Fig. 1: Trimethoprim-resistant derivatives of three clinical isolates of Escherichia coli display collateral resistance to nitrofurantoin.

Minimum inhibitory concentrations of ancestor clinical isolates (Ancestor) and trimethoprim-resistant derivatives (Trim-R) for (a) trimethoprim, (b) nitrofurantoin, and (c) fosfomycin. Dotted lines represent the clinical breakpoint for the corresponding antibiotic, and error bars represent the standard error of the mean. The colour of the data points indicates the ancestor clinical isolate and their linked trimethoprim-resistant derivatives: UTI-34 (purple), UTI-39 (green) and UTI-59 (yellow). Three biological replicates were performed for each antibiotic-isolate combination (n = 3).