柯萨奇病毒A组2、6、8、12型山东地方株型别鉴定及其基因特征分析

在前期研究中,对山东省1989～2011年急性弛缓性麻痹(Acute flaccid paralysis,AFP)和手足口病(Hand,foot and mouth disease,HFMD)患者标本中分离到的部分人类肠道病毒(Human enteroviruses,HEVs)进行分子定型,发现了8个HEV-A血清型。为进一步探究HEV-A组病毒在山东省的基因型分布及分子进化特征,本研究继续对剩余分离株进行核酸提取,以HEV-A组特异性引物对VP1完整编码区进行序列扩增、测序和分子定型,又鉴定出4个血清型,分别为柯萨奇病毒A组(Coxsackievirus A,CVA)2、6、8、12型,共7株病毒。同源性分析显示,7株HEV-A山东分离株与其原型株核苷酸同源性介于80.8%～85.0%之间。系统进化树表明,CVA8、12型山东分离株与国内分离株存在一定亲缘关系,而CVA2、6型山东株同国内外分离株亲缘关系均较远,并且CVA2、6型在山东省内可能存在多个传播链。本研究将我省HEV-A组的血清型别增加至12个,进一步丰富了HEV-A山东地方株的遗传进化特征,并且发现CVA2、6、8、12血清型在山东省甚至全国范围内存在不同基因特征的传播链的共循环。

Identification and Genetic Characterization of Coxsackieviruses A2,6,8 and 12 Isolated in Shandong Province

In previous study,molecular typing method was performed to identify human enteroviruses(HEVs) isolates collected from acute flaccid paralysis(AFP) cases from 1989 to 2011 and hand,foot and mouth disease(HFMD) patients,and 8 HEV-A serotypes were identified.In order to explore the genotypes and molecular evolution characteristics of HEV-A in Shandong province,viral RNA of the remaining isolates was extracted and entire VP1 coding region was amplified,sequenced and identified with HEV-A primers.Another 7 HEV-A Shandong isolates were obtained,and identified as Coxsackievirus A(CVA) 2,6,8 and 12 by molecular typing method.Homologous comparison showed that the nucleotide acid identities of Shandong strains ranged from 80.8% to 85.0% with prototype strains.Phylogenetic analysis based on VP1 sequences indicated that CVA8 and CVA12 strains were genetically related with domestic strains.However,CVA2 and CVA6 strains were distinct from both domestic and foreign strains.In addition,multiple transmission chains of CVA2 and CVA6 existed within Shandong province.So far,a total of 12 HEV-A serotypes were identified in Shandong province.This study enriched the distribution of serotypes and genetic evolution characteristics of HEV-A isolates in Shandong,and revealed different transmission chains of CVA2,6,8,12 serotypes co-circulated in Shandong province or in China.