Table 2.
Presence (+) or absence (−) of bactericidal activity and synergy for antibiotic combinations against planktonic and biofilm populations of CRAB isolates. Bactericidal activity was defined as a ≥3 log10 CFU/mL reduction in viable cell count at 24 h and synergy was defined as a ≥2 log10 CFU/mL reduction by the combination compared to the most active agent alone at 24 h. PMB, polymyxin B; MER, meropenem; MIN, minocycline; AMP/SUL, ampicillin/sulbactam; RIF, rifampin.
| PMB/MER | PMB/MIN | PMB/AMP/SUL | PMB/RIF | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Bactericidal | Synergy | Bactericidal | Synergy | Bactericidal | Synergy | Bactericidal | Synergy | ||
| AR-276 | Planktonic | + | + | − | − | + | + | − | + |
| Biofilm | − | − | − | − | − | − | + | + | |
| AR-279 | Planktonic | + | + | − | − | − | + | + | + |
| Biofilm | − | − | − | − | − | − | − | − | |
| AR-285 | Planktonic | + | + | − | − | + | + | − | − |
| Biofilm | − | − | − | − | − | − | − | + | |
| AR-313 | Planktonic | − | − | − | + | + | + | + | + |
| Biofilm | − | − | − | − | − | − | + | − | |