Kojom Foko Loick P, Hawadak Joseph, Singh Vineeta
Parasite and Host Biology Group, ICMR-National Institute of Malaria Research, Delhi, 110077, India.
Academy of Scientific and Innovative Research (AcSIR), Ghaziabad, 201002, India.
Acta Parasitol. 2025 Jul 12;70(4):154. doi: 10.1007/s11686-025-01097-w.
Plasmodium falciparum (Pf) is the deadliest malaria parasite species, and its genetic diversity is a significant obstacle to its effective control. Here, we analyzed the genetic diversity and phylogeny of Pf isolates collected in Cameroon using merozoite surface proteins 1 and 2 (msp1/2) markers.
Samples were collected in three malaria epidemiological facets of three regions of Cameroon (Littoral, North, Far North). The msp1 block 2 and msp2 block 3 were genotyped using polymerase chain reaction and Sanger sequencing. The structural organization the msp1/2 allelic families (K1, MAD20, and RO33 for msp1, IC/3D7, and FC27 for msp2) was analyzed, while their phylogenetic relatedness was assessed in comparison with ~ 2500 good quality sequences from various geographical areas.
The K1 and MAD20 families had high structural diversity due to the repetition of 3-amino acid repeats (SGT, SGP, and SAQ for K1, SGG, and SVA for MAD20). RO33 sequences presented several mutation points. Tetramer to decamer repetitive amino acids were identified in IC/3D7 sequences mainly GSGA (31.3%) and GASGSA (25%). The 32-aa sequence of the FC27 family showed non-synonymous substitution, insertion, and deletions. The K1 and RO33 sequences were phylogenetically closer to those from China/Myanmar, while MAD20, IC/3D7, and FC27 sequences were closer to those from India, Panama, and Papua New Guinea. The Cameroonian Pfmsp1/2 sequences showed a high genetic structure with phylogenetic patterns outlining a complex Pf population structure.
恶性疟原虫（Pf）是最致命的疟原虫种类，其遗传多样性是有效控制疟疾的重大障碍。在此，我们使用裂殖子表面蛋白1和2（msp1/2）标记分析了在喀麦隆收集的Pf分离株的遗传多样性和系统发育。
在喀麦隆三个地区（滨海区、北部、极北区）的三个疟疾流行层面采集样本。使用聚合酶链反应和桑格测序对msp1第2区和msp2第3区进行基因分型。分析了msp1/2等位基因家族（msp1的K1、MAD20和RO33，msp2的IC/3D7和FC27）的结构组织，同时与来自不同地理区域的约2500条高质量序列比较评估它们的系统发育相关性。
由于3个氨基酸重复序列（K1的SGT、SGP和SAQ，MAD20的SGG和SVA）的重复，K1和MAD20家族具有高度的结构多样性。RO33序列呈现出几个突变点。在IC/3D7序列中鉴定出四聚体至十聚体重复氨基酸，主要是GSGA（31.3%）和GASGSA（25%）。FC27家族的32个氨基酸序列显示非同义替换、插入和缺失。K1和RO33序列在系统发育上更接近来自中国/缅甸的序列，而MAD20、IC/3D7和FC27序列更接近来自印度、巴拿马和巴布亚新几内亚的序列。喀麦隆的Pfmsp1/2序列显示出高度的遗传结构，其系统发育模式勾勒出复杂的Pf种群结构。
