Table 3.
Post-Antibiotic Effect (PAE) and Score of Post-Antibiotic Effect-associated Permeabilization (S-PAEP) induced by antibiotics on Ps4
| Agent used as pre-treatmenta | MIC/MBC (μg/mL) | Final concentration (μg/mL) | PAEb (h) | PAEPc (h) | Snov-PAEPd (h) | ||
|---|---|---|---|---|---|---|---|
| 0 | 1 | 2 | |||||
| GEN | 2/2 | 4 | 0.75 + 0,01 | 0 | < 0.25 | < 0.25 | < 0.25 |
| CIP | 2/2 | 4 | 1.5 + 0,06 | 0 | < 0.25 | < 0.25 | < 0.25 |
| IPM | 2/2 | 4 | 0 | 0 | < 0.25 | < 0.25 | < 0.25 |
| PMB | 1/1 | 2 | 0.1 + 0,02 | 2–3 | 3.2 + 0.06 | 2.7 + 0.05 | 1.1 + 0.03 |
a GEN, gentamicin; CIP, ciprofloxacin; IPM, imipenem; PMB, polymyxin B
b Post-antibiotic effect assessed by turdidimetry (Bioscreen)
c Duration of Post-Antibiotic Effect-associated Permeabilization. PAEs y S-PAEPs values are the average of two independent experiments performed in triplicate. Differences were analyzed by Kruskal–Wallis test followed by Mann–Whitney’s U test
d Score of Post-Antibiotic Effect-associated Permeabilization. Delay in h caused by exposure to a sub-MIC concentration of novobiocin (1/8 x MIC) added at the indicated time (0 h, 1 h, 2 h) after the beginning of growth in peptide-free medium. S-PAEP was assessed by turdidimetry (Bioscreen)