TABLE 1.

pfcrt haplotypes in relation to in vitro response of Cambodian P. falciparum isolates to chloroquinea

Code isolateArea of samplingIn vitro responsePfCRT amino acid (codon) encoded at position:
SitePosition within regionbIC50 (nM)Out- comec72 (TGT)73 (GTA)74 (ATT)75 (GAA)76 (ACA)77 (ATT)78 (TTT)218 (ATT)219 (AGT)220 (TCC)
159dSampovloumNW665RCVIETIFISS
170dSampovloumNW592RCVIETIFISS
209dSampovloumNW410RCVIETIFISS
194dSampovloumNW368RCVIETIFISS
186dSampovloumNW349RCVIETIFISS
197dSampovloumNW338RCVIETIFISS
176dSampovloumNW228RCVIETT (ACT)FISS
164dSampovloumNW206RCVIETIFISS
183dSampovloumNW73.8SCVIETIFISS
182dSampovloumNW71.3SCVIETIFISS
201dSampovloumNW65.0SCVIETIFISS
172dSampovloumNW42.3SCVIETIFISS
173dSampovloumNW27.8SCVIETIFISS
174dSampovloumNW27.0SCVIETIFISS
200dSampovloumNW18.0SCVIETIFISS
171dSampovloumNW18.0SCVIET (ACT)IFISS
91Kampong SpeuW1,146RCVIETIFISS
73dKampong SpeuW504RCVIETIFISS
112dKampong SpeuW442RCVIETIFISS
85Kampong SpeuW315RCVIETIFISS
75Kampong SpeuW241RCVIETIFISS
108dKampong SpeuW238RCVID (GAT)TIFISS
110dKampong SpeuW210RCVIETIFISS
128dKampong SpeuW118RCVIETIFISS
103dKampong SpeuW95.3SCVIETIFISS
125dKampong SpeuW4.8SCVIETIFISS
46RattanakiriNE57.0SCVM (ATG)N (AAT)TIFISA (GCC)
56dRattanakiriNE55.8SCVID (GAT)TIFISS
32dRattanakiriNE51.0SCVID (GAT)TIFISS
60RattanakiriNE21.4SCVID (GAT)TIFISS
36dRattanakiriNE17.0SCV (GTC)T (ACC)N (AAT)T (ACC)IFISS
63dRattanakiriNE9.3SCVM (ATG)N (AAT)K (AAA)IFISA (GCC)
42RattanakiriNE8.7SCVM (ATG)N (AAT)K (AAA)IFISA (GCC)
35RattanakiriNENDeNDCVIETIFISS
53RattanakiriNENDNDCVM (ATG)N (AAT)K (AAA)IFISA (GCC)
HB3 cloneHondurasC (TGT)V (GTA)M (ATG)N (AAT)K (AAA)I (ATT)F (TTT)I (ATT)S (AGT)A (GCC)
  • a The sequences at positions 72 to 78 and positions 218 to 220 of pfcrt isolates from the Sampovloum, Kampong Speu, and Ratanakiri areas of Cambodia were determined by sequencing fragments of amplified genomic DNA. The nucleotide sequence of the canonical resistant haplotype (CVIETIF//ISS) is indicated at the top of the table. The sequence of the HB3 sensitive haplotype is indicated at the bottom of the table.

  • b Abbreviations: NW, northwestern; W, western; NE, northeastern.

  • c In vitro chloroquine resistance (R) and sensitivity (S) are defined as an IC50 of >100 nM and <100 nM, respectively.

  • d Single genotype.

  • e ND, not determined.