TABLE 1.
In vitro activity of AZD2563 compared to those of 10 other antimicrobial agents tested against 384 strains of S. aureus and 219 strains of CoNS
| Organism (no. of strains tested) and antimicrobial agent | MIC (μg/ml)a
|
||
|---|---|---|---|
| 50% | 90% | Range (% susceptible)b | |
| S. aureus | |||
| Oxacillin susceptible (208) | |||
| AZD2563 | 1 | 2 | 0.25-4 |
| Linezolid | 2 | 2 | 0.5-(100.0) |
| Q/D | 0.25 | 0.5 | 0.06-1(100.0) |
| Vancomycin | 1 | 1 | 0.25-1(100.0) |
| Azithromycin | ≤2 | >8 | ≤2->4(81.7) |
| Clarithromycin | ≤2 | >4 | ≤2->4(80.3) |
| Erythromycin | 0.25 | >16 | ≤0.12->16(81.3) |
| Clindamycin | ≤0.5 | ≤0.5 | ≤0.5->4(95.2) |
| Gentamicin | ≤0.25 | 1 | ≤0.25->8(94.7) |
| Levofloxacin | 0.12 | 0.5 | 0.03->8(94.7) |
| Oxacillin | 0.25 | 0.5 | 0.06-2(100.0) |
| Oxacillin resistant (176) | |||
| AZD2563 | 1 | 2 | 0.25-2 |
| Linezolid | 2 | 2 | 0.5-4(100.0) |
| Q/D | 0.5 | 1 | 0.25->8(97.7) |
| Vancomycin | 1 | 1 | 0.5-2(100.0) |
| Azithromycin | >4 | >4 | ≤2->4(8.5) |
| Clarithromycin | >4 | >4 | ≤2->4(10.8) |
| Erythromycin | >16 | >16 | ≤0.25->16(9.1) |
| Clindamycin | >4 | >4 | ≤0.5->4(25.6) |
| Gentamicin | >8 | >8 | ≤0.25->8(35.2) |
| Levofloxacin | 8 | >8 | 0.06->8(9.7) |
| Oxacillin | >16 | >16 | 4->16(0.0) |
| CoNS | |||
| Oxacillin susceptible (57) | |||
| AZD2563 | 0.5 | 1 | 0.25-2 |
| Linezolid | 1 | 1 | 0.5-2(100.0) |
| Q/D | 0.12 | 0.25 | 0.06-0.5(100.0) |
| Vancomycin | 1 | 2 | 0.5-2(100.0) |
| Azithromycin | ≤2 | >4 | ≤2->4(59.6) |
| Clarithromycin | ≤2 | >4 | ≤2->4(61.4) |
| Erythromycin | 0.25 | >16 | ≤0.12->16(61.4) |
| Clindamycin | ≤0.5 | >4 | ≤0.5->4(87.7) |
| Gentamicin | ≤0.25 | >8 | ≤0.25->8(89.5) |
| Levofloxacin | 0.12 | 8 | 0.06->8(84.2) |
| Oxacillin | 0.12 | 0.25 | 0.03-0.25(100.0) |
| Oxacillin resistant (162) | |||
| AZD2563 | 0.5 | 1 | 0.12-1 |
| Linezolid | 1 | 2 | 0.5-2(100.0) |
| Q/D | 0.25 | 0.5 | 0.06-1(100.0) |
| Vancomycin | 1 | 2 | 0.25-4(100.0) |
| Azithromycin | >4 | >4 | ≤2->4(21.6) |
| Clarithromycin | >4 | >4 | ≤2->4(21.6) |
| Erythromycin | >16 | >16 | ≤0.1->16(21.6) |
| Clindamycin | ≤0.5 | >4 | ≤0.5->4(64.8) |
| Gentamicin | 8 | >8 | ≤0.25->8(48.1) |
| Levofloxacin | 2 | >8 | 0.06->8(50.6) |
| Oxacillin | >16 | >16 | 0.5->16(0.0) |
a
MICs were determined by the NCCLS broth microdilution method (8); 50% and 90%, MIC50 and MIC90, respectively.
b
Percentages of strains susceptible by NCCLS criteria are listed in parentheses (9). No breakpoint for AZD2563 has been determined, but the proportion of strains inhibited at ≤4 μg/ml was used for comparisons to linezolid (100.0% susceptible overall).