Table 2.
Effect of 32 and 64 mg/L RV in presence or absence of CHX and BZK sub-MIC concentrations, alone or in combination, on biofilm formation in A. baumannii ATCC 19606 and isogenic mutants of AmvA, AdeB, AdeJ, AceI EPs.
| Strains | ||||||
|---|---|---|---|---|---|---|
| Treatment | ATCC 19606 | ∆adeB | ∆adeJ | ∆aceI | ∆amvA | |
| TSB | 1.02 ± 0.05 | 0.59 ± 0.03 | 0.54 ± 0.01 | 0.76 ± 0.06 | 0.57 ± 0.06 | |
| 32 RV | 0.74 ± 0.06 | 0.54 ± 0.06 | 0.63 ± 0.03 | 0.78 ± 0.01 | 0.69 ± 0.06 | |
| 0 RV | 1/8 CHX MIC | 0.99 ± 0.01 | 0.52 ± 0.01 | 0.61 ± 0.03 | 0.71 ± 0.03 | 0.50 ± 0.03 |
| 1/4 CHX MIC | 0.98 ± 0.03 | 0.49 ± 0.01 | 0.55 ± 0.03 | 0.61 ± 0.04 | 0.50 ± 0.01 | |
| 1/2 CHX MIC | 0.87 ± 0.08 | 0.47 ± 0.02 | 0.53 ± 0.03 | 0.54 ± 0.03 | 0.53 ± 0.04 | |
| 1/8 BZK MIC | 0.74 ± 0.01 | 0.54 ± 0.06 | 0.54 ± 0.03 | 0.77 ± 0.04 | 0.34 ± 0.04 | |
| 1/4 BZK MIC | 0.64 ± 0.1* | 0 ± 0.02*** | 0.21 ± 0.03** | 0.59 ± 0.04 | 0.34 ± 0.01 | |
| 1/2 BZK MIC | 0.67 ± 0.04* | 0 ± 0.02*** | 0 ± 0.02*** | 0.61 ± 0.04 | 0.35 ± 0.01 | |
| 1/8 CHX MIC+1/8 BZK MIC | 0.73 ± 0.01 | 0.53 ± 0.01 | 0 ± 0.1*** | 0.64 ± 0.03 | 0.45 ± 0.01 | |
| 1/4 CHX MIC+1/4 BZK MIC | 0.5 ± 0.03** | 0 ± 0.02*** | 0 ± 0.03*** | 0.19 ± 0.06*** | 0.42 ± 0.06 | |
| ½ CHX MIC+ ½ BZK MIC | 0.41 ± 0.03** | 0 ± 0.1*** | 0 ± 0.1*** | 0 ± 0.03*** | 0 ± 0.03*** | |
| 32 RV | 1/8 CHX MIC | 0.75 ± 0.01 | 0.5 ± 0.02 | 0.60 ± 0.04 | 0.42 ± 0.03* | 0.52 ± 0.04 |
| 1/4 CHX MIC | 0.70 ± 0.04 | 0.49 ± 0.02 | 0.51 ± 0.04 | 0.45 ± 0.03* | 0.50 ± 0.01 | |
| 1/2 CHX MIC | 0.73 ± 0.04 | 0 ± 0.04*** | 0.42 ± 0.01 | 0.41 ± 0.01* | 0.42 ± 0.01 | |
| 1/8 BZK MIC | 0.71 ± 0.0* | 0.55 ± 0.02 | 0.59 ± 0.06 | 0.70 ± 0.04 | 0.45 ± 0.01 | |
| 1/4 BZK MIC | 0.64 ± 0.03* | 0 ± 0.02*** | 0 ± 0.02*** | 0.62 ± 0.01 | 0.44 ± 0.03 | |
| 1/2 BZK MIC | 0.67 ± 0.02* | 0 ± 0.1*** | 0 ± 0.01*** | 0.40 ± 0.04* | 0.43 ± 0.01 | |
| 1/8 CHX MIC+1/8 BZK MIC | 0.44 ± 0.02** | 0 ± 0.02*** | 0 ± 0.04*** | 0.52 ± 0.03 | 0.54 ± 0.04 | |
| 1/4 CHX MIC+1/4 BZK MIC | 0 ± 0.02*** | 0 ± 0.1*** | 0 ± 0.01*** | 0.0 ± 0.01*** | 0.0 ± 0.03*** | |
| 1/2 CHX MIC+1/2 BZK MIC | 0 ± 0.02*** | 0 ± 0.03*** | 0 ± 0.03*** | 0 ± 0.03*** | 0 ± 0.03*** | |
The results are shown as OD595 nm/600 nm; Synergistic inhibitory effects of RV and/or CHX and BZK on biofilm formation are shown in bold; p-values were calculated using two-way ANOVA (*p < 0.05; **p < 0.01; ***p < 0.001). Assays were performed in triplicate.