TABLE 2.

Antimicrobial susceptibility and molecular typing of resistance mechanisms of clinical isolates and transconjugant strains

Antimicrobial agent or genetic determinantaMIC (μg/ml) or molecular typing resultb
Donor clinical isolatescE. coli transconjugant strainsdE. coli transf.eE. coli acceptors
Ecl Q4010Ecl Q3039Ecl Q2054Ecl Q5161Cfr Q1174Cfr Q4143Eae Q4079ER-4010ER-3039J-2054J-5161J-1174J-4143J-4079ER1793J53
Antimicrobial susceptibility testing
    AMK≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥2560.51.5
    GEN≥1,024≥1,024256256≥1,024≥1,024256≥1,024≥256≥256≥256768768256≥2560.1251.5
    KAN≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥2560.752
    NET≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥256≥2560.1250.125
    TOB≥1,024≥1,024≥1,024≥1,024≥1,024768256≥1,024≥256256≥256≥1,024256256≥2560.0941
    APR8488848NDNDNDNDNDNDNDND44
    AMP≥256≥256≥256≥256≥256≥256≥25664≥25648≥25696≥256≥256ND66
    PIP≥256≥256≥256≥256≥256≥256≥2568166≥2564≥256≥256ND12
    FOX≥256≥256≥256≥256≥256≥256≥25624128121216ND88
    CAZ192≥256128≥256≥25624120.1250.250.1250.50.19816ND0.1250.19
    CTX≥256≥256≥256≥256≥256≥256≥2560.0470.0640.0940.380.094192≥256ND0.0940.094
    FEP6192424122561280.0940.0940.1250.380.0942448ND0.0470.064
    IPM0.751.5220.750.380.750.250.250.250.250.750.250.25ND0.250.38
    ERT82416≥3260.750.50.0120.0160.0120.0120.0120.0320.023ND0.0160.008
    MEM10.51.5330.250.0940.0230.0230.0230.0230.0320.0470.023ND0.0230.023
    CIP≥32≥32≥32≥32≥32≥320.190.1250.190.0160.0080.0160.750.016ND0.1250.012
    TET48489625625648241.5426444ND0.51
    CHL25696128256≥25624≥256122416164848≥256ND36
PCR
    armANDNDNDNDNDNDNDNDNDND
    rmtANDNDNDNDNDNDNDNDNDND
    rmtBNDNDNDNDNDNDNDNDNDND
    rmtCNDNDNDNDNDNDNDNDNDND
    rmtD++++++++++++++NDNDND
    npmANDNDNDNDNDNDNDNDNDND
    blaTEM+++++NDNDND+NDNDND
    blaSHVNDNDNDNDNDNDNDNDNDND
    blaKPCNDNDNDNDNDNDNDNDNDND
    blaCTX-M+++NDNDND+ND++NDNDND
    qnrB+NDNDNDNDND+NDNDNDND
  • a AMK, amikacin; GEN, gentamicin; KAN, kanamycin; NET, netilmicin; TOB, tobramycin; APR, apramycin; AMP, ampicillin; PIP, piperacillin; FOX, cefoxitin; CAZ, ceftazidime; CTX, cefotaxime; FEP, cefepime; IPM, imipenem; ERT, ertapenem; MEM, meropenem; CIP, ciprofloxacin; TET, tetracycline; CHL, chloramphenicol.

  • b + and −, positive and negative amplification, respectively; ND, not determined.

  • c Ecl, E. cloacae; Cfr, C. freundii; Eae, E. aerogenes.

  • d Transconjugant strains are designated with the letter from the acceptor E. coli strain (ER- and J- indicate derivation from E. coli ER1793 and J53, respectively) and the number from the donor clinical strain.

  • e E. coli transformed with the rmtD2 gene.