Table 3.

MICs of β-lactam antibiotics for clonally relatedK. pneumoniae strains expressing different porins

StrainPlasmidPorin phenotypeaPorin expressionbMIC (μg/ml)c of:
CTXFOXMPIP
CSUB10SOmpK36+OmpK35OmpK37 420.060.125
CSUB10ROmpK36 OmpK35OmpK37 51212820.5
CSUB10RpSHA25K OmpK36+ OmpK35OmpK37 High420.060.06
CSUB10RpSHA16KOmpK36 OmpK35+ OmpK37 High440.12–0.060.06
CSUB10RpQE1KOmpK36 OmpK35 OmpK37+ Not detectable5126420.25
CSUB10RpQE3KOmpK36 OmpK35 OmpK37+ Low25664–3220.25
CSUB10RpQE7KOmpK36 OmpK35 OmpK37+ High128320.060.125
  • a Analyzed by SDS-PAGE and Coomassie blue staining. In strain CSUB10R(pQE1K), OmpK37 expression was detected by Western blot analysis with anti-OmpK37 serum. Plasmid-encoded porins are in boldface.

  • b The level of each expressed porin from the corresponding plasmid was determined by SDS-PAGE analysis and Coomassie blue staining (Fig. 3).

  • c CTX, cefotaxime; FOX, cefoxitin; M, meropenem; IP, imipenem.