间日疟原虫裂殖子表面蛋白1和环子孢子蛋白基因多态性分析

Analysis of genetic polymorphisms of merozoite surface protein-1 and circumsporozoite protein of Plasmodium vivax

目的对杭州市间日疟病例感染的间日疟原虫(Plasmodium vivax)裂殖子表面蛋白1(MSP-1)和环子孢子蛋白(CSP)基因的多态性进行描述性分析。方法收集杭州市2008-2019年报告的间日疟病例的血样和流行病学资料。采用全血DNA抽提试剂盒提取疟原虫基因组DNA,巢式PCR分别扩增Pvmsp-1和Pvcsp基因的特异性片段,并进行双向测序。应用DNAStar、MEGA 6.0软件对氨基酸序列进行序列比对和遗传进化分析,并采用邻接法构建系统进化树。采用SPSS 17.0统计学软件对基因多态性及感染来源地进行描述性和归纳分析。结果共收集间日疟病例血样56份,巢式PCR扩增的Pvmsp-1和Pvcsp基因片段分别测序成功44份和54份血样。序列分析显示,44条Pvmsp-1序列可分为4种基因型,分别为SalⅠ型18份、Belem型8份、R-Ⅲ型17份和R-Ⅳ型1份;54条Pvcsp序列分为两种基因型,分别为VK210型52份和VK247型2份。对Pvmsp-1基因的分型特征和感染来源地分析发现,SalⅠ型分布广泛,在我国华东地区,东南亚地区,印度,埃塞俄比亚等多个国家或地区存在。我国华东地区的主要分布类型为R-Ⅲ型,此外,R-Ⅲ型在南亚、东南亚地区也有分布。Belem型主要分布在东南亚、南亚和埃塞俄比亚等国家或地区。对Pvcsp基因的多态性特征和感染来源地分析发现,共有4种多态性特征具有一定的地域特征。结论杭州市2008-2019年报告的间日疟病例的Pvmsp-1和Pvcsp基因存在较丰富的多态性特征,部分特征具有一定地域性。

Objective This study aimed to conduct descriptive analysis of the genetic polymorphisms of Plasmodium vivax gene merozoite surface protein-1(PvMSP-1)and circumsporozoite protein(PvCSP)in vivax malaria cases in Hangzhou City.Methods Blood samples and epidemiological information of vivax malaria cases reported in Hangzhou during 2008-2019 were collected.P.vivax genomic DNA was extracted by QIAamp DNA blood mini kit.Pvmsp-1 and Pvcsp were amplified by nested PC.R and the amplification products were sequenced.The aminoacid sequences were analyzed using DNAStar and MEGA 6.0 softwares and the phylogenetic tree was constructed using the neighbor-joining method.The descriptive and inductive analysis of genetic polymorphism and place of infection origin were performed using SPSS 17.0.Results Fiftv-six vivax malaria cases were sampled,of whom 44 and 54 samples were successfully sequenced for Pvmsp-1 and Pvcsp,respectively.Sequence analysis indicated that 44 Pvmsp-1 sequences were clustered into four genotypes:SalⅠ(18 samples),Belem(8),R-Ⅲ(17)and R-Ⅳ(1);54 Pvesp sequences were devided into two genotypes:VK210(52 samples)and VK247(2).Analysis of the genotyping and place of infection origin of Pvmsp-1gene showed that the SalⅠtype was widely distributed in East China,Southeast Asia,India,and Ethiopia.The main type of Pvmsp-1 in East C.hina was R-Ⅲ.In addition,the R-Ⅲtype was also distributed in South Asia and Southeast Asia.The Belem type was mainly distributed in Southeast Asia,South Asia and Ethiopia.Analysis of Pvcsp gene polymorphism and place of infection origin revealed four types of polymorphism with some regional features.Conclusion The Pvmsp-1 and Pvcsp genes in vivax malaria cases reported in Hangzhou during 2008-2019 were characterized being highly polymorphic,with some genotypes having certain regional features.