Table 2.
Discrepant results (n = 26) between blood culture and multiplex-PCR.
| Carbapenem MIC (µg/ml) & interpretationa |
|||
|---|---|---|---|
| Organism (n) | MEM | IMP | Carbapenemase(s)b |
| Validation panel (7) | |||
| E. coli (1) | 4, R | ≥16, R | None |
| P. aeruginosa (1) | 8, R | 8, R | None |
| A. baumannii (1) | ≥16, R | ≥16, R | None |
| K. pneumoniae (1) | 0.5, S | ≤0.25, S | OXA-48-type |
| E. cloacae (2) | ≤0.25, S | ≤0.25, S | NDM |
| A. baumannii (1) | 0.5, S | 0.5, S | NDM |
| Evaluation panel (19) | |||
| E. coli (1) | 8, R | 4, R | None |
| E. cloacae (1) | ≥16, R | 8, R | None |
| P. aeruginosa (1) | ≥16, R | ≥16, R | None |
| Pseudomonas spp. (1) | 8, I | 8, I | None |
| A. junii (1) | 8, R | 8, R | None |
| Chryseobacterium indologenes (2) | ≥16, R | ≥16, R | None |
| Brevundimonas diminuta (1) | ≥16, R | 8, I | None |
| Burkholderia cepacia (1) | ≥16, R | ≥16, R | None |
| E. coli (2) | ≤0.25, S | 0.5–1, S | OXA-48-type |
| K. pneumoniae (1) | ≤0.25, S | ≤0.25, S | OXA-48-type |
| E. cloacae (1) | ≤0.25, S | 1, S | NDM |
| A. baumannii (1) | 0.5, S | 0.5, S | NDM |
| Sphingomonas paucimobilis (2) | ≤0.25, S | 0.5–1, S | NDM/OXA-48-type |
| Sphingomonas spp. (1) | 0.5, S | 1, S | NDM |
| Achomobacter xylosoxidans (1) | 1, S | 1, S | NDM |
| Pantoae agglomerans (1) | 1, S | 0.5, S | OXA-48-type |
Note: MIC, minimum inhibitory concentration; MEM, meropenem; IMP, imipenem; S, susceptible; I, intermediate; R, resistant.
aMIC obtained by VITEK2 and interpretation based on clinical breakpoints available in CLSI, 2021.
bConfirmed by PCR using isolated colonies.