Table 4. Detection of resistance determinants mecA, vanA, and vanB in prospectively collected monomicrobial blood cultures by Verigene BC-GP (n = 599 S. aureus/S. epidermidis, n = 81 E. faecalis/E. faecium).
| Target | Site | TP | FP | TN | FN | Totala | Sensitivity (CI)b | Specificity (CI) |
| mecA c | A | 41 | 1 | 36 | 0 | 78 | 100% (91–100) | 97.3% (58–99) |
| B | 92 | 2 | 49 | 0 | 143 | 100% (96–100) | 96.1% (86–99) | |
| C | 29 | 3 | 30 | 0 | 62 | 100% (88–100) | 90.9% (75–98) | |
| D | 89 | 2 | 69 | 4 | 164 | 95.7% (89–98) | 97.2% (90–99) | |
| E | 97 | 6 | 48 | 1 | 152 | 99.0% (94–100) | 88.9% (77–95) | |
| Total | 348 | 14 d | 232 | 5 e | 599 | 98.6% (96–99) | 94.3% (90–96) | |
| vanA f | A | 4 | 0 | 11 | 0 | 15 | 100% (39–100) | 100% (79–100) |
| B | 9 | 0 | 11 | 0 | 20 | 100% (66–100) | 100% (71–100) | |
| C | 0 | 0 | 6 | 0 | 6 | NA | 100% (54–100) | |
| D | 10 | 0 | 15 | 0 | 25 | 100% (69–100) | 100% (78–100) | |
| E | 3 | 0 | 12 | 0 | 15 | 100% (29–100) | 100% (73–100) | |
| Total | 26 | 0 | 55 | 0 | 81 | 100% (86–100) | 100% (93–100) | |
| vanB f, g | Total | 0 | 0 | 0 | 0 | 0 | NA | NA |
a
Total number of cultures with reported result.
b
95% confidence interval.
c
mecA is reported only for cultures with positive S. aureus or S. epidermidis species targets. Inferred based upon resistance to cefoxitin using disk diffusion method.
d
mecA specific PCR was positive for eight of 14 isolates. Final specificity of 97.5%.
e
mecA specific PCR was negative for four of five isolates. Final sensitivity of 99.7%.
f
vanA and vanB are reported only for cultures with positive E. feacium or E. faecalis targets.
g
vanB was not detected in any prospectively collected cultures.
FN, false negative; FP, false positive; TN, true negative; TP, true positive.