四株水貂肠炎病毒的分离鉴定及遗传进化分析

Isolation,identification and phylogenetic analysis of fourstrains of mink enteritis viruses

为了调查我国水貂肠炎病毒(mink enteritis virus,MEV)的流行情况,本研究以山东某水貂养殖场疑似发生水貂病毒性肠炎的病貂为材料,对其进行剖检以及病原检测。将PCR检测为MEV阳性的水貂肠道内容物处理后用F81细胞进行病毒分离培养,通过电镜形态学观察、血清学、分子生物学等方法证实,分离出的4株病毒为MEV毒株,分别将其命名为MEV SD-1、MEV SD-4、MEV SD-5和MEV SD-6。完成了这4株病毒的近全基因组序列测定分析,对分离株之间以及与参考毒株的主要蛋白氨基酸序列进行了同源性比较。结果显示分离株之间VP2和NS1蛋白的氨基酸相似性分别为99.5%~99.7%和99%~99.9%,而分离株与GenBank的32株参考序列之间VP2和NS1蛋白的氨基酸相似性分别为96.5%~99.7%和98.4%~99.6%。本研究结果为进一步开展MEV的流行病学调查、疫苗研制以及诊断方法研究奠定了基础。

In order to investigate the prevalence of mink enteritis virus(MEV)in China,clinical samples of mink suspected of mink viral enteritis from Shandong Province were subject to testing for MEV detection and isolation.The intestinal contents of mink that were positive for MEV by PCR were isolated for MEV using F81 cells.Four MEV isolates,MEV SD-1,MEV SD-4,MEV SD-5,and MEV SD-6,were identified through electron microscopy morphology observation,serology,molecular biology,and sequencing.The genomes of the four viruses were sequenced and analyzed,and the homology analysis of the main protein amino acid sequences between the isolates and the reference strains was carried out.The results showed that the isolates share 99.5%—99.7%and 99%—99.9%amino acid sequence identities with each other in VP2 and NS1 proteins,respectively,and that was 96.5% —99.7% and98.4%—99.6% with the 32 reference strains deposited in GenBank.This study laid a foundation for theepidemiology,development of vaccines,and establishment of diagnostic methods for MEV.