Yagya Dutta Sharma

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The combination of sulfadoxine-pyrimethamine (SP) is used as a second line of therapy for the treatment of uncomplicated chloroquine-resistant Plasmodium falciparum malaria. Resistance to SP arises due to certain point mutations in the genes for the dihydrofolate reductase (DHFR) and dihydropteroate synthetase (DHPS) enzymes of the parasite. We have(More)
Mutations in the chloroquine resistance (CQR) transporter gene of Plasmodium falciparum (Pfcrt; chromosome 7) play a key role in CQR, while mutations in the multidrug resistance gene (Pfmdr1; chromosome 5) play a significant role in the parasite's resistance to a variety of antimalarials and also modulate CQR. To compare patterns of genetic variation at(More)
Chloroquine-resistant Plasmodium falciparum needs to be monitored in the field for effective malaria control strategies. A point mutation K76T in the P. falciparum chloroquine resistance transporter (Pfcrt) protein has recently been proposed as a molecular marker for the faster detection of chloroquine-resistant falciparum malaria in field. We describe here(More)
To assess sulfadoxine and pyrimethamine resistance (SPR), we describe here the dihydropteroate synthetase (DHPS) mutations among the Plasmodium falciparum isolates in which dihydrofolate reductase (DHFR) mutations had recently been described by us (A. Ahmed, M. K. Das, V. Dev, M. A. Saifi, Wajihullah, and Y. D. Sharma, Antimicrob. Agents Chemother.(More)
Present study describes the characterization of apical membrane antigen 1 (PvAMA1) polymorphisms among Indian Plasmodium vivax isolates. The partial PvAMA1 gene (covering domain I and domain II regions) sequenced from sixty-one (n=61) isolates in this study resulted into 49 haplotypes. Comparison with the previously available PvAMA1 sequences in the GenBank(More)
BACKGROUND Effective malaria control programs require continuous monitoring of drug pressure in the field, using molecular markers. METHODS We used sequence analysis to investigate the pfcrt and pfmdr1 mutations in Indian Plasmodium falciparum isolates. To evaluate the chloroquine drug pressure in the field, isolates were collected from 5 different areas(More)
The antifolate drugs sulfadoxine and pyrimethamine are commonly used to treat Plasmodium falciparum malaria. However, they can also affect the Plasmodium vivax parasite if it coexists with P. falciparum, as both species have common drug targets. Resistance to the antifolate drugs arises due to point mutations in the target enzymes of the respective(More)
The malaria parasite contains a nuclear genome with 14 chromosomes and two extrachromosomal DNA molecules of 6 kb and 35 kb in size. The smallest genome, known as the 6 kb element or mitochondrial DNA, has been sequenced from several Plasmodium falciparum isolates because this is a potential drug target. Here we describe the complete nucleotide sequence of(More)
BACKGROUND Enormous amounts of drugs were used to contain the outbreak of infectious diseases in areas of India affected by the tsunami in December 2004. The impact of this drug use on the Plasmodium falciparum population needs to be investigated. METHODS The nucleotide sequence of the pfcrt, pfdhps, and pfdhfr genes was determined for 229 clinical P.(More)
Plasmodium vivax merozoite surface protein 1 (PvMSP-1) is a leading malaria vaccine candidate. This protein is processed to give rise to various sized fragments during merozoite maturation. Here, we describe the analysis of genetic diversity in the 42 kDa C-terminal part of this protein among 33 Indian P. vivax isolates. A total of 27 haplotypes with 72(More)