Figure 4. Potent synergistic combinations against Gram-negative MDR clinical isolates.

a) In vitro synergies, shown as 8x8 checkerboards, for 3 MDR strains (more strains and synergies in ED Fig. 11). One of two biological replicates is shown. b) Drug synergies against the same MDR strains in the Galleria mellonella infection model (see also ED Fig. 11). Larvae were infected by E. coli and K. pneumoniae MDR isolates (10⁶ and 10⁴ CFU, respectively) and left untreated, or treated with single drugs or combination. % larvae survival was monitored at indicated intervals after infection – n=10 larvae per treatment. The average of 4 biological replicates are shown; error bars depict standard deviation.