牛肠道病毒北京株的分离鉴定及全基因组分析

Isolation and identification of bovine enterovirus Beijing isolate and sequence analysis of whole genome of the isolate

采用RT-PCR方法从北京某牛场有腹泻症状牛的粪便样品中检测到牛肠道病毒（bovine enterovirus,BEV）,分离出1株病毒并将其命名为BJ101。然后,通过电镜观察、全基因组序列测定和同源性分析,对该毒株进行了验证。结果,BJ101分离株在MDBK细胞上的TCID50为1×10^-6.42/0.1 m L,电镜观察到病毒颗粒直径为25～30 nm,无囊膜,呈典型的小RNA病毒粒子形态;BJ101株的基因组长度为7 409 bp,其中5′非编码区（UTR）长812 bp,3′UTR长72 bp,病毒基因组开放阅读框（ORF）全长6 525 bp。对全基因组序列进行比对分析显示,在5′UTR区、编码区和3′UTR区,BJ101分离株与BEV E2型毒株的核苷酸相似性最高。基于VP1基因的系统进化树表明,BJ101株是BEV E2型的成员。上述结果丰富了国内牛肠道病毒的基因库,为BEV的诊断及预防奠定了良好的基础。

A strain of bovine enterovirus（bovine enterovirus,BEV）was isolated from the fecal samples of cattle affected with diarrhea in Beijing and was identified as a strain of bovine enterovirus by RT-PCR,and was named BJ101 isolate.The full-length genome of BJ101 isolate was sequenced and its molecular characteristic was analyzed. In result,the TCID50 of the isolate was 1×10^-6.42/0.1 mL and the virion was observed as non-enveloped particles about 25-35 nm in diameter.The full genomic size of BJ101 was 7 409 bp,which contained 5′UTR（812 bp）,the open reading frame（ORF,6 525 bp）and 3′UTR（72 bp）.The sequence alignments showed that the BJ101 strain shared the highest nucleotide identities with the strains of BEV E2 in the 5′UTR,the coding region and the 3′UTR.The phylogenetic analysis based on the VP1 region shows that the BJ101 strain belongs to BEV E2 sub-genotype.The above-mentioned results have enriched the gene pool of bove enterovirus and laid a good foundation for the diagnosis and prevention of bovine enterovirus.