TABLE 2.
Cross-resistance after drug exposure/removala
| Drug(s) | Ceftazidime | Meropenem | Piperacillin-tazobactam | Tobramycin | Ciprofloxacin |
|---|---|---|---|---|---|
| Ceftazidime | +27/25 | +23/+22 | +23/+22 | –b | – |
| Meropenem | +24/– | +29/+29 | +22/– | – | – |
| Piperacillin-tazobactam | +24/+22 | +22/– | +27/+27 | – | – |
| Tobramycin | −22/−24 | – | −22/−23 | +28/+24 | −23/−24 |
| Ciprofloxacin | – | – | – | – | +27/+25 |
a
Shown are the increases (+) or decreases (−) in the MICs of the antibiotics at the top upon acquisition of resistance to the antibiotics on the left. After P. aeruginosa became resistant to tobramycin, it was more sensitive to the other antibiotics.
b
–, no change in the MIC.