TABLE 5.
In vitro activities of plazomicin and comparator agents against clinical isolates of Gram-positive bacteria
| Organism (no. of isolates) and agent | MIC (µg/ml) |
% of isolates |
||||
|---|---|---|---|---|---|---|
| 50% | 90% | Range | Susceptible | Intermediate | Resistant | |
| Methicillin-susceptible Staphylococcus aureus (3,009) | ||||||
| Plazomicin | 0.5 | 1 | ≤0.12 to 16 | NAa | NA | NA |
| Amikacin | 2 | 4 | ≤1 to >64 | NA | NA | NA |
| Gentamicin | ≤0.5 | ≤0.5 | ≤0.5 to >32 | 98.6 | 0.1 | 1.3 |
| Tobramycin | ≤0.5 | ≤0.5 | ≤0.5 to >64 | NA | NA | NA |
| Clindamycin | ≤0.12 | ≤0.12 | ≤0.12 to >8 | 94.8 | 0.4 | 4.8 |
| Doxycycline | ≤0.12 | 0.25 | ≤0.12 to 32 | 98.8 | 0.9 | 0.3 |
| Linezolid | 2 | 4 | ≤0.12 to 4 | 100 | NA | 0 |
| Tigecycline | 0.12 | 0.25 | ≤0.03 to 2 | 99.7 | NA | NA |
| Trimethoprim-sulfamethoxazole | ≤0.12 | ≤0.12 | ≤0.12 to >8 | 99.7 | NA | 0.3 |
| Vancomycin | 0.5 | 1 | ≤0.12 to 2 | 100 | 0 | 0 |
| Methicillin-resistant Staphylococcus aureus (687) | ||||||
| Plazomicin | 0.5 | 1 | ≤0.12 to 4 | NA | NA | NA |
| Amikacin | 8 | 32 | ≤1 to >64 | NA | NA | NA |
| Gentamicin | ≤0.5 | ≤0.5 | ≤0.5 to >32 | 96.2 | 0.6 | 3.2 |
| Tobramycin | ≤0.5 | >64 | ≤0.5 to >64 | NA | NA | NA |
| Clindamycin | ≤0.12 | >8 | ≤0.12 to >8 | 65.2 | 0 | 34.8 |
| Doxycycline | ≤0.12 | 1 | ≤0.12 to 16 | 97.2 | 1.2 | 1.6 |
| Linezolid | 2 | 4 | 0.5 to 4 | 100 | NA | 0 |
| Tigecycline | 0.25 | 0.25 | ≤0.03 to 1 | 98.3 | NA | NA |
| Trimethoprim-sulfamethoxazole | ≤0.12 | ≤0.12 | ≤0.12 to >8 | 98.0 | NA | 2.0 |
| Vancomycin | 0.5 | 1 | ≤0.12 to 4 | 99.7 | 0.3 | 0 |
| Methicillin-susceptible Staphylococcus epidermidis (339) | ||||||
| Plazomicin | ≤0.12 | 0.25 | ≤0.12 to 2 | NA | NA | NA |
| Amikacin | ≤1 | 4 | ≤1 to 64 | NA | NA | NA |
| Gentamicin | ≤0.5 | 32 | ≤0.5 to >32 | 69.3 | 7.4 | 23.3 |
| Tobramycin | ≤0.5 | 16 | ≤0.5 to >64 | NA | NA | NA |
| Clindamycin | ≤0.12 | >8 | ≤0.12 to >8 | 68.4 | 2.4 | 29.2 |
| Doxycycline | 0.25 | 1 | ≤0.12 to 32 | 96.2 | 1.2 | 2.6 |
| Linezolid | 1 | 2 | ≤0.12 to 2 | 100 | NA | 0 |
| Tigecycline | 0.12 | 0.25 | ≤0.03 to 1 | NA | NA | NA |
| Trimethoprim-sulfamethoxazole | ≤0.12 | 8 | ≤0.12 to >8 | 69.3 | NA | 30.7 |
| Vancomycin | 1 | 2 | ≤0.12 to 2 | 100 | 0 | 0 |
| Methicillin-resistant Staphylococcus epidermidis (25) | ||||||
| Plazomicin | 0.25 | 0.5 | ≤0.12 to 0.5 | NA | NA | NA |
| Amikacin | 8 | 16 | ≤1 to 32 | NA | NA | NA |
| Gentamicin | >32 | >32 | ≤0.5 to >32 | 20.0 | 0 | 80.0 |
| Tobramycin | 32 | >64 | ≤0.5 to >64 | NA | NA | NA |
| Clindamycin | >8 | >8 | ≤0.12 to >8 | 20.0 | 4.0 | 76.0 |
| Doxycycline | 0.5 | 1 | ≤0.12 to 2 | 100 | 0 | 0 |
| Linezolid | 1 | 1 | 0.5 to 2 | 100 | NA | 0 |
| Tigecycline | 0.25 | 0.25 | 0.06 to 0.5 | NA | NA | NA |
| Trimethoprim-sulfamethoxazole | 4 | 8 | ≤0.12 to 8 | 12.0 | NA | 88.0 |
| Vancomycin | 1 | 2 | 1 to 2 | 100 | 0 | 0 |
| Enterococcus faecalis (301) | ||||||
| Plazomicin | 64 | >64 | 1 to >64 | NA | NA | NA |
| Amikacin | >64 | >64 | 4 to >64 | NA | NA | NA |
| Gentamicin | 8 | >32 | ≤0.5 to >32 | NA | NA | NA |
| Tobramycin | 16 | >64 | ≤0.5 to >64 | NA | NA | NA |
| Ciprofloxacin | 1 | >16 | ≤0.06 to >16 | 75.0 | 7.9 | 17.1 |
| Doxycycline | 8 | 16 | ≤0.12 to 32 | 37.1 | 44.8 | 18.1 |
| Linezolid | 2 | 4 | 0.5 to 4 | 3.3 | 16.7 | 0 |
| Tigecycline | 0.12 | 0.25 | ≤0.03 to 1 | 99.8 | NA | NA |
| Vancomycin | 1 | 2 | 0.5 to 4 | 100 | 0 | 0 |
| Enterococcus faecium (120) | ||||||
| Plazomicin | 4 | 16 | 1 to 16 | NA | NA | NA |
| Amikacin | 32 | >64 | 8 to >64 | NA | NA | NA |
| Gentamicin | 4 | >32 | ≤0.5 to >32 | NA | NA | NA |
| Tobramycin | 64 | >64 | 4 to >64 | NA | NA | NA |
| Ciprofloxacin | >16 | >16 | 0.25 to >16 | 5.6 | 0.9 | 93.5 |
| Doxycycline | 1 | 16 | ≤0.12 to 32 | 66.7 | 9.2 | 24.1 |
| Linezolid | 2 | 4 | 0.25 to 16 | 87.5 | 11.6 | 0.9 |
| Tigecycline | 0.12 | 0.12 | ≤0.03 to 0.5 | NA | NA | NA |
| Vancomycin | 0.5 | >32 | ≤0.12 to >32 | 80.1 | 0.5 | 19.4 |
a
NA, MIC breakpoint not applicable.