Evaluation of Updated Interpretative Criteria for Categorizing Klebsiella pneumoniae with Reduced Carbapenem Susceptibility

摘要: We studied the accuracy of various susceptibility testing methods, including 2009, 2010, and updated 2010 CLSI recommendations, to identify Klebsiella pneumoniae isolates with reduced carbapenems associated different mechanisms resistance. Forty-three wild-type (WT) strains, 42 extended-spectrum β-lactamase (ESBL) producers, 18 ESBL producers outer membrane porin protein loss (ESBL/Omp strains), blaKPC-possessing K. (KPC-Kp) were evaluated. Imipenem (IPM), meropenem (MEM), ertapenem (ERT), doripenem (DOR) tested by broth microdilution (BMD), Etest, disk diffusion (DD), modified Hodge test (MHT) was performed using IPM MEM disks. Results interpreted according original as well recently interpretative criteria. MHT positive for all KPC-Kp 10 ESBL/Omp strains therefore had poor specificity in differentiating between isolates. Based on standards, phenotypic BMD DD differentiated most carbapenem-susceptible from carbapenem-nonsusceptible without need MHT, while Etest method characterized many susceptible, breakpoints may be lowered this method. However, both criteria do not adequately differentiate group, which are unlikely respond carbapenem therapy, those likely therapy if MICs within pharmacokinetic/pharmacodynamic targets. Further studies required determine there is a clinical groups.