Single-nucleotide polymorphisms in genes associated with drug resistance of Plasmodium vivax in two regions of South India

Background: Plasmodium vivax is reported to be the predominant cause of malaria in India. Recent emergence of resistance to chloroquine (CQ) and sulfadoxine-pyrimethamine (SP) drugs has been attributed to multiple mutations in pvmdr-1 and pvdhfr regions of P. vivax, respectively. Hence, in this study, we have assessed the single-nucleotide polymorphisms (SNPs) in pvmdr-1 and pvdhfr genes for CQ and SP drug resistance, respectively, in cases of malaria from two regions of South India. Materials and Methods: A total of 36 P. vivax isolates from Bengaluru and Vijayapura were collected and sequenced for pvmdr-1 and pvdhfr genes, and the SNPs were analyzed. Results: Out of the total 45 positive P. vivax samples assessed in this study, 36 samples were mono infection cases. No wild-type pvmdr-1 gene was observed in any of the samples analyzed. Predominant presence (83.3%) of double mutations (T958M and F1076L) was observed. In the pvdhfr gene, wild-type (36.1%) and two mutations (41.6%; S58R and S117N) were observed. New mutations were not detected in pvmdr-1 or pvdhfr gene in this study. Conclusion: The present study reports the presence of SNPs in both pvmdr-1 and pvdhfr genes in P. vivax isolates from Bengaluru and Vijayapura. Continuous monitoring of drug resistance to antimalarial drugs is essential for undertaking optimal public health measures tailored to selected regions.