Table 3.
Sensitivity and specificity for the mCIM combined with eCIM to detect different types of carbapenemase
| mCIM + eCIM | blaOXA-48 | blaKPC | blaNDM | blaIMP | blaVIM | blaNDM/blaOXA-48d | blaKPC/blaOXA-48 | total |
|---|---|---|---|---|---|---|---|---|
| TP (n) | – | – | 15 | 6 | 3 | 1 | – | 25 |
| FN (n) | – | – | 0 | 1 | 0 | 2 | – | 3 |
| TN (n) | 40c | 34 | – | – | – | – | 2 | 76 |
| FP (n) | 1 | 0 | – | – | – | – | 0 | 1 |
| Sensitivity (%)a | – | – | 100 | 85.7 | 100 | 33.3 | – | 89.3 |
| Specificity (%)b | 97.6 | 100 | – | – | – | – | 100 | 98.7 |
aSensitivity = TP/TP + FN
bSpecificity = TN/TN + FP
cThe results of 2 mCIM tests were interpreted as “indeterminate” (pinpoint colonies were present within a 16- to 18-mm zone)
dIsolates with blaNDM/blaOXA-48 were defined as metallo-carbapenemase positive
TP true positive, FN false negative