30 research outputs found

    Prevalence Of Newcastle Disease Virus In Broiler Chickens (gallus Gallus) In Brazil.

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    This study was carried out during 2002/2003, aiming to determine the prevalence of virulent Newcastle disease virus strains (NDV) in Brazilian commercial poultry farms. Clinical samples were obtained from the Southeastern, Southern and Central-Western regions, which comprise the main area of the Brazilian poultry production. Serum samples and tracheal and cloacal swabs of 23,745 broiler chickens from 1,583 flocks, including both vaccinated chickens and those with no vaccination information, were tested for NDV using a diagnostic ELISA kit. The seropositivity was 39.1%, and the isolation percentage by flock varied from 1.0 to 7.6%, and by region from 6.5 to 58.4%. Higher isolation rates (74.3-83.3%) were obtained after three passages in embryonated chicken eggs. All isolates preliminarily identified as NDV were characterized as nonpathogenic strains, as their Intracerebral Pathogenicity Index (ICPI) was below 0.7. Based on results of this study, Brazil can claim a virulent NDV-free status for commercial flocks.41349-5

    A Survey For Maintenance Of Virulent Newcastle Disease Virus-free Area In Poultry Production In Brazil.

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    In 2003, Brazil was recognized as a pathogenic Newcastle Disease Virus (NDV) strain-free country for commercial poultry. This research was conducted in Brazil between December 2003 and March 2005 to verify the maintenance of this virulent NDV-free status. Serum samples from 5,455 flocks for commercial poultry farms were collected, comprising 81,825 broiler chickens. The farms were located in nine states of the country, grouped in three geographic regions. Serological evidence of NDV infection was detected in 28.8% of the surveyed farms. However, all fifteen viruses isolated and identified as Newcastle Disease Virus (NDV) were characterized as nonpathogenic strains, based on the Intracerebral Pathogenicity Index. These results showed that Brazil preserves the virulent NDV-free status for commercial flocks.41368-7

    Adequação de uma semeadora para a semeadura/implantação de sorgo sacarino e biomassa em área de descanso da cana-de-açúcar.

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    Neste trabalho, vislumbrou-se utilizar as áreas de descanso de cana-de-açúcar das usinas para plantar cultivares de sorgo biomassa e sacarino, com alta capacidade de produção de massa e grão, para produção de energia e de etanol. Entretanto, a implantação da cultura do sorgo sacarino ou biomassa era comprometida face à dificuldade de semear, nas áreas com alta densidade de palhada. Durante os semeios iniciais, o mecanismo de preparo do solo na linha e o de distribuição da semente não era eficiente e dificultava o estabelecimento do estande técnico inicial, recomendado para esta cultura. Em uma parceria com a Empresa Marchesan Implementos e Máquinas Agrícolas - Tatu S.A., de Matão-SP, foi possível utilizar uma semeadora-adubadora comercial, já desenvolvida para semente graúda, como milho, feijão e soja, nestas mesmas áreas. O resultado deste trabalho foi muito bom e, com a adequação da semeadora-adubadora, permitiu a implantação do estande técnico inicial recomendado de 120 mil plantas/ha, com as modificações e os ajustes realizados nas áreas da Usina Bom Retiro, da empresa Raízen, no município de Capivari-SP.bitstream/item/169030/1/doc-215.pd

    Detecção de anticorpos heterólogos contra o vírus da leucose enzoótica bovina em caprinos.

