Rapid Fire Presentation 8th International Conference on Plasmodium vivax Research 2022

Global genetic diversity of serological markers of Plasmodium vivax infections (#410)

Noelia Coronado 1 , Anthony Gave Zuñiga 1 , Carlos Fernandez Miñope 2 , Christopher Delgado Ratto 1 3
  1. Instituto de Medicina Tropical Alexander von Humboldt, Universidad Peruana Cayetano Heredia, Lima, Peru
  2. University of Antwerp, Antwerp, ANTWERP, Belgium
  3. Global Health Institute, Malaria ResearcH group (MarRCH), University of Antwerp, Antwerp, Belgium

Residual malaria brings multiple challenges to the malaria elimination programs and requires tailored strategies and interventions. Serological markers provide crucial information about malaria transmission even in areas where malaria cases are sub-optimally detected by microscopy or PCR. The choice of serological markers to study malaria transmission should be made with proper knowledge of the biomarkers' coding genes to achieve a more efficient performance and better explain the outcome. In Peru, significant antibody responses against PvMSP8 y PvMSP10 have been detected, even in people experiencing asymptomatic infections. As a result, we aimed to evaluate the genetic diversity of MSP8 y MSP10 and provide insights into the impact of evolutionary events on the genetic sequences of these proteins and the antibody response.

We preliminary analyzed 27, and 30 P. vivax sequences coding for MSP8 and MSP10 obtained from global sequences deposited at GenBank. Polymorphic characteristics and the effect of natural selection were analyzed using MEGA and DnaSP software. Mutation prediction was performed using the Provean web server.

MSP8 had an overall haplotypic and nucleotide diversity of 0.940 and 0.004, respectively. Thirty-seven polymorphic sites were also detected, of which 19 were nonsynonymous substitutions, and only one was determined to be deleterious. However, these mutations do not suffer selection pressure (Tajima's D-test, D=-1.8067, p>0.05). Regarding MSP10, 29 polymorphic sites (8 synonymous and 21 nonsynonymous substitutions) were found with an overall haplotypic and nucleotide diversity of 0.900 and 0.003, respectively. MSP10 does not experience selection pressure (Tajima's D-test, D=-1.66973, p>0.05) and H316R, R329I, E386G, F452L mutations were predicted as deleterious.

Our preliminary findings describe high genetic diversity in the genes encoding MSP8 and MSP10. No selection pressure was evident on them. Further genetic analysis involving the analysis of more sequences will reveal if the geographic origin influences the diversity and potentially the host antibody response.