TABLE 1.
pfcrt haplotypes in relation to in vitro response of Cambodian P. falciparum isolates to chloroquinea
| Code isolate | Area of sampling
|
In vitro response
|
PfCRT amino acid (codon) encoded at position:
|
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Site | Position within regionb | IC50 (nM) | Out- comec | 72 (TGT) | 73 (GTA) | 74 (ATT) | 75 (GAA) | 76 (ACA) | 77 (ATT) | 78 (TTT) | 218 (ATT) | 219 (AGT) | 220 (TCC) | |
| 159d | Sampovloum | NW | 665 | R | C | V | I | E | T | I | F | I | S | S |
| 170d | Sampovloum | NW | 592 | R | C | V | I | E | T | I | F | I | S | S |
| 209d | Sampovloum | NW | 410 | R | C | V | I | E | T | I | F | I | S | S |
| 194d | Sampovloum | NW | 368 | R | C | V | I | E | T | I | F | I | S | S |
| 186d | Sampovloum | NW | 349 | R | C | V | I | E | T | I | F | I | S | S |
| 197d | Sampovloum | NW | 338 | R | C | V | I | E | T | I | F | I | S | S |
| 176d | Sampovloum | NW | 228 | R | C | V | I | E | T | T (ACT) | F | I | S | S |
| 164d | Sampovloum | NW | 206 | R | C | V | I | E | T | I | F | I | S | S |
| 183d | Sampovloum | NW | 73.8 | S | C | V | I | E | T | I | F | I | S | S |
| 182d | Sampovloum | NW | 71.3 | S | C | V | I | E | T | I | F | I | S | S |
| 201d | Sampovloum | NW | 65.0 | S | C | V | I | E | T | I | F | I | S | S |
| 172d | Sampovloum | NW | 42.3 | S | C | V | I | E | T | I | F | I | S | S |
| 173d | Sampovloum | NW | 27.8 | S | C | V | I | E | T | I | F | I | S | S |
| 174d | Sampovloum | NW | 27.0 | S | C | V | I | E | T | I | F | I | S | S |
| 200d | Sampovloum | NW | 18.0 | S | C | V | I | E | T | I | F | I | S | S |
| 171d | Sampovloum | NW | 18.0 | S | C | V | I | E | T (ACT) | I | F | I | S | S |
| 91 | Kampong Speu | W | 1,146 | R | C | V | I | E | T | I | F | I | S | S |
| 73d | Kampong Speu | W | 504 | R | C | V | I | E | T | I | F | I | S | S |
| 112d | Kampong Speu | W | 442 | R | C | V | I | E | T | I | F | I | S | S |
| 85 | Kampong Speu | W | 315 | R | C | V | I | E | T | I | F | I | S | S |
| 75 | Kampong Speu | W | 241 | R | C | V | I | E | T | I | F | I | S | S |
| 108d | Kampong Speu | W | 238 | R | C | V | I | D (GAT) | T | I | F | I | S | S |
| 110d | Kampong Speu | W | 210 | R | C | V | I | E | T | I | F | I | S | S |
| 128d | Kampong Speu | W | 118 | R | C | V | I | E | T | I | F | I | S | S |
| 103d | Kampong Speu | W | 95.3 | S | C | V | I | E | T | I | F | I | S | S |
| 125d | Kampong Speu | W | 4.8 | S | C | V | I | E | T | I | F | I | S | S |
| 46 | Rattanakiri | NE | 57.0 | S | C | V | M (ATG) | N (AAT) | T | I | F | I | S | A (GCC) |
| 56d | Rattanakiri | NE | 55.8 | S | C | V | I | D (GAT) | T | I | F | I | S | S |
| 32d | Rattanakiri | NE | 51.0 | S | C | V | I | D (GAT) | T | I | F | I | S | S |
| 60 | Rattanakiri | NE | 21.4 | S | C | V | I | D (GAT) | T | I | F | I | S | S |
| 36d | Rattanakiri | NE | 17.0 | S | C | V (GTC) | T (ACC) | N (AAT) | T (ACC) | I | F | I | S | S |
| 63d | Rattanakiri | NE | 9.3 | S | C | V | M (ATG) | N (AAT) | K (AAA) | I | F | I | S | A (GCC) |
| 42 | Rattanakiri | NE | 8.7 | S | C | V | M (ATG) | N (AAT) | K (AAA) | I | F | I | S | A (GCC) |
| 35 | Rattanakiri | NE | NDe | ND | C | V | I | E | T | I | F | I | S | S |
| 53 | Rattanakiri | NE | ND | ND | C | V | M (ATG) | N (AAT) | K (AAA) | I | F | I | S | A (GCC) |
| HB3 clone | Honduras | C (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.