FIG 1.

Relationship between β-lactam MICs and inhibitor concentrations. (A) Ampicillin-sulbactam; (B) piperacillin-tazobactam; (C) ceftazidime-avibactam. Filled boxes represent E. coli MG1655 (DA5438), and clear circles represent E. coli MG1655 containing the pUUH239.2 plasmid (DA63522). Note that for SAM, the ampicillin MIC was >256 mg/L at sulbactam concentrations of <16 mg/L (gray circles), and no growth was detected at sulbactam concentrations of >16 mg/L for DA5438 and >32 mg/L for DA63522. Values are medians from 3 to 4 biological replicates.