but not maternal immunity, relative lymphoid organ weights, or blood glucose levels. A significant interaction between age and density was determined for BWG, FI and FCR, and maternal antibody titers against IBD and NDV. The results also indicated that the effects of SD were age-dependent: as SD increased, worse performance, lighter lymphoid organs, and stronger stress responses were observed as broilers aged. It is concluded that the higher the SD during the first two weeks of life, the worse is the performance as broilers age.

Effect of stocking density on the performance and immunity of 1- to 14-d- old broiler chicks / 10.1590/1806-9061-2016-0289

The current experiment was conducted to evaluate the effect of stocking density (SD) on the performance and immunity of 1- to 14-d-old broilers. A total of 1836 one-day-old Cobb 500 broilers were housed at four different SD (30, 60, 90 and 120 chicks/m2). Body weight gain (BWG), feed intake (FI) and feed conversion ratio (FCR) were estimated on d 2, 5, 8, 11 and 14. Relative lymphoid organ weights, maternal antibody titers against IBV, IBD and NDV, and stress indicators were estimated on d 3, 6, 9 and 12.The results indicated that age significantly (p 0.001) affected the performance and immunity of broiler chicks. Stocking density significantly (p 0.001) affected the performance and physiological stress indicators of broiler chicks, but not maternal immunity, relative lymphoid organ weights, or blood glucose levels. A significant interaction between age and density was determined for BWG, FI and FCR, and maternal antibody titers against IBD and NDV. The results also indicated that the effects of SD were age-dependent: as SD increased, worse performance, lighter lymphoid organs, and stronger stress responses were observed as broilers aged. It is concluded that the higher the SD during the first two weeks of life, the worse is the performance as broilers age.(AU)

Influência na resposta sorológica de aves vacinadas contra Bronquite Infecciosa das Galinhas por Mycoplasma Synoviae em aves de produção

Especialmente nos últimos anos a avicultura brasileira tem alcançado índices elevados de crescimento, tornando-se o terceiro principal produtor mundial de carne de frango e líder de exportações, atingindo 142 países. Fatores como saúde e bem-estar animal, qualidade e preço contribuíram para aperfeiçoar a produtividade no setor. Diante disso, a preocupação com a sanidade dos animais é um dos grandes desafios do mercado, sendo que o controle da Bronquite Infecciosa das galinhas (BI) e a erradicação do Mycoplasma synoviae (Ms) em granjas de reprodução são questões de enorme relevância sanitária. A BI, causada por um coronavírus, o Vírus da Bronquite Infecciosa (IBV), trata-se de uma doença viral aguda e altamente contagiosa. Já a micoplasmose, causada pela menor bactéria existente, o Ms, possui uma grande capacidade de disseminação no lote de matrizes sendo que, uma vez positivo, o lote permanece com esse status até o fim da sua vida. Ambas as doenças apresentam sinais clínicos semelhantes afetando a parte respiratória, tornando-se secundária uma à outra. Assim sendo, é importante avaliar se as aves que apresentavam sintomas sugestivos à IBV e que já eram sabidamente positivas para Ms, estavam realmente protegidas através da vacinação. No presente estudo foram avaliados os títulos vacinais de Bronquite Infecciosa a fim de verificarmos a existência de interferência na resposta sorológica frente ao IBV pela positividade de Ms. Para isso, foram verificados os resultados de 326 amostras de soro coletadas no período de 2014 à 2018, em lotes de matrizes de uma agroindústria do Oeste catarinense. Para avaliar o efeito da presença de Ms sobre o titulo médio de bronquite foi aplicado o teste t para comparação de dados não pareados. Através da presente análise verificou-se que não houve interferência de Ms nos títulos de anticorpos frente ao vírus da Bronquite Infecciosa (IBV).

