Department of Pharmaceutical Microbiology and Biotechnology, Nnamdi Azikiwe University, Awka, Nigeria.
Department of Pharmacology and Toxicology, University of Nigeria, Nsukka, Nigeria.
J Infect Dev Ctries. 2022 Mar 31;16(3):557-563. doi: 10.3855/jidc.14815.
The genetic diversity of Plasmodium falciparum poses a threat to the development and implementation of malaria control strategies. Thus, there is a need for continuous surveillance of its genetic diversity, especially amongst the parasite's reservoir's asymptomatic population.
Three cohorts comprising children under ten years old, pregnant women and other adults were recruited into this study. Blood sample was collected from all consenting individuals and screened by the polymerase chain reaction (PCR) method. The genetic diversity of P. falciparum was determined by genotyping the merozoite surface protein-1 (msp-1), merozoite surface protein-2 (msp-2) and glutamate-rich protein (glurp). The size of alleles was visualized on the agarose gel. The multiplicity of infection (MOI) and expected heterozygosity (He) were determined.
The majority of the patients showed polyclonal infections, while the multiplicity of infection with msp-2 and glurp of isolates from pregnant women were 2.5 and 1.8, respectively. Children and adults were 2.3 and 1.1; 2.4 and 1.3, respectively. The estimated number of genotypes was 10 msp-1 (4 KI; 4 MAD; 2 RO33), 27 msp-2 (14 FC27; 13 IC/3D7) and 8 glurp. K1 (36/100) was more frequent than the MAD20 (22.33/100) allele, which was, in turn, more frequent than the RO33 (13.59/100). The samples with the 3D7 allele (53.40/100) of msp-2 occurred more frequently than the FC27 type (45.63/100). Polymorphism in the glurp gene occurred most frequently (72.82/100).
The study samples exhibited a high degree of genetic polymorphism in msp-2 allele typing with multiple clones, reflecting the complexity of parasite populations.
恶性疟原虫的遗传多样性对疟疾控制策略的制定和实施构成了威胁。因此，需要持续监测其遗传多样性，尤其是在寄生虫无症状的储存宿主人群中。
本研究纳入了三个队列，包括 10 岁以下儿童、孕妇和其他成年人。采集所有同意参与的个体的血样，并通过聚合酶链反应（PCR）方法进行筛查。通过基因分型恶性疟原虫表面蛋白-1（msp-1）、恶性疟原虫表面蛋白-2（msp-2）和谷氨酸丰富蛋白（glurp）来确定恶性疟原虫的遗传多样性。等位基因的大小在琼脂糖凝胶上可视化。多重感染（MOI）和预期杂合度（He）也被确定。
大多数患者表现为多克隆感染，而来自孕妇的 msp-2 和 glurp 感染的多重感染率分别为 2.5 和 1.8。儿童和成年人分别为 2.3 和 1.1；2.4 和 1.3。估计的基因型数量为 10 个 msp-1（4 KI；4 MAD；2 RO33）、27 个 msp-2（14 FC27；13 IC/3D7）和 8 个 glurp。K1（36/100）比 MAD20（22.33/100）等位基因更常见，而 RO33（13.59/100）则比 MAD20 更常见。msp-2 中 3D7 等位基因（53.40/100）的样本比 FC27 型（45.63/100）更常见。glurp 基因的多态性最常见（72.82/100）。
本研究样本在 msp-2 等位基因分型中表现出高度的遗传多态性，存在多个克隆，反映了寄生虫群体的复杂性。
