In vitro antiviral activity of seeds from Guettarda angelica against avian viruses.

The aim of this study was to evaluate the inhibition of the aqueous extract of seeds (AEs) from Guettarda angelica on cell infection by two avian RNA viruses: avian reovirus (ARV) and metapneumovirus (AMPV). The cytotoxic and antiviral activities were evaluated by MTT assay to determine the 50% cytotoxic (CC50) and inhibitory concentrations (IC50). The selectivity index (SI=CC50/IC50) also carried out. AEs exhibited antiviral activity only against ARV presenting IC50 of 23.59μg/mL. This inhibition was not due to any cytotoxic effect of AEs since the CC50 on Vero cells was of 400.60μg/mL and its SI was of 17.00; this extract also showed a virucidal effect on ARV. Previous studies also demonstrated antiviral activity of AEs extract against three animal herpesviruses. Thus, the seeds from G. angelica showing antiviral activity against DNA and RNA viruses, enveloped and non-enveloped, could be promising source of new antiviral agents encouraging its fractionation to isolate the active compound.

The occurrence of orthoreovirus, rotavirus and chicken anemia virus in chickens of the poultry industry in Minas Gerais, Brazil / Ocorrência de orthoreovirus, rotavirus e vírus da anemia das galinhas em frangos de corte da indústria avícola de Minas Gerais

Fifty-four fecal samples taken from broiler chickens from 1 to 45 days of age, and of pullets from 10 to 13 weeks of age, original from eight different poultry regions in the state of Minas Gerais, Brazil, were collected from March 2008 to January 2010 for avian Orthoreovirus (ARV) and avian Rotavirus (AvRV) analyses. For the assay of ARV, RNA was immediately extracted (Trizolâ) and transcribed into cDNA for assaying in a nested-PCR with ARV-specific primers. For AvRV, polyacrylamide gel electrophoresis (PAGE) was performed with RNA extracts obtained by phenol-chloroform extraction. CAV was additionally investigated through a nested-PCR of thymus and spleen. Results found 5.55% positive for ARV and 9.25% for AvRV. Also, CAV and ARV genomes were detected in co-infection, in a highly prostrated and claudicating chicken flock. No ARV or AvRV infections were detected in pullets. Material of a clinically affected flock was inoculated into SPF embryos, resulting in embryonic hemorrhage, whitish foci in the chorio-allantoic membrane and death. Sequencing of ARV amplicons and isolate cDNA grouped local strains with the ARV S1133 strain, historically used in live vaccines, suggesting the continued circulation of this vaccine virus strain in intensive poultry regions. Detection rates for ARV and AvRV, as well as the presence of CAV, were additionally indicative of failing biosecurity strategies for the intensive poultry regions examined.

Avaliou-se a ocorrência de Orthoreovirus (ARV) e Rotavirus (AvRV) aviários na avicultura industrial de Minas Gerais. Foram colhidas cinquenta e quatro amostras de fezes de frangos de corte entre um e 45 dias e de frangas de postura de 10 a 13 semanas de idade. Para análise de ARV, o RNA foi imediatamente extraído (Trizol), transcrito em cDNA e avaliado em uma PCR com oligonucleotídeos iniciadores específicos para ARV. Para a investigação de AvRV, os extratos de RNA foram obtidos por fenol-clorofórmio e submetidos à eletroforese em gel de poliacrilamida. Todas as amostras foram também avaliadas para o DNA do vírus da anemia das galinhas (CAV) em uma nested-PCR específica. Em frangos de corte, a positividade encontrada para ARV foi de 5,55% e para AvRV de 9,25%. CAV foi detectado em coinfecção em um plantel com refugagem, claudicação e prostração. Nenhuma amostra de poedeiras foi positiva para ARV ou AvRV. Material de plantel com sinais clínicos foi purificado e inoculado em ovos SPF embrionados, sendo obtidas lesões hemorrágicas e focos brancos na membrana cório-alantóide. O sequenciamento dos produtos de PCR e de embrião agrupou os isolados de ARV com a estirpe S1133, historicamente usada como vacina viva. Os resultados sugerem a continuada circulação da infecção por estirpes assemelhadas a ARV S1133 nas regiões de avicultura industrial. Os índices de detecção de ARV, AvRV e CAV indicam que a intensificação nas regiões produtoras tem resultado em falhas de biosseguridade.

Cloning and expression of the σC gene of avian reovirus / 中国兽医学报

The σC gene of ARV S1133 was designed to amplify by reverse transcription chain reaction(RTPCR).The σC gene was inserted into the vector pMD19-T,identified by PCR method and restriction enzyme,and sequenced.It showed that the insert cloned gene fragment was the σC gene of ARV.Then the gene was inserted intc the pET32a(+) and indicated that fusion expression vector pET32a-σC was constructed.The recombinant fusion protein was highly expressed in E.coli BL21 induced by 1.0 mmol/L IPTG for 5 hours in the form of inclusion bodies.The weight of recombinant fusion protein molecular is 54 000.Western-blot with ARV antibodies against the fusion protein showed the recombinant protein has a favourable reactivity.