Table 1.

Strains and plasmids used in the study

Strain or plasmidRelevant genotype or phenotype (place and yr of isolation)Source or reference
Strains
E. cloacae Rio-1Broad-spectrum cephalosporin resistant (Rio de Janeiro, Brazil, 1996)This study
C. amalonaticusRio-2Broad-spectrum cephalosporin resistant (Rio de Janeiro, Brazil, 1997)This study
E. aerogenesRio-3Broad-spectrum cephalosporin resistant (Rio de Janeiro, Brazil, 1997)This study
P. mirabilisRio-4CTX-M-2-producing P. mirabilis (Rio de Janeiro, Brazil, 1997)This study
E. coliMENCTX-M-1-producing E. coli 4
E. coli TR4TEM-1-producing E. coliHB101 38
E. coliHB101 supE44 hsdS20 (rB mB ) recA13 ara-14 proA2 lacY1 galK2 rpsL20 xyl-5 mtl-1 35
E. coli DH5α supE44 ΔlacU169 (Φ80lacZΔM15) hsdR17 recA1 endA1 gyrA96 thi-1 relA1 35
Plasmids
 pRio-2Natural plasmid from C. amalonaticus Rio-2 containing bla CTX-M-8 andbla TEM-1; resistance phenotype: ESBL, amikacin, gentamicin, kanamycin, netilmicin, tobramycinThis study
 pRio-3Natural plasmid from E. aerogenes Rio-3 containing bla CTX-M-8 andbla TEM-1; resistance phenotype: ESBL, amikacin, gentamicin, kanamycin, netilmicin, tobramycinThis study
 pC1Rio-2Recombinant plasmid containing a 10-kbEcoRI fragment withbla CTX-M-8 This study