Table 1.

Bacterial strains and plasmids used in this study

Strain or plasmidRelevant genotype or phenotypeSource or referencea
Strains
E. coliJM109 endA1 hsdR17 gyrA96 Δ(lac proA) recA1 relA supE44 thiF′ (lacI q lacZΔM15 proAB+traD36) 52
 In vitro-obtained ciprofloxacin-resistant E. coliJM109Ciprofloxacin resistant 37
E. coli NCTC 50192154-, 66-, 48-, and 7-kb reference plasmids 37
E. coli MG-1Extended spectrum cephalosporin resistantThis study
Plasmids
 pBK-CMV phagemidNeomycinr, kanamycinr Stratagene (La Jolla, Calif.)
 pBR322Recombinant plasmid containing the 560-bpSspI-PstI internal fragment ofbla TEM-1 48
 pHUC37Recombinant plasmid containing the 435-bpPstI-NotI internal fragment ofbla SHV-3 32
 pPZ1Recombinant plasmid containing the 1.1-kbSnaBI internal fragment ofbla PER-1 34
 pPL1Recombinant plasmid containing the 450-bpSnaBI internal fragment ofoxa18 37
 pRLT1Recombinant plasmid containing a 1.3-kb Sau3A fragment withbla VEB1 This report
 pNLT1Natural plasmid from E. coli MG-1 containingbla VEB1. Resistance phenotype: ESBL, Kan, Tm, AN, Net, Tet, Cm, Sul
 pNLT2Natural plasmid fromE. coli MG-1 containingbla TEM-1. Resistance phenotype: TEM, Cm
 pNLT3Natural plasmid from K. pneumoniae MG-2 containing bla VEB1. Resistance phenotype: ESBL, Kan, Tm, AN, Net, Tet, Cm, Sul
 pRLT50Recombinant plasmid containing 1.4-kb genomic Sau3A fragment containingbla TEM-1 This report
  • a Abbreviations: Kan, kanamycin; Tm, tobramycin; Net, netilmicin; AN, amikacin; Cm, chloramphenicol; Tet, tetracycline; Sul, sulfamide.