Table 4.
Performance of the Carba NP/CarbAcineto tests in the analysis of 1282 surveillance isolates submitted to the National Reference Centre for Susceptibility Testing (NRCST) from April to December 2014
| Enterobacteriaceae (total, n = 915)a | Pseudomonas spp. (total, n = 309)a | Acinetobacter spp. (total, n = 58)a |
|---|---|---|
| Carbapenemase-positive, n = 451 | Carbapenemase-positive, n = 118 | Carbapenemase-positive, n = 54 |
| Carba NP positive, n = 432 | Carba NP positive, n = 115 | CarbAcineto positive, n = 48 |
| KPC, n = 77 | VIM, n = 115 | A. baumannii VIM, n = 2 |
| K. pneumoniae, n = 75 | P. aeruginosa, n = 111 | A. lwoffii VIM, n = 3 |
| E. coli, n = 1 | P. putida, n = 4 | A. junii VIM, n = 3 |
| E. cloacae, n = 1 | A. baumannii OXA-24/40-like, n = 30 | |
| NDM, n = 275 | A. baumannii OXA-23-like, n = 10 | |
| K. pneumoniae, n = 267 | ||
| E. coli, n = 2 | ||
| E. cloacae, n = 4 | ||
| S. marcescens, n = 2 | ||
| VIM, n = 57 | ||
| K. pneumoniae, n = 12 | ||
| E. coli, n = 6 | ||
| E. cloacae, n = 26 | ||
| C. freundii, n = 8 | ||
| S. marcescens, n = 4 | ||
| K. oxytoca, n = 1 | ||
| OXA-48, n = 23 | ||
| K. pneumoniae, n = 7 | ||
| E. coli, n = 14 | ||
| E. aerogenes, n = 2 | ||
| Carba NP questionable, n = 18 | Carba NP questionable, n = 3 | CarbAcineto questionable, n = 6 |
| K. pneumoniae NDM, n = 14 | P. aeruginosa VIM, n = 3 | A. baumannii OXA-24/40-like, n = 1 |
| K. pneumoniae OXA-48, n = 1 | A. baumannii OXA-23-like, n = 3 | |
| E. coli OXA-48, n = 1 | A. baumannii OXA-58, n = 2 | |
| E. cloacae KPC, n = 1 | ||
| C. freundii VIM, n = 1 | ||
| Carba NP not interpretable, n = 1 | ||
| K. pneumoniae NDM, n = 1 | ||
| Carbapenemase-negative, n = 464 | Carbapenemase-negative, n = 191 | Carbapenemase-negative, n = 4 |
| Carba NP negative, n = 433 | Carba NP negative, n = 189 | CarbAcineto negative, n = 4 |
| Carba NP questionable, n = 30 | Carba NP questionable, n = 2 | |
| K. pneumoniae, n = 19 | P. aeruginosa, n = 2 | |
| E. cloacae, n = 9 | ||
| S. marcescens, n = 1 | ||
| P. mirabilis, n = 1 | ||
| Carba NP not interpretable, n = 1 | ||
| K. pneumoniae, n = 1 | ||
| Sensitivity 95.8% (95% CI, 93.9–97.6%) |
Sensitivity 97.5% (95% CI, 94.6–100%) |
Sensitivity 88.9% (95% CI, 80.4–97.4%) |
| Specificity 93.3% (95% CI, 90.9–95.6%) |
Specificity 99.0% (95% CI, 97.6–100%) |
|
| PPV 95.8% (95% CI, 93.9–97.6%) |
PPV 97.5% (95% CI, 94.6–100%) |
PPV 88.9% (95% CI, 80.4–97.4%) |
| NPV 93.3% (95% CI, 90.9–95.6%) |
NPV 99.0% (95% CI, 97.6–100%) |
aPPV, positive predictive value; NPV, negative predictive value; CI, confidence interval