TABLE 2.
Rates of antimicrobial nonsusceptibility of serogroup 6 isolates
| Antimicrobial agent | No. (%) of nonsusceptible isolatesa |
|||||
|---|---|---|---|---|---|---|
| Serogroup 6 (n = 147) | Serotype 6A (n = 64) | Serotype 6B (n = 34) | Serotype 6C (n = 6) | Serotype 6D (n = 19) | Putative serotype 6E (n = 24) | |
| Penicillin | 3 (2.0) | 2 (3.1) | 1 (2.9) | 0 | 0 | 0 |
| Amoxicillin | 4 (2.7) | 0 | 2 (5.9) | 0 | 0 | 2 (8.3) |
| Amoxicillin-clavulanate | 4 (2.7) | 0 | 2 (5.9) | 0 | 0 | 2 (8.3) |
| Ceftriaxone | 3 (2.0) | 2 (3.1) | 1 (2.9) | 0 | 0 | 0 |
| Cefuroxime | 129 (87.8) | 60 (93.8) | 28 (82.4) | 2 (33.3) | 16 (84.2) | 23 (95.8) |
| Erythromycin | 137 (93.2) | 63 (98.4) | 34 (100) | 3 (50.0) | 17 (89.5) | 20 (83.3) |
| Azithromycin | 129 (87.8) | 57 (89.1) | 34 (100) | 3 (50.0) | 13 (68.4) | 22 (91.7) |
| Clarithromycin | 135 (91.8) | 60 (93.8) | 34 (100) | 3 (50.0) | 15 (78.9) | 23 (95.8) |
| Levofloxacin | 8 (5.4) | 1 (1.6) | 1 (2.9) | 0 | 5 (26.4) | 1 (4.2) |
| Moxifloxacin | 2 (1.4) | 1 (1.6) | 1 (2.9) | 0 | 0 | 0 |
| Gatifloxacin | 8 (5.4) | 1 (1.6) | 1 (2.9) | 0 | 5 (26.4) | 1 (4.2) |
| Clindamycin | 101 (68.7) | 44 (68.8) | 32 (94.1) | 3 (50.0) | 5 (26.4) | 17 (70.8) |
| Trimethoprim-sulfamethoxazole | 124 (84.4) | 55 (85.9) | 34 (100) | 3 (50.0) | 8 (42.1) | 24 (100) |
a
The MIC nonsusceptibility breakpoints of the antimicrobial agents are as follows: penicillin, 4 mg/liter; amoxicillin, 4 mg/liter; amoxicillin-clavulanate, 4/2 mg/liter; ceftriaxone, 2 mg/liter; cefuroxime, 1 mg/liter; erythromycin, 0.5 mg/liter; azithromycin, 1 mg/liter; clarithromycin, 0.5 mg/liter; levofloxacin, 4 mg/liter; moxifloxacin, 2 mg/liter; gatifloxacin, 2 mg/liter; clindamycin; 0.5 mg/liter; trimethoprim-sulfamethoxazole, 1/19 mg/liter.