Especially in recent years, Brazilian poultry has achieved high growth rates, becoming the third major worldwide producer of chicken meat and leader in exports, reaching 142 countries. Factors such as animal health and welfare, quality and price have contributed to improving productivity in the sector. Given this, the concern with the health of animals is one of the main challenges of the market, and the control of Infectious Bronchitis of chickens (IB) and the eradication of Mycoplasma synoviae (Ms) in breeding farms are issues of enormous animal health relevance. IB, caused by a coronavirus, the Infectious Bronchitis Virus (IBV), is an acute and highly contagious viral disease. Mycoplasmosis, on the other hand, is caused by the smallest existing bacteria, Mycoplasma synoviae (Ms), has great capacity for dissemination in the breeding flock, and once the flock is positive, it remains with this status until the end of its life. Both diseases show similar clinical signs affecting the respiratory part, becoming secondary to each other. Therefore, it is important to assess whether birds that had symptoms suggestive of IBV and that were already known to be positive for Ms, were actually protected through vaccination. In the present study the vaccine titers of Infectious Bronchitis were evaluated in order to verify the existence of interference in the serological response against IBV by the positivity of Ms. For this, the results of 326 serum samples collected in the period from 2014 to 2018 in batches of matrices of an agribusiness in the West of Santa Catarina were verified. To evaluate the effect of the presence of Ms on the mean titer of bronchitis, the t test was applied in order to compare unpaired data. Through the present analysis it was verified there were no interference of Ms in the antibody titers against the Infectious Bronchitis virus (IBV).

Increased expression of Interleukin-6 related to nephritis in chickens challenged with an Avian infectious bronchitis virus variant / Aumento da expressão de Interleucina-6 relacionada com nefrite in galinhas desafiadas com uma variante do vírus da bronquite infecciosa

A Brazilian field isolate (IBV/Brazil/PR05) of avian infectious bronchitis virus (IBV), associated with development of nephritis in chickens, was previously genotyped as IBV variant after S1 gene sequencing. The aim of this study was to evaluate the levels of IL-6 in kidneys and trachea of birds vaccinated and challenged with IBV/Brazil/PR05 strain, correlating these results with scores of microscopic lesions, specific IBV antigen detection and viral load. The up-regulation of IL-6 and the increased levels of viral load on renal and tracheal samples were significantly correlated with scores of microscopic lesions. Reduced levels of viral load were detected in kidneys of birds previously vaccinated and challenged, compared to non-vaccinated challenged group, although markedly microscopic lesions were observed for both groups. The expression of IL-6, present both in the kidney and in the tracheas, was dependent on the load of the virus present in the tissue, and the development of lesions was related with IL-6 present in the tissues. These data suggest that variant IBV/Brazil/PR05 can induce the expression of proinflammatory cytokines in a manner correlated with viral load and increased IL-6 is involved in the tissue with the influx of inflammatory cells and subsequent nephritis. This may contribute with a model to the development of immunosuppressive agents of IL-6 to prevent acute inflammatory processes against infection with IBV and perhaps other coronaviruses, as well as contribute to the understanding of the immunopathogenesis of IBV nephropatogenic strains.(AU)

Uma estirpe variante do vírus da bronquite infecciosa (VBI) associada com o desenvolvimento de nefrite em galinhas, foi isolado e identificado como variante por análise do gene S1. A estirpe IBV/Brazil/PR05 foi testada quanto à sua capacidade de induzir a expressão de interleucina-6 (IL-6) nos tecidos renais e traqueais. Galinhas vacinadas com a estirpe Massachusetts H120 e não vacinadas foram desafiadas com a estirpe IBV/Brazil/PR05. Cinco dias após a infecção, traquéias e rins foram coletados para análise por RT-qPCR, imunohistoquímica e histopatologia. Foi determinada a expressão relativa de IL-6 e da carga viral. A expressão de IL-6 e carga viral foram correlacionadas com o desenvolvimento de nefrite e lesão traqueal. A expressão de IL-6 foi maior quando houve aumento da carga viral na traqueia e nos rins. A carga viral presente nos rins foi inferior quando as aves foram vacinadas, entretanto foi observada nefrite acentuada. Houve alta correlação entre o desenvolvimento de nefrite e o nível de expressão de IL-6, bem como a expressão de IL-6 e a carga viral. A expressão de IL-6, presente tanto nos rins e nas traqueias, foi relacionada a carga viral presente nestes tecidos, e o desenvolvimento das lesões foi relacionado com a expressão de IL-6. Estes dados sugerem que a variante IBV/Brazil/PR05 pode induzir a expressão de citocinas pró-inflamatórias de forma correlacionada com a carga viral, e o aumento de IL-6 está envolvido com o influxo de células inflamatórias no tecido, o que evolui para o desenvolvimento de nefrite. Isto pode contribuir como um modelo para o desenvolvimento de agentes imunossupressores da IL-6 para evitar processos inflamatórios agudos contra infecção com o VBI e talvez outros coronavírus, bem como contribuir para o entendimento da imunopatogênese das estirpes nefropatogênicas deste vírus.(AU)

