title: Double mutation in the pfmdr1 gene is associated with emergence of chloroquine-resistant Plasmodium falciparum malaria in Eastern India.
abstract: Malaria is a major public health problem in tropical and subtropical countries, including India. This study elucidates the cause of chloroquine treatment failure (for Plasmodium falciparum infection) before the introduction of artemisinin combination therapy. One hundred twenty-six patients were randomized to chloroquine treatment, and the therapeutic efficacy was monitored from days 1 to 28. An in vitro susceptibility test was performed with all isolates. Parasitic DNA was isolated, followed by PCR and restriction digestion of different codons of the pfcrt gene (codons 72 to 76) and the pfmdr1 gene (N86Y, Y184F, S1034C, N1042D, and D1246Y). Finally, sequencing was done to confirm the mutations. Forty-three (34.13%) early treatment failure cases and 16 (12.69%) late treatment failure cases were observed after chloroquine treatment. In vitro chloroquine resistance was found in 103 isolates (81.75%). Twenty-six (60.47%) early treatment failure cases and 6 (37.5%) late treatment failure cases were associated with the CVMNK-YYSNY allele (the underlined amino acids are those that were mutated). Moreover, the CVIEK-YYSNY allele was found in 8 early treatment failure (18.60%) and 2 late treatment failure (12.5%) cases. The presence of the wild-type pfcrt (CVMNK) and pfmdr1 (YYSNY) double mutant allele in chloroquine-nonresponsive cases was quite uncommon. In vivo chloroquine treatment failure and in vitro chloroquine resistance were strongly correlated with the CVMNK-YYSNY and CVIEK-YYSNY haplotypes (P < 0.01).
authors: Immunology and Microbiology Laboratory, Department of Human Physiology with Community Health, Vidyasagar University, Midnapore, West Bengal, India.
authors: Sabyasachi
authors: S
authors: Das
authors: Department of Biotechnology, School of Chemical and Biotechnology, SASTRA University, Thanjavur, Tamil Nadu, India.
authors: Santanu Kar
authors: SK
authors: Mahapatra
authors: Immunology and Microbiology Laboratory, Department of Human Physiology with Community Health, Vidyasagar University, Midnapore, West Bengal, India.
authors: Satyajit
authors: S
authors: Tripathy
authors: Immunology and Microbiology Laboratory, Department of Human Physiology with Community Health, Vidyasagar University, Midnapore, West Bengal, India.
authors: Sourav
authors: S
authors: Chattopadhyay
authors: Immunology and Microbiology Laboratory, Department of Human Physiology with Community Health, Vidyasagar University, Midnapore, West Bengal, India.
authors: Sandeep Kumar
authors: SK
authors: Dash
authors: Immunology and Microbiology Laboratory, Department of Human Physiology with Community Health, Vidyasagar University, Midnapore, West Bengal, India.
authors: Debasis
authors: D
authors: Mandal
authors: Immunology and Microbiology Laboratory, Department of Human Physiology with Community Health, Vidyasagar University, Midnapore, West Bengal, India.
authors: Balaram
authors: B
authors: Das
authors: Department of Medical Entomology and Chairman, Division of Parasitology, Calcutta School of Tropical Medicine, Kolkata, West Bengal, India.
authors: Amiya Kumar
authors: AK
authors: Hati
authors: Immunology and Microbiology Laboratory, Department of Human Physiology with Community Health, Vidyasagar University, Midnapore, West Bengal, India roysomenath@hotmail.com.
authors: Somenath
authors: S
authors: Roy
mesh_terms: D000962:Antimalarials / Q000627:therapeutic use*; D002738:Chloroquine / Q000627:therapeutic use*; D004351:Drug Resistance / Q000235:genetics*; D006801:Humans; D007194:India; D016778:Malaria, Falciparum / Q000188:drug therapy* / Q000235:genetics; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics*; D009154:Mutation; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000235:genetics* / Q000472:pathogenicity
chemical_list: D000962:Antimalarials; D002738:Chloroquine; D027425:ATP-Binding Cassette, Sub-Family C Proteins; C513498:Mdr1 protein, Plasmodium falciparum