Table 3. Distribution of MICs and occurrence of resistance among Enterococcus isolates using the Sensititre test system.
| Class | Antimicrobial | Species | N = | % Resistant | 95% CI | Antimicrobial concentration (μg/ml) | |||||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0.015 | 0.03 | 0.06 | 0.12 | 0.25 | 0.5 | 1 | 2 | 4 | 8 | 16 | 32 | 64 | 128 | 256 | 512 | 1024 | >1024 | ||||||
| Aminoglycoside | Gentamicin | Enterococcus faecalis | 96 | 0.0 | 0.00–3.77 | 100.0 | |||||||||||||||||
| Enterococcus faecium | 120 | 0.0 | 0.00–3.03 | 99.2 | 0.8 | ||||||||||||||||||
| Enterococcus spp | 584 | NA | NA | 99.7 | 0.3 | ||||||||||||||||||
| Kanamycin | Enterococcus faecalis | 96 | 1.0 | 0.03–5.67 | 92.7 | 5.2 | 1.0 | 1.0 | |||||||||||||||
| Enterococcus faecium | 120 | 0.8 | 0.02–4.56 | 99.2 | 0.8 | ||||||||||||||||||
| Enterococcus spp | 584 | NA | NA | 95.0 | 3.8 | 0.3 | 0.3 | 0.5 | |||||||||||||||
| Streptomycin | Enterococcus faecalis | 96 | 1.0 | 0.03–5.67 | 99.0 | 1.0 | |||||||||||||||||
| Enterococcus faecium | 120 | 0.0 | 0.00–3.03 | 100.0 | |||||||||||||||||||
| Enterococcus spp | 584 | NA | NA | 99.1 | 0.9 | ||||||||||||||||||
| Glycopeptides | Teicoplanin | Enterococcus faecalis | 96 | 0.0 | 0.00–3.77 | 30.2 | 46.9 | 17.7 | 5.2 | ||||||||||||||
| Enterococcus faecium | 120 | 0.0 | 0.00–3.03 | 42.5 | 40.0 | 14.2 | 3.3 | ||||||||||||||||
| Enterococcus spp | 584 | NA | NA | 33.2 | 41.1 | 19.7 | 6.0 | ||||||||||||||||
| Vancomycin | Enterococcus faecalis | 96 | 0.0 | 0.00–3.77 | 1.0 | 40.6 | 34.4 | 11.5 | 10.4 | 2.1 | |||||||||||||
| Enterococcus faecium | 120 | 0.0 | 0.00–3.03 | 46.7 | 22.5 | 15.0 | 15.0 | 0.8 | |||||||||||||||
| Enterococcus spp | 584 | NA | NA | 0.5 | 41.6 | 28.3 | 13.4 | 12.3 | 3.9 | ||||||||||||||
| Glycylcycline | Tigecycline | Enterococcus faecalis | 96 | 2.1 | 0.25–7.32 | 2.1 | 45.8 | 41.7 | 3.1 | 5.2 | 2.1 | ||||||||||||
| Enterococcus faecium | 120 | 2.5 | 0.52–7.13 | 43.3 | 44.2 | 5.8 | 4.2 | 2.5 | |||||||||||||||
| Enterococcus spp | 584 | NA | NA | 2.1 | 45.0 | 37.7 | 8.0 | 4.3 | 2.7 | 0.2 | |||||||||||||
| Lincosamide | Lincomycin | Enterococcus faecalis | 96 | 85.4 | 76.74–91.79 | 10.4 | 1.0 | 3.1 | 8.3 | 25.0 | 34.4 | 17.7 | |||||||||||
| Enterococcus faecium | 120 | 94.2 | 88.35–97.62 | 4.2 | 0.8 | 0.8 | 2.5 | 27.5 | 50.0 | 14.2 | |||||||||||||
| Enterococcus spp | 584 | NA | NA | 12.3 | 1.9 | 2.1 | 6.2 | 30.7 | 37.5 | 9.4 | |||||||||||||
| Lipopeptide | Daptomycin | Enterococcus faecalis | 96 | 9.4 | 4.38–17.05 | 75.0 | 15.6 | 9.4 | |||||||||||||||
| Enterococcus faecium | 120 | 2.5 | 0.52–7.13 | 5.8 | 45.0 | 46.7 | 2.5 | ||||||||||||||||
| Enterococcus spp | 584 | NA | NA | 0.2 | 3.3 | 24.8 | 40.6 | 24.5 | 6.7 | ||||||||||||||
