Isolation and characterization of a variant porcine epidemic diarrhea virus in China.
Isolation and characterization of a variant porcine epidemic diarrhea virus in China.
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DOI：
10.1186/1743-422x-9-195
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发表时间：
2012-09-12
期刊：
影响因子：
4.8
通讯作者：
Song Y
中科院分区：
文献类型：
--
作者：
Pan Y;Tian X;Li W;Zhou Q;Wang D;Bi Y;Chen F;Song Y
2011年1月，广东南部中国开始暴发猪腹泻疫情。4例以水样腹泻、脱水、呕吐为特征，仔猪发病率为80-100%，死亡率为50-90%。此次腹泻的病原最终确定为猪流行性腹泻病毒(PEDV)。在本研究中，我们利用Vero细胞培养从仔猪肠道中分离到一株PEDV，命名为CHGD-01，并通过直接免疫荧光试验和电子显微镜证实了其在易感细胞中的特异性细胞病变作用。CHGD-01株基因组全长28,035个核苷酸，结构与PEDV参考毒株相似。基于全基因组的系统发育分析表明，CHGD-01与同年报道的另外两个中国分离株的核苷酸序列同源性为98.2-98.4%，构成了一个新的簇。基于单个病毒基因的氨基酸序列分析表明，CHGD-01株的S蛋白基因与韩国野毒株KNU0802有较近的亲缘关系。然而，其ORF3和核蛋白基因与所有其他已测序的PEDV分离物簇不同，因此形成了一个新的群，提示中国分离株是一个新的变种。需要进一步的研究来确定这种新变种的免疫原性和致病性。
An outbreak of diarrhea in pigs started in Guangdong, South China in January 2011. Cases were characterized by watery diarrhea, dehydration and vomiting, with 80–100% morbidity and 50–90% mortality in suckling piglets. The causative agent of the diarrhea was ultimately identified as porcine epidemic diarrhea virus (PEDV). In this study, we isolated a PEDV strain designated CHGD-01 from piglet intestines using Vero cell cultures, and its specific cytopathic effects were confirmed in susceptible cells by direct immunofluorescence testing and electron microscopy. The complete genome of CHGD-01 was shown to be 28,035 nucleotides in length, with a similar structure to that of PEDV reference strains. Phylogenetic analyses based on the whole genome revealed that CHGD-01 shared nucleotide sequence identities of 98.2–98.4% with two other Chinese isolates reported in the same year, thus constituting a new cluster. Amino acid sequence analysis based on individual virus genes indicated a close relationship between the spike protein gene of CHGD-01 and the field strain KNU0802 in Korea. Its ORF3 and nucleoprotein genes, however, were divergent from all other sequenced PEDV isolate clusters and therefore formed a new group, suggesting a new variant PEDV isolate in China. Further studies will be required to determine the immunogenicity and pathogenicity of this new variant.