FIG. 1.

Histograms of broth microdilution MICs (μg/ml) of the four carbapenems studied against the 145 K. pneumoniae isolates. MIC₅₀ and MIC₉₀ values (μg/ml) are also shown. The original (black) and updated (red) susceptibility breakpoints for imipenem, meropenem, doripenem, and ertapenem are indicated (6, 7). S, susceptible; I, intermediate; R, resistant; NS, nonsusceptible; MHT, modified Hodge test. Arrows labeled MHT indicate when the MHT should be performed. WT K. pneumoniae isolates are shown in green, ESBL-positive (ESBL) isolates are shown in yellow, ESBL-positive isolates with Omp loss (ESBL/Omp) are shown in lavender, and bla_KPC-possessing (KPC-Kp) isolates are shown in red. All isolates that tested positive with the MHT are designated by diagonal hatching.