TABLE 1.
Strains used in this study
| Strain | Relevant properties | Source or reference |
|---|---|---|
| EC38 | Patients isolate with hyperproduction of AmpC | This study |
| EC44 | Patient isolate with hyperprodution of AmpC | This study |
| ATCC 25922 | Ampicillin-susceptible A control strain | ATCCa |
| JP995 | Rifampin-resistant E. coli recipient for conjugation | 26 |
| T-EC38 | Transconjugant of EC38 | This study |
| EC-IS1 | Transformant containing cloned vector (PCR-ScriptCamSK+) with full-length ampC sequence with −10 and −35 promoter sequences from ATCC 25922 | This study |
| EC-IS2 | Transformant containing cloned vector (PCR-ScriptCamSK+) with full-length ampC sequence with the promoter sequence from EC38 | This study |
| EC-IS3 | Transformant containing cloned vector (PCR-ScriptCamSK+) with full-length ampC sequence with truncation of the −35 promoter sequence from EC38 at position −26 | This study |
| XL10 | Epicurian Coli XL10-Gol Kan ultracompetent cells | Stratagene |
a
ATCC, American Type Culture Collection, Manassas, Va.