About 50% of malaria infections in India are attributed to Plasmodium falciparum but relatively little is known about the genetic structure of the parasite populations. The molecular genotyping of the parasite populations by merozoite surface protein (msp1 and msp2) and glutamate-rich protein (glurp) genes identifies the existing parasite population in the regions which help in understanding the molecular mechanisms involved in the parasite's drive for survival. This study reveals the genetic profile of the parasite population in selected regions across the country with varying degree of endemicity among them. We also report the prevalence of Pfcrt mutations in this parasite population to evaluate the pattern of drug resistance development in them.

The production of gametocytes in field isolates of Plasmodium falciparum is not clearly understood even though the gametocytes are crucial for disease transmission. Samples collected during the malaria transmission period from two different regions of India were cultured in vitro for gametocyte production and analyzed by PCR and RT-PCR assay for Pfs25 gene. A total of 20 P. falciparum field isolates were collected which showed varying intensity of in vitro gametocyte production. The isolates which produced mature gametocytes in vitro also had an increase in their Pfs25 expression, indicating that the gametocyte produced is directly proportional to the Pfs25 gene expression. The expression ranged from 0.32 to 4.56 fold in field isolates when compared to the reference strain. The in vitro gametocyte production in fresh field isolates directly correlated with the expression of Pfs25 gene in these isolates as shown by ANOVA test.