TABLE 1.
In vitro activities of RWJ-416457 and comparators against gram-positive bacteria and respiratory tract pathogens
| Organism | No. of isolates | Compound | MIC range (μg/ml) | MIC50 (μg/ml) | MIC90 (μg/ml) |
|---|---|---|---|---|---|
| S. aureus | |||||
| All | 191 | RWJ-416457 | 0.25-16 | 1 | 2 |
| 191 | Linezolid | 0.5->32 | 4 | 4 | |
| 181 | Vancomycin | 0.5-8 | 1 | 4 | |
| Methicillin-susceptible | 72 | RWJ-416457 | 0.5-4 | 1 | 2 |
| Linezolid | 2-4 | 2 | 4 | ||
| Vancomycin | 1-2 | 1 | 2 | ||
| Methicillin-resistant (hospital-associated MRSA, linezolid-susceptible)a | 102 | RWJ-416457 | 0.25-4 | 1 | 2 |
| Linezolid | 0.5-4 | 4 | 4 | ||
| Vancomycin | 0.5-8 | 1 | 4 | ||
| Oxacillin | 4->32 | >32 | >32 | ||
| Vancomycin-intermediate (MRSA)a | 13 | RWJ-416457 | 0.25-2 | 0.5 | 2 |
| Linezolid | 0.5-4 | 1 | 4 | ||
| Vancomycin | 2-8 | 4 | 8 | ||
| Oxacillin | 4->32 | >32 | >32 | ||
| Linezolid-resistant (MRSA)a | 4 | RWJ-416457 | 4-16 | NAb | NA |
| Linezolid | 8->32 | NA | NA | ||
| Vancomycin | 1-2 | NA | NA | ||
| Oxacillin | >32 | NA | NA | ||
| Community-acquired MRSA | 13 | RWJ-416457 | 1-2 | 1 | 2 |
| Linezolid | 2-4 | 4 | 4 | ||
| Vancomycin | 1 | 1 | 1 | ||
| Oxacillin | 16-32 | 32 | 32 | ||
| Coagulase-negative staphylococci | |||||
| All | 67 | RWJ-416457 | 0.25-1 | 0.5 | 1 |
| Linezolid | 0.5-2 | 2 | 2 | ||
| Vancomycin | 0.5-4 | 2 | 4 | ||
| Oxacillin | 0.12->16 | >16 | >16 | ||
| Methicillin-susceptible | 14 | RWJ-416457 | 0.25-1 | 0.5 | 0.5 |
| Linezolid | 1-2 | 1 | 2 | ||
| Vancomycin | 1-4 | 2 | 4 | ||
| Oxacillin | 0.12-0.25 | 0.12 | 0.25 | ||
| Methicillin-resistant | 53 | RWJ-416457 | 0.25-1 | 0.5 | 1 |
| Linezolid | 0.5-2 | 2 | 2 | ||
| Vancomycin | 0.5-4 | 2 | 4 | ||
| Oxacillin | 0.5->16 | >16 | >16 | ||
| E. faecalis | |||||
| Linezolid-susceptible | 42 | RWJ-416457 | 0.5-2 | 0.5 | 1 |
| Linezolid | 1-4 | 2 | 2 | ||
| Vancomycin | 1->16 | 4 | >16 | ||
| Linezolid-resistant | 1 | RWJ-416457 | 32 | NA | NA |
| Linezolid | 64 | NA | NA | ||
| Vancomycin | >128 | NA | NA | ||
| E. faecium | |||||
| Linezolid-susceptible | 36 | RWJ-416457 | 0.25-1 | 1 | 1 |
| Linezolid | 0.5-4 | 2 | 4 | ||
| Vancomycin | 1->16 | >16 | >16 | ||
| Linezolid-resistant | 2 | RWJ-416457 | 16 | NA | NA |
| Linezolid | 32-64 | NA | NA | ||
| Vancomycin | >128 | NA | NA | ||
| Enterococcus gallinarum (linezolid-resistant) | 1 | RWJ-416457 | 16 | NA | NA |
| Linezolid | 64 | NA | NA | ||
| Vancomycin | >128 | NA | NA | ||
| Streptococcus pyogenes (37 macrolide-resistant isolates) | 39 | RWJ-416457 | 0.25-0.5 | 0.5 | 0.5 |
| Linezolid | 1-2 | 1 | 2 | ||
| Erythromycin | 0.03->16 | 8 | >16 | ||
| S. pneumoniae | 108 | RWJ-416457 | 0.06-1 | 0.5 | 0.5 |
| All | Linezolid | 0.25-2 | 1 | 1 | |
| Penicillin-resistant | 31 | RWJ-416457 | 0.25-1 | 0.5 | 0.5 |
| Linezolid | 0.5-2 | 1 | 1 | ||
| Penicillin | 2-4 | 2 | 4 | ||
| Macrolide-resistant | 51 | RWJ-416457 | 0.25-1 | 0.5 | 0.5 |
| Linezolid | 0.5-2 | 1 | 1 | ||
| Erythromycin | 1->16 | 4 | >16 | ||
| Fluoroquinolone-resistant | 20 | RWJ-416457 | 0.06-1 | 0.5 | 0.5 |
| Linezolid | 0.5-2 | 0.5 | 1 | ||
| Levofloxacin | 8->32 | 16 | >16 | ||
| H. influenzae | 4 | RWJ-416457 | 8->16 | NA | NA |
| Linezolid | 4-16 | NA | NA | ||
| Erythromycin | 2-8 | NA | NA | ||
| M. catarrhalis | 12 | RWJ-416457 | 2-4 | 2 | 4 |
| Linezolid | 4-8 | 8 | 8 | ||
| Erythromycin | 0.12-0.25 | 0.25 | 0.25 | ||
| L. pneumophila | 17 | RWJ-416457 | 2-64 | 4 | 8 |
| Linezolid | 1-64 | 4 | 16 | ||
| Levofloxacin | 0.03-0.5 | 0.12 | 0.5 | ||
| M. pneumoniae | 17 | RWJ-416457 | 16-32 | 16 | 32 |
| Linezolid | 64->64 | >64 | >64 | ||
| Levofloxacin | 0.5-1 | 0.5 | 1 | ||
| C. pneumoniae | 3 | RWJ-416457 | 16-64 | NA | NA |
| Linezolid | 64->64 | NA | NA | ||
| Levofloxacin | 0.5 | NA | NA |
a
Isolates received through the Network on Antimicrobial Resistance in S. aureus (NARSA) program.
b
NA, not applicable.