TABLE 4.
Tetracycline MICs for E. coli strains containing M. elsdenii tetracycline resistance determinants
| Strain | Description | M. elsdenii tet gene | MIC (μg/ml)a
|
|
|---|---|---|---|---|
| Tet | Ctc | |||
| ATCC 25922 | TcS reference | None | 1-2 | 4-8 |
| TOP10 | Cloning parent strain | None | 2 | 8 |
| B-1 | TOP10 containing pZErO-2 with fla insertb | None | 2 | 8 |
| STR7-11 | TOP10 containing pZero-2 with 7-11 amplicon | 7-11 Str amplicon | 32 | 64-128 |
| FUS7-11 | TOP10 containing pZero-2 with 7-11 amplicon | 7-11 Fus amplicon | 32 | 128 |
| STR14-14 | TOP10 containing pZero-2 with 14-14 amplicon | 14-14 Str amplicon | 64 | 128 |
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.