TABLE 6.
Discrepancy resolution
| Carbapenemase gene | No. detected by: |
No. of positive results after discrepancy resolution via carbapenemase multiplex PCRa | |
|---|---|---|---|
| MB | PCR/ESI-MS | ||
| blaOXA-24/40 | 11 (1 false positive, 4 false negatives) | 29 (15 false positives) | 14 |
| blaOXA-23 | 84 (8 false positives, 3 false negatives) | 84 (7 false positives, 2 false negatives) | 79 |
| blaOXA-58 | 1 (1 false positive, 2 false negatives) | 3 (1 false positive) | 2 |
| blaIMP | 0 | 0 | 0 |
| blaKPC | 0 | 0 | 0 |
| blaNDM | 0 | 0 | 0 |
| blaVIM | 0 | 0 | 0 |
a
Results are from the OXA carbapenemase multiplex PCR on crude lysates to resolve observed discrepancies due to differences between platform results on a genotypic level, differences between genotype and predicted CR phenotype, and examining those isolates in which a non-baumannii species identification was obtained on the PCR/ESI-MS platform. An independent third method, the carbapenemase multiplex PCR, was used to evaluate false-positive or false-negative genotypes and inconsistencies in CR.