Hijawi Kamal J F, Hijjawi Nawal S, Ibbini Jwan H
Department of Medical Laboratory Sciences, Faculty of Applied Health Sciences, The Hashemite University, PO Box 150459, Zarqa, 13115, Jordan.
Department of Land Management and Environment, Faculty of Natural Resources and Environment, Hashemite University, Zarqa, 13115, Jordan.
Parasitol Res. 2019 Mar;118(3):793-805. doi: 10.1007/s00436-019-06222-z. Epub 2019 Feb 7.
Leishmania is a parasitic protozoan which is transmitted to humans through the bite of an infected female Phlebotomus and Lutzomyia sand flies. Cutaneous leishmaniasis (CL), caused by Leishmania major and L. tropica, is an endemic disease in many areas of Jordan and considered as a major public health problem. The political instability in the Syrian Arab Republic has resulted in the immigration of large number of refugees into Jordan where most of them resided in camps near the Syrian borders. Therefore, the main objective of the present study was to inspect Leishmania species/genotypes which are responsible for CL infections among Syrian refugees and compare them with the recovered species/genotypes isolated from Jordanian patients. Three molecular-based assays (ITS1-PCR-RFLP, Nested ITS1-5.8S rDNA PCR, and Kinetoplast DNA PCR) followed by sequencing and phylogenetic analysis were undertaken and compared for their efficiency to confirm CL diagnosis and genotype the infecting Leishmania species. Thereafter, the evolutionary relationships among various Leishmania isolates from Syrian and Jordanian CL patients were elucidated. Results from the present study indicated that 20 and 9 out of the inspected 66 patients (39 Jordanian and 27 Syrian) were infected with L. major and L. tropica respectively. ITS1-PCR RFLP typing proved to be more sensitive in the detection of Leishmania species (positive in 44% of the isolates) compared to both ITS1-5.8S rDNA gene and Kinetoplast DNA PCR which were successful in identifying Leishmania species only in 23% and 33% of the isolates respectively. Sequencing and phylogenetic analysis of ITS1 and ITS1-5.8S rDNA genes revealed high levels of heterogeneity among the sequenced isolates. One sample typed as L. tropica from Jordanian patient showed high similarity with L. tropica sample isolated from a Syrian patient in a Lebanon refugee camp; therefore, the need for comprehensive studies to confirm if any new L. tropica strains might be introduced to Jordan by Syrian refugees is urgently indicated. These observations highlighted the need for further studies to clarify the risk status of species and strains which might be introduced from Syria to Jordan.
利什曼原虫是一种寄生性原生动物，通过受感染的雌性白蛉叮咬传播给人类。由硕大利什曼原虫和热带利什曼原虫引起的皮肤利什曼病（CL）在约旦的许多地区是一种地方病，被视为一个主要的公共卫生问题。阿拉伯叙利亚共和国的政治不稳定导致大量难民涌入约旦，其中大多数人居住在靠近叙利亚边境的难民营中。因此，本研究的主要目的是检查导致叙利亚难民感染CL的利什曼原虫种类/基因型，并将它们与从约旦患者中分离出的种类/基因型进行比较。采用了三种基于分子的检测方法（ITS1-PCR-RFLP、巢式ITS1-5.8S rDNA PCR和动基体DNA PCR），随后进行测序和系统发育分析，并比较它们在确认CL诊断和对感染的利什曼原虫种类进行基因分型方面的效率。此后，阐明了来自叙利亚和约旦CL患者的各种利什曼原虫分离株之间的进化关系。本研究结果表明，在检查的66名患者（39名约旦人和27名叙利亚人）中，分别有20人和9人感染了硕大利什曼原虫和热带利什曼原虫。与ITS1-5.8S rDNA基因和动基体DNA PCR相比，ITS1-PCR RFLP分型在检测利什曼原虫种类方面更为敏感（在44%的分离株中呈阳性），而ITS1-5.8S rDNA基因和动基体DNA PCR仅在23%和33%的分离株中成功鉴定出利什曼原虫种类。ITS1和ITS1-5.8S rDNA基因的测序和系统发育分析显示，测序分离株之间存在高度异质性。一名约旦患者中分型为热带利什曼原虫的样本与从黎巴嫩难民营一名叙利亚患者中分离出的热带利什曼原虫样本高度相似；因此，迫切需要进行全面研究，以确认叙利亚难民是否可能将任何新的热带利什曼原虫菌株引入约旦。这些观察结果突出表明，需要进一步研究以阐明可能从叙利亚引入约旦的种类和菌株的风险状况。
