Table 1.

Antimicrobial susceptibilities, IEF of β-lactamases, and plasmid sizes of E. coli clinical isolates and their transconjugants

StrainMIC (μg/ml)aIsoelectric point(s)Plasmid size(s) (kb)
PIPCEPCFXCTXCAZATMIMP
Ec11>25632816168<0.55.985, 63
Transconjugant1684882<0.55.963
Ec116324323216<0.55.4, 5.9115, 102
Transconjugant1616416164<0.55.9102
Ec15>25632432328<0.55.9103
Transconjugant>25632432328<0.55.9103
Ec7>25616832164<0.55.4, 5.9130, 90
Transconjugant>25684884<0.55.4, 5.9130
Ec8>25616832164<0.55.4, 5.9130
Transconjugant>256168884<0.55.4, 5.9130
Ec1011281616882<0.55.4, 5.9103
Transconjugant1281632882<0.55.4, 5.9103
Ec106>25632163232815.4, 5.991
Transconjugant>256161632168<0.55.4, 5.991
Ec111>2566416326416<0.55.4, 5.9135, 97
Transconjugant>2566416326416<0.55.4, 5.9135, 97
Ec118256163216168<0.55.4, 5.9103, 84
Transconjugant1288432164<0.55.4, 5.9103, 84
Ec147>256643212812864<0.55.4, 5.963, 47
Transconjugant12824882<0.55.4, 5.947
Ec133>256>25632128>256>25645.4, 8.277, 44
Transconjugant12832841616<0.55.444
Ec145256116211<0.57.659, 41
Transconjugant160.2516120.25<0.57.641
Ec132>25632>2566432815.4, 7.6, 8.0104, 56
Transconjugant>2561648164<0.55.4, 7.6104
Ec108>25632>2562563240.55.4, 8.077, 52
Transconjugant>256825612882<0.55.4, 8.077, 52
Ec12>256642563264825.4, 8.571, 50
Ec102>256128642561286425.4, >8.564
  • a Abbreviations: PIP, piperacillin; CEP, cephalothin; CFX, cefoxitin; CTX, cefotaxime; CAZ, ceftazidime; ATM, aztreonam; IMP, imipenem.