TABLE 1.
P. aeruginosa strains used for pharmacodynamic studies of ceftazidime and avibactam, including magnitude of the PDI %fT>MIC of monotherapy ceftazidime
| Isolate no. | Resistance summarya | MIC (mg/liter) |
Static % fT>MIC (ceftazidime) |
||
|---|---|---|---|---|---|
| Ceftazidime | Ceftazidime-avibactamb | Thigh | Lung | ||
| 1 | Nitrocefinase activity, ++; AmpC transcript, overexpressed; β-lactamase genotype, blaAmpC; class A−, class B− | 128 | 8 | Not done | 0 |
| 3 | Nitrocefinase activity, baseline; AmpC transcript, basal; β-lactamase genotype, blaAmpC blaTEM-24 (CAZ-6); class B− | 64 | 2 | 0 | 0 |
| 5 | Nitrocefinase activity, ++++; AmpC transcript, overexpressed; β-lactamase genotype, blaAmpC; class A−, class B− | 128 | 8 | 0 | 0 |
| 7 | Nitrocefinase activity, +++; AmpC transcript, overexpressed; β-lactamase genotype, blaAmpC; class A−, class B− | 64 | 4 | 0 | 0 |
| 11 | OprD−, AmpCcon, class A−, class B− | 128 | 16 | No stasisc | 0 |
| 18 | OprD−, AmpCind?, class A−, class B− | 32 | 2 | 28.6 | 27.0 |
| 19 | OprD−, AmpCcon, class A−, class B− | 64 | 4 | 29.6 | 0 |
a
con, constitutive; ind, inducible; OprD−, outer membrane protein deficiency causing resistance to carbapenems in Pseudomonas species; blaAmpC, possesses β-lactamase gene coding for AmpC; blaTEM-24, possesses β-lactamase gene coding for TEM24.
b
The MIC of ceftazidime-avibactam was the value of the ceftazidime MIC measured in the presence of a fixed concentration of avibactam of 4 mg/liter.
c
The highest dose used did not result in a bacteriostatic effect.