Pfcrt and pfmdr1 alleles associated with chloroquine resistance in Plasmodium falciparum from Guyana, South America.
Using DNA extracted from 112 parasitised blood blots, we screened for the population marker of chloroquine resistance (CQR) pfcrt K76T in Plasmodium falciparum infections from Guyana. Pfmdr1 mutations S1034C, N1042D, and D1246Y also associated with CQR were surveyed as well in 15 isolates for which the in vitro responses to CQ were known. Results indicate that the pfcrt K76T is ubiquitous in this environment, and confirmatory sequencing of codons 72 and 76 revealed two novel allelic sequences SVMIT and RVMNT in addition to the previously identified CVMNT and SVMNT haplotypes. The frequency of the pfcrt K76T despite its presence in both CQR and CQS (chloroquine sensitive) infections measured in vivo and in vitro, suggests that it is a useful population marker in this low-transmission setting of sweeping CQR.
Pharmacology and Biochemistry Units, Faculty of Medical Sciences, University of the West Indies, St. Augustine, Trinidad and Tobago. wsb2000@yahoo.com
Wallis
W
Best Plummer
Lexley M
LM
Pinto Pereira
Christine V F
CV
Carrington
D018528:ATP-Binding Cassette Transporters / Q000235:genetics*; D000483:Alleles; D000818:Animals; D000962:Antimalarials / Q000494:pharmacology*; D002738:Chloroquine / Q000494:pharmacology*; D016054:DNA, Protozoan / Q000187:drug effects / Q000235:genetics; D004351:Drug Resistance / Q000235:genetics*; D005819:Genetic Markers; D006172:Guyana; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics*; D026901:Membrane Transport Proteins; D009154:Mutation; D021261:Parasitic Sensitivity Tests; D010963:Plasmodium falciparum / Q000187:drug effects* / Q000235:genetics*; D015800:Protozoan Proteins / Q000235:genetics*
D018528:ATP-Binding Cassette Transporters; D000962:Antimalarials; D016054:DNA, Protozoan; D005819:Genetic Markers; D008565:Membrane Proteins; D026901:Membrane Transport Proteins; C416369:PfCRT protein, Plasmodium falciparum; D015800:Protozoan Proteins; C059987:mdr gene protein, Plasmodium; D002738:Chloroquine