中文摘要：

目的利用SSU rRNA分子探讨中国利什曼原虫基因多态性及其分子系统发育学。方法采用PCR法获得中国不同地区利什曼原虫SSU rDNA，通过Clustal X软件比对序列碱基，构建贝叶斯进化树。结果中国不同地区流行利什曼原虫分属于不同的支序，在中国除了有杜氏利什曼原虫外，还有热带利什曼原虫和一支在国际上还没有定种的未定种存在。结论在中国有未定种利什曼原虫存在。

英文摘要：

Objective Partial fragment of small subunit ribosomal RNA （ SSU rRNA） gene sequences was used to infer the phylogenetic relationship of Chinese Leishmania isolates. Methods SSU rRNA gene segments of Chinese Leishmania isolates were obtained by PCR. Combined sequence matrix was aligned using Clustal X with default settings and refined manually. Bayesian analyses were performed in Mrbayes - 3. 1.2. Results In both phylogenetic trees, all Chinese Leishmania isolates did not form a monophyletic group, while they showed complex phylogenetic relationships among them, further indicating that Chinese isolates of Leishmania may has a more complex evolutionary history than expected. Conclusions Inferring the relationships of Chinese Leishmania isolates based on small subunit ribosomal RNA genes fragments, indicating that an unclassified Leishmania group may exist in China.