Plasmodium vivax msp-3α polymorphisms: analysis in the Indian subcontinent. (December 2016)

• Record Type: Journal Article
• Authors: Verma, Anju; Joshi, Hema; Singh, Vineeta; Anvikar, Anup; Valecha, Neena
• Is Part Of: Malaria journal. Volume 15:Number 1(2016)
• Page Start: 1
• Page End: 13
• Publication Date: 2016-12
• Subjects: Plasmodium vivax -- Merozoite surface protein-3α -- PCR-RFLP -- Genetic variability; Malaria -- Periodicals; 616.9362
• DOI: 10.1186/s12936-016-1524-y
• Languages: English
• ISSNs: 1475-2875

Abstract

Abstract Background Plasmodium vivax is the most widely distributed human malaria parasite and accounts for approximately the same number of malaria cases asPlasmodium falciparum in India. Compared withP. falciparum, P. vivax is difficult to eradicate because of its tendency to cause relapses, which impacts treatment and control strategies. The genetic diversity of these parasites, particularly of the merozoite surface protein-3 alpha (msp -3α ) gene, can be used to help develop a potential vaccine. The present study aimed to investigate the genetic diversity ofP. vivax using the highly polymorphic antigen genemsp -3α and to assess the suitability of using this gene for population genetic studies ofP. viv ax isolates and was carried out in 2004–06. No recent study has been reported for MSP 3α in the recent decade in India. Limited reports are available on the genetic diversity of theP. vivax population in India; hence, this report aimed to improve the understanding of the molecular epidemiology of the parasite by studying theP. vivax msp -3α (Pvmsp -3α ) marker fromP. vivax field isolates from India. Methods Field isolates were collected from different sites distributed across eight states in India. A total of 182 blood samples were analysed by a nested polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) technique using theHha I andAlu I restriction enzymes to determine geneticmsp -3α variation among clinicalP. vivax isolates. Results Based on the length variants of the PCR products ofPvmsp -3α gene, three allele sizes, Type A (1.8 kb), Type B (1.5 kb) and Type C (1.2 kb) were detected among the 182 samples. Type A PCR amplicon was more predominant (75.4 %) in the samples compared with the Type B (14.3 %) and Type C (10.0 %) polymorphisms. Among all of the samples analysed, 8.2 % were mixed infections detected by PCR alone. Restriction fragment length polymorphism (RFLP) analysis involving the restriction enzymesAlu I andHha I generated fragment sizes that were highly polymorphic and revealed substantial diversity at the nucleotide level. Conclusions The present study is the first extensive study in India using thePvmsp -3α marker. The results indicated thatPvmps -3α, a polymorphic genetic marker ofP. vivax, exhibited considerable variability in infection prevalence in field isolates from India. Additionally, the mean multiplicity of infection observed at all of the study sites indicated thatP. vivax is highly diverse in nature in India, andPvmsp -3α is likely an effective and promising epidemiological marker.