Genetic Differentiation and Flow of Plasmodium falciparum dhfr Gene Sequences Associated with Pyrimethamine Drug Resistance

The present study was conducted in Chirang, North Cachar Hills and Karbi Anglong district in Assam with an aim to find out the genetic differentiations and flow of Plasmodium falciparum dihydrofolate reductase (Pfdhfr) gene associated with Pyrimethamine resistance. Therefore, a total of 116 participants were enrolled for the study. Presence of malaria parasites were confirmed by microscopic slide examination method. P. falciparum mono-infection was observed in 69 cases. A 648 base pair portion of Pfdhfr gene containing major single nucleotide polymorphisms were amplified, sequenced, and then analyzed in BioEdit v7.0.9 software, Mega 5 software and DnaSP version v.5.10.01. Three polymorphic sites were observed in the dhfr gene sequences of P. falciparum field isolates in Assam. The value of neutrality test did not show any statistically significant result. The highest level of haplotype diversity (0.38889) was observed in the P. falciparum isolates in Chirang district of Assam. Little to moderate genetic differentiation was observed between the P. falciparum field isolates in Chirang and NC hills. It specifies that the gene flow levels were high enough to counteract the effects of genetic drift.