TABLE 1.

Phenotypes, susceptibilities, and gene expression of P. aeruginosa parents and mutantsa

StrainPhenotypebMIC (μg/ml)cExpressiond
CIPLEVIMPmexCoprD
164Wt0.25141.01.0
164-921CCDJ280.57361.3
164-922CCDJ280.57991.1
164M1PD0.25141.01.0
164M1-94CCDJ2811,3320.75
164M1-84CCDJ280.51,2961.0
164CDFD0.25181.01.0
164CD-921CCDJ2821,3040.76
164CD-822CCDJ2811,4860.91
244ΔOprD0.1250.5161.0ND
244-921CCDJ242926ND
244-911CCDJ242687ND
  • a Parent strains and their phenotypes and data are shown in bold type.

  • b Wt, phenotypic wild type for ampC expression; PD, partially derepressed for ampC expression; FD, fully derepressed for ampC expression; ΔOprD, OprD deficient; CDJ, overexpression of mexCD-oprJ.

  • c Abbreviations: CIP, ciprofloxacin; LEV, levofloxacin; IMP, imipenem.

  • d Transcriptional expression of mexC and oprD as measured by real-time RT-PCR. Values represent the difference (n-fold) in gene expression of the mutants relative to their respective parent strain. ND, not determined.