Summary of detection methods for carbapenemase producing Enterobacterales
| Tests method | Accuracy | TAT | Detection | Limitation | Accessibility |
|---|---|---|---|---|---|
| Modified Hodge test | Moderate | Next day | Carbapenemase activity | Poor sensitivity for NDM | High (LDT) |
| Poor specificity with AmpC* | |||||
| mCIM | High | Next day | Carbapenemase activity | None known | High (LDT) |
| Carba NP | Moderate | Next day | Carbapenemase activity | Poor sensitivity for OXA-48 | Moderate (commercial) |
| Double disk synergy test | High | Next day | Carbapenemase activity | None known | Moderate (LDT) |
| Gradient MIC strip (E-test KPC or MBL) |
Moderate | Next day | KPC or MBL | Detects only KPC or MBL | Moderate (commercial) |
| Poor specificity with AmpC | |||||
| MALDI-TOF MS | High | Within day | Carbapenemase activity | None known | Low-moderate |
| (LDT) | |||||
| PCR (multiplex PCR, real-time PCR) | High | Within day | Specific carbapenemase gene | Unable to detect novel carbapenemase | Low-moderate (commercial) |
| Microarray | High | Within day | Specific carbapenemae gene | Unable to detect novel carbapenemase | Low-moderate (commercial) |
| Whole-genome sequencing | High | Several days | Carbapenem resistance mechanism | Unable to detect novel carbapenemase | Low (LDT) |
Abbreviations: TAT, turnaround time; mCIM, modified carbapenemase inactivation methods; LDT, laboratory developed test
aAccuracy: high, >90% sensitivity and specificity, moderate, 70~90% sensitivity and specificity; low, <70% sensitivity and specificity
bTurnaround time, time to results from pure culture of isolate
cAccessibility; High, all clinical microbiology laboratories could perform this test; moderate, advanced clinical microbiology laboratories could perform this test; low, reference laboratories could perform this test
