海南省消除疟疾前期间日疟原虫环子孢子蛋白多态性研究及其分子进化关系分析

Study on the polymorphism in circumsporozoite protein of Plasmodium vivax before thecompletion on elimination program of malaria, in Hainan province

目的分析海南省消除疟疾前期间日疟原虫环子孢子蛋白（CSP）基因型。方法采用PCR扩增特异性目的片段，基因测序，序列比对及进化树构建等方法。结果19份本地感染问13疟样本中18份为VK210，1份为VK247，VK210为优势亚型。与参考株相比，VK210又分为7个亚型，VK247仅有1个亚型。VK210各亚型中GDRAD（A）GQPA重复序列均存在不同数量的D或A点突变，属于高度突变区域；其余重复序列（GNGAGGQAA和GGNA）大多数仅发生基因数量的增减变化。海南省疟疾控制阶段和消除阶段间日疟VK210和VK247基因型构成比的差异无统计学意义（P〉0．05），进化树分析显示两基因型分别属于不同的进化簇。结论海南省消除疟疾前期仍存在两种基因型间日疟。与控制阶段相比，种型间构成比差异不显著，间日疟虫株消失结果相一致。

Objective To explore the polymorphism in circumsporozoite protein of Plasmodium vivax before malaria was eliminated in Hainan island. Methods PCR amplification, sequencing, and alignment methodologies were conducted and phylogenetic tree constructed. Results From all the cases, 19 of them belonged to two types,with 18 as VK219 type and 1 as VK247 type. VK210 type could be divided into seven kinds of subtypes but VK247 had only one type. Ratio of tropical strain with temperate stain in VK210 type was explored between the two stages： control or elimination. Phylogenetic tree was constructed by amino acid sequencings which clearly manifested that VK210 type and VK247 type belonged to different clusters. Conclusion Compared the proportion of two types in the control stage, there was no significant difference seen in the stage of elimination.