TABLE 2.
Clinical breakpoints for carbapenems according to CLSI and EUCAST guidelinesa
| Carbapenem | Susceptibility breakpoint (μg/ml) according to: |
|||
|---|---|---|---|---|
| CLSI document M100-S20, 2010 (196) | CLSI document M100-S20U, 2010 (197) | CLSI document M100-S22, 2012 (198) | EUCAST, 2009–2014 | |
| Doripenem | Not defined | ≤1 | ≤1 | ≤1 |
| Ertapenem | ≤2 | ≤0.25 | ≤0.5 | ≤0.5 |
| Meropenem | ≤4 | ≤1 | ≤1 | ≤2 |
| Imipenem | ≤4 | ≤1 | ≤1 | ≤2 |
a
An intermediate result is interpreted as an MIC that is 1 dilution higher, and a resistant result is interpreted as an MIC ≥2 dilutions higher, except for the EUCAST interpretation of ertapenem results, where an organism with an MIC of >1 μg/ml is considered resistant. CLSI documents M100-S23 (199) and M100-S24 (200) (2013 and 2014) do not change the interpretative criteria for carbapenems. CLSI document M100-S22 (2012) (198) changed interpretative criteria only for ertapenem. The criteria for other carbapenems were not changed. Doripenem was not included in the 2009 and 2010 editions of CLSI document M100.