【摘要】 口蹄疫是由口蹄疫病毒引起的主要侵袭偶蹄动物的一种急性热性高度接触性传染病。口蹄疫病毒存在7个不同血清型,病毒VP1蛋白抗原性差异是病毒血清型划分依据,而其编码基因核苷酸序列差异是同型病毒Topotype型或基因型划分依据。采用RT-PCR及O/A/C/Asia1多重RT-PCR技术,对2006年期间自云南边境地区采集境外流动动物组织样品120份,进行口蹄疫病原监测,检出Asia1型口蹄疫病毒阳性样品7份。对阳性样品中病毒vp1基因全序列进行扩增、纯化后,克隆至pMD18-T载体测序,并与已知代表性毒株进行比对及系统发育分析。结果发现:云南边境Aisa1型口蹄疫病毒阳性样品vp1基因核苷酸序列同源性介于83.4%～99.5%,不同分离毒株以15%序列差异作为分型标准,存在1个新拓朴型或基因型Ⅴ,且与已知的4个拓朴型或基因型不同。系统发育分析确定了1个新的遗传谱系Ⅶ。部分VP1蛋白表位关键性氨基酸位点存在变异。更多还原

【Abstract】 FMDV is a member of the genus Aphthovirus, family Picornaviridae with seven different serotypes based on antigenicity difference of viral VP1 protein. To identify different topotypes and genotypes among the same serotype virus, we tested 120 tissue samples collected from foreign movement animal in boundary region of Yunnan province during 2006 by O/A/C/Asia 1 multiplex RT-PCR assay and 7 samples were detected FMDV type Asia 1 positive. The vp1 genes of those viruses were amplified, cloned into pMD18-T vector and sequenced. phylogenetic analysis showed that the vp1 genes shared 83.4 %-99.5 % nucleotide identities with reference FMD type Asia 1 virus strains. Those vp1 genes could be classified into one new topotype or genotype (Genotype Ⅴ) and 4 known topotypes or genotypes using a 15 % nucleotide divergence between isolates as the cutoff value. Several variations at critical amino acid sites within the VP1 protein epitopes were identified.更多还原