Fig. 4.

Co-culture experiments validate the selectivity model predictions. a mCherry expressing S. cerevisiae and GFP expressing C. albicans cells were co-cultured in single or combination drug treatments in liquid media and growth of each species was quantified using flow cytometry. b Selectivity scores (log₂(C. albicans/S. cerevisiae)) for mixed culture assays before treatment (t0), at no drug condition, CAL, DYC, and CAL + DYC co-culture experiments are shown (n = 2). Also shown is the average selectivity from CAL and DYC conditions, which is the expected selectivity in the absence of drug interactions. Comparison of the no drug condition to t0 shows that the amount of C. albicans in co-culture increases without any selective pressure, which is expected due to the shorter doubling time of C. albicans. Comparison of CAL and DYC to no drug condition validates the model prediction of single-drug selectivity for S. cerevisiae. Comparison of CAL + DYC to no drug condition indicates that the combination is selective for C. albicans, as predicted by the selectivity model (inverted selectivity). c MMS and RAP both individually select for C. albicans. As predicted by the model, the MMS + RAP combination has greater selectivity for C. albicans (selectivity increase due to antagonism). (n = 2)