Genetic diversity and complexity of Plasmodium falciparum infections in the microenvironment among siblings of the same household in North-Central Nigeria

Malaria Journal

Olusola Ojurongbe¹  Peter Usman Bassi²  Samuel Adeola Oyedeji³  Segun Isaac Oyedeji⁴  Henrietta Oluwatoyin Awobode⁵ 

[1] Department of Medical Microbiology and Parasitology, Ladoke Akintola University of Technology, Osogbo, Nigeria;Department of Pharmacology and Therapeutics, University of Abuja, Abuja, Nigeria;Department of Zoology, University of Ilorin, Ilorin, Nigeria;Molecular Genetics and Parasitology Unit, Department of Animal & Environmental Biology, Federal University Oye-Ekiti, Oye-Ekiti, Nigeria;Parasitology Unit, Department of Zoology, University of Ibadan, Ibadan, Nigeria;

关键词: Plasmodium falciparum;    Genetic diversity;    Malaria;    Multiplicity of infection;    MSP;    Transmission intensity;    Micro-environment;    Nigeria;   

DOI  :  10.1186/s12936-020-03415-1

来源: Springer

【 摘 要 】

BackgroundPlasmodium falciparum parasites are known to exhibit extensive genetic diversity in areas of high transmission intensity and infected individuals in such communities often harbour several complex mixtures of parasite clones with different genetic characteristics. However, in the micro-environment, the extent of genetic diversity of P. falciparum parasites remain largely unknown. In this study therefore, the complexity of P. falciparum infections in households was investigated among symptomatic siblings, living under the same roof in north-central Nigeria.MethodsChildren were enrolled into the study if they were at least two from a household and presented with symptoms of uncomplicated malaria. Clinical malaria was confirmed by light microscopy of Giemsa-stained thick and thin blood films. Genomic DNA was isolated from blood spots on filter paper. Molecular characterization of P. falciparum isolates was done by allele-specific nested PCR of the highly polymorphic merozoite surface protein-2 (msp-2) gene.ResultsNinety-three children from 43 households were enrolled into this study. A total of 26 different msp-2 alleles were identified from 215 fragments (range: 180–480 bp). Majority of the isolates [65.6% (n = 61)] were polyclonal infections consisting of 2–6 clones and were significantly more common with the FC27 allelic family (p = 0.036). The multiplicity of infection (MOI) per household ranged from 1.0 to 4.5 while the overall MOI in the study population was 2.31. The pattern of distribution of msp-2 allele types among the households fell into two categories: households where both msp-2 allele types (FC27 and 3D7) were present; households where only one msp-2 allele type (FC27 or 3D7) was present. Majority of the households [88.4% (n = 38)], had both msp-2 allele types but they were disproportionately distributed among the children while in a few households [11.6% (n = 5)], all the children were infected with only one type of msp-2 allele.ConclusionThese findings showed that P. falciparum isolates exhibit remarkable degree of genetic diversity in the micro-environment and are composed mainly of multiclonal infections, which is an indication of a high ongoing parasite transmission. This suggests that the micro-environment is an important area of focus for malaria control interventions and for evaluating intervention programmes.

【 授权许可】

CC BY