Department of Parasitology and Medical Entomology, Institute of Endemic Diseases, University of Khartoum, Khartoum, Sudan; Faculty of Medical Laboratory Sciences, Sinnar University, Sudan.
Department of Bioinformatics and Genomics, University of North Carolina, Charlotte, NC 28223, USA.
Infect Genet Evol. 2024 Sep;123:105643. doi: 10.1016/j.meegid.2024.105643. Epub 2024 Jul 23.
Plasmodium vivax, traditionally overlooked has experienced a notable increase in cases in East Africa. This study investigated the geographical origin and genetic diversity of P. vivax in Sudan using 14 microsatellite markers. A total of 113 clinical P. vivax samples were collected from two different ecogeographical zones, New Halfa and Khartoum, in Sudan. Additionally, 841 geographical samples from the database were incorporated for a global genetic analysis to discern genetic relationships among P. vivax isolates on regional and worldwide scales. On the regional scale, our findings revealed 91 unique and 8 shared haplotypes among the Sudan samples, showcasing a remarkable genetic diversity compared to other geographical isolates and supporting the hypothesis that P. vivax originated from Africa. On a global scale, distinct genetic clustering of P. vivax isolates from Africa, South America, and Asia (including Papua New Guinea and Solomon Island) was observed, with limited admixture among the three clusters. Principal component analysis emphasized the substantial contribution of African isolates to the observed global genetic variation. The Sudanese populations displayed extensive genetic diversity, marked by significant multi-locus linkage disequilibrium, suggesting an ancestral source of P. vivax variation globally and frequent recombination among the isolates. Notably, the East African P. vivax exhibited similarity with some Asian isolates, indicating potential recent introductions. Overall, our results underscore the effectiveness of utilizing microsatellite markers for implementing robust control measures, given their ability to capture extensive genetic diversity and linkage disequilibrium patterns.
间日疟原虫（Plasmodium vivax）曾被忽视，但在东非的病例显著增加。本研究采用 14 个微卫星标记，调查了苏丹间日疟原虫的地理来源和遗传多样性。共收集了来自苏丹两个不同生态地理区（新哈法和喀土穆）的 113 例临床间日疟原虫样本。此外，还整合了数据库中的 841 个地理样本，进行全球遗传分析，以辨别区域和全球范围内间日疟原虫分离株之间的遗传关系。在区域尺度上，我们的研究结果显示苏丹样本中有 91 个独特的单倍型和 8 个共享的单倍型，与其他地理分离株相比，表现出显著的遗传多样性，支持间日疟原虫起源于非洲的假说。在全球尺度上，观察到来自非洲、南美洲和亚洲（包括巴布亚新几内亚和所罗门群岛）的间日疟原虫分离株存在明显的遗传聚类，三个聚类之间的混合程度有限。主成分分析强调了非洲分离株对观察到的全球遗传变异的重要贡献。苏丹人群表现出广泛的遗传多样性，显著的多基因座连锁不平衡，表明全球间日疟原虫变异的祖先来源和分离株之间频繁的重组。值得注意的是，东非的间日疟原虫与一些亚洲分离株相似，表明可能有近期的引入。总的来说，我们的研究结果强调了利用微卫星标记来实施强有力的控制措施的有效性，因为它们能够捕捉到广泛的遗传多样性和连锁不平衡模式。
