Comparative Evaluation of Combined-Disk Tests Using Different Boronic Acid Compounds for Detection of Klebsiella pneumoniae Carbapenemase-Producing Enterobacteriaceae Clinical Isolates

摘要: The accurate phenotypic detection of Klebsiella pneumoniae carbapenemase (KPC)-producing Enterobacteriaceae is an increasing necessity worldwide. We evaluated the performance boronic acid combined-disk tests using as substrate imipenem or meropenem and inhibitor KPC production 300 μg aminophenylboronic (APBA), 600 APBA, 400 phenylboronic (PBA). Tests were considered positive when increase in growth-inhibitory zone around a carbapenem disk with was 5 mm greater diameter containing alone. comparison performed 112 genotypically confirmed KPC-possessing isolates. To measure specificity tests, 127 KPC-negative isolates that nonsusceptible to at least one chosen for testing. Using disks without PBA, 72, 92, producers, respectively, gave results (sensitivities, 64.3%, 82.1%, 100%, respectively). 87, 108, 77.7%, 96.4%, Among potentiation PBA demonstrated largest differences inhibition zones (P < 0.001). All correctly identified 124 non-KPC producers (specificity, 97.6%). This comparative study showed most effective enzymes, its use may give easily interpreted results.