Table 1.
Primers for genes to characterize the expression profiles of dispersal cells and the reference gene that were used in this study.
Fig 1.
P. aeruginosa CF27 biofilm dispersal after treatment with buffer control (non-treated), or 16 μg/mL tobramycin (TOB) or with 250 U/mL AlyP1400 and 16 μg/mL tobramycin in a combinational (AlyP1400+TOB) or sequential (AlyP1400→TOB) manner.
(A) Live events per millilitre (events/mL) as determined using flow cytometric analysis of the cell populations for living cells (events negative for FVS520 and positive for FVS700). (B) The total viable count (CFU/mL) of P. aeruginosa CF27 living dispersed biofilm cells. (C) Dead events per millilitre (events/mL) as determined using flow cytometric analysis of the dead populations (events positive for both FVS520 and FVS700). (D) The percentage of dispersed live and dead cells from biofilms. Bars with different letters (a and b) are statistically different (p<0.05, ANOVA two-way with Tukey’s multiple comparison test). Data were analyzed for samples collected immediately after the treatments. The standard error of mean of three independent flow cells is indicated by the error bars.
Fig 2.
Relative expression of genes measured by RT-qPCR in CF27 biofilm dispersal cells.
Gene expressions are measured as the gene expression fold difference compared to planktonic control cells, which were used as the inoculum for the biofilm cultivation. Biofilm dispersal cells were collected immediately after a 2-hour treatment with buffer control (non-treated), or 16 μg/mL tobramycin (TOB) or with 250 U/mL AlyP1400 and 16 μg/mL tobramycin (AlyP1400+TOB). The mean and standard deviation are presented for the data from three replicates. Statistical significance was determined using ANOVA one-way analysis with Tukey’s test. Tobramycin (TOB). * P < 0.05 compared with both non-treated control and TOB only treatment.
Fig 3.
Tobramycin tolerant fraction (%) of P. aeruginosa CF27 planktonic and biofilm dispersal cells to 1 μg/mL of tobramycin.
Bars with different letters (a, b and c) are statistically different (p<0.05, ANOVA one-way with Tukey’s multiple comparison test). Data were analyzed for samples collected immediately after a 2-hour treatment with buffer control (non-treated), or 16 μg/mL tobramycin (TOB) or with 250 U/mL AlyP1400 and 16 μg/mL tobramycin (AlyP1400+TOB). The standard error of mean of three independent flow cells is indicated by the error bars.
Fig 4.
Synergistic effect of tobramycin with AlyP1400 on P. aeruginosa CF27 biofilm dispersal cells.