Mutational Analysis of Plasmodium vivax dhfr Gene Among Cases in South East of Iran

Background: Plasmodium vivax and P. falciparum have been detected in south east of Iran. Plasmodium vivax has a higher prevalence in this area. Point mutation in P. vivax dihydrofolate reductase (pvdhfr) gene is the key mechanism of Sulfadoxine and Pyrimethamine (SP) resistance. Objectives: This study aimed at investigating pvdhfr mutations and haplotypes in Sistan and Baluchestan endemic province of Iran. Methods: Seventy-five blood samples from Sistan and Baluchistan province of Iran, infected with P. vivax, between years 2013 and 2015, were enrolled in this study. The samples were examined for probable point mutations in pvdhfr gene using Polymerase Chain Reaction-Restriction Fragment Length Polymorphism (PCR-RFLP) and sequencing methods. Results: Most of the isolates (59%) had wild type codons at 4 locations of pvdhfr gene. The F57S58T61N117 was the most common haplotype among the mutant cases (24.3%); in these cases, the haplotypes with triple and quadruple mutations in 57, 58, 61, and 117 codons were not identified. In addition, haplotypes with double mutations at location FRTN (7.7%) and FRTT (2.6%) were identified in studied cases. Conclusions: This study showed that the presence of mutant pvdhfr haplotypes, which are resistant to the SP is increasing, therefore, performing a molecular surveillance via the PCR method in endemic areas is very important.