TABLE 1

MICs of AxyXY-OprZ antibiotic substrates for Achromobacter isolates and their mutants

DrugMIC (μg/ml)a
AXX-AAXX-A-ΔZACH-CF-490ACH-CF-911CIP-102236CIP-102236V29GCIP-102236R105SACH-NCF-39ACH-NCF-39V29GACH-CF-842ACH-CF-842V29G
Tobramycin16128 (8)3264 (2)32256 (8)>256 (>8)2496 (4)832 (4)
Amikacin256>256≥256>256>256>256>256192>256 (>1.3)32>256 (>8)
Gentamicin48>256 (>5.3)48256 (5.3)192>256 (>1.3)>256 (>1.3)48>256 (>5.3)12≥256 (≥21)
Netilmicin24>256 (>10.7)64≥256 (≥4)>256>256>25664>256 (>4)16>256 (>16)
Ceftazidime44441.54 (2.6)3 (2)1.53 (2)1.51.5
Cefepime16128 (8)192>256 (>1.3)48>256 (>5.3)>256 (>5.3)24>256 (>10)832 (4)
Imipenem1124 (2)22268 (1.3)24 (2)
Meropenem0.0640.0640.0646 (94)0.0940.125 (1.3)0.125 (1.3)0.0940.125 (1.3)0.750.75
Doripenem0.250.250.252 (8)0.380.5 (1.3)0.5 (1.3)0.250.38 (1.5)11
Ofloxacin212 (6)≥32>3216>32 (>2)>32 (>2)6>32 (>5.3)24>32 (>1.3)
Levofloxacin14 (4)3>32 (>10)312 (4)32 (>10)1.56 (4)48 (2)
Ciprofloxacin0.752 (2.6)1.5>32 (>21)28 (4)>32 (>16)1.58 (5.3)26 (3)
Tetracycline4864 (1.3)192>256 (>1.3)96128 (1.3)>256 (>2.7)192≥256 (≥1.3)48192 (4)
Doxycycline812 (1.5)2496 (4)1216 (1.3)32 (2.7)1624 (1.5)68 (1.3)
Tigecycline48 (2)33223 (1.5)1.52 (1.3)0.380.5 (1.3)
Erythromycin128256 (2)192>256 (>1.3)96>256 (>2.7)>256 (>2.7)32128 (4)>256>256
  • a Values in parentheses represent relative MIC increases (ratio of the MIC for the mutant isolate to the MIC for the original isolate).