Nemati Sara, Fazaeli Asghar, Hajjaran Homa, Khamesipour Ali, Anbaran Mohsen Falahati, Bozorgomid Arezoo, Zarei Fatah
Department of Medical Parasitology and Mycology, School of Medicine, Zanjan University of Medical Sciences, Zanjan 4515613191, Iran.
Department of Medical Parasitology and Mycology, School of Public Health, Tehran University of Medical Sciences, Tehran 14155-6446, Iran.
Korean J Parasitol. 2017 Aug;55(4):367-374. doi: 10.3347/kjp.2017.55.4.367. Epub 2017 Aug 31.
Despite the broad distribution of leishmaniasis among Iranians and animals across the country, little is known about the genetic characteristics of the causative agents. Applying both HSP70 PCR-RFLP and sequence analyses, this study aimed to evaluate the genetic diversity and phylogenetic relationships among Leishmania spp. isolated from Iranian endemic foci and available reference strains. A total of 36 Leishmania isolates from almost all districts across the country were genetically analyzed for the HSP70 gene using both PCR-RFLP and sequence analysis. The original HSP70 gene sequences were aligned along with homologous Leishmania sequences retrieved from NCBI, and subjected to the phylogenetic analysis. Basic parameters of genetic diversity were also estimated. The HSP70 PCR-RFLP presented 3 different electrophoretic patterns, with no further intraspecific variation, corresponding to 3 Leishmania species available in the country, L. tropica, L. major, and L. infantum. Phylogenetic analyses presented 5 major clades, corresponding to 5 species complexes. Iranian lineages, including L. major, L. tropica, and L. infantum, were distributed among 3 complexes L. major, L. tropica, and L. donovani. However, within the L. major and L. donovani species complexes, the HSP70 phylogeny was not able to distinguish clearly between the L. major and L. turanica isolates, and between the L. infantum, L. donovani, and L. chagasi isolates, respectively. Our results indicated that both HSP70 PCR-RFLP and sequence analyses are medically applicable tools for identification of Leishmania species in Iranian patients. However, the reduced genetic diversity of the target gene makes it inevitable that its phylogeny only resolves the major groups, namely, the species complexes.
尽管利什曼病在伊朗人和该国动物中广泛传播，但对病原体的遗传特征却知之甚少。本研究应用HSP70 PCR-RFLP和序列分析，旨在评估从伊朗地方病疫源地分离的利什曼原虫属物种与现有参考菌株之间的遗传多样性和系统发育关系。使用PCR-RFLP和序列分析对全国几乎所有地区的36株利什曼原虫分离株进行了HSP70基因的遗传分析。将原始的HSP70基因序列与从NCBI检索到的同源利什曼原虫序列进行比对，并进行系统发育分析。还估计了遗传多样性的基本参数。HSP70 PCR-RFLP呈现出3种不同的电泳模式，没有进一步的种内变异，对应于该国存在的3种利什曼原虫，即热带利什曼原虫、硕大利什曼原虫和婴儿利什曼原虫。系统发育分析呈现出5个主要分支，对应于5个物种复合体。伊朗谱系，包括硕大利什曼原虫、热带利什曼原虫和婴儿利什曼原虫，分布在硕大利什曼原虫、热带利什曼原虫和杜氏利什曼原虫3个复合体中。然而，在硕大利什曼原虫和杜氏利什曼原虫物种复合体内，HSP70系统发育分析无法分别清楚地区分硕大利什曼原虫和图兰利什曼原虫分离株，以及婴儿利什曼原虫、杜氏利什曼原虫和恰加斯利什曼原虫分离株。我们的结果表明，HSP70 PCR-RFLP和序列分析都是用于鉴定伊朗患者利什曼原虫物种的医学适用工具。然而，目标基因遗传多样性的降低使得其系统发育只能解析主要类群，即物种复合体，这是不可避免的。
