title: Polymorphisms in Pfcrt and Pfmdr-1 genes after five years withdrawal of chloroquine for the treatment of Plasmodium falciparum malaria in West Bengal, India.
abstract: The emergence of resistant power against different antimalarial agents particularly by Plasmodium falciparum is a challenge to combat malaria. Regular monitoring is essential not only to determine the efficacy and development of resistance by the parasite but also to detect early sign of regaining sensitivity to any anti-malarial agent that has been withdrawn for a long period. Studies on molecular markers associated with antimalarial drug resistance of prevailing Plasmodium population play an important role in this aspect. The present protocol was designed to study the polymorphisms in pfcrt and pfmdr-1 gene to determine any sign of regaining sensitivity to chloroquine among P. falciparum after five years of artemisinin combination therapy (ACT) implementation.
  
  
  
  Clinical isolates were collected from P. falciparum positive patients attending the malaria clinic of Calcutta School of Tropical Medicine during December 2014 to December 2015. Genomic parasitic DNA was extracted and subjected to sequencing of pfcrt and pfmdr-1 gene directly from purified PCR products.
  
  
  
  A total of 89 isolates were sequenced for pfcrt and 73 isolates for pfmdr-1 genes. In pfcrt gene mutant K76T was detected in all isolates and all were SVMNT haplotype. Out of three important polymorphisms in pfmdr-1 gene mutant Y184F was detected among all isolates. One synonymous G182G and one non-synonymous S232F/Y, mutation were detected in 99% isolates.
  
  
  
  All isolates carrying mutant K76T in pfcrt gene, considered as hall mark for CQ resistance, indicate that there is no sign of regaining CQ sensitivity among the prevailing P. falciparum population of the study area after five years of ACT implementation.
authors.affiliation: Protozoology Unit, Department of Microbiology, Calcutta School of Tropical Medicine, 108, C. R. Avenue, Kolkata 700 073, India. Electronic address: moytreychatterjee@yahoo.in.
authors.forename: Moytrey
authors.initials: M
authors.lastname: Chatterjee
authors.affiliation: Department of Microbiology, NRS Medical College, 138 AJC Bose Road, Kolkata 700 014, India. Electronic address: swagatamedicine@gmail.com.
authors.forename: Swagata
authors.initials: S
authors.lastname: Ganguly
authors.affiliation: Department of Zoology, APC Roy Government College, Himachal Bihar, Matigara, Siliguri 734 010, West Bengal, India. Electronic address: pabitra.saha82@gmail.com.
authors.forename: Pabitra
authors.initials: P
authors.lastname: Saha
authors.affiliation: Department of Tropical Medicine, Calcutta School of Tropical Medicine, 108, C. R. Avenue, Kolkata 700 073, India. Electronic address: drskguha@gmail.com.
authors.forename: Subhasish Kamal
authors.initials: SK
authors.lastname: Guha
authors.affiliation: Calcutta School of Tropical Medicine, 108, C. R. Avenue, Kolkata 700 073, India. Electronic address: stmkolkatadirector@gmail.com.
authors.forename: Nandita
authors.initials: N
authors.lastname: Basu
authors.affiliation: Protozoology Unit, Department of Microbiology, Calcutta School of Tropical Medicine, 108, C. R. Avenue, Kolkata 700 073, India. Electronic address: bera_dk.helminthology@yahoo.in.
authors.forename: Dilip K
authors.initials: DK
authors.lastname: Bera
authors.affiliation: Protozoology Unit, Department of Microbiology, Calcutta School of Tropical Medicine, 108, C. R. Avenue, Kolkata 700 073, India. Electronic address: maji_ardhendu@yahoo.com.
authors.forename: Ardhendu Kumar
authors.initials: AK
authors.lastname: Maji
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D000962:Antimalarials / Q000627:therapeutic use; D002648:Child; D002675:Child, Preschool; D002738:Chloroquine / Q000627:therapeutic use*; D004352:Drug Resistance, Microbial / Q000187:drug effects / Q000235:genetics; D005260:Female; D006239:Haplotypes; D006801:Humans; D007194:India; D016778:Malaria, Falciparum / Q000188:drug therapy / Q000469:parasitology; D008297:Male; D026901:Membrane Transport Proteins / Q000235:genetics*; D008875:Middle Aged; D027425:ATP-Binding Cassette, Sub-Family C Proteins / Q000235:genetics*; D009154:Mutation; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000235:genetics*; D011110:Polymorphism, Genetic; D015800:Protozoan Proteins / Q000235:genetics*; D055815:Young Adult
chemical_list: D000962:Antimalarials; D002738:Chloroquine; 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
keywords: Chloroquine sensitivity; India; Pfcrt; Pfmdr-1; Plasmodium falciparum