Table 2.
Antimicrobial resistance, macrolide resistance genotype, and pilus islet (PI) carriage within individual clonal groups of serotype 19A pneumococci
| CC (No. of isolates) | No. (%) of isolates | |||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Nonsusceptible to the corresponding antimicrobial | MDR | Macrolide resistance genotype* | PI1† | PI2 | ||||||||
| PEN | AMX | CTX | ERY | CLI | SXT | CHL | TET | |||||
| CC663 (14) | 14 (100%) | 13 (93%) | 11 (79%) | 14 (100%) | 9 (64%) | 3 (21%) | 7 (50%) | 6 (43%) | 11 (79%) | erm(B)/mef, 3 (21%); erm(B), 6 (43%); mef, 3 (21%); no erm(B)/mef, 2 (14%) | 14 (100%) | 0 |
| CC230 (12) | 12 (100%) | 0 | 0 | 5 (42%) | 2 (17%) | 12 (100%) | 1 (8%) | 2 (17%) | 5 (42%) | erm(B)/mef, 2 (40%); mef, 3 (60%) | 0 | 0 |
| CC320 (7) | 7 (100%) | 7 (100%) | 7 (100%) | 7 (100%) | 6 (86%) | 7 (100%) | 0 | 4 (57%) | 7 (100%) | erm(B)/mef, 6 (86%); mef, 1 (14%) | 7 (100%) | 7 (100%) |
| CC156 (7) | 7 (100%) | 7 (100%) | 4 (57%) | 1 (14%) | 1 (14%) | 6 (86%) | 0 | 1 (14%) | 1 (14%) | erm(B), 1 | 7 (100%) | 0 |
| CC63 (1) | 0 | 0 | 0 | 1 | 1 | 0 | 0 | 1 | 1 | erm(B), 1 | 0 | 0 |
| Singleton, 10 433(1) | 1 | 0 | 0 | 1 | 1 | 0 | 0 | 0 | 1 | erm(B), 1 | 0 | 0 |
| Singleton, 10 436(1) | 1 | 1 | 1 | 0 | 0 | 1 | 0 | 0 | 0 | No ERY-R | 1 | 0 |
| PEN-S‡ (6): CC180, ST10511 (1); singleton, ST10512 (3); group of two STs, ST5954 (1), ST10430 (1) | 0 | 0 | 0 | 0 | 0 | 4 (67%) | 0 | 1 (17%) | 0 | No ERY-R | 0 | 0 |
| Overall (49) | 43 (88%) | 28 (57%) | 23 (47%) | 29 (59%) | 20 (41%) | 33 (67%) | 8 (16%) | 13 (27%) | 25 (51%) | erm(B)/mef, 11 (38%); erm(B), 9 (31%); mef, 7 (24%); no erm(B)/mef, 2 (7%) | 29 (59%) | 7 (14%) |
AMX, amoxicillin; CC, clonal complex; CHL, chloramphenicol; CLI, clindamycin; CTX, ceftriaxone; ERY, erythromycin; MDR, multidrug resistant; PEN, penicillin; SXT, trimethoprim/sulfamethoxazole; TET, tetracycline.
*
The percentage indicates proportions of isolates carrying a macrolide resistance determinant among ERY-resistant isolates. R, resistant.
†
PI, pilus islet.
‡
PEN-S, a group of six PEN-susceptible isolates.