FIG 1.

Selection of P. falciparum with decreased sensitivity to lopinavir. Each selection from wild type (WT) to generations R1 to R4 is indicated by an arrow, with the selection concentration and time indicated. Sensitivities of selected strains are shown (50% inhibitory concentration [IC₅₀]; mean of triplicate measures ± standard error of the mean [SEM]). WT sensitivity is the mean of assessments at each time point for cultures grown in parallel without lopinavir. Polymorphisms in R3 and R4 parasites are shown. The copy numbers of PFE1150w were 1 in WT and 4 in R3 and R4 parasites.