Bronquite infecciosa das galinhas

A bronquite infecciosa das galinhas(BIG) é doença aguda altamente contagiosa de frangos e galinhas (Gallusgallus domesticus). A BIG é considerada atualmente uma das doenças que mais causa prejuízos à avicultura industrial de galinhas e frangos no Brasil e no mundo. Há grande impacto econômico,por causar aumento da mortalidade, perdas em desempenho produtivo, queda quantitativa e qualitativa na produção de ovos, infertilidade, facilitação de infecções oportunistas, que exigem ouso de antibióticos, e aumento na condenação de carcaças de frangos de corte no abatedouro [2,5]. É importante desta carque, em codornas domésticas (Coturnix japonicae Coturnix coturnix),a bronquite é causada por um adenovírus(Aviadenovirus), sem qualquer relação com a etiologia de BIG.

Bronquite infecciosa das galinhas

A bronquite infecciosa das galinhas(BIG) é doença aguda altamente contagiosa de frangos e galinhas (Gallusgallus domesticus). A BIG é considerada atualmente uma das doenças que mais causa prejuízos à avicultura industrial de galinhas e frangos no Brasil e no mundo. Há grande impacto econômico,por causar aumento da mortalidade, perdas em desempenho produtivo, queda quantitativa e qualitativa na produção de ovos, infertilidade, facilitação de infecções oportunistas, que exigem ouso de antibióticos, e aumento na condenação de carcaças de frangos de corte no abatedouro [2,5]. É importante desta carque, em codornas domésticas (Coturnix japonicae Coturnix coturnix),a bronquite é causada por um adenovírus(Aviadenovirus), sem qualquer relação com a etiologia de BIG.

VIGILÂNCIA DE DOENÇAS VIRAIS EM AVES DE SUBSISTÊNCIA CRIADAS PRÓXIMAS A SÍTIOS DE AVES MIGRATÓRIAS NO ESTADO DE MATO GROSSO

No estado de Mato Grosso, nos municípios de Cáceres e Araguaiana há áreas de interface entre aves migratórias e de subsistência. A circulação dos vírus da influenza aviária (AIV), doença de Newcastle (NDV), metapneumovirus aviário (aMPV) e da bronquite infecciosa aviária (IBV) é desconhecida nesses locais devido à escassez de estudos. Este trabalho teve como objetivo realizar inquérito soro epidemiológico em aves domésticas de subsistência para estes agentes que causam prejuízos econômicos e sociais na avicultura comercial mundialmente. Infecções por AIV e NDV foram avaliadas por meio dos testes de ELISA, Inibição da Hemaglutinação e RT-PCR em tempo real em amostras de soro, suabes de cloaca e traqueia de 1.068 aves, entre galinhas, codornas, perus, patos e gansos. Para aMPV e IBV foram analisadas 623 amostras de soro de galinhas por ELISA. A frequência de aves soropositivas ao ELISA para AIV, NDV, aMPV e IBV em Araguaiana foram de 0,7%, 23%, 85% e 69% respectivamente; enquanto em Cáceres a frequência foi de 0,8%, 43,5%, 88,5% e 70%, respectivamente. Somente em Cáceres houve um pato (0,6%) positivo ao HI para NDV. Não houve amostras reagentes ao PCR para AIV e NDV. A análise espacial detectou a presença de aglomeração entre as propriedades com aves soropositivas ao NDV na zona urbana de Cáceres, sugerindo a participação dessa área na manutenção ou disseminação do virus. Este estudo evidenciou infecção por patógenos virais, em aves de subsistência nas regiões de sítio de aves migratórias no estado de Mato Grosso demonstrando a importância dessas aves como fontes de infecção para outras aves.

