Global and local genetic diversity at two microsatellite loci in Plasmodium vivax parasites from Asia, Africa and South America

Abstract

BackgroundEven though Plasmodium vivax has the widest worldwide distribution of the human malaria species and imposes a serious impact on global public health, the investigation of genetic diversity in this species has been limited in comparison to Plasmodium falciparum. Markers of genetic diversity are vital to the evaluation of drug and vaccine efficacy, tracking of P. vivax outbreaks, and assessing geographical differentiation between parasite populations.MethodsThe genetic diversity of eight P. vivax populations (n = 543) was investigated by using two microsatellites (MS), m1501 and m3502, chosen because of their seven and eight base-pair (bp) repeat lengths, respectively. These were compared with published data of the same loci from six other P. vivax populations.ResultsIn total, 1,440 P. vivax samples from 14 countries on three continents were compared. There was highest heterozygosity within Asian populations, where expected heterozygosity (He) was 0.92-0.98, and alleles with a high repeat number were more common. Pairwise FST revealed significant differentiation between most P. vivax populations, with the highest divergence found between Asian and South American populations, yet the majority of the diversity (~89%) was found to exist within rather than between populations.ConclusionsThe MS markers used were informative in both global and local P. vivax population comparisons and their seven and eight bp repeat length facilitated population comparison using data from independent studies. A complex spatial pattern of MS polymorphisms among global P. vivax populations was observed which has potential utility in future epidemiological studies of the P. vivax parasite.Electronic supplementary materialThe online version of this article (doi:10.1186/1475-2875-13-392) contains supplementary material, which is available to authorized users.

Human Plasmodium vivax diversity, population structure and evolutionary origin

“…Results based on NJ tree, MDS and structure analyses reveals patterns of population genetic structure that are consistent with previous studies (e.g. [16][17][18][19][20][21]). The South East Asian populations are the most diverse populations as measured by allelic richness and genetic diversity Hs and present the lowest levels of multilocus linkage disequilibrium (Fig 2).…”

“…In recent years, due to the importance of understanding the demography of populations, the migration patterns as well as the evolutionary history of the parasite, there has been increased interest in describing the distribution of genetic variation in the global P. vivax population. Several studies on P. vivax have been published, from those focusing on a small set of genetic markers to those describing population genetic structure at the scale of the entire genome (including [16][17][18][19][20][21]). Although these studies all brought their set of information, none of them was able to describe the relationship and the diversity of P. vivax populations over the entire range including East and Western African strains.…”

Molecular Epidemiology of P. vivax in Iran: High Diversity and Complex Sub-Structure Using Neutral Markers, but No Evidence of Y976F Mutation at pvmdr1

“…Furthermore, a previous STR-based study of P . vivax diversity in populations from Afghanistan and Pakistan revealed extensive diversity ( H E = 0.98) [54]. …”

Genetic Variability of Plasmodium vivax in the North Coast of Peru and the Ecuadorian Amazon Basin

“…Multiplicity of infection (MOI) refers to the average number of distinct parasite genotypes concurrently infecting a patient and was calculated using the number of different alleles at each locus; single infections were reported by only one allele per locus at all of the genotype loci. 10,14,22 We measured intra-and interpopulation diversity using the statistic expected heterozygosity (He) of each locus, which may be defined as the average probability that two alleles randomly obtained for each locus are different. We calculated the expected heterozygosity using…”

“…Studies of P. vivax using microsatellite markers in populations from endemic areas of South America such as the Amazon jungle of Colombia, Brazil, and Peru revealed high levels of heterogeneity (He = 0.44-0.80) and strong differentiation in P. vivax populations. [10][11][12][13][14][15] In Peru, the analysis of the genetic variability and population structure of P. vivax populations using microsatellite markers has been described for the Peruvian Amazon Basin only. 10,16,17 Van den Eede et al, 10 found high levels of genetic variability, highly structured populations, and strong genetic differentiation.…”