Phenotypic Detection of Metallo-β-Lactamase in Imipenem-Resistant Pseudomonas aeruginosa
Figure 1
Phenotypic tests to detect MBL production. (a) Combined disk test (CDT) showing enhanced inhibition zone of >7 mm around IPM + EDTA disc indicating MBL positivity. (b) Double-disk synergy test (DDST) with synergistic zone of inhibition surrounding IPM and 2-mercaptopropionic acid (2-MPA) disks indicating MBL activity. (c) MBL IP/IPI E-test demonstrating enhanced MIC of imipenem in the presence of EDTA IPI with IP/IPI of ≥8 for MBL activity.
