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 strainMIC (μg/ml)a
AMPCAZCTXMMER
E264 strainsb
    E264281.571
    E264/pRK415K281.571
    E264/pRK415K::penB256214.71.5
    E264/pRK415K::ampC32213.31
E264 (ΔpenA) strainsc
    E264 (ΔpenA)40.750.91
    E264 (ΔpenA)/pRK415K40.750.91
    E264 (ΔpenA)/pRK415K::penB2561.59.31.2
    E264 (ΔpenA)/pRK415K::ampC7.31.55.31
  • 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.