Table 2.

In vitro susceptibility to various antimicrobial agents ofE. coli MG-1, E. coli DH10B, E. coliDH10B harboring natural plasmid pNLT1 and of E. coliDH10B harboring recombinant plasmids that display some of the resistance markers of In53

AntibioticMIC (μg/ml) fora:
E. coli MG-1bE. coliDH10BE. coli DH10B
pNLT1cpRLT2dpRLT3dpRLT4epRLT5epRLT6epRLT7fpRLT8epRLT9epRLT10e
ababababababab
Imipenem0.250.250.250.250.250.250.250.250.250.250.25
Ceftazidime256256>256>256444440.250.25
Amoxicillin>512>512>512>512g g >512>512>512>512>51222
Cephalothin>25612812812825625625625625622
Streptomycin>400h h h h h h h h h h h h h h h h h h
Spectinomycin>400>400>400>400>400>400>400>4004
Kanamycin>256>256g g >128<0.5
Gentamicin32161<0.5
Tobramycin12864>128<0.5
Amikacin6432<1281
Netilmicin3232>128<0.5
Chloramphenicol16163232g g g g g g 3216g g g g g g 2
Tetracycline>3222
CTAB300300300300400400100
EtBr20020020020025025075
Rifampin>256>256>256>256>25688
Sulfonamide>1,0001,000>1,000>1,00015
  • a For “a” and “b” plasmids, the gene is inserted in the same orientation as the Placpromoter and in the opposite orientation, respectively. —, not assayed.

  • b E. coli MG-1 produces VEB-1 β-lactamase along with a TEM-1 penicillinase.

  • c Natural plasmid containingbla VEB-1.

  • d Recombinant plasmid backbone is pBKCMV (Kmr).

  • e Recombinant plasmid backbone is pPCRscript-Cam (Cmr).

  • f Recombinant plasmid backbone is pPCRscript-Amp (Ampr).

  • g Resistance carried on the cloning vector.

  • h Resistance carried by the host strain.