In Mato Grosso, in the counties of Cáceres and Araguaiana there are areas of interface between migratory birds and backyard poultry. Circulation of avian influenza virus (AIV), Newcastle disease virus (NDV), avian metapneumovirus (aMPV), and avian infectious bronchitis virus (IBV) are unknown in these sites due to the scarcity of studies. The objective of this work was to conduct an serum epidemiological survey on backyard poultry for these agents that cause economic and social losses in commercial poultry worldwide. Samples (serum, cloacal swabs and trachea swabs) of 1068 birds, among chickens, quails, turkeys, ducks and geese, were analyzed for AIV and NDV by ELISA, Hemagglutination Inhibition and RT-PCR in real-time. For aMPV and IBV were analized 623 chickens in the ELISA test. The frequency sample positive of ELISA for AIV, NDV, aMPV and IBV in Araguaiana were 0.7%, 23%, 85% and 69%, respectively; whereas in Cáceres the frequency was 0.8%, 43.5%, 88.5% and 70%, respectively. Only in Caceres there was a duck (0.6%) positive for HI for NDV. There were no PCR reagent samples for AIV and NDV. The spatial analysis demonstrated the agglomeration of properties with NDV seropositive birds within the urban zone of Cáceres, suggesting the participation of this area in viral dissemination. This study evidenced infection by viral pathogens in backyard poultry in the site of migratory birds in the state of Mato Grosso, demonstrating the importance of these birds as sources of infection for other birds.

Eggshell apex abnormalities in a free-range hen farm with mycoplasma synoviae and infectious bronchitis virus in Rio de Janeiro state, Brazil

A farm with 3,000 free-range hens between 24 and 65 weeks of age was investigated. These hens were separated in small flocks of 400 to 700 birds, presenting 10 to 23% egg production reduction. Twenty serum samples were collected during the period of drop in egg production and three weeks later for the investigation of Mycoplasma synoviae (MS), M. gallisepticum (MG) and Infectious Bronchitis Virus (IBV) antibodies using ELISA. At the time of the second collection, egg production had resumed to normal levels; however, with 10.23% of the eggs showed eggshell abnormalities limited to the apex. Eggshell strength was significantly different between normal and those with eggshell apex abnormalities, but not other egg-quality parameters. ELISA tests showed that MS and IBV titers increased during the evaluated period. MS infection was confirmed by culture and by PCR of tracheal swabs. All samples were negative for MG by ELISA and PCR. Further studies with larger samples to ensure the occurrence of this disease in industrial layer flocks in Brazil are under way.

Eggshell apex abnormalities in a free-range hen farm with mycoplasma synoviae and infectious bronchitis virus in Rio de Janeiro state, Brazil

A farm with 3,000 free-range hens between 24 and 65 weeks of age was investigated. These hens were separated in small flocks of 400 to 700 birds, presenting 10 to 23% egg production reduction. Twenty serum samples were collected during the period of drop in egg production and three weeks later for the investigation of Mycoplasma synoviae (MS), M. gallisepticum (MG) and Infectious Bronchitis Virus (IBV) antibodies using ELISA. At the time of the second collection, egg production had resumed to normal levels; however, with 10.23% of the eggs showed eggshell abnormalities limited to the apex. Eggshell strength was significantly different between normal and those with eggshell apex abnormalities, but not other egg-quality parameters. ELISA tests showed that MS and IBV titers increased during the evaluated period. MS infection was confirmed by culture and by PCR of tracheal swabs. All samples were negative for MG by ELISA and PCR. Further studies with larger samples to ensure the occurrence of this disease in industrial layer flocks in Brazil are under way.(AU)

