TABLE 1.
Antimicrobial profiles among key organism groups
| Organism (total no. of isolates) | Agent | MIC (μg/ml)
|
No. (%) of isolatesa
|
|||||
|---|---|---|---|---|---|---|---|---|
| Range | Mode | 50% | 90% | S | I | R | ||
| S. aureus (2,872) | Oxacillin | ≤0.06->2 | >2 | >2 | >2 | 1,316 (45.8) | —b | 1,556 (54.2) |
| Erythromycin | ≤0.12->8 | >8 | >8 | >8 | 885 (30.8) | 66 (2.3) | 1,921 (66.9) | |
| Clindamycin | ≤0.5->4 | ≤0.5 | ≤0.5 | >4 | 1,986 (69.2) | 35 (1.2) | 851 (29.6) | |
| Levofloxacin | ≤0.03->8 | 0.12 | 0.25 | >8 | 1,596 (55.6) | 279 (9.7) | 997 (34.7) | |
| Quinupristin-dalfopristin | ≤0.06-8 | 0.25 | 0.25 | 1 | 2,868 (99.9) | 2 (<0.1) | 2 (<0.1) | |
| Rifampin | ≤0.002->4 | 0.008 | 0.008 | 0.015 | 2,818 (98.1) | 10 (0.3) | 44 (1.5) | |
| Trimethoprim-sulfamethoxazole | ≤0.25->4 | ≤0.25 | ≤0.25 | ≤0.25 | 2,790 (97.1) | — | 82 (2.9) | |
| Vancomycin | 0.5-4 | 1 | 1 | 1 | 2,872 (100) | 0 (0) | 0 (0) | |
| Linezolid | 0.25-4 | 2 | 2 | 2 | 2,872 (100) | — | — | |
| CNS (496) | Oxacillin | ≤0.06->2 | >2 | >2 | >2 | 114 (23.0) | — | 382 (77.0) |
| Erythromycin | ≤0.12->8 | >8 | >8 | >8 | 140 (28.2) | 8 (1.6) | 348 (70.2) | |
| Clindamycin | ≤0.5->4 | ≤0.5 | ≤0.5 | >4 | 291 (58.7) | 12 (2.4) | 193 (38.9) | |
| Levofloxacin | 0.06->8 | >8 | 4 | >8 | 204 (41.1) | 54 (10.9) | 238 (48.0) | |
| Quinupristin-dalfopristin | ≤0.06-2 | 0.25 | 0.25 | 0.5 | 492 (99.2) | 4 (0.8) | 0 (0.0) | |
| Rifampin | ≤0.002->4 | 0.008 | 0.008 | 0.015 | 475 (95.8) | 3 (0.6) | 18 (3.6) | |
| Trimethoprim-sulfamethoxazole | ≤0.25->4 | ≤0.25 | 0.5 | >4 | 296 (59.7) | — | 200 (40.3) | |
| Vancomycin | ≤0.25-8 | 2 | 2 | 2 | 495 (99.8) | 1 (0.2) | 0 (0) | |
| Linezolid | 0.12-32 | 1 | 1 | 1 | 495 (99.8)c | — | — | |
| E. faecalis (428) | Ampicillin | 0.12-8 | 1 | 1 | 2 | 428 (100) | 0 (0) | 0 (0) |
| Teicoplanin | 0.06->128 | 0.25 | 0.25 | 0.25 | 401 (93.7) | 1 (0.2) | 26 (6.1) | |
| Vancomycin | 0.5->128 | 1 | 2 | 8 | 385 (90.0) | 2 (0.5) | 41 (9.6) | |
| Linezolid | 0.25-64 | 2 | 2 | 2 | 426 (99.5) | 1 (0.2) | 1 (0.2) | |
| E. faecium (196) | Ampicillin | 0.12->128 | >128 | 128 | >128 | 20 (10.2) | 0 (0) | 176 (89.8) |
| Teicoplanin | 0.12->128 | 32 | 32 | 128 | 65 (33.2) | 6 (3.1) | 125 (63.8) | |
| Vancomycin | ≤0.25->128 | >128 | >128 | >128 | 53 (27.0) | 1 (0.5) | 142 (72.4) | |
| Quinupristin-dalfopristin | 0.25-16 | 1 | 1 | 2 | 170 (86.7) | 11 (5.6) | 15 (7.7) | |
| Linezolid | 0.25-32 | 2 | 2 | 2 | 189 (96.4) | 3 (1.5) | 4 (2.0) | |
| S. pneumoniae (422) | Penicillin | ≤0.06->2 | ≤0.06 | ≤0.06 | 2 | 282 (66.8) | 78 (18.5) | 62 (14.7) |
| Amoxicillin-clavulanate | ≤0.015-8 | 0.03 | 0.03 | 2 | 399 (94.5) | 2 (0.5) | 21 (5.0) | |
| Cefuroxime-axetil | ≤0.03->4 | ≤0.03 | 0.06 | 4 | 343 (81.3) | 11 (2.6) | 68 (16.1) | |
| Ceftriaxone | ≤0.015->4 | ≤0.015 | 0.03 | 1 | 412 (97.6) | 7 (1.7) | 3 (0.7) | |
| Erythromycin | ≤0.015->1 | 0.06 | 0.06 | >1 | 302 (71.6) | 6 (1.4) | 114 (27.0) | |
| Clindamycin | ≤0.25->1 | ≤0.25 | ≤0.25 | >1 | 371 (87.9) | 3 (0.7) | 48 (11.4) | |
| Levofloxacin | 0.5->8 | 1 | 1 | 1 | 415 (98.3) | 0 (0) | 7 (1.7) | |
| Trimethoprim-sulfamethoxazole | ≤0.06->2 | 0.12 | 0.25 | >2 | 307 (72.7) | 39 (9.2) | 76 (18.0) | |
| Vancomycin | 0.12-0.5 | 0.5 | 0.5 | 0.5 | 422 (100) | — | — | |
| Linezolid | 0.25-1 | 1 | 1 | 1 | 422 (100) | — | — | |
a
S, susceptible; I, intermediate; R, resistant. Susceptibilities were determined according to standards established by the Clinical and Laboratory Standards Institute (M100-S15) (2).
b
—, CLSI interpretative criteria not available.
c
One isolate was linezolid nonsusceptible (MIC, >4 μg/ml).