Laboratory of Bacteriology-Virology, Hospital Aristide Le Dantec, BP 7325, Dakar, Senegal.
Institut de Recherche en Santé, de Surveillance Épidémiologique et de Formations, Arrondissement 4 Rue 2D1 Pôle Urbain de Diamniadio, Dakar, Senegal.
Malar J. 2020 Sep 3;19(1):320. doi: 10.1186/s12936-020-03384-5.
Despite several control interventions resulting in a considerable decrease in malaria prevalence in the Union of the Comoros, the disease remains a public health problem with high transmission in Grande Comore compared to neighbouring islands. In this country, only a few studies investigating the genetic diversity of Plasmodium falciparum have been performed so far. For this reason, this study aims to examine the genetic diversity of P. falciparum by studying samples collected in Grande Comore in 2012 and 2013, using merozoite surface protein 1 (msp1), merozoite surface protein 2 (msp2) and single nucleotide polymorphism (SNP) genetic markers.
A total of 162 positive rapid diagnostic test (RDT) samples from Grande Comore were used to extract parasite DNA. Allelic families K1, Mad20 and RO33 of the msp1 gene as well as allelic families IC3D7 and FC37 of the msp2 gene were determined by using nested PCR. Additionally, 50 out of 151 samples were genotyped to study 24 SNPs by using high resolution melting (HRM).
Two allelic families were predominant, the K1 family of msp1 gene (55%) and the FC27 family of msp2 gene (47.4%). Among 50 samples genotyped for 24 SNPs, 42 (84%) yielded interpretable results. Out of these isolates, 36 (85%) were genetically unique and 6 (15%) grouped into two clusters. The genetic diversity of P. falciparum calculated from msp1 and msp2 genes and SNPs was 0.82 and 0.61, respectively.
In summary, a large genetic diversity of P. falciparum was observed in Grande Comore. This may favour persistence of malaria and might be one of the reasons for the high malaria transmission compared to neighbouring islands. Further surveillance of P. falciparum isolates, mainly through environmental management and vector control, is warranted until complete elimination is attained.
尽管联合科摩罗采取了几项控制干预措施，疟疾发病率已大幅下降，但该病仍是一个公共卫生问题，与周边岛屿相比，格兰德科摩罗的疟疾传播率仍较高。迄今为止，该国仅进行了少数关于恶性疟原虫遗传多样性的研究。因此，本研究旨在通过研究 2012 年和 2013 年在格兰德科摩罗采集的样本，利用裂殖子表面蛋白 1（msp1）、裂殖子表面蛋白 2（msp2）和单核苷酸多态性（SNP）遗传标记来检测恶性疟原虫的遗传多样性。
使用嵌套 PCR 方法检测来自格兰德科摩罗的 162 份经快速诊断检测（RDT）阳性的样本，以确定 msp1 基因的 K1、Mad20 和 RO33 等位基因家族以及 msp2 基因的 IC3D7 和 FC37 等位基因家族。此外，对 151 个样本中的 50 个进行基因分型，通过高分辨率熔解（HRM）分析 24 个 SNP。
两种等位基因家族占主导地位，msp1 基因的 K1 家族（55%）和 msp2 基因的 FC27 家族（47.4%）。对 24 个 SNP 进行基因分型的 50 个样本中，有 42 个（84%）产生了可解释的结果。在这些分离株中，有 36 个（85%）是遗传独特的，有 6 个（15%）分为两个聚类。从 msp1 和 msp2 基因以及 SNP 计算得出的恶性疟原虫遗传多样性分别为 0.82 和 0.61。
总之，在格兰德科摩罗观察到恶性疟原虫具有较大的遗传多样性。这可能有利于疟疾的持续存在，并且可能是与周边岛屿相比疟疾传播率较高的原因之一。需要通过环境管理和病媒控制等措施进一步监测恶性疟原虫分离株，直到完全消除为止。
