TABLE 1.
Antibiotic susceptibility phenotype: performance characteristics to predict USA300
| Susceptible to antibiotica | Sensitivity (%) |
Specificity (%) | Positive LR (95% CI) |
Prevalence, 25% |
Prevalence, 50% |
Prevalence, 75% |
|||
|---|---|---|---|---|---|---|---|---|---|
| PPV (%) |
NPV (%) |
PPV (%) |
NPV (%) |
PPV (%) |
NPV (%) |
||||
| Levofloxacin and clindamycin | 45.4 | 94.4 | 8.2 (2.7–24.8) | 73.2 | 83.9 | 89.1 | 63.4 | 96.1 | 36.6 |
| Clindamycin and tetracycline | 62.8 | 90.7 | 6.8 (2.9–15.7) | 69.4 | 88.0 | 87.2 | 71.0 | 95.3 | 44.9 |
| Clindamycin b | 63.3 | 88.9 | 5.7 (2.7–12.2) | 65.5 | 87.9 | 85.1 | 70.8 | 94.5 | 44.7 |
| Levofloxacin | 62.4 | 81.5 | 3.4 (1.9–6.0) | 53.0 | 86.7 | 77.1 | 68.5 | 91.0 | 42.0 |
| Levofloxacin or clindamycin | 80.7 | 75.9 | 3.4 (2.1–5.4) | 52.8 | 92.2 | 77.0 | 79.8 | 91.0 | 56.8 |
| Tetracycline | 99.1 | 18.5 | 1.2 (1.1–1.4) | 28.9 | 98.4 | 54.9 | 95.3 | 78.5 | 87.2 |
| Gentamicin | 100 | 7.4 | 1.1 (1.0–1.2) | 26.5 | 100 | 51.9 | 100 | 76.4 | 100 |
| Rifampin | 99.1 | 5.6 | 1.1 (1.0–1.1) | 25.9 | 94.9 | 51.2 | 86.0 | 75.9 | 67.2 |
a
Antibiotics excluded due to resistance >90% included erythromycin; antibiotics excluded due to susceptibility >99% included trimethoprim-sulfamethoxazole, linezolid, Synercid, and vancomycin.
b
Bolded text indicates the most discriminatory antibiotic(s) to predict USA300 MRSA.