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为了保证制苗及攻毒用毒种的质量和稳定性，在对制苗和攻毒毒种的毒力、特异性、保存期、扩繁代次等进行研究的基础上，建立了口蹄疫A型灭活疫苗制苗和攻毒用毒种种子批。结果表明，原始毒种和基础毒种的扩繁代次均控制在5代以内，适宜的保存方法和保存期均为加含500mL／L甘油的PBS后在-30℃保存1年、-70℃保存2年；用于生产抗原的工作毒种，最高扩繁代次控制在15代以内，最佳保存方法和保存期为加保护剂后在-20℃保存半年、-70℃保存1年；用于效力检验的攻毒毒种采用原始毒种。通过制苗和攻毒用毒种种子批的建立，规范了口蹄疫疫苗生产和检验过程中的毒种管理。 相似文献
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A Flagstad 《Acta veterinaria Scandinavica》1977,18(1):1-9
The serological relationship of Danish feline panleukopaenia virus and mink enteritis virus and strains from Great Britain, USA, Germany and Canada was examined in neutralization tests using a direct immunofluorescence technique. Vaccine strains of the virus were used representing virus strains from the different countries. It was found that all Danish feline panleukopaenia virus strains and the mink enteritis strain belong to the same serotype and further that they are of similar antigenicity as feline panleukopaenia virus strains and mink enteritis strains isolated in other countries. 相似文献
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The genome of influenza A virus consists of eight negative-stranded RNA segments which contain one or two coding regions flanked by the 3' and 5' non-coding regions (NCRs). Despite the importance of NCRs in replication and pathogenesis of influenza virus, sequencing of influenza virus genome has mainly been focused on coding regions of the individual genes and very limited NCR sequences are available. In this study, we sequenced the NCRs of seven influenza A virus strains of different host origin and varying pathogenicity using two recently developed methods [de Wit, E., Bestebroer, T.M., Spronken, M.I., Rimmelzwaan, G.F., Osterhaus, A.D., Fouchier, R.A., 2007. Rapid sequencing of the non-coding regions of influenza A virus. J. Virol. Methods 139, 85-89; Szymkowiak, C., Kwan, W.S., Su, Q., Toner, T.J., Shaw, A.R., Youil, R., 2003. Rapid method for the characterization of 3' and 5' UTRs of influenza viruses. J. Virol. Methods 107, 15-20]. In addition to sequence and length variation present in the segment-specific NCRs among different influenza strains, we also observed sequence variations at the fourth nucleotide of 3' NCR of polymerase genes. To evaluate the role of sequence change in the NCRs in reporter gene expression, we introduced mutations at the NCRs of two polymerase gene segments, PB1 and PA, and created the green fluorescent protein (GFP) reporter plasmids. By measuring the GFP expression level, we confirmed that single or two mutations introduced at the 3' and 5' NCRs of PB1 and PA gene could alter the protein expression levels. Our study reaffirms the importance of NCRs in influenza virus replication and further analysis of their roles will lead to better understanding of influenza pathogenesis. 相似文献
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A review of feline leukemia virus and feline immunodeficiency virus seroprevalence in cats in Canada
Little S 《Veterinary immunology and immunopathology》2011,143(3-4):243-245
Feline leukemia virus (FeLV) and feline immunodeficiency virus (FIV) are common and important infectious diseases of cats in Canada. Prevalence data are necessary to define prophylactic, management, and therapeutic measures for stray, feral and owned cats. Recently, comprehensive data on the seroprevalence of retrovirus infections of cats in Canada have become available and are reviewed. Further investigation into geographic variations in retrovirus seroprevalence within Canada is warranted, and may provide information to improve recommendations for testing and prevention. As well, more information is needed on FIV subtypes in Canada to improve diagnostics and vaccines, as well as to provide information on disease outcomes. 相似文献
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Saito T Yamaguchi I 《The Journal of veterinary medical science / the Japanese Society of Veterinary Science》2000,62(6):575-581
N-glycosylation and glucose trimming of the influenza virus hemagglutinin (HA) and neuraminidase (NA) were studied by using glycosylation inhibitor (tunicamycin; TM) and glucosidase inhibitors. TM treatment of MDCK cells infected with a reassortant virus NWS-N8 resulted in reduced transport of the viral glycoproteins to the cell surface. The degree of the effects differed between the HA and the NA (80% reduction for the HA and 97% reduction for the NA), indicating a difference in dependency on N-glycosylation between these glycoproteins. Differential dependency on glucose trimming was clearly demonstrated when the surface transport of the glycoproteins was compared after treatment of the virus-infected cells with glucosidase inhibitors. Fluorescence-activated cell sorting (FACS) analysis revealed that the surface transport of the NA reduced to 50% after castanospermine (CST) treatment but not did that of the HA. An anti-viral effect of a glucosidase inhibitor on the NWS-N8 strain was also demonstrated. The correlation between the expression of the NA on the cell surface and virus yield suggests that CST may interfere with virus release through its effect on the NA. 相似文献
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反向遗传操作技术是最近几年迅速兴起的一项分子生物学技术,它将解决对RNA病毒基因组难以操作的多年难题,并为负链RNA病毒的研究开创新的途径,使负链RNA病毒得以深入认识。目前,该技术已应用于多种负链RNA病毒的研究,特别在探寻甲型流感病毒基因组复制、转录和研发新型疫苗上发挥着重要作用,使甲型流感病毒研究工作取得了巨大进步,为大流感的再次流行及防控增添了新的研究方法和防控策略。文章就甲型流感病毒基因组特征、致病机理、新型疫苗及病毒载体的研究等最新进展进行了综述,重点介绍了反向遗传操作技术在甲型流感病毒中的应用。 相似文献
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参考GenBank中伪狂犬病病毒(PRV)gE基因的序列设计了1对引物,对PRV粤A株gE基因进行了PCR扩增,PCR产物克隆到PMD18-T载体.对重组质粒进行限制性内切酶分析和基因测序,证实了克隆片段的可靠性,并与2株不同来源的毒株进行了同源性分析和比较. 相似文献