TABLE 5.
AmgRS- and MexXY-dependent rifampin potentiation of aminoglycoside activity against an aminoglycoside-resistant clinical isolate of P. aeruginosaa
| Strain | Genotype | RIF | MIC (μg/ml) forb: |
|||||
|---|---|---|---|---|---|---|---|---|
| PAR | NEO | AMI | KAN | GEN | STR | |||
| K2156 | Wild type | − | 512 | 64 | 16 | 128 | 8 | 256 |
| + | 32 | 8 | 1 | 32 | 1 | 8 | ||
| K3630 | ΔamgR | − | 16 | 8 | 1 | 16 | 1 | 16 |
| + | 16 | 8 | 1 | 16 | 1 | 16 | ||
| K2167 | ΔmexXY | − | 32 | 16 | 1 | 32 | 2 | 4 |
| + | 16 | 8 | 1 | 32 | 1 | 2 | ||
a
The MICs for the indicated antimicrobials were determined for the clinical (cystic fibrosis) P. aeruginosa isolate K2156 and its AmgR− and MexXY− derivatives in the absence (−) and presence (+) of one-half MIC of rifampin (RIF) for each strain (8 μg/ml).
b
PAR, paromomycin; NEO, neomycin; AMI, amikacin; KAN, kanamycin; GEN, gentamicin; STR, streptomycin.