Table 1.
Overall agreement between PCR for ermB, separate erythromycin, and clindamycin MICs, D-zone tests, and single-well broth induction tests
| Institution (na) | No. of strains PCR pos. for ermBb | MIC, range (μg/ml) |
No. of strains positive by: |
||
|---|---|---|---|---|---|
| Erythromycin | Clindamycin | D-zone | Broth (1 + 0.5)c | ||
| UTHSCSA (58) | 38 | >32 | 0.06-0.25 | 38 | 38 |
| MDH (25) | 15 | 32->32 | 0.06-0.25 | 15 | 14 |
| CDC (19) | 13d | 32->32 | 0.06-0.12 | 12 | 12 |
a
n, no. of strains.
b
All strains were tested for the ermB determinant; pos., positive.
c
One microgram per milliliter erythromycin + 0.5 μg/ml clindamycin.
d
One isolate was PCR positive for ermB but was negative for inducible resistance by both D-zone and broth combination well tests.