TABLE 2.
Interisolate summary of clavulanate fT>threshold Emax model fits along with stasis and 1-log CFU reduction exposure requirementsa
| Isolate | CTB-CLA MICb (μg/ml) | fT>threshold (μg/ml) | R2 | AIC | % fT>CTB to achieve stasis | % fT>CTB to achieve 1-log10 CFU reduction |
|---|---|---|---|---|---|---|
| EC477 | 1/0.5 | >2 | 0.67 | 95.3 | 24.9 | 27.7 |
| >1 | 0.85 | 58.6 | 31.0 | 35.9 | ||
| >0.5 | 0.83 | 80.1 | 36.3 | 41.0 | ||
| >0.25 | 0.83 | 80.1 | 42.4 | 47.9 | ||
| >0.125 | 0.83 | 80.3 | 48.6 | 54.9 | ||
| EC478 | 0.5/0.25 | >1 | 0.46 | 46.7 | 8.1 | 21.5 |
| >0.5 | 0.86 | 30.5 | 22.7 | 44.0 | ||
| >0.25 | 0.85 | 30.9 | 32.0 | 54.4 | ||
| >0.125 | 0.84 | 32.1 | 40.2 | 63.7 | ||
| KP547 | 0.25/0.125 | >1 | 0.07 | 49.3 | 23.5 | NA |
| >0.5 | 0.80 | 30.7 | 66.1 | 85.7 | ||
| >0.25 | 0.79 | 31.8 | 74.6 | 91.0 | ||
| >0.125 | 0.74 | 34.1 | 80.2 | 96.7 | ||
| >0.06 | 0.70 | 35.6 | 85.0 | 100.0 | ||
| KP548 | 0.25/0.125 | >1 | 0.78 | 35.0 | 5.0 | NA |
| >0.5 | 0.90 | 24.4 | 19.4 | 30.9 | ||
| >0.25 | 0.91 | 23.4 | 29.4 | 47.7 | ||
| >0.125 | 0.91 | 23.1 | 39.4 | 66.0 | ||
| >0.06 | 0.91 | 23.0 | 49.9 | 84.4 | ||
a
Ceftibuten was coadministered to achieve 59% fT>MIC (i.e., ceftibuten concentration in the CTB-CLA MIC [the median observed exposure was 57% fT>MIC]) during all experiments. EC, E. coli; KP, Klebsiella pneumoniae; AIC, Akaike information criterion; NA, not applicable.
b
For CTB-CLA, the MIC is listed as the concentration of ceftibuten/concentration of clavulanate.