北京再发黑热病利什曼原虫K26基因和ITS-1序列的多态性分析  

ANALYSIS OF K26 GENE AND ITS-1 SEQUENCE POLYMORPHISMS IN THE REEMERGING CASE OF VISCERAL LEISHMANIASIS IN BEIJING

作　　者：孙玉兰[1] 王小梅[1] 吴文婷 张代涛[1] 何战英[1] SUN Yu-lan;WANG Xiao-mei;WU Wen-ting;ZHANG Dai-tao;HE Zhan-ying(Beijing Center for Disease Prevention and Control,Beijing Research Cener for Preventive Medicine,Beijing 100013,China)

机构地区：[1]北京市疾病预防控制中心,北京100013

出　　处：《寄生虫与医学昆虫学报》2024年第1期1-5,52,共6页Acta Parasitologica et Medica Entomologica Sinica

摘　　要：目的了解北京市再发黑热病病例的病原分子遗传背景。方法使用PCR方法分别扩增其亲水性酰化表面蛋白B(K26)和核糖体DNA内转录间隔区Ⅰ(ITS-1),然后克隆测序,分析其多态性,构建系统发育树以确定患者感染原虫的虫种类型及其遗传关系。结果K26基因扩增出626 bp大小片段,其长度与国内流行株差异明显,其氨基酸序列由14个氨基酸的基序重复排列组成,但个别位置发生氨基酸替代。K26序列的系统进化树分析显示,北京病例虫株与法国和西班牙的婴儿利什曼原虫相近,但与国内新疆、四川、河北等地的婴儿利什曼原虫虫株距离较远;ITS-1序列扩增出314 bp大小的片段,其系统发育分析显示与婴儿利什曼原虫Leishmania infantum属于同一分支。结论该病例感染的为婴儿利什曼原虫L.infantum,且与国内其他流行区的虫株有一定差异。Objective To understand the molecular genetic background of the reported case of reemerging visceral leishmaniasis in Beijing.Methods The PCR was used to amplify the hydrophilic acylated surface protein B(K26)gene and internal transcribed spacer 1(ITS-1)sequence of ribosomal DNA.The amplified fragments were cloned and sequenced to analyze their genetic polymorphisms and to construct phylogenetic trees to determine the causative parasitic species in the infected patient and its genetic relationships.Results The K26 gene yielded a 626 bp amplicon,which exhibited significant differences in length compared to domestic epidemic strains.The amino acid sequence of this amplicon consisted of a repetitive arrangement of a 14-amino-acid motif,but amino acid substitutions were observed at certain positions.Phylogenetic analysis of the K26 sequence revealed that the Beijing strain was closely related to[WTBX]Leishmania infantum[WTBZ]strains from France and Spain but distant from those in other regions of China,such as Xinjiang,Sichuan,and Hebei.Moreover,phylogenetic analysis of a 314 bp fragment amplified from the ITS-1 sequence also showed that the Beijing strain belonged to the same branch as[WTBX]L.infantum[WTBZ]strains.Conclusion These results indicate that the infection in this patient was caused by[WTBX]L.infantum,[WTBZ]with the strain having some differences from those in other endemic areas in China.

关 键 词：黑热病 婴儿利什曼原虫 多态性 K26 ITS-1 北京 

分 类 号：R382.2[医药卫生—医学寄生虫学]