# The RND Efflux Pump Gene Expression in the Biofilm Formation of _Acinetobacter baumannii_
## 2 Results
#### 2.2.1 Efflux Pump Substrate (Levofloxacin)
\begin{table}
\begin{tabular}{c c c c c c} \hline
**ERIC Cluster** & **Isolate Number** & **BFI \#** & **Biofilm Formation** & **BFI with Sub-MIC of** & **BFI with CCCP** \\
**Group** & **Isolate Number** & **BFI \#** & **Pattern** & **Levoffloxacin (Fold Change)** & **(Fold Change)** \\ \hline
**A** & 25 \# & 2.60 & Strong & 2.30(0.91) & 2.20 (0.88) \\  & 30 & 1.30 & Strong & 1.24 (0.92) & 1.04 (0.80) \\  & 7 \# & 0.70 & Weak & 0.95 (1.35) \({}^{*}\) & 0.70 (1.00) \\ B & 9 & 0.70 & Weak & 0.73 (1.05) & 0.80 (1.17) \\  & 37 & 0.60 & Weak & 0.54 (0.90) & 0.61 (1.02) \\  & 22 & 1.27 & Strong & 1.10 (0.90) & 1.20 (0.94) \\ C & 27 \# & 2.37 & Moderate & 2.48 (1.05) & 2.08 (0.88) \({}^{*}\) \\  & 39 & 1.43 & Strong & 1.37 (0.89) & 1.43 (1.00) \\  & 43 & 1.10 & Strong & 0.99 (0.90) & 1.10 (0.90) \({}^{*}\) \\  & 1 & 0.80 & Moderate & 0.84 (1.05) & 0.90 (1.12) \\  & 26 & 0.70 & Moderate & 0.88 (1.26) \({}^{*}\) & 1.24 (1.77) \\ D & 44 & 0.90 & Moderate & 1.80 (2.00) \({}^{**}\) & 0.85 (0.95) \\  & 45 \# & 0.79 & Moderate & 0.86 (1.08) & 0.66 (0.83) \({}^{*}\) \\  & 47 & 0.90 & Moderate & 1.00 (1.10) & 0.80 (0.88) \({}^{*}\) \\  & 32 & 0.95 & Moderate & 0.90 (0.94) & 0.95 (1.00) \\ E & 33 \# & 0.96 & Moderate & 0.86 (0.90) & 0.96 (1.00) \\  & 46 & 0.80 & Moderate & 0.90 (1.12) & 0.85 (1.06) \\ F & 31 & 0.90 & Moderate & 0.95 (1.05) & 1.00 (1.10) \\  & 35 \# & 1.68 & Moderate & 1.39 (0.83) & 1.30 (0.78) \\  & 3 & 0.65 & Weak & 0.70 (1.07) & 0.80 (1.23) \\  & 6 & 0.60 & Weak & 0.65 (1.08) & 0.58 (0.96) \\  & 24 & 0.29 & Non-Adherent & 0.28 (0.99) & 0.49 (1.70) \\
**G** & 28 \# & 1.50 & Strong & 1.48 (0.98) & 1.29 (0.86) \({}^{*}\) \\  & 29 & 0.62 & Weak & 0.56 (0.90) & 0.62 (1.00) \\  & 36 \# & 0.29 & Non-Adherent & 0.46 (1.30) \({}^{*}\) & 0.29 (1.00) \\  & 40 & 0.04 & Non-Adherent & 0.19 (5.00) \({}^{*}\) & 0.035 (0.90) \\  & 41 & 0.11 & Non-Adherent & 0.27 (2.50) \({}^{**}\) & 0.09 (0.90) \\  & 2 & 0.60 & Weak & 0.64 (1.08) & 0.67 (1.12) \\  & 4 \# & 2.00 & Strong & 1.78 (0.89) & 2.34 (1.17) \\ H & 14 & 0.55 & Weak & 0.48 (0.89) & 0.42 (0.76) \\  & 15 & 0.59 & Weak & 0.87 (1.49) \({}^{*}\) & 0.67 (0.40) \({}^{*}\) \\  & 23 \# & 2.40 & Strong & 2.16 (0.90) & 0.79 (0.33) \({}^{*}\) \\ I & 12 \# & 0.52 & Weak & 0.58 (1.13) & 0.42 (0.80) \\  & 21 & 0.50 & Weak & 0.60 (1.20) & 0.55 (1.10) \\ \hline \end{tabular} \({}^{\dagger}\) S: Susceptibility (MIC \(\leq\) 1 ug/mL), I: Intermediate (MIC = 2 ug/mL), R: Resistant (MIC \(\geq\) 4 ug/mL). # Phenotypic efflux factor (F) = MIC without CCCP (EPI)/MIC with CCCP (EPI); * Isolates showing ¿ 4 phenotypic efflux factor with CCCP 12.5 ug/mL.  
\end{table} 
Table 3: Biofilm formation potential by _Acinetobacter baumannii_ isolates and the effect of efflux pump inhibitor (CCCP) and efflux pump substrate (levofloxacin at 0.25x MIC) on biofilm formation. addition of sub-MICs of levofloxacin to bacterial culture significantly increased (\(p<0.05\)) the biofilm formation pattern of 20.5% (7/34) of the isolates (Table 3). No correlation was detected between fold change in the BFI using sub-MIC of levofloxacin and the biofilm formation potential of the isolates ([PERSON]'s \(r_{s}=-0.47\), \(p>0.05\)).