Table 3.

MICs of β-lactams forbla VEB-1-positive clinical isolates, their transformants in E. coli DH10B, and the E. coli DH10B reference strain

IsolateMIC (μg/ml)a
AMXPIPTZBCEFFOXCAZCAZ-CLACTXCTX-CLAAZT
E. coliDH10B221480.120.120.060.060.12
E. coli1>512256412881280.2580.12128
Transformant>51212886441280.2540.0664
E. coli2>512644256321280.25160.25256
Transformant5123246482560.2520.0664
E. coli3>512128425681280.2580.06128
Transformant5121643281280.2520.0664
E. coli4>5126426441280.1220.0664
Transformant5121646482560.2540.0664
E. coli5>5126446441280.1220.0664
Transformant5121643241280.2520.0632
E. coli6>5126421284640.2580.0664
Transformant5121623241280.2520.0664
E. coli7>512>512212841280.1280.0664
Transformant5121643241280.1240.1264
E. coli8>51225646441280.540.0632
Transformant2561623241280.2520.0664
E. coli9>512322322640.0640.0632
Transformant5121623241280.2540.1264
E. coli10>512>5123212841280.2540.0664
Transformant2561623241280.2540.0632
E. cloacae11>5126432>51251225632643264
Transformant2561641284640.2510.0616
E. cloacae12>5126464>512>51212832646464
Transformant256821284640.2510.0616
E. cloacae13>512>5122>51264640.5160.5256
Transformant>51212822564640.2510.06128
E. cloacae14>512>512256>512256512128256256128
Transformant>51225625128>5120.5640.06>512
E. sakazakii15>5125128>5126451281616128
Transformant>512512464162560.2540.0664
K. pneumoniae16>51264425682560.1280.06128
Transformant512164328180.2540.0664
K. pneumoniae17>512128812885120.580.12256
Transformant>5123226481280.540.0664
K. pneumoniae18>51264425642560.12160.06128
Transformant>51264212881280.2540.0664
  • a Abbreviations: AMX, amoxicillin; PIP, piperacillin; TZB, piperacillin and tazobactam at a fixed concentration of 4 μg/ml; CEF, cephalothin; FOX, cefoxitin; CAZ, ceftazidime; CLA, clavulanic acid at a fixed concentration of 2 μg/ml; CTX, cefotaxime; AZT, aztreonam.