TABLE 5.
Validation set resultsa
| Antimicrobial agent | No. of isolates resistant by phenotype |
No. of isolates susceptible by phenotype |
Total no. of isolates | Very major error rate (%) (95% CI) | Major error rate (%) (95% CI) | Sensitivity (95% CI) | Specificity (95% CI) | ||
|---|---|---|---|---|---|---|---|---|---|
| Susceptible by genotypeb | Resistant by genotype | Susceptible by genotype | Resistant by genotypeb | ||||||
| Penicillin | 3 (2) | 379 | 84 | 25 (9) | 491 | 0.6 (0.1–1.8) | 5.1 (3.3–7.4) | 0.99 (0.98–1.00) | 0.77 (0.68–0.84) |
| Methicillin | 2 (1) | 55 | 432 | 2 (1) | 491 | 0.4 (0.05–1.5) | 0.4 (0.05–1.5) | 0.96 (0.87–0.99) | 1.00 (0.98–1.00) |
| Ciprofloxacin | 6 (4) | 64 | 420 | 1 (0) | 491 | 1.2 (0.4–2.6) | 0.2 (0.05–1.1) | 0.91 (0.82–0.96) | 1.00 (0.98–1.00) |
| Erythromycin | 4 (2) | 79 | 405 | 3 (3) | 491 | 0.8 (0.2–2) | 0.6 (0.1–1.8) | 0.95 (0.87–0.98) | 0.99 (0.98–1.00) |
| Clindamycin | 2 (2) | 77 | 2 | 0 | 81 | 2.5 (0.3–8.6) | 0.0 (0–4.4) | 0.97 (0.90–1.00) | 1 (0.20–1.00) |
| Tetracycline | 0 | 18 | 471 | 2 (2) | 491 | 0.0 (0–0.7) | 0.4 (0.05–1.5) | 1.00 (0.78–1.00) | 1.00 (0.98–1.00) |
| Vancomycin | 0 | 0 | 491 | 0 | 491 | 0.0 (0–0.7) | 0.0 (0–0.7) | N/Ac | 1.00 (0.99–1.00) |
| Fusidic acid | 4 (4) | 39 | 448 | 0 | 491 | 0.8 (0.2–2) | 0.0 (0–0.7) | 0.91 (0.77–0.97) | 1.00 (0.99–1.00) |
| Trimethoprim | 2 (2) | 1 | 197 | 2 (1) | 202 | 1.0 (0.1–3.5) | 1.0 (0.1–3.5) | 0.33 (0.02–0.87) | 0.99 (0.96–1.00) |
| Gentamicin | 2 (2) | 2 | 487 | 0 | 491 | 0.4(0.05–1.5) | 0.0 (0–0.7) | 0.50 (0.09–0.91) | 1.00 (0.99–1.00) |
| Mupirocin | 0 | 2 | 489 | 0 | 491 | 0.0(0–0.7) | 0.0 (0–0.7) | 1.00 (0.20–1.00) | 1.00 (0.99–1.00) |
| Rifampin | 0 | 5 | 486 | 0 | 491 | 0.0 (0–0.7) | 0.0 (0–0.7) | 1.00 (0.46–1.00) | 1.00 (0.99–1.00) |
| Overall | 25 (19) | 644 | 4,410 | 35 (16) | 5,112 | 0.5 (0.3–0.7) | 0.7 (0.5–0.9) | 0.97 (0.95–0.98) | 0.99 (0.99–1.00) |
a
Comparison of susceptibility results for 491 bacteremia and carriage isolates by phenotype (Phoenix/disc diffusion consensus result) and genotype prediction tool v2.0. The result (resistant or susceptible) by phenotype refers to Phoenix or disc diffusion consensus results, and the result by genotype refers to the predicted susceptibility using the v2.0 genotypic prediction method.
b
Figures in parentheses are numbers of isolates with discrepant phenotype confirmed on repeat testing.
c
N/A, not applicable.