对来自土耳其和塞浦路斯的菌株进行多位点微卫星分型（MLMT）显示出一个新的单系利什曼原虫复合种。
Multilocus microsatellite typing (MLMT) of strains from Turkey and Cyprus reveals a novel monophyletic L. donovani sensu lato group.
机构信息
Laboratory of Molecular Parasitology, Hellenic Pasteur Institute, Athens, Greece.
出版信息
PLoS Negl Trop Dis. 2012;6(2):e1507. doi: 10.1371/journal.pntd.0001507. Epub 2012 Feb 14.
BACKGROUND
New foci of human CL caused by strains of the Leishmania donovani (L. donovani) complex have been recently described in Cyprus and the Çukurova region in Turkey (L. infantum) situated 150 km north of Cyprus. Cypriot strains were typed by Multilocus Enzyme Electrophoresis (MLEE) using the Montpellier (MON) system as L. donovani zymodeme MON-37. However, multilocus microsatellite typing (MLMT) has shown that this zymodeme is paraphyletic; composed of distantly related genetic subgroups of different geographical origin. Consequently the origin of the Cypriot strains remained enigmatic.
METHODOLOGY/PRINCIPAL FINDINGS: The Cypriot strains were compared with a set of Turkish isolates obtained from a CL patient and sand fly vectors in south-east Turkey (Çukurova region; CUK strains) and from a VL patient in the south-west (Kuşadasi; EP59 strain). These Turkish strains were initially analyzed using the K26-PCR assay that discriminates MON-1 strains by their amplicon size. In line with previous DNA-based data, the strains were inferred to the L. donovani complex and characterized as non MON-1. For these strains MLEE typing revealed two novel zymodemes; L. donovani MON-309 (CUK strains) and MON-308 (EP59). A population genetic analysis of the Turkish isolates was performed using 14 hyper-variable microsatellite loci. The genotypic profiles of 68 previously analyzed L. donovani complex strains from major endemic regions were included for comparison. Population structures were inferred by combination of bayesian model-based and distance-based approaches. MLMT placed the Turkish and Cypriot strains in a subclade of a newly discovered, genetically distinct L. infantum monophyletic group, suggesting that the Cypriot strains may originate from Turkey.
CONCLUSION
The discovery of a genetically distinct L. infantum monophyletic group in the south-eastern Mediterranean stresses the importance of species genetic characterization towards better understanding, monitoring and controlling the spread of leishmaniasis in this region.
背景
最近在塞浦路斯和位于塞浦路斯以北 150 公里的土耳其库拉地区（土耳其婴儿利什曼原虫（L. infantum））发现了由利什曼原虫（L. donovani）复合体菌株引起的新人类 CL 病灶。使用蒙彼利埃（MON）系统对塞浦路斯菌株进行了多位点酶电泳（MLEE）分型，结果为 L. donovani 生物型 MON-37。然而，多位点微卫星分型（MLMT）表明该生物型是并系的；由不同地理起源的不同遗传亚群组成。因此，塞浦路斯菌株的起源仍然是个谜。
方法/主要发现：将塞浦路斯菌株与一组从土耳其东南部 CL 患者和沙蝇媒介中获得的分离株（库拉地区；CUK 株）以及从西南部 VL 患者（库萨达斯；EP59 株）进行了比较。这些土耳其分离株最初使用 K26-PCR 检测进行分析，该检测通过扩增子大小区分 MON-1 株。与之前的 DNA 数据一致，这些菌株被推断为利什曼原虫复合体，并被鉴定为非 MON-1。对这些菌株进行的 MLEE 分型显示出两种新的生物型；L. donovani MON-309（CUK 株）和 MON-308（EP59）。对土耳其分离株进行了种群遗传分析，使用了 14 个高变微卫星位点。为了比较，包括了来自主要流行地区的 68 株先前分析的利什曼原虫复合体菌株的基因型谱。种群结构通过贝叶斯模型和基于距离的方法相结合进行推断。MLMT 将土耳其和塞浦路斯菌株置于新发现的遗传上独特的婴儿利什曼原虫单系群的一个亚群中，表明塞浦路斯菌株可能起源于土耳其。
结论
在地中海东南部发现一个遗传上独特的婴儿利什曼原虫单系群，强调了对物种遗传特征进行鉴定的重要性，以便更好地了解、监测和控制该地区的利什曼病传播。
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