Laboratory of Parasitology and Vector-Borne-Diseases, Institut Pasteur du Maroc, Casablanca, Morocco.
Laboratory of Management and Valorization of Natural Resources, FST, Sultan Moulay Slimane University, Beni Mellal, Morocco.
Transbound Emerg Dis. 2019 Jan;66(1):373-380. doi: 10.1111/tbed.13031. Epub 2018 Oct 22.
In Morocco, cutaneous leishmaniasis (CL) caused by Leishmania tropica is endemic to locations where the predominantly anthropophilic blood-feeding Phlebotomus sergenti and humans co-perpetuate. The objective of this study was to explore whether the range of epidemiological features of CLcould be linked to the range of L. tropica genetic heterogeneity and to further explore the relationships between the genetic diversity of L. tropica in both P. sergenti and humans. L. tropica DNAwas extracted from dermal scarping smears of 125 CLpatients. Genetic polymorphisms were analyzed by sequencing the internal transcribed spacer (ITS) 1 and 5.8S rDNAgene. Nucleotide diversity (π), haplotype diversity (Hd) and Tajima's D test for neutrality, as well as overall and pairwise FSTvalues, were calculated using Arlequin ver 3.5 software. Out of the 125 amplified DNAsequences, 93 were completely sequenced and 13 L. tropica haplotypes were identified, which confirmed the significant genetic heterogeneity of L. tropica in Morocco. The most common haplotype included 74 out of 93 sequences; this haplotype is not only widely represented but was also detected in P. sergenti, which is known to be the most abundant species in the studied foci. Considering the negative value calculated using Tajima's D index, we briefly discussed the hypothesis that the L. tropica common haplotype propagation could be a sign of its fitness in P. sergenti and human hosts. Furthermore, analysis of molecular variance (AMOVA) shows significant correlations between intraspecific variants of L. tropica and patients' geographic origins. The long-term goals of the present pilot study are to further explore the relationships between the genetic diversity of L. tropica in human and P. sergenti populations.
在摩洛哥，由利什曼原虫热带亚种引起的皮肤利什曼病（CL）流行于以主要嗜人血的鳞蝠属（Phlebotomus）sergenti 和人类为宿主的地区。本研究的目的是探讨 CL 的流行病学特征范围是否与利什曼原虫热带亚种遗传异质性范围有关，并进一步探讨人类和鳞蝠属（Phlebotomus）sergenti 中利什曼原虫热带亚种遗传多样性之间的关系。从 125 例 CL 患者的皮肤刮痕涂片提取利什曼原虫热带亚种 DNA。通过对内部转录间隔区（ITS）1 和 5.8S rDNA 基因测序分析遗传多态性。使用 Arlequin ver 3.5 软件计算核苷酸多样性（π）、单倍型多样性（Hd）和 Tajima's D 中性检验以及总体和成对的 FST 值。在扩增的 125 个 DNA 序列中，93 个完全测序并鉴定了 13 种利什曼原虫热带亚种单倍型，证实了摩洛哥利什曼原虫热带亚种的遗传高度异质性。最常见的单倍型包括 93 个序列中的 74 个；这种单倍型不仅广泛存在，而且在已知是研究热点中最丰富的物种鳞蝠属（Phlebotomus）sergenti 中也有发现。考虑到 Tajima's D 指数计算的负值，我们简要讨论了利什曼原虫热带亚种常见单倍型传播可能是其在鳞蝠属（Phlebotomus）sergenti 和人类宿主中适应性的标志的假说。此外，分子方差分析（AMOVA）表明，利什曼原虫热带亚种种内变异与患者的地理起源之间存在显著相关性。本初步研究的长期目标是进一步探讨人类和鳞蝠属（Phlebotomus）sergenti 种群中利什曼原虫热带亚种遗传多样性之间的关系。
