Distinct Allelic Diversity of Plasmodium vivax Merozoite Surface Protein 3-Alpha (PvMSP-3α) Gene in Thailand Using PCR-RFLP

Kanyanan Kritsiriwuthinan; Warunee Ngrenngarmlert; Rapatbhorn Patrapuvich; Supaksajee Phuagthong; Kantima Choosang

doi:10.1155/2023/8855171

Distinct Allelic Diversity of Plasmodium vivax Merozoite Surface Protein 3-Alpha (PvMSP-3α) Gene in Thailand Using PCR-RFLP

J Trop Med. 2023 Aug 11:2023:8855171. doi: 10.1155/2023/8855171. eCollection 2023.

Authors

Kanyanan Kritsiriwuthinan¹, Warunee Ngrenngarmlert², Rapatbhorn Patrapuvich³, Supaksajee Phuagthong¹, Kantima Choosang¹

Affiliations

¹ Faculty of Medical Technology, Rangsit University, Pathumthani 12000, Thailand.
² Department of Community Medical Technology, Faculty of Medical Technology, Mahidol University, Nakhon Pathom 73170, Thailand.
³ Drug Research Unit for Malaria (DRUM), Center of Excellence in Malaria Research, Faculty of Tropical Medicine, Mahidol University, Bangkok 10400, Thailand.

Abstract

Considering the importance of merozoite surface proteins (MSPs) as vaccine candidates, this study was conducted to investigate the polymorphism and genetic diversity of Plasmodium vivax merozoite surface protein 3-alpha (PvMSP-3α) in Thailand. To analyze genetic diversity, 118 blood samples containing P. vivax were collected from four malaria-endemic areas in western and southern Thailand. The DNA was extracted and amplified for the PvMSP-3α gene using nested PCR. The PCR products were genotyped by PCR-RFLP with Hha I and Alu I restriction enzymes. The combination patterns of Hha I and Alu I RFLP were used to identify allelic variants. Genetic evaluation and phylogenic analysis were performed on 13 sequences, including 10 sequences from our study and 3 sequences from GenBank. The results revealed three major types of PvMSP-3α, 91.5% allelic type A (∼1.8 kb), 5.1% allelic type B (∼1.5 kb), and 3.4% allelic type C (∼1.2 kb), were detected based on PCR product size with different frequencies. Among all PvMSP-3α, 19 allelic subtypes with Hha I RFLP patterns were distinguished and 6 allelic subtypes with Alu I RFLP patterns were identified. Of these samples, 73 (61%) and 42 (35.6%) samples were defined as monoallelic subtype infection by Hha I and Alu I PCR-RFLP, respectively, whereas 77 (65.3%) samples were determined to be mixed-allelic subtype infection by the combination patterns of Hha I and Alu I RFLP. These results strongly indicate that PvMSP-3α gene is highly polymorphic, particularly in blood samples collected from the Thai-Myanmar border area (the western part of Thailand). The combination patterns of Hha I and Alu I RFLP of the PvMSP-3α gene could be considered for use as molecular epidemiologic markers for genotyping P. vivax isolates in Thailand.