Table 2. Non-susceptibility rates for penicillin, cefotaxime, erythromycin, and MDR* .
| Serotype | No. (%) of non-susceptible isolates | ||||
|---|---|---|---|---|---|
| Penicillin (oral)† | Penicillin (non-meningitis)‡,∥ | Cefotaxime (non-meningitis)∥ | Erythromycin | MDR§ | |
| PCV (n = 87) | 85 (97.7) | 36 (41.4) | 35 (40.2) | 85 (97.7) | 85 (97.7) |
| PCV7 (n = 33) | 33 (100.0) | 14 (42.4) | 8 (24.2) | 32 (97.0) | 32 (97.0) |
| 6B (n = 5) | 5 (100.0) | 4 (80.0) | - | 5 (100.0) | 5 (100.0) |
| 9V (n = 2) | 2 (100.0) | - | - | 2 (100.0) | 2 (100.0) |
| 14 (n = 2) | 2 (100.0) | - | - | 1 (50.0) | 1 (50.0) |
| 19F (n = 16) | 16 (100.0) | 9 (56.3) | 7 (43.8) | 16 (100.0) | 16 (100.0) |
| 23F (n = 8) | 8 (100.0) | 1 (12.5) | 1 (12.5) | 8 (100.0) | 8 (100.0) |
| PCV13 specific (n = 54) | 52 (96.3) | 22 (40.7) | 27 (50.0) | 53 (98.1) | 53 (98.1) |
| 3 (n = 2) | - | - | - | 1 (50.0) | 1 (50.0) |
| 6A (n = 17) | 17 (100.0) | 1 (5.9) | 2 (11.8) | 17 (100.0) | 17 (100.0) |
| 19A (n = 35) | 35 (100.0) | 21 (60.0) | 25 (71.4) | 35 (100.0) | 35 (100.0) |
| Non-PCV (n = 180) | 176 (97.8) | 25 (13.9) | 39 (21.7) | 170 (94.4) | 158 (87.8) |
| 6C (n = 18) | 18 (100.0) | 1 (5.6) | 1 (5.6) | 17 (94.4) | 16 (88.9) |
| 6D (n = 3) | 3 (100.0) | 1 (33.3) | - | 3 (100.0) | 3 (100.0) |
| 10A (n = 12) | 12 (100.0) | - | 2 (16.7) | 9 (75.0) | 9 (75.0) |
| 11A (n = 31) | 30 (96.8) | 7 (22.6) | 12 (38.7) | 31 (100.0) | 30 (96.8) |
| 13 (n = 5) | 5 (100.0) | 1 (20.0) | 1 (20.0) | 5 (100.0) | 5 (100.0) |
| 15A (n = 13) | 13 (100.0) | - | 2 (15.4) | 13 (100.0) | 13 (100.0) |
| 15B/C (n = 29) | 29 (100.0) | 5 (17.2) | 6 (20.7) | 29 (100.0) | 27 (93.1) |
| 22F (n = 1) | - | - | - | 1 (100.0) | - |
| 23A (n = 36) | 36 (100.0) | 9 (25.0) | 15 (41.7) | 34 (94.4) | 32 (88.9) |
| 23B (n = 2) | - | - | - | 2 (100.0) | - |
| 24F (n = 3) | 3 (100.0) | - | - | 3 (100.0) | 3 (100.0) |
| 34 (n = 12) | 12 (100.0) | 1 (8.3) | - | 8 (66.7) | 8 (66.7) |
| 35B (n = 15) | 15 (100.0) | - | - | 15 (100.0) | 12 (80.0) |
| Total (n = 267) | 261 (97.8) | 61 (22.8) | 74 (27.7) | 255 (95.5) | 243 (91.0) |
MDR = multidrug resistance, PCV = pneumococcal conjugate vaccine, CLSI = Clinical & Laboratory Standards Institute, MIC = minimal inhibitory concentration.
*Susceptibility criteria of 2014 CLSI guideline were employed; †Breakpoints of MIC ≤ 0.06 were employed for the classification of susceptibility; ‡Breakpoints of MIC ≤ 2 were employed for the classification of susceptibility; §Multidrug resistance was defined as non-susceptibility to ≥ 3 antimicrobial drug classes; ∥Statistically significant P value < 0.050 by χ2 between PCV and non-PCV serotypes.