陕西省急性弛缓性麻痹病例中柯萨奇病毒A组4型的基因特征

Genetic Characteristics of Coxsackievirus Group A Type 4 Isolated from Patients with Acute Flaccid Paralysis in Shaanxi,China

阐明从陕西省2006~2010年急性弛缓性麻痹（Acute Flaccid Paralysis,AFP）病例中分离的柯萨奇病毒A组4型（Coxsackievirus A4,CV-A4）VP1编码区的基因特征,探索其在我国流行的优势基因型及其与AFP病例之间的关系。本研究通过逆转录-聚合酶链反应（Reverse Transcription-Polymerase Chain Reaction,RT-PCR）对连续5年从AFP病例中分离的68株非脊灰肠道病毒（non-polio enteroviruses,NPEVs）进行分子定型,其中7株鉴定为CV-A4（7/68,10.3%）;使用特异性引物扩增CV-A4VP1编码区并进行核苷酸序列测定分析和基因进化分析,将CV-A4划分为A（基因组1）、B（基因组2）和C三个基因型,其中C基因型又划分为C1（基因组3）和C2（基因组4）两个基因亚型。中国分离的CV-A4均位于第4基因组,属于C2基因亚型,提示其可能为中国大陆CV-A4的优势基因亚型;7株陕西CV-A4毒株依据分离年代的不同位于不同的三个小进化分支里,且和来自山东和吉林两省的邻近年份的CV-A4毒株位于同一小分支,提示7株陕西CV-A4分离株和它们存在共同进化和共循环。在无脊髓灰质炎时代应进一步加强监测CV-A4在AFP病例NPEV所占的比例和动态变化。

We analyzed the genetic characteristics of coxsackievirus A4（CV-A4）based on the entire VP1 coding region.Samples were isolated from patients with acute flaccid paralysis（AFP）in Shaanxi,China from 2006 to 2010.We wished to ascertain the predominant genotype and the relationship between CV-A4 infection and AFP.Sixty-eight non-polio enteroviruses were inoculated onto RD cells（to increase the virus titer）and molecular typing was undertaken.The entire VP1 coding region was amplified.Percentage of CV-A4 was 10.3%（7/68）.Analyses of genetic identify and creation of phylogenetic trees revealed that CV-A4 could be classified into A,B and C genotypes.Seven CV-A4 strains from Shaanxi and other CV-A4 strains from China formed an independent evolution lineage located in group 4and belonged to the C2 subgenotype.These data suggested that CV-A4 strains of sub-genotype C2 were the predominant genotypes in China.These strains co-evolved and co-circulated with those from other provinces in China,so continued monitoring of CV-A4（by clinical and genetic surveillance）should be enhanced.