TABLE 2.

Decreases in MICs of penicillin G, ceftriaxone, and cefixime upon reversion of penB or deletion of mtrD

StrainFold decrease in MICa
Penicillin GCeftriaxoneCefixime
Par/wtPIBPar/mtrDPar/wtPIBPar/mtrDPar/wtPIBPar/mtrD
FA61402.315.74.410.72.34.5
FA6140 penA352.616.03.69.62.22.9
35/024.015.72.36.01.72.8
    Avg fold decrease2.9 ± 0.915.8 ± 0.23.4 ± 1.18.8 ± 2.42.1 ± 0.33.4 ± 0.9
  • a The average decreases were surprisingly consistent among the three strains. Par/wtPIB, ratio of the MIC for the parental strain to the MIC for the penB reversion strain; Par/mtrD, ratio of the MIC for the parental strain to the MIC for the strain with the mtrD deletion.