TABLE 3.

Phenotypic and genotypic characterization of the 15 clinical isolates

Genus speciesMICa (μg/ml)pIβ-Lactamase(s) detected by PCRbPFGE patternPlasmid profile (kb)
ATMCTXCTX+CAZCAZ+
E. coli 112880.56445.4, 8.2SHV-12, TEM-1B∗Eco-1130, 10, 8.5
Transconjugantc3220.5162NTdSHV-12130
E. coli 2832≤0.252≤0.255.4, 8.1CTX-M-9, TEM-1BEco-2150, 7.0, 5.0, 4.0
Transconjugant416≤0.251≤0.25NTCTX-M-9150, 5.0, 4.0
E. coli 3416≤0.251≤0.255.4, 8.1CTX-M-9, TEM-1BEco-2150, 7.0, 5.0, 4.0
Transconjugant28≤0.250.5≤0.25NTCTX-M-9150, 5.0, 4.0
E. coli 4232NT0.5≤0.258.1CTX-M-9Eco-3150
E. coli 5>128128NT>1280.258.1CTX-M-14, SHV-12, TEM-1BEco-4130, 3.5
E. coli 612864NT6418.1CTX-M-14, SHV-12, TEM-1BEco-4130, 3.5
E. coli 7432≤0.251≤0.255.4, 8.1CTX-M-14, TEM-1BFailede130
Transconjugant416≤0.250.5≤0.25NTCTX-M-14130
E. coli 81664≤0.2540.55.4, 8.1CTX-M-14, TEM-1B∗Eco-5130, 5.5, 4.8, 3.5, 2.5, 1.9
Transconjugant48≤0.251≤0.25NTCTX-M-14130
K. pneumoniae 1161281632645.4, 7.6, 8.2CTX-M-13, TEM-1B, SHV-11Kp-155, 35, 7.0
Transconjugant832≤0.252≤0.25NTCTX-M-1335
K. pneumoniae 2128>128≤0.253217.6, 8.1CTX-M-14, SHV-11Kp-2150, 60, 7.0
Transconjugant432≤0.251≤0.25NTCTX-M-1460
K. pneumoniae 31632NT8168.1CTX-M-9Kp-3150, 7.0, 2.7, 1.9
E. cloacae 132>1280.580.58.1, 9.25CTX-M-9Ecl-185, 2.4
Transconjugant832≤0.252≤0.25NTCTX-M-9Plasmid not found
E. cloacae 264160.564≤0.255.4, 9.25SHV-12, TEM-1BEcl-2Plasmid not found
Transconjugant80.5≤0.258≤0.25NTSHV-12, TEM-1BPlasmid not found
E. cloacae 3>128128NT12848.1CTX-M-14, SHV-12Ecl-3150, 2.4
C. freundii 1288NT128≤0.255.4, 8.2SHV-12, TEM-1BNT7.0
  • a ATM, aztreonam; CAZ, ceftazidime; CAZ+, ceftazidime plus 4 μg of clavulanic acid per ml; CTX, cefotaxime; CTX+, cefotaxime plus 4 μg of clavulanic acid per ml.

  • b The blaSHV and blaCTX-M genes were characterized by nucleotide sequence analysis, and the blaTEM gene was characterized by PCR-RFLP (2). An asterisk indicates the blaTEM gene that was confirmed by nucleotide sequence analysis.

  • c All transconjugants except those of E. cloacae 2 were E. coli UB1637 transconjugants; the E. cloacae 2 transconjugant was an E. coli UB5201 transconjugant.

  • d NT, not tested.

  • e Despite retesting, no DNA fragments were seen.