Figure 7: Prevention of biofilm formation: (A) and biofilm reduction (1-dayold biofilms) (B) in the presence of free or liposomal NAC was examined. At the prevention of biofilm formation experiment, PA-13572 were grown in 96- well plates at 37°Cfor 18 h in the presence of different concentrations (1/2– 1/64 the MIC) of both F- and L-NAC. Nonattached bacteria were washed with PBS while attached bacteria were stained with CV and absorbance read at 590 nm was measured. For the biofilm reduction, PA-13572 were grown as above without any treatment then treated with sub-MIC or concentration above MICs F- and L- NAC then incubation for another 18 h. Same washing and staining steps were applied and absorbance was measured as described above. All experiments were repeated tree times in triplicate. P values were considered significant when compared to control *** P<0.001. All experiments were repeated 3 times in triplicates.