Table 3.
Minimal inhibitory concentrations (MIC) of 12 antibiotics against E. coli carrying pVCR94 or its Δ X mutant.
| VB111 | NC213 (VB111 pVCR94) | NC367 (VB111 pVCR94Δ X) | ||||
|---|---|---|---|---|---|---|
| Antibiotic | MIC (μg/mL)a | Phenotypeb | MIC (μ/mL)a | Phenotypeb | MIC (μg/mL)a | Phenotypeb |
| Ampicillin | <3.125 | S | >3 200 | R | <3.125 | S |
| Chloramphenicol | 5 | S | 320 | R | 10 | S |
| Erythromycin | 100 | S | 100 | S | 100 | S |
| Gentamycin | 5 | S | 2.5 | S | 5 | S |
| Kanamycin | 6.25 | S | 6.25 | S | 6.25 | S |
| Nalidixic acidc | <5 | S | <5 | S | nd | S |
| Rifampicin | nd | S | nd | S | nd | S |
| Streptomycin | 12.5 | S | >6 400 | R | 12.5 | S |
| Spectinomycin | 25 | S | 25 | S | 25 | S |
| Sulfamethoxazole | nd | S | 1 280 | R | 1 280 | R |
| Tetracycline | 3 | S | 384 | R | 3 | S |
| Trimethoprim | <1 | S | 1 024 | R | <1 | S |
a
nd, not determined, test was only done on solid agar plate. All assays were carried out in three independent replicates.
b
R, resistant; S, susceptible.
c
These assays were carried out using the RfR derivatives VB112, NC207 (VB112 pVCR94) and NC222 (VB112 pVCR94Δ X), respectively.