福建分离株(FJ96-71)肠道病毒新血清型的鉴定及特征分析

Identification and characterization of a new enterovirus serotype of the FJ96-71 strain isolated in Fujian province

目的对肠道病毒福建分离株FJ96-71进行新血清型鉴定及其特征分析。方法应用传统的血清中和试验及分子生物学方法进行血清型的鉴定,并通过序列比对分析其遗传特征。结果FJ96-71无法被常规用于型别鉴定的血清所中和,且其特异性型中和抗体也无法中和本实验室保存的其它22个血清型分离株病毒,提示FJ96-71可能为一新血清型。全基因组序列分析显示其VP1基因序列与美国分离株USA/OK85-10362(AY556070)核苷酸同源性80.6%(氨基酸同源性95.5%),而与其它血清型的参考株序列同源性均低于69.7%,说明FJ96-71与USA/OK85-10362为同一血清型,即新近拟定的肠道病毒75型(EV75)。针对P1区序列分析结果进一步确证此结果。FJ96-71与USA/OK85-10362在5’非编码区以及P2、P3非结构编码区的差异性说明EV75早已在外界循环且波及范围较广。结论FJ96-71与USA/OK85-10362一样同属于肠道病毒一新血清型—EV75。

The new enterovirus serotype of the FJ96-71 strain isolated in Fujian province was identified by using serotype-specific antisera in a virus neutralization test, and characterized by RT-PCR coupled with amplicon sequencing and comparison to database of the enterovirus nucleotide sequence. It was demonstrated that the FJ96-71 strain of virus was not neutralized the standard enterovirus typing antisera, indicating that it may be a new serotype of enterovirus. The complete nucleofide sequence of FJ96-71 was 7426 bp, exclusive of the poly （A） tract, which was typical to the human enterovirus genome organization. Analyzing the gene se- quence in the VP1 region, FJ96-71 was 80.6% identical （95.5% amino acid identity） with USA/OK85 - 10362 （AY556070） strain, which was proposed to be classified as 75 type of enterovirus （EV75）, but it has only 69.7 % of identity to the reference strain of any serotype of enterovirus. The result of sequence identity in P1 region and the phylogenetic analysis further confirmed these resnlts. The difference between FJ96-71 and AY556070 in 5＇ un-translated region （UTR） and the non-capsid protein code indicated that this new serotype of EV75 had circulated over a wide geographical area for a long time. It is concluded that the FJ96-71 is a member of the new enterovirus serotype, EV75, somewhat similar to USA/OK85-10362 （AY556070）.