TABLE 2.
Performance characteristics of the Carba-R NxG and commercially available Carba-R assays in a genotypically diverse cohort of P. aeruginosa (n = 123)
| Test and targeta | True positive (n) | False positive (n) | True negative (n) | False negative (n) | Test performance [% (CI)] |
|
|---|---|---|---|---|---|---|
| Sensitivity | Specificity | |||||
| Carba-R NxG | ||||||
| VIM | 31 | 0 | 92 | 0 | 100 (89–100) | 100 (95–100) |
| IMP | 26 | 0 | 97 | 0 | 100 (87–100) | 100 (96–100) |
| NDM | 13 | 0 | 110 | 0 | 100 (75–100) | 100 (97–100) |
| SPM | 14 | 0 | 109 | 0 | 100 (77–100) | 100 (97–100) |
| KPC | 8 | 0 | 115 | 0 | 100 (63–100) | 100 (97–100) |
| GES | 14 | 0 | 110 | 0 | 100 (75–100) | 100 (97–100) |
| Non-CP | 0 | 20 | —b | — | ||
| Commercially available Carba-R | ||||||
| VIM | 31 | 0 | 92 | 0 | 100% (89–100) | 100% (95–100) |
| IMP | 15 | 0 | 97 | 11 | 58% (37–77) | 100% (96–100) |
| NDM | 13 | 0 | 110 | 0 | 100% (75–100) | 100% (97–100) |
| SPM | 0 | 0 | 109 | 14 | — | — |
| KPC | 8 | 0 | 115 | 0 | 100% (63–100) | 100% (97–100) |
| GES | 0 | 0 | 109 | 14 | — | — |
| Non-CP | 0 | 20 | — | — | ||
a
Carba-R NxG, research-use-only Carba-R NxG; Carba-R, commercially available Carba-R; VIM, Verona integron-encoded metallo-β-lactamase; IMP, imipenemase; NDM, New Delhi metallo-β-lactamase; SPM, Sao Paulo metallo-β-lactamase; KPC, Klebsiella pneumoniae carbapenemase; GES, Guiana extended spectrum; Non-CP, non-carbapenemase producing.
b
—, not calculated.