Fig. 4: Gene amplification did not incur a fitness cost in the piperacillin/tazobactam-resistant isolate compared to the piperacillin/tazobactam-susceptible isolate.

Relative fitness of the piperacillin/tazobactam (TZP)-resistant isolate compared to the TZP-susceptible isolate and the TZP-susceptible isolate grown in the presence of TZP compared to the TZP-susceptible isolate grown in the absence of TZP, assessed comparatively in LB broth (LB, black circles), iso-sensitest broth (ISO, pink squares) and M9 (green triangles). All error bars represent the standard error of the mean (n = 3). Source data are provided as a Source Data file.