Table 2 Antibiotic susceptibility profiles of 43 GBS isolates from pregnant women
Antibiotic |  | MIC (μg/ml) c | ||||
|---|---|---|---|---|---|---|
| Â | Resistant no. (%) | Intermediate no. (%) | Susceptible no. (%) | MIC50 | MIC90 | Range |
Disk diffusiona | ||||||
 Penicillin G (10 units) | 30/43 (69.8%) | 0 (0%) | 13/43 (30.2%) | d— | – | – |
 Ampicillin (10 μg) | 25/43 (58.1%) | 0 (0%) | 18/43 (41.9%) | – | – | – |
 Tetracycline (30 μg) | 42/43 (97.6%) | 0 (0%) | 1 (2.3%) | – | – | – |
 Clindamycin (2 μg) | 24/43 (55.8%) | 11/43 (25.6%) | 8/43 (18.6%) | – | – | – |
 Erythromycin (15 μg) | 13/43 (30.2%) | 16/43 (37.2%) | 14/43 (32.6%) | – | – | – |
 Vancomycin (30 μg) | 13/43 (30.2%) | 0 (0%) | 30/43 (69.8%) | – | – | – |
 Cefazolin (30 μg) | 31/43 (72.1%) | 0 (0%) | 12/43 (27.9%) | – | – | – |
 Chloramphenicol (30 μg) | 15/43 (34.9%) | 16/43 (37.2%) | 12/43 (27.9%) | – | – | – |
 Ceftriaxone (30 μg) | 20/43 (46.5%) | 0 (0%) | 23/43 (53.5%) | – | – | – |
E-testb | ||||||
 Ampicillin | 20/43 (46.5%) | 0 (0%) | 23/43 (53.5%) | 0.25 | 0.75 | 0.016 to 4 |
 Vancomycin | 16/43 (37.2%) | 0 (0%) | 30/43 (63.7%) | 1 | 4 | 0.25 to 8 |
 Chloramphenicol | 0/43 (0%) | 2/43 (4.7%) | 12/43 (95.3%) | 1.5 | 4 | 0 to 12 |