TABLE 3.
MICs of B. thailandensis strains for β-lactam antibiotics with and without penB or ampC genes from B. cenocepacia strain J2315
| B. thailandensis strain | MIC (μg/ml)a |
|||
|---|---|---|---|---|
| AMP | CAZ | CTXM | MER | |
| E264 strainsb | ||||
| E264 | 28 | 1.5 | 7 | 1 |
| E264/pRK415K | 28 | 1.5 | 7 | 1 |
| E264/pRK415K::penB | 256 | 2 | 14.7 | 1.5 |
| E264/pRK415K::ampC | 32 | 2 | 13.3 | 1 |
| E264 (ΔpenA) strainsc | ||||
| E264 (ΔpenA) | 4 | 0.75 | 0.9 | 1 |
| E264 (ΔpenA)/pRK415K | 4 | 0.75 | 0.9 | 1 |
| E264 (ΔpenA)/pRK415K::penB | 256 | 1.5 | 9.3 | 1.2 |
| E264 (ΔpenA)/pRK415K::ampC | 7.3 | 1.5 | 5.3 | 1 |
a
MICs were determined by the agar dilution method. Abbreviations: AMP, ampicillin; CAZ, ceftazidime; CTXM, cefotaxime; MER, meropenem.
b
Wild-type strain E264 is the host for the plasmid pRK415K. Wild-type penA and ampC genes are from B. cenocepacia strain J2315.
c
A mutant strain of E264 that lacks penL is the host for the plasmid pRK415K. Wild-type penA and ampC genes are from B. cenocepacia strain J2315.