NoteEvaluation of the modified carbapenem inactivation method and sodium mercaptoacetate-combination method for the detection of metallo-β-lactamase production by carbapenemase-producing Enterobacteriaceae

•CIM and mCIM were useful to screen for carbapenemase-producing Enterobacteriaceae.•mCIM with carbapenem-SMA combination was valuable for metallo-β-lactamase detection.•The SMA-mCIM had 100% sensitivity and specificity to detect metallo-β-lactamase.

We evaluated the effectiveness of carbapenem inactivation method (CIM) and modified CIM (mCIM). Our results indicated that mCIM with 4 h incubation improved sensitivity and specificity for detecting carbapenemase-producing Enterobacteriaceae compared to CIM. Additionally, we developed a sodium mercaptoacetate-combination method (SMA-mCIM) to detect metallo-β-lactamase (MBL) with high sensitivity and specificity.