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    O presente estudo foi idealizado com o intuito de investigar a possibilidade da transmissão do vírus da leucose enzoótica bovina (VLB) para cabritos recém-nascidos amamentados com colostro de vacas soropositivas para leucose enzoótica bovina (LEB). Para tanto, foram utilizados 31 caprinos que foram separados das mães logo após o nascimento, para em seguida receber colostro proveniente de 11vacas testadas sorologicamente para LEB. Amostras de soro sangüí neo dos caprinos foram colhidas ao 3, 45, 80,120 e 160 dias de idade e, depois, quando tinham aproximadamente 4 anos. Então, foram feitas as análises laboratoriais por meio do teste da imunodifusão em gel de ágar (IDGA) utilizando o antígeno gp51 para diagnóstico da LEB. Desse modo, constatou-se que uma parte dos cabritos que receberam colostro de vacas soropositivas para LEB estavam reagentes aos 3 dias de idade e negativos nas outras idades. Entretanto, todos os outros que receberam colostro de vacas soro negativas não reagiram nos testes sorológicos. Esses resultados permitiriam supor então que os anticorpos detectados eram de origem colostral. Após o declínio da imunidade passiva e na vida adulta, nenhum caprino soroconverteu. Portanto, pôde-se concluir que o colostro de vacas soropositivas para LEB não foi considerado um meio eficiente para a transmissão do VLB

    Evaluation of passive immunity transfer against G6P[1] rotavirus in Holstein Calves by ELISA.

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    The main strategy to prevent bovine rotavirus group A (RVA) diarrhea in calves is to vaccinate late-term dams aiming to enhance passive immunity transfer of specific immunoglobulins against the virus. This study aimed to evaluate influence of parity in titers of immunoglobulin G (IgG), IgG1 and IgM in serum and colostrum of vaccinated or unvaccinated Holstein cows and in serum of its calves, associated with monitoring for RVA diarrhea in calves. Cows and its calves were allotted into groups according to parity and vaccination (primiparous/multiparous; vaccinated/unvaccinated) and serum and colostrum samples of cows were taken as well as serum and fecal samples of its calves. Parturition influenced colostral titers of IgG and IgG1, which were higher in multiparous cows, whilst IgM titers were influenced by vaccination, being higher in colostrum of vaccinated dams. Lowest serum titers of IgG and IgG1 were found in calves born to unvaccinated primiparous dams. Eleven calves presented RVA diarrhea, and genotypes G6P[11] and G6P[5] were found in the vaccinated and unvaccinated herds, respectively. Vaccination of dams prolongs humoral immunity in calves and enhances colostrum quality and should be a primary concern in primiparous cows

    The Fecal Viral Flora of Wild Rodents

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    The frequent interactions of rodents with humans make them a common source of zoonotic infections. To obtain an initial unbiased measure of the viral diversity in the enteric tract of wild rodents we sequenced partially purified, randomly amplified viral RNA and DNA in the feces of 105 wild rodents (mouse, vole, and rat) collected in California and Virginia. We identified in decreasing frequency sequences related to the mammalian viruses families Circoviridae, Picobirnaviridae, Picornaviridae, Astroviridae, Parvoviridae, Papillomaviridae, Adenoviridae, and Coronaviridae. Seventeen small circular DNA genomes containing one or two replicase genes distantly related to the Circoviridae representing several potentially new viral families were characterized. In the Picornaviridae family two new candidate genera as well as a close genetic relative of the human pathogen Aichi virus were characterized. Fragments of the first mouse sapelovirus and picobirnaviruses were identified and the first murine astrovirus genome was characterized. A mouse papillomavirus genome and fragments of a novel adenovirus and adenovirus-associated virus were also sequenced. The next largest fraction of the rodent fecal virome was related to insect viruses of the Densoviridae, Iridoviridae, Polydnaviridae, Dicistroviriade, Bromoviridae, and Virgaviridae families followed by plant virus-related sequences in the Nanoviridae, Geminiviridae, Phycodnaviridae, Secoviridae, Partitiviridae, Tymoviridae, Alphaflexiviridae, and Tombusviridae families reflecting the largely insect and plant rodent diet. Phylogenetic analyses of full and partial viral genomes therefore revealed many previously unreported viral species, genera, and families. The close genetic similarities noted between some rodent and human viruses might reflect past zoonoses. This study increases our understanding of the viral diversity in wild rodents and highlights the large number of still uncharacterized viruses in mammals
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