Table 3.
Sensitivity and specificity of genotypic resistance predictions versus comparison with standard phenotype results for 74 E. coli bloodstream isolates.
| Antibiotic | Susceptible by comparison standard phenotype |
Resistant by comparison standard phenotype |
Sensitivity (95% CI) | Specificity (95% CI) | ||
|---|---|---|---|---|---|---|
| susceptible by genotype (row %) | resistant by genotype (row %; major error) | susceptible by genotype (row %; very major error) | resistant by genotype (row %) | |||
| Amoxicillin | 23 (31) | 1 (1) | 0 (0) | 50 (68) | 1.00 (0.91–1.00) | 0.96 (0.77–1.00) |
| Co-amoxiclav | 46 (62) | 0 (0) | 0 (0) | 28 (38) | 1.00 (0.85–1.00) | 1.00 (0.90–1.00) |
| Gentamicin | 60 (81) | 0 (0) | 0 (0) | 14 (19) | 1.00 (0.73–1.00) | 1.00 (0.93–1.00) |
| Ciprofloxacin | 48 (65) | 0 (0) | 0 (0) | 26 (35) | 1.00 (0.84–1.00) | 1.00 (0.91–1.00) |
| Ceftriaxone | 43 (58) | 1 (1) | 1 (1) | 29 (39) | 0.97 (0.81–1.00) | 0.98 (0.87–1.00) |
| Ceftazidime | 43 (58) | 11 (15) | 1 (1) | 19 (26) | 0.95 (0.73–1.00) | 0.80 (0.66–0.89) |
| Meropenem | 74 (100) | 0 (0) | 0 (0) | 0 (0) | — | 1.00 (0.94–1.00) |
| Total | 337 (65) | 13 (3) | 2 (0.3) | 166 (32) | 0.99 (0.95–1.00) | 0.96 (0.94–0.98) |