TABLE 1.
Characterization of nfxC2 mutants
| Strain | CmrA sequence variation | Transcript level ofa: |
MIC (μg ml−1) ofb: |
|||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| cmrA | mexE | mexS | mexT | oprD | mexB | mexY | CIP | CHL | TMP | IPM | ATM | GEN | ||
| PA14 | WT | 1 | 1 | 1 | 1 | 1 | 1 | 1 | 0.125 | 64 | 64 | 1 | 4 | 1 |
| PA14ΔmexS | WT | 0.6 | 116 | ND | 0.9 | 0.1 | 0.1 | 0.2 | 4 | 2,048 | 1,024 | 4 | 2 | 0.25 |
| PA14ΔmexT | WT | 1 | 0.4 | 1.1 | ND | 1 | 1 | 1 | 0.125 | 64 | 64 | 1 | 4 | 1 |
| PJ01 | A68V | 71 | 38 | 5.6 | 1.6 | 0.2 | 0.2 | 0.4 | 1 | 1,024 | 512 | 2 | 2 | 0.5 |
| PJ02 | H204L | 84 | 34 | 2.4 | 1.3 | 0.2 | 0.2 | 0.4 | 1 | 1,024 | 512 | 2 | 2 | 0.5 |
| PJ03 | L89Q | 53 | 74 | 2.3 | 1.6 | 0.2 | 0.1 | 0.4 | 2 | 2,048 | 1,024 | 2 | 2 | 0.5 |
| PJ04 | N214K | 120 | 62 | 2.8 | 1 | 0.2 | 0.1 | 0.4 | 2 | 2,048 | 1,024 | 2 | 2 | 0.5 |
| PA14ΔcmrA | —c | ND | 0.5 | 1.1 | 0.6 | 1 | 1.1 | 0.9 | 0.125 | 64 | 64 | 1 | 4 | 1 |
| PJ01ΔcmrA | — | ND | 0.6 | 1.6 | 1.1 | 1.5 | 1.1 | 1.2 | 0.125 | 64 | 64 | 1 | 4 | 1 |
| PA14ΔcmrAPA14 | WT | 1.8 | 1.7 | 1.9 | 0.9 | 1 | 0.8 | 0.9 | 0.125 | 64 | 64 | 1 | 4 | 1 |
| PA14ΔcmrAPJ01 | A68V | 68 | 29 | 6.1 | 2.7 | 0.2 | 0.1 | 0.4 | 1 | 512 | 256 | 2 | 2 | 0.5 |
| PJ01ΔmexT | WT | 76 | <0.1 | 1.3 | ND | 2.7 | 1 | 1.5 | 0.125 | 64 | 64 | 1 | 4 | 1 |
| PJ01ΔmexS | WT | 70 | <0.1 | ND | 1.9 | 1.3 | 0.8 | 1.7 | 0.125 | 64 | 64 | 1 | 4 | 1 |
a
Expressed as the ratio to the value for wild-type reference strain PA14. Mean values were calculated from two independent bacterial cultures each assayed in duplicate. ND, not determined.
b
CIP, ciprofloxacin; CHL, chloramphenicol; TMP, trimethoprim; IPM, imipenem; ATM, aztreonam; GEN, gentamicin.
c
—, strain lacks the gene.