TABLE 3.
blaZ types detected in S. aureus isolates with susceptible and resistant penicillin MICs
| Penicillin MIC (μg/ml) | No. (%) of isolates: |
No. of isolates with blaZ type detected |
||||
|---|---|---|---|---|---|---|
| Tested for blaZ | blaZ positive | A | B | C | NT | |
| Susceptibility | ||||||
| 0.015 | 1 (100) | |||||
| 0.03 | 24 (100) | |||||
| 0.06 | 370 (100) | 14 (3.4)a | 2 | 2 | 8 | 2 |
| 0.12 | 53 (100) | 17 (32.1)b | 6 | 2 | 8 | 1 |
| Resistance | ||||||
| 0.25 | 8 (14.8) | 8 (100) | 5 | 3 | ||
| 0.5 | 1 (0.7) | 1 (100) | 1 | |||
| 1 | 10 (3.0) | 10 (100) | 3 | 3 | 4 | |
| 2 | 4 (4.5) | 4 (100) | 2 | 1 | 1 | |
| 4 | 10 (3.8) | 10 (100) | 2 | 8 | ||
| 8 | 11 (2.6) | 11 (100) | 3 | 1 | 7 | |
| 16 | 3 (1.6) | 3 (100) | 1 | 1 | 1 | |
| >16 | 4 (0.4) | 4 (100) | 1 | 3 | ||
| Total | 499 | 82 | 25 | 10 | 43 | 4 |
a
The blaZ types of the 10 isolates with a penicillin MIC of 0.06 μg/ml and not detected by the penicillin zone edge test were types A (n = 2), B (n = 1), C (n = 6), and nontypeable (NT [n = 1]).
b
The blaZ type of the isolate with a penicillin MIC of 0.12 μg/ml and not detected by the penicillin zone edge test was type A.