TABLE 1.
Susceptibility profile relationship with type of β-lactamase
| pI by IEF (no. of strains) | No. (%) of strains resistant toa:
|
|||||
|---|---|---|---|---|---|---|
| AMP | AMP + CLA | MEZ | MEZ + CLA | CAR | CEF | |
| 5.4 (10) | 10 (100) | 6 (60) | 9 (90) | 0 (0) | 10 (100) | 6 (60) |
| 7.6 + 5.4 (20) | 20 (100) | 8 (40) | 11 (55) | 1 (5) | 20 (100) | 11 (55) |
| 7.6 (34) | 34 (100) | 6 (18) | 17 (50) | 0 (0) | 34 (100) | 19 (56) |
| 7.6 + 7.1 (20) | 20 (100) | 2 (10) | 9 (44) | 0 (0) | 20 (100) | 6 (30) |
| 7.1 (13) | 13 (100) | 0 (0) | 2 (15) | 0 (0) | 12 (92) | 2 (15) |
a
AMP, ampicillin; CLA, clavulanic acid; MEZ, mezlocillin; CAR, carbenicillin; CEF, cephalothin. The following breakpoints were used: for ampicillin, ampicillin-clavulanic acid, and cephalothin, ≥16 μg/ml; for mezlocillin and mezlocillin-clavulanic acid, ≥64 μg/ml; for carbenicillin, ≥32 μg/ml.