尼日利亚中北部明纳地区恶性疟原虫分离株的遗传多样性通过对裂殖子表面蛋白 1 和 2 的 PCR 基因分型推断。

Genetic diversity of plasmodium falciparum isolates in Minna, North Central Nigeria inferred by PCR genotyping of Merozoite surface protein 1 and 2.

机构信息

Department of Animal Biology, Federal University of Technology, Minna, Niger State, Nigeria.

Department of Biochemistry, Federal University of Technology, Minna, Niger State, Nigeria.

出版信息

Infect Genet Evol. 2021 Dec;96:105143. doi: 10.1016/j.meegid.2021.105143. Epub 2021 Nov 17.

DOI:10.1016/j.meegid.2021.105143

PMID:34800712

Abstract

North Central Nigeria is one region in Nigeria with a significant incidence of malaria caused majorly by Plasmodium falciparum. This study utilizes the msp1 and msp2 genes of P. falciparum to examine its diversity and multiplicity of infection (MOI). Blood samples were collected from 247 children across selected healthcare facilities in Minna, from infants and children aged 6 months to 17 years. Of the total collection, 143 (58%) of the children were infected with P. falciparum with parasite density ≥ 1000 μl, and from which fifty (50) samples was randomly selected and presented for PCR for the characterization of msp1 and msp2 gene using nested-PCR method. Overall, 57 msp1 genotypes, including K1, MAD20 and RO33 were identified, ranging from (250-1000 bp), (100-500 bp) and (400-500 bp), respectively. In addition, 54 different msp2 genotypes of FC27 and 3D7 alleles ranging from (100-900 bp) and (100-800 bp), respectively were selected. A monoclonal infection of 39% and a polyclonal infection of 61% was recorded, however, a particularity about this study is the polyclonal nature of RO33. Determination of gene diversity revealed MAD20 as the predominant allele for msp1 with a mean MOI of 1.35 and FC27 for msp2 with 1.72 MOI. The overall MOI recorded for the study was 1.60. There was, however, no statistical significance difference between MOI and age of the child (P > 0.05). Meanwhile, findings from this study revealed P. falciparum populations were not genetically diverse with Heterozygosity (He) index of 0.0636. However, a significant level gene diversity within the antigenic markers of msp1 and msp2 was observed with He index of 0.714 and 0.830, respectively. This study has demonstrated the potential of gene diversity and MOI of P. falciparum, as important markers for assessing differences in malaria transmission intensity. Continuous malaria genetic surveillance is therefore recommended as a fundamental tool for monitoring changes in gene types and for intervention programs' effectiveness.

摘要

尼日利亚中北部是尼日利亚疟疾发病率较高的地区之一，主要由恶性疟原虫引起。本研究利用恶性疟原虫 msp1 和 msp2 基因来检测其多样性和多重感染（MOI）。从明纳选定的医疗保健机构采集了 247 名儿童的血液样本，这些儿童年龄在 6 个月至 17 岁之间。在总共采集的样本中，有 143 名（58%）儿童感染了恶性疟原虫，寄生虫密度≥1000μl，其中随机选择了 50 个样本进行 PCR，使用巢式 PCR 方法对 msp1 和 msp2 基因进行特征分析。总体而言，鉴定出了 57 种 msp1 基因型，包括 K1、MAD20 和 RO33，其范围分别为（250-1000bp）、（100-500bp）和（400-500bp）。此外，还选择了 54 种不同的 msp2 基因型 FC27 和 3D7 等位基因，其范围分别为（100-900bp）和（100-800bp）。记录到单克隆感染率为 39%，多克隆感染率为 61%，然而，这项研究的一个特点是 RO33 的多克隆性质。基因多样性的测定结果显示，MAD20 是 msp1 的主要等位基因，平均 MOI 为 1.35，FC27 是 msp2 的主要等位基因，MOI 为 1.72。研究中记录的总 MOI 为 1.60。然而，MOI 与儿童年龄之间没有统计学意义上的差异（P>0.05）。同时，本研究发现恶性疟原虫种群的遗传多样性并不丰富，杂合度（He）指数为 0.0636。然而，在 msp1 和 msp2 的抗原标记物中观察到了显著的基因多样性，He 指数分别为 0.714 和 0.830。这项研究表明，恶性疟原虫的基因多样性和 MOI 是评估疟疾传播强度差异的重要标志物。因此，建议连续进行疟疾基因监测，作为监测基因类型变化和干预计划效果的基本工具。