FIG 1.

MIC distributions of meropenem alone or in combination with QPX7728 against carbapenem-resistant Enterobacterales producing either serine beta-lactamases (n = 374) or metallo-beta-lactamases (n = 224). The 374 strains that contain no MBLs include 324 strains producing serine carbapenemases from class A (n = 285; 274 KPC, 8 SME, and 3 NMC-A) and class D (n = 39) and 50 strains that do not carry any known carbapenemases but have meropenem MICs of ≥4 μg/ml (non-carbapenemase-producing CRE [non-CP-CRE]). The 224 strains producing metallo-beta-lactamases include 151 NDM-, 53 VIM-, and 20 IMP-producing strains. Out of the 224 MBL-producing strains, 34 also carry class A or class D serine carbapenemases.