TABLE 4.

Tetracycline MICs for E. coli strains containing M. elsdenii tetracycline resistance determinants

StrainDescriptionM. elsdenii tet geneMIC (μg/ml)a
TetCtc
ATCC 25922TcS referenceNone1-24-8
TOP10Cloning parent strainNone28
B-1TOP10 containing pZErO-2 with fla insertbNone28
STR7-11TOP10 containing pZero-2 with 7-11 amplicon7-11 Str amplicon3264-128
FUS7-11TOP10 containing pZero-2 with 7-11 amplicon7-11 Fus amplicon32128
STR14-14TOP10 containing pZero-2 with 14-14 amplicon14-14 Str amplicon64128
  • a Expressed per milliliter of Mueller-Hinton agar. Results of at least two determinations. Tet, tetracycline; Ctc, chlortetracycline.

  • b Strain B-1 containing plasmid pZero-2 with a Brachyspira hyodysenteriae fla insert was used as a control since pZero-2 plasmid without insert is lethal for E. coli TOP10 cells.