Efeito da vitamina E sobre o sistema imununológico de aves SPF vacinadas contra o vírus da bronquite infecciosa / Effect of vitamin E on the immune system of SPF birds vaccinated against infectious bronchitis virus

A fim de analisar a influência da vitamina E sobre a resposta imunológica de aves vacinadas e desafiadas com o Vírus da Bronquite Infecciosa das aves (VBI), e qual dose da vitamina E é melhor para essa resposta, foi realizado um e experimento utilizando 50 aves SPF alojadas com um dia de vida na Embrapa Suínos e Aves. As aves foram divididas em 10 grupos de cinco aves cada, incluindo grupo controle positivo e negativo, suplementadas com 15, 50 e 200 UI/Kg de vitamina E na ração. No décimo quarto dia de vida as aves foram vacinadas com a vacina comercial para Bronquite Infecciosa (H-120) e após 28 dias, um grupo por tratamento foi desafiado com VBI cepa clássica (M-41). Cinco dias após o desafio as aves foram necropsiadas e os macrófagos abdominais foram coletados para análise da atividade microbicida e dosagem de óxido nítrico (NO). O pulmão foi coletado para contagem de células através de citometria de fluxo e também dosagem de NO. Órgãos de eleição também foram coletados para análise histológica e realização do isolamento viral para analisar a eficiência vacinal. Os resultados foram avaliados pelo teste ANOVA e Student t-test. Um aumento da atividade microbicida dos macrófagos abdominais foi observado nas aves com maior suplementação de vitamina E (200 UI/ Kg) quando comparado com os grupos que não receberam ou receberam quantidades menores (0, 15, 50 UI/Kg), indicando uma melhora na resposta imune inata influenciada pela suplementação de vitamina E na dieta. A suplementação desta vitamina em altas dosagens também aumenta a capacidade dos macrófagos em produzir NO. E, através da citometria, sugere-se que os macrófagos são as principais células recrutadas no tecido pulmonar no combate a BI e esta ação foi potencializada pela adição da vitamina independente de dosagem.(AU)

In order to analyze the influence of vitamin E on the immune response of birds vaccinated and challenged with Infectious Bronchitis Virus in poultry (IBV), and which dose of vitamin E is the best to answer this, an experiment was conducted using 50 SPF birds housed with one day of life at Embrapa Suínos e Aves. All birds were divided into 10 groups of five birds each, including positive and negative control groups, supplemented with 15, 50, and 200 IU of vitamin E/Kg added into the feed. On the 14th day of life the birds were vaccinated with a commercial vaccine for infectious bronchitis (H-120) and after 28 days, one group for each treatment was challenged with IBV, strain classical (M-41). Five days after challenge birds were necropsied and abdominal macrophages were collected for analysis of microbicidal activity and measurement of nitric oxide (NO). The lung was collected for cell count by flow cytometry and also for NO dosage. Organs of predilection were also collected for histological analysis and virus isolation to analyze the efficiency of the vaccine. The results were evaluated by ANOVA and Student t-test. An increased of microbicidal activity of abdominal macrophages was observed in the groups of birds with higher levels of vitamin E (200 IU/Kg) supplementation when compared with groups that did not receive or received minor amounts (0, 15, 50 IU/Kg), indicating an improvement in the innate immune response influenced by vitamin E supplementation in the diet. The supplementation of this vitamin in high doses also increases the ability of macrophages to produce NO. And, by flow cytometry, suggests that the macrophages are the primary cells recruited in the lung tissue to combat infectious bronchitis and this action was potentiated by the addition of vitamin E, independent of the dosage.(AU)