Genetic Diversity of Plasmodium falciparum Parasites in Pregnant and Non-pregnant Women and Potential Resistance to Antimalarial Drugs in Kenya

Genetic Diversity of Plasmodium falciparum Parasites in Pregnant and Non-pregnant Women and Potential Resistance to Antimalarial Drugs in Kenya
 
Brenda Makena^1,2, Martha Nginya^1,2, Marcel Nyambute¹, Charles Okello¹, Edwin Mwakio¹, Gladys Chemwor¹, Raphael Okoth¹, Redemptah Yeda¹, Agnes Cheruiyot¹, Benjamin Opot¹, Dennis Juma¹, Victor Mobegi², Hosea Akala¹, Ben Andagalu^1
1United States Army Medical Research Directorate-Kenya (USAMRD-K), Kenya Medical Research Institute (KEMRI)
²Centre for Biotechnology and Bioinformatics (CEBIB). University of Nairobi, Nairobi, Kenya.
 
During pregnancy, malaria causes maternal anaemia, placental accumulation of parasites, low birth weight, infant mortality as well as maternal mortality. Pregnant women are presumed non-immune to malaria whereas the non-pregnant are thought to be semi-immune. Non-pregnant women therefore have faster parasite clearance compared to pregnant women. The non-immune environment in pregnant women may select for parasite populations that are associated with resistance to artemisinin. This study will determine genetic variations in Plasmodium falciparum parasites in pregnant versus non-pregnant women due to differences in their immunity. Samples were collected at hours 0, 8, 24 and at days 7 and 28 from 75 participants in an efficacy study. Rapid diagnostic test and microscopy will be done followed by 18s rRNA PCR for speciation analysis. Sanger sequencing and MassARRAY SNP genotyping will be done to determine mutations in parasites without fast clearance as well as microsatellite genotyping to determine genetic variations in the parasites between the two populations. Genotyping for both MSP1 and MSP2 will then follow to determine recrudescence and reinfection. Twelve microsatellite markers will be used to calculate allele frequencies, heterozygosity (H_e) values, molecular variance, haplotypes, principal coordinates and fixation indices using GenAIEx and Arlequin softwares. For MassARRAY SNP genotyping, genotype calls will be made using SpectroTyper 4.0 software (Agena). For the K13 and Sanger sequencing SNPs will be analyzed by doing multiple sequence alignment using CLC Genomics Workbench software. This study will contribute to knowledge on guiding the World Health Organization implementation of intermittent preventive treatment in pregnancy with sulfadoxine-pyrimethamine if found to influence parasites response to artemisinins.
Funding: Armed Forces Health Surveillance Branch (AFHSB) and Developing Excellence in Leadership and Genetics Training for Malaria Elimination in Sub-Africa (DELGEME)