title: Correlation of molecular markers, Pfmdr1-N86Y and Pfcrt-K76T, with in vitro chloroquine resistant Plasmodium falciparum, isolated in the malaria endemic states of Assam and Arunachal Pradesh, Northeast India.
abstract: The mechanism of chloroquine (CQ) resistance in Plasmodium falciparum is not clearly understood. However, CQ resistance has been shown to be associated with point mutations in Pfcrt and Pfmdr1. These genes encode for digestive vacuole transmembrane proteins Pfcrt and Pgh1, respectively. The present study was carried out to analyze the association of Pfcrt-K76T and Pfmdr1-N86Y mutations with CQ resistance in Northeast Indian P. falciparum isolates. 115 P. falciparum isolates were subjected to in vitro CQ sensitivity testing and PCR-RFLP analysis for the Pfmdr1-N86Y and Pfcrt-K76T mutations. 100 isolates of P. falciparum were found to be resistant to CQ by the in vitro susceptibility test (geometric mean EC50 2.21 µM/L blood) while 15 were found to be CQ sensitive (geometric mean EC50 0.32 µM/L blood). All the CQ resistant isolates showed the presence of Pfmdr1 and Pfcrt mutations. CQ sensitive isolates were negative for these mutations. Strong linkage disequilibrium was observed between the alleles at these two loci (Pfmdr1-N86Y and Pfcrt-K76T). The results indicate that Pfmdr1-N86Y and Pfcrt-K76T mutations can be used as molecular markers to identify CQ resistance in P. falciparum. The result necessitates the evaluation of CQ in vivo therapeutic efficacy in endemic areas for more effective malaria control strategies.
authors.affiliation: Department of Parasitology, Post Graduate Institute of Medical Education and Research, Chandigarh, India; Basic and Clinical Immunology of Parasitic Diseases, Centre for Infection and Immunity of Lille, Institut Pasteur de Lille, France.
authors.forename: Sandeep Kumar
authors.initials: SK
authors.lastname: Shrivastava
authors.affiliation: Central Research Institute, Kasauli (H.P.) India.
authors.forename: Ravi Kumar
authors.initials: RK
authors.lastname: Gupta
authors.affiliation: Regional Medical Research Centre (ICMR), Dibrugarh, Assam, India.
authors.forename: Jagdish
authors.initials: J
authors.lastname: Mahanta
authors.affiliation: Department of Parasitology, Post Graduate Institute of Medical Education and Research, Chandigarh, India.
authors.forename: Mohan Lal
authors.initials: ML
authors.lastname: Dubey
mesh_terms: D002738:Chloroquine; D017931:DNA Primers / Q000235:genetics; D004351:Drug Resistance / Q000235:genetics; D019353:Endemic Diseases; D005819:Genetic Markers / Q000235:genetics*; D007194:India / Q000453:epidemiology; D015810:Linkage Disequilibrium; D008288:Malaria / Q000453:epidemiology* / Q000517:prevention & control; D026901:Membrane Transport Proteins / Q000235:genetics*; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics*; D020125:Mutation, Missense / Q000235:genetics*; D010963:Plasmodium falciparum / Q000235:genetics*; D012150:Polymorphism, Restriction Fragment Length; D015800:Protozoan Proteins / Q000235:genetics*
chemical_list: D002738:Chloroquine; D017931:DNA Primers; D005819:Genetic Markers; D026901:Membrane Transport Proteins; D027425:ATP-Binding Cassette, Sub-Family C Proteins; D015800:Protozoan Proteins; C513498:Mdr1 protein, Plasmodium falciparum; C416369:PfCRT protein, Plasmodium falciparum
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