Abstract
BackgroundWith the premise of diminishing parasite genetic diversity following the reduction of malaria incidence, the analysis of polymorphic antigenic markers may provide important information about the impact of malaria control on local parasite populations. Here we evaluated the genetic diversity of Plasmodium vivax apical membrane antigen 1 (Pvama1) gene in a parasite population from the China-Myanmar border and compared it with global P. vivax populations.MethodsWe performed evolutionary analysis to examine the genetic diversity, natural selection, and population differentiation of 73 Pvama1 sequences acquired from the China-Myanmar border as well as 615 publically available Pvama1 sequences from seven global P. vivax populations.ResultsA total of 308 Pvama1 haplotypes were identified among the global P. vivax isolates. The overall nucleotide diversity of Pvama1 gene among the 73 China-Myanmar border parasite isolates was 0.008 with 41 haplotypes being identified (Hd = 0.958). Domain I (DI) harbored the majority (26/33) of the polymorphic sites. The McDonald Kreitman test showed a significant positive selection across the ectodomain and the DI of Pvama1. The fixation index (F ST) estimation between the China-Myanmar border, Thailand (0.01) and Myanmar (0.10) showed only slight geographical genetic differentiation. Notably, the Sal-I haplotype was not detected in any of the analyzed global isolates, whereas the Belem strain was restricted to the Thai population. The detected mutations are mapped outside the overlapped region of the predicted B-cell epitopes and intrinsically unstructured/disordered regions.ConclusionsThis study revealed high levels of genetic diversity of Pvama1 in the P. vivax parasite population from the China-Myanmar border with DI displaying stronger diversifying selection than other domains. There were low levels of population subdivision among parasite populations from the Greater Mekong Subregion.Electronic supplementary materialThe online version of this article (doi:10.1186/s13071-016-1899-1) contains supplementary material, which is available to authorized users.
Highlights
With the premise of diminishing parasite genetic diversity following the reduction of malaria incidence, the analysis of polymorphic antigenic markers may provide important information about the impact of malaria control on local parasite populations
Genetic diversity of Plasmodium vivax apical membrane antigen 1 (Pvama1) among P. vivax isolates from the China-Myanmar border The 1,290 bp sequence corresponding to the ectodomain of Pvama1 was amplified from 73 P. vivax samples acquired from the China-Myanmar border
Within Domain I (DI), 10 of the 26 Pvama1 mutations were mapped to the same positions as the Pfama1 c1, cluster 1 loop (c1L), c2, and c3 clusters
Summary
With the premise of diminishing parasite genetic diversity following the reduction of malaria incidence, the analysis of polymorphic antigenic markers may provide important information about the impact of malaria control on local parasite populations. In China, autochthonous malaria incidence is mostly located in counties bordering with Myanmar, where malaria burden is the highest in the GMS [5, 6]. In these border regions, crossborder human migration as a major source of malaria introduction presents a significant challenge to the malaria elimination course [7, 8]. Since control efforts are expected to have great impacts on the genetic diversity of the parasite populations [9, 10], tracking their spatial and temporal dynamics may provide timely measurement of the progress of regional malaria elimination
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Free) 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
