The optimized carbapenem inactivation method for objective and accurate detection of carbapenemase-producing Acinetobacter baumannii

The modified carbapenem inactivation method (mCIM) recommended by the Clinical and Laboratory Standards Institute is not applicable for detecting carbapenemases in Acinetobacter baumannii . Four currently reported phenotypic detection methods, namely, Hodge test, mCIM, adjusted simplified (sCIM), did perform well our 90 clinical A. isolates. Thus, minimal inhibitory concentrations (MICs) of carbapenems existence expression carbapenemase-encoding genes were detected to explain results. According E-test, which was more accurate than VITEK 2 system, 80.0 41.1% resistant imipenem (IPM) meropenem (MEM), respectively, 14.4 53.3% exhibited intermediate resistance, respectively. Five β-lactamase found, bla OXA-51-like , TEM OXA-23-like frequently 85 non-susceptible strains. positively correlated with MIC values IPM MEM. Therefore, an improved approach based on designated optimized CIM (oCIM), developed this study detect accurately reproducibly. condition evaluating factors inoculum, incubation broth volume, MEM disk time. Obvious high sensitivity (92.94%) specificity (100.00%) obtained using oCIM, cost-effective reproducible routine laboratory work.