| Macrolide | Erythromycin | Enterococcus faecalis | 96 | 10.4 | 5.11–18.32 | 33.3 | 15.6 | 14.6 | 20.8 | 5.2 | 1.0 | 9.4 | |||||||||||
| Enterococcus faecium | 120 | 8.3 | 4.07–14.79 | 53.3 | 13.3 | 12.5 | 9.2 | 3.3 | 4.2 | 4.2 | |||||||||||||
| Enterococcus spp | 584 | NA | NA | 45.9 | 13.2 | 11.0 | 17.6 | 6.3 | 1.2 | 4.8 | |||||||||||||
| Oxazolidinones | Linezolid | Enterococcus faecalis | 96 | 0.0 | 0.00–3.77 | 6.3 | 87.5 | 6.3 | |||||||||||||||
| Enterococcus faecium | 120 | 0.0 | 0.00–3.03 | 5.8 | 87.5 | 6.7 | |||||||||||||||||
| Enterococcus spp | 584 | NA | NA | 0.3 | 5.0 | 88.2 | 6.5 | ||||||||||||||||
| Penicillins | Ampicillin | Enterococcus faecalis | 96 | 0.0 | 0.00–3.77 | 44.8 | 52.1 | 3.1 | |||||||||||||||
| Enterococcus faecium | 120 | 0.0 | 0.00–3.03 | 30.0 | 60.0 | 10.0 | |||||||||||||||||
| Enterococcus spp | 584 | NA | NA | 45.9 | 29.5 | 22.3 | 2.4 | ||||||||||||||||
| Penicillin | Enterococcus faecalis | 96 | 0.0 | 0.00–3.77 | 13.5 | 28.1 | 26.0 | 31.3 | 1.0 | ||||||||||||||
| Enterococcus faecium | 120 | 0.0 | 0.00–3.03 | 12.5 | 34.2 | 30.8 | 20.8 | 1.7 | |||||||||||||||
| Enterococcus spp | 584 | NA | NA | 19.3 | 27.1 | 22.8 | 21.2 | 9.2 | 0.2 | 0.2 | |||||||||||||
| Phenicol | Chloramphenicol | Enterococcus faecalis | 96 | 0.0 | 0.00–3.77 | 17.7 | 82.3 | ||||||||||||||||
| Enterococcus faecium | 120 | 0.0 | 0.00–3.03 | 1.7 | 51.7 | 40.8 | 5.8 | ||||||||||||||||
| Enterococcus spp | 584 | NA | NA | 0.3 | 38.4 | 59.4 | 1.9 | ||||||||||||||||
| Phosphoglycolipid | Flavomycin# | Enterococcus faecalis | 96 | 80.2 | 70.83–87.64 | 15.6 | 1.0 | 2.1 | 1.0 | 2.1 | 78.1 | ||||||||||||
| Enterococcus faecium | NA | NA | NA | ||||||||||||||||||||
| Enterococcus spp | 584 | NA | NA | 11.8 | 1.0 | 0.7 | 1.0 | 0.7 | 2.1 | 82.7 | |||||||||||||
| Streptogramins | Virginiamycin* | Enterococcus faecalis | NA | NA | NA | ||||||||||||||||||
| Enterococcus faecium | 120 | 0.0 | 0.00–3.03 | 85.0 | 5.8 | 9.2 | |||||||||||||||||
| Enterococcus spp | 584 | NA | NA | 86.6 | 6.8 | 6.0 | 0.2 | 0.3 | |||||||||||||||
| Tetracycline | Tetracycline | Enterococcus faecalis | 96 | 7.3 | 2.98–14.45 | 86.5 | 2.1 | 4.2 | 3.1 | 4.2 | |||||||||||||
| Enterococcus faecium | 120 | 11.7 | 6.53–18.80 | 78.3 | 8.3 | 1.7 | 1.7 | 10.0 | |||||||||||||||
| Enterococcus spp | 584 | NA | NA | 83.2 | 3.9 | 2.1 | 1.9 | 8.9 | |||||||||||||||
* Enterococcus faecalis isolates are intrinsically resistant to streptogramins
# Enterococcus faecium isolates are inherently nonsuceptible to flavomycin.
Solid vertical lines indicate breakpoints for resistance. The white fields indicate the dilution range tested for each antimicrobial. Values in the shaded area indicate MIC values greater than the highest concentration tested.