福建省2011年病毒性脑炎暴发病原Echo30分子流行病学分析

摘要

目的 了解福建省2011年病毒性脑炎暴发的病原特点及福建省近10年Echo30分子流行病学特征.方法 应用细胞培养法获得病毒株,微量血清中和试验或RT-PCR序列分析鉴定Echo30血清型,提取病毒RNA核酸,逆转录为cDNA,分段扩增VP1基因序列全长,测定并分析扩增产物的序列.结果 2011年4月1日-6月2日,从福建省4个县(市)区病毒性脑炎病例标本中分离的病毒经鉴定均为Echo30;VP1基因序列分析显示,泉州市安溪和德化两地流行株高度同源(核苷酸与氨基酸序列同源性分别为99.0%和99.6%),同福安和厦门流行株(核苷酸与氨基酸序列同源性分别为98.5%和100%)核苷酸差异约9%,3个位点氨基酸出现了变异.近10年福建省Echo30分子流行病学分析显示,2011年泉州流行株并非由2005年当地流行株进化而来,而与2008年河南省分离株(HQ625646-Henan/04/2008)同源性最高;近10年福建省Echo30存在多基因型、多谱系的同时传播,并在2006年发现了两株第III新基因型病毒.结论 造成2011年福建省病毒性脑炎暴发的病原为Echo30,且至少存在两条不同传播链病毒同时流行.Echo30福建株呈多基因型、多谱系分布流行特点.%In Fujian, an outbreak of aseptic meningitis caused by echovirus 30 (Kcho30) occurred from April to June in 2011, which involved Anxi and Dehua cities of Quanzhou Prefecture,and Fuan city of Ninde Prefecture. In order to explore the characterization of the primary etiologic agent, enteroviruses were isolated from 24 of 40 outbreak cases and 1 sporadic case. The isolates were all identified as Kcho30, but were divided into two clusters in phylogenetic tree based on the entire VP1, which suggested that there were at least two transmission chains responsible for the outbreak. Analysis of Kcho30 molecular epidemiology showed that 2011 Quanzhou strains weren't developed from the local strains isolated from an outbreak in 2005, but were closely related to an Henan isolate in 2008. Phylogenetic analysis of Echo30 during recent decades revealed that two I-solates in 2006 belonged to a new genotype named III genotype and there were existence of multiple genotypes and lineages in Fujian Province.