Prevalence of polymorphisms in marker genes associated with antimalarial drug resistance in following 10 years of artemisinin-based combination therapy implementation in urban Kolkata.

CONTEXT

Resistance to antimalarial drugs is one of the major challenges for malaria elimination. In India, artemisinin combination therapy (artesunate-sulfadoxin pyrimethamine) was introduced in place of chloroquine (CQ) for the treatment of uncomplicated falciparum malaria in 2010. Periodical monitoring of polymorphisms in antimalarial drug resistance marker genes will be useful for assessing drug pressure, mapping and monitoring of drug resistance status; and will be helpful for searching alternative treatments.

OBJECTIVES

This study was conducted to study the polymorphisms in antimalarial drug resistance marker genes among clinical isolates collected from Kolkata after 10 years of artemisinin-based combination therapie (ACT) implementation.

MATERIALS AND METHODS

Blood samples were collected from mono-infected patients and polymorphisms in CQ resistance transporter , multidrug resistance , dihydrofolate reductase , dihydropteroate synthetase , and propeller genes were analysed by polymerase chain reaction and DNA sequencing.

RESULTS

In gene, C72S, and K76T mutation was recorded in 100% isolates and no mutations was detected in any of the targeted codons of gene. A double mutant haplotype SVMNT and wildtype haplotype NYD in were prevalent in 100% of study isolates. Triple mutant haplotype ANRNI-SGKAA was recorded. No polymorphism in gene was documented in any of the isolates.

CONCLUSIONS

Observed wild codon N86 along with Y184 and D1246 of gene might be an indication of the reappearance of CQ sensitivity. The absence of quadruple and quintuple haplotypes in gene along with the wild haplotype of pfK13 is evidence of ACT effectivity. Hence, similar studies with large sample size are highly suggested for monitoring the drug resistance status of .