Table 1.

Clinical strains from Rio de Janeiro (Brazil) and recombinant plasmids used in the study

Strain or plasmidRelevant genotype or phenotypeβ-Lactamase pI(s)
Strains
E. coli Rio-6Clinical strain harboring ESBL resistance phenotype (1996)a 5.4, 8.2
E. coliRio-7Clinical strain harboring ESBL resistance phenotype (1996)a 5.4, 6.3, 7.9
E. cloacae Rio-9Clinical strain harboring ESBL resistance phenotype (1999)a 5.4, 6.3, 7.9, >8
E. coli DH5α supE44 hsdS20(rB mB )recA13 ara-14 proA2 lacY1 galK2 rpsL20 xyl-5 mtl-1
E. coli HB101 supE44 ΔlacU169(φ80 lacZDM15) hsdR17 recA1 endA1 gyrA96 thi-1 relA1
Plasmids
 pRio-6Natural plasmid of 70 kb from E. coli Rio-6 containingbla CTX-M-16 5.4, 8.2
 pRio-7Natural plasmid of 98 kb from E. coli Rio-7 containingbla CTX-M-9 Not obtained
 pRio-9Natural plasmid of 180 kb from E. cloacaeRio-9 containing bla CTX-M-9 5.4, 7.9
 pCPRio-6Recombinant pBK-CMV plasmid containing 0.9-kb fragment with bla CTX-M-16 8.2
 pCPRio-7Recombinant pBK-CMV plasmid containing 0.9-kb fragment with bla CTX-M-9 7.9
 pBK-CMVPhagemid vector kanamycin resistance phenotype
  • a Year isolated is shown in parentheses.