Table 4. Clindamycin susceptibility profiles of GBS isolates from 45 infants with invasive GBS disease, Minnesota, USA, 2010*.
| Antimicrobial susceptibility profile† |
CPS serotype |
Total | ||||||||
|---|---|---|---|---|---|---|---|---|---|---|
| Clindamycin | Erythromycin | D-test | Ia | Ib | II | III | IV | V | ||
| S | S | Not done | 7 | 1 | 0 | 13 | 1 | 2 | 24 | |
| S | R | Negative | 4 | 0 | 0 | 3 | 0 | 0 | 7 | |
| S→R | R | Positive | 1 | 1 | 0 | 2 | 0 | 0 | 4 | |
| R |
R |
Not done |
|
0 |
2 |
1 |
0 |
4 |
3 |
10 |
| Total no. | 12 | 4 | 1 | 18 | 5 | 5 | 45 | |||
| No. (%) resistant | 1 (8.3) | 3 (75.0) | 1 | 2 (11.1) | 4 (80.0) | 3 (60.0) | 14 (31.1) | |||
*GBS, group B Streptococcus; CPS, capsular polysaccharide serotype. †S, susceptible, MIC <0.25 μg/mL; R, resistant, MIC >1 μg/mL; S→R, inducible resistance to clindamycin indicated by positive D-zone test (double-disk diffusion test).