Table 2.
Antimicrobial Susceptibilities of Streptococcus pneumoniae serotype 6C isolates in metropolitan Salvador, Brazil from 1996-20071
| Antimicrobial agents | MIC (μg/ml)2 |
No. (%) of isolates3 |
||||
|---|---|---|---|---|---|---|
| Range | MIC50 | MIC90 | S | I | R | |
| Cefotaxime | 0.016 - 64 | 0.016 | 0.031 | 19 (100) | — | — |
| Chloramphenicol | 0.016 - 64 | 2.0 | 4.0 | 17 (89.5) | NA | 2 (10.5) |
| Clindamycin | 0.016 - 64 | 0.031 | 0.062 | 19 (100) | — | — |
| Erythromycin | 0.016 - 64 | 0.062 | 0.25 | 18 (94.7) | — | 1 (5.3) |
| Ofloxacin | 0.016 - 64 | 1.0 | 2.0 | 19 (100) | — | — |
| Penicillin | 0.016 - 64 | 0.031 | 0.062 | 18 (94.7) | 1 (5.3) | — |
| Rifampicin | 0.016 - 64 | 0.031 | 0.062 | 19 (100) | — | — |
| Tetracycline | 0.016 - 64 | 0.5 | 8.0 | 15 (78.9) | — | 4 (21.1) |
| Trimethoprim / Sulfamethoxaxole | 0.0625/1.1875 – 32/608 | 1.0 | 2.0 | 6 (31.6) | 11 (57.9) | 2 (10.5) |
| Vancomycin | 0.016 - 64 | 0.5 | 0.5 | 19 (100) | NA | — |
1
A total of 19 isolates were tested (16 isolates from meningitis patients and 3 isolates from NP carriages).
2
MICs were determined by the broth microdilution method (CLSI, 2007). MIC50 and MIC90 concentrations at which the growth of 50 and 90%, respectively, of the isolates is inhibited.
3
S, susceptible; I, intermediate; R, resistant; NA, not applicable; —, no isolates were identified. The breakpoints used to define susceptibility categories were those recommended by the Clinical Laboratory Standards Institute (CLSI, 2007).