陕西省韩城市利什曼原虫SSU rRNA基因系统发育研究

目的 了解陕西省韩城市黑热病区利什曼原虫种类及分子遗传特征。方法 对来自韩城市的利什曼原虫阳性标本,进行SSU rRNA基因序列扩增,扩增产物进行测序,与其它不同种类、不同地区利什曼原虫的SSU rRNA基因序列进行比对,分析突变位点规律,建立系统发育树。结果 有3份标本SSU rRNA基因序列扩增测序成功,其基因序列与杜氏利什曼原虫、夏科氏利什曼原虫、婴儿利什曼原虫的SSU rRNA序列同源性较高,与婴儿利什曼原虫在UQ-II突变区有一个位点的变异,并与新疆荒漠虫株、甘肃省利什曼虫株聚为一类。结论 结合流行病学与SSU rRNA序列分析结果,陕西省韩城市黑热病病原体应为婴儿利什曼原虫。

Phylogenetic analysis based on small subunit ribosomal RNA (SSU rRNA) of Leishmania in Hancheng City,Shaanxi Province,China

We identified the species and molecular genetic characteristics of Leishmania protozoa in Hancheng City, Shaanxi Province. The SSU rRNA genes of Leishmania positive samples were amplified and sequenced. The sequencing results were compared with the SSU rRNA gene sequences of Leishmania in different regions and species reported in the literature. The mutation sites were analyzed and the phylogenetic tree was constructed. Three specimens’ SSU rRNA gene amplification sequences, which were highly homologous to L.donovani, L.Chagas and L.infantum, were successfully sequenced. The sequences had one base variation, comparing with the L. infantum in the UQ-II mutant region. Phylogenetic tree analysis showed that Leishmania from Shaanxi Province, Gansu Province and L. infantum strains from Xinjiang were gathered into one cluster. Epidemiological data and SSU rRNA sequence analysis showed that the pathogens of visceral leishmaniasis in Hancheng City, Shaanxi Province should be Leishmania infantum.