TABLE 4.

Expression of qnr alleles

Strain and plasmidInducing agentRelative RNA transcript level ata:
15 min30 min
J53 (lexA+ recA+)
    pMG298 (qnrB1)Ciprofloxacin3.73.2
Mitomycin C2.62.8
    pMG301 (qnrB2)Ciprofloxacin5.9
    pMG317 (qnrB3)Ciprofloxacin2.1
    pMG319 (qnrB4)Ciprofloxacin9.99.0
Mitomycin C8.27.9
    pMG252 (qnrA1)Ciprofloxacin0.9-1.0
Mitomycin C0.9-1.5
AB1157 (lexA+ recA+)
    pMG319 (qnrB4)Ciprofloxacin3.9
Mitomycin C2.0
AB1157 LexA300::spec (lexA[Def] recA+)
    pMG319 (qnrB4)Ciprofloxacin1.1
Mitomycin C1.0
DM49 (lexA3[Ind] recA+)
    pMG319 (qnrB4)Ciprofloxacinb1.2
Mitomycin C1.0
  • a All measurements were repeated at least twice.

  • b The ciprofloxacin MIC of DM49 pMG319 was 0.064 μg/ml, compared to the MIC of of 0.25 μg/ml for AB1157 pMG319 and AB1157 LexA300::spec pMG319, and so a ciprofloxacin concentration of 0.05 μg/ml was used for induction.