TABLE 1.
Characteristics of the 37 C. difficile isolates examined in the study
| PCR ribotype | MICs/MIC range (mg/liter)a
|
Detection of:
|
erm(B)-negative strains resistant to erythromycin | Detection of:
|
|||||
|---|---|---|---|---|---|---|---|---|---|
| ERY | CLI | TET | erm(B) | tet(M) | erm(B)/tet(M) | tndX | int | ||
| A (21)b | 256 (4)/12-48 (17) | 256 (21) | 256 (2)/12-64 (19) | − | − | + (21) | + (21) | − | |
| D (4) | 256 (4) | 256 (3)/3 (1)c | 32 (1)/0.016-0.064 (3) | + (3) | − | + (1) | 1 | + (1) | − |
| L (1) | 1.0 (1) | 4 (1) | 1.0 (1) | − | + (1) | − | − | + (1) | |
| R (11) | 256 (8)/0.032-1.0 (3) | 256 (4)/4-12 (3)/0.5-1.5 (4)c | 12-16 (6)/0.023-4 (5) | + (2) | + (7) | + (2) | 4 | − | + (9) |
a
ERY, erythromycin; CLI, clindamycin; TET, tetracycline.
b
The number of strains is shown in parentheses throughout.
c
One strain of PCR ribotype D and one of PCR ribotype R were inducibly resistant to clindamycin. Resistance to clindamycin was induced by a pregrowth on blood agar plates containing 0.05 mg/liter of erythromycin.