Sequence variation in Plasmodium falciparum merozoite surface protein-2 is associated with virulence causing severe and cerebral malaria

Geographical and temporal dynamics of genetic diversity of Plasmodium falciparum merozoite surface proteins 1/2 in India

The high genetic diversity of Plasmodium falciparum (Pf) is a big obstacle to successful vaccine development programs. Here, the geographical and temporal dynamics of the genetic diversity of Indian Pf isolates from patients living in Ranchi, Raipur, Mewat, and Rourkela were analyzed. Typing and frequency of merozoite surface protein 1 and 2 genes (pfmsp1/2), their genotypes, clonality, heterozygosity, multiplicity of infection, and neutral evolution metrics were computed. A phylogenetic analysis was also performed for these two genes. The dominant allelic types were K1 (55%) and MAD20 (55%) for msp1, and FC27 (64.7%) for msp2. Infections were mainly monoclonal in Ranchi and Mewat while polyclonal in Raipur and Rourkela. Polyclonal infections dropped from 57.1 to 71.3% in 2013 to 33.3-33.4% in 2016 in Raipur. K1 and MAD20 sequences were highly diverse due to the organization of the amino acid units SGG, SVA, SVT, and SGN. The IC/3D7-related G,S,A-rich region showed a large variation of four to eight amino acid repeats, including mostly GAVASA (81.8%), GSGA (54.5%), and GASGSA (45.5%). The 32-amino acid sequence of the FC27 type was present in all isolates with several mutations. The msp1/2 sequences were not under neutral evolution, except the K1 family, which is under balancing selection. The msp1/2 sequences are phylogenetically closer to previous Indian sequences than those from Africa, Asia, the Americas, and Oceania. This study outlines a high genetic diversity of Pf infections with complex structure, and evolutionary signature changed with time.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12639-024-01698-8.

Dynamics of Plasmodium falciparum genetic diversity among asymptomatic and symptomatic children in three epidemiological areas in Cote d'Ivoire

Asymptomatic carriers of Plasmodium are considered a reservoir of the parasite in humans. Therefore, in order to be effective, new malaria elimination strategies must take these targets into account. The aim of this study was to analyse genetic diversity of Plasmodium falciparum among schoolchildren in three epidemiological areas in Côte d'Ivoire. This was a cross-sectional study carried out from May 2015 to April 2016 in a primary school in rural and urban areas of San Pedro, Grand-Bassam and Abengourou, during the rainy season and the dry season. A total of 282 Plasmodium falciparum isolates were genotyped using Nested PCR of Pfmsp1 and Pfmsp2 genes. The overall frequency of K1, Mad20 and RO33 alleles was 81.6%, 53.4% and 57% for Pfmsp1 respectively. For Pfmsp2, this frequency was 84.3% and 72.2% for 3D7 and FC27. K1, Mad20 and FC27 Frequencies were significantly higher in Abengourou compared to other sites. Overall, the frequency of MIs was significantly higher in Abengourou for Pfmsp1 and Pfmsp2. However, Mad20 and RO33 alleles were significantly higher in the rainy season. No significant difference was observed between Pfmsp2 alleles in both seasons. Frequency of the 3D7 allele was significantly higher in symptomatic patients. MIs and COI increased with parasitemia for Pfmsp1and Pfmsp2. The data can be added to that available for monitoring and control of P. falciparum malaria. Further studies combining the entomological inoculation rate and the genetic diversity of P. falciparum will allow us to shed light on our understanding of the epidemiology of this parasite.

Correction: Sequence variation in Plasmodium falciparum merozoite surface protein-2 is associated with virulence causing severe and cerebral malaria

[This corrects the article DOI: 10.1371/journal.pone.0190418.].