Leishmania infantum is the main causative agent responsible for visceral leishmaniasis (VL), a disease with global distribution. The genomic structure and genetic variation of this species have been widely studied in different parts of the world. However, in some countries, this information is still yet unknown, as is the genomic behaviour of the main antigens used in VL diagnosis (rK39 and rK28), which have demonstrated variable sensitivity and specificity in a manner dependent on the geographic region analysed. The objective of this study was to explore the genomic architecture and diversity of four Colombian L. infantum isolates obtained in this study and to compare these results with the genetic analysis of 183 L. infantum isolates from across the world (obtained from public databases), as well as to analyse the whole rK39 and rK28 antigen sequences in our dataset. The results showed that, at the global level, L. infantum has high genetic homogeneity and extensive aneuploidy. Furthermore, we demonstrated that there are distinct populations of L. infantum circulating in various countries throughout the globe and that populations of distant countries have close genomic relationships. Additionally, this study demonstrated the high genetic variability of the rK28 antigen worldwide. In conclusion, our study allowed us to (i) expand our knowledge of the genomic structure of global L. infantum; (ii) describe the intra-specific genomic variability of this species; and (iii) understand the genomic characteristics of the main antigens used in the diagnosis of VL. Additionally, this is the first study to report whole-genome sequences of Colombian L. infantum isolates.

中文翻译：

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重新审视婴儿利什曼原虫的异质全球基因组种群结构

婴儿利什曼原虫是导致内脏利什曼病 (VL) 的主要病原体，VL 是一种全球分布的疾病。该物种的基因组结构和遗传变异已在世界不同地区得到广泛研究。然而，在一些国家，这一信息仍然未知，VL 诊断中使用的主要抗原（rK39 和 rK28）的基因组行为也是未知的，这些抗原的敏感性和特异性取决于所分析的地理区域。本研究的目的是探索本研究中获得的四种哥伦比亚L. infantum分离株的基因组结构和多样性，并将这些结果与 183 L.的遗传分析进行比较。婴儿来自世界各地的分离株（从公共数据库获得），以及分析我们数据集中的整个 rK39 和 rK28 抗原序列。结果表明，在全球范围内，L. infantum具有高度的遗传同质性和广泛的非整倍性。此外，我们证明了在全球不同国家流通的婴儿乳杆菌的不同种群，并且遥远国家的种群具有密切的基因组关系。此外，这项研究证明了全球范围内 rK28 抗原的高遗传变异性。总之，我们的研究使我们能够（i）扩展我们对全球L. infantum基因组结构的了解; (ii) 描述该物种的种内基因组变异性；(iii) 了解用于诊断 VL 的主要抗原的基因组特征。此外，这是第一项报告哥伦比亚L. infantum分离株全基因组序列的研究。