TABLE 2.
Relationship between PM and QN254 median inhibitory concentrations that kill 50% of parasitemia (IC50) and dihydrofolate reductase (dhfr) genotypes of clinical isolatesa
| DHFR genotypeb | IC50 (nM)c |
|
|---|---|---|
| PM | QN254 | |
| Double mutant* | 371 (8) | 4.48 (6) |
| Triple mutant* | 778.28 (24) | 11.66 (20) |
| Quadruple mutant | 3,690.79 (1) | 7.61 (1) |
a
No WT dhfr isolate was identified.
b
The double mutants are S108N and N51I or S108N and C59R; the triple mutants are S108, N51I and C59R; and the quadruple mutants are S108N, N51, C59R, and I164L. *, None of the tested differences between double and triple mutants were significant at P = 0.05 (Kruskal-Wallis test).
c
The number of isolates is given in parentheses. Data pertaining to PM were already published elsewhere (38).