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Plasmodium falciparum Genetic Diversity in Coincident Human and Mosquito Hosts.
Lapp, Zena; Obala, Andrew A; Abel, Lucy; Rasmussen, David A; Sumner, Kelsey M; Freedman, Elizabeth; Taylor, Steve M; Prudhomme-O'Meara, Wendy.
Affiliation
  • Lapp Z; Duke Global Health Institute, Duke Universitygrid.26009.3d, Durham, North Carolina, USA.
  • Obala AA; School of Medicine, College of Health Sciences, Moi University, Eldoret, Kenya.
  • Abel L; Academic Model Providing Access to Healthcare (AMPATH), Eldoret, Kenya.
  • Rasmussen DA; Department of Entomology and Plant Pathology, North Carolina State University, Raleigh, North Carolina, USA.
  • Sumner KM; Bioinformatics Research Center, North Carolina State University, Raleigh, North Carolina, USA.
  • Freedman E; Department of Epidemiology, Gillings School of Global Public Health, University of North Carolina, Chapel Hill, North Carolina, USA.
  • Taylor SM; Division of Infectious Diseases, School of Medicine, Duke Universitygrid.26009.3d, Durham, North Carolina, USA.
  • Prudhomme-O'Meara W; Division of Infectious Diseases, School of Medicine, Duke Universitygrid.26009.3d, Durham, North Carolina, USA.
mBio ; 13(5): e0227722, 2022 10 26.
Article in En | MEDLINE | ID: mdl-36073811
Population genetic diversity of Plasmodium falciparum antigenic loci is high despite large bottlenecks in population size during the parasite life cycle. The prevalence of genetically distinct haplotypes at these loci, while well characterized in humans, has not been thoroughly compared between human and mosquito hosts. We assessed parasite haplotype prevalence, diversity, and evenness using human and mosquito P. falciparum infections collected from the same households during a 14-month longitudinal cohort study using amplicon deep sequencing of two antigenic gene fragments (ama1 and csp). To a prior set of infected humans (n = 1,175/2,813; 86.2% sequencing success) and mosquito abdomens (n = 199/1,448; 95.5% sequencing success), we added sequences from infected mosquito heads (n = 134/1,448; 98.5% sequencing success). The overall and sample-level parasite populations were more diverse in mosquitoes than in humans. Additionally, haplotype prevalences were more even in the P. falciparum human population than in the mosquito population, consistent with balancing selection occurring at these loci in humans. In contrast, we observed that infections in humans were more likely to harbor a dominant haplotype than infections in mosquitoes, potentially due to removal of unfit strains by the human immune system. Finally, within a given mosquito, there was little overlap in genetic composition of abdomen and head infections, suggesting that infections may be cleared from the abdomen during a mosquito's lifespan. Taken together, our observations provide evidence for the mosquito vector acting as a reservoir of sequence diversity in malaria parasite populations. IMPORTANCE Plasmodium falciparum is the deadliest human malaria parasite, and infections consisting of concurrent, multiple strains are common in regions of high endemicity. During transitions within and between the parasite's mosquito and human hosts, these strains are subject to population bottlenecks, and distinct parasite strains may have differential fitness in the various environments encountered. These bottlenecks and fitness differences may lead to differences in strain prevalence and diversity between hosts. We investigated differences in genetic diversity and evenness between P. falciparum parasites in human and mosquito hosts collected from the same households during a 14-month longitudinal study in Kenya. Compared to human parasite populations and infections, P. falciparum parasites observed in mosquito populations and infections were more diverse by multiple population genetic metrics. This suggests that the mosquito vector acts as a reservoir of sequence diversity in malaria parasite populations.
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Full text: 1 Collection: 01-internacional Database: MEDLINE Main subject: Plasmodium falciparum / Genetic Variation / Malaria, Falciparum / Culicidae Type of study: Observational_studies / Risk_factors_studies Limits: Animals / Humans Language: En Journal: MBio Year: 2022 Document type: Article Affiliation country: United States Country of publication: United States

Full text: 1 Collection: 01-internacional Database: MEDLINE Main subject: Plasmodium falciparum / Genetic Variation / Malaria, Falciparum / Culicidae Type of study: Observational_studies / Risk_factors_studies Limits: Animals / Humans Language: En Journal: MBio Year: 2022 Document type: Article Affiliation country: United States Country of publication: United States