TABLE 5

MIC distributions for 86 OP0595-selected mutants of 18 MBL-producing strains

MIC (μg/ml) or parameteraNo. of mutants with the indicated MICs (μg/ml) for drug alone or in combinationb:
Piperacillin + OP0595Cefepime + OP0595Aztreonam + OP0595Meropenem + OP0595Ceftazidime + avibactam
024802480124024804
≤0.016323213137244
0.03111228192222221
0.061231315121
0.121121775151863212
0.2512339931361532
0.55681965164323233
14332425122375684
24635171614222111819184
43245101211322522242012
8278791212153111598103
164911101610107101586717
32523182017311111667789
6421314119445103332117
1285676111119111176
25675562221255
>25661422855336
GM28018.815.613.326.42.542.251.974.680.0720.0450.0365.752.962.832.7023674.6
%S2.330.233.736.04.731.432.636.036.093.096.510024.443.043.045.308.1
  • a The MICs of piperacillin, cefepime, etc., are shown. The geometric mean (GM) and percent susceptible (%S) at current EUCAST susceptibility breakpoints for the unprotected compounds are shown. The current EUCAST susceptibility breakpoints for the unprotected compounds are 1 μg/ml for aztreonam, cefepime, and ceftazidime, 2 μg/ml for meropenem, and 8 μg/ml for piperacillin. MICs of >256 μg/ml were counted as 512 μg/ml when calculating geometric means, and MICs of ≤0.016 were counted as 0.014 μg/ml.

  • b The MIC distribution of drugs alone or in combination with the OP0595 diazabicyclooctane is shown as the number of mutants with the indicated MICs. All MICs are shown in micrograms per milliliter. The MICs of the drugs (e.g., piperacillin, cefepime, etc.) were determined in the presence of OP0595 at 2, 4, and 8 μg/ml (0 for no OP0595). The MIC distribution of ceftazidime alone and with avibactam (4 μg/ml) is shown for comparison. Modal MICs are indicated in bold type.