13 43 ± 0.13 41 ± 0.33 35 ± 0.20 32 ± 0.20 31 ± 0.07 25 ± YM155 clinical trial 0.13 0 Staphylococcus epidermidis KCTC 1917 43 ± 0.07 39 ± 0.26 37 ± 0.07 36 ± 0.07 23 ± 0.13 20 ± 0.13 17 ± 0.26 0 Proteus mirabilis ATCC 21100 45 ± 0.26 42 ± 0.26 40 ± 0.13 34 ± 0.13 28 ± 0.07 24 ± 0.07 21 ± 0.07 0 Candida albicans

ATCC 20231 29 ± 0.26 22 ± 0.07 21 ± 0.07 16 ± 0.07 11 ± 0.07 6 ± 0.07 3 ± 0.07 0 Candida albicans SC5314 39 ± 0.07 31 ± 0.07 24 ± 0.13 20 ± 0.13 17 ± 0.07 7 ± 0.13 6 ± 0.13 0 Negative controls (PBS) were set at 0%. Values ± confidence interval, n = 9 The adhesion of pathogenic bacteria to polystyrene surfaces was inhibited by two lipopeptide biosurfactants produced by B. subtilis and B. licheniformis [9], and adhesion of Listeria monocytogenes to polystyrene find more microplates was reduced by 84% on pretreating the surface with surfactin (1 mg/ml), and by 82% when it was treated with purified rhamnolipid (7.5 mg/ml) [29]. Gudina et al. [30] characterized the anti-adhesive activity of biosurfactants against several microorganisms including Gram-positive and Gram-negative bacteria. This biosurfactant at concentration 25 mg/ml showed high anti-adhesive activity against Staphylococcus aureus (72.0%), S. epidermidis (62.1%), Streptococcus agalactiae (60.0%) and low anti-adhesive activity against

P. aeruginosa (16.5%) and E. coli (11.5%). Coating with pseudofactin II was effective above critical micelle concentration (0.072 mg/ml) [19]. Our results suggest that when the surface is covered by pseudofactin II micelles BIBF 1120 price below attached to polystyrene by van der Waals forces, the adhesion is inhibited more strongly than it is with monomers. Pseudofactin II reduces biofilm formation on polystyrene, glass and silicone Biofilms are defined

as microorganisms attached to a diverse range of biotic and abiotic surfaces and proliferating on them. The human body and medical devices or implants including: urinary catheters, voice prostheses, orthopedic implants, ocular prostheses and contact lenses are exposed to adhesion and biofilm formation by many opportunistic microorganisms. Thus we have tested the influence of pseudofactin II on biofilm formation on different materials. The activity of pseudofactin II against biofilm formation was visualized by confocal laser scanning microscopy (Figure 1). The biofilm growth of E. coli, E. faecalis, E. hirae and C. albicans on polystyrene, glass and silicone from urethral catheters is shown in Figures 1A-D, 1I-L and 1R-U, respectively. The biosurfactant inhibited biofilm formation at the concentration 0.25 mg/ml on polystyrene, glass and silicone surfaces (Figures 1E-H, 1M-P and 1W-Z). E. faecalis ATCC 29212 adhesion to all tested surfaces is less intensive than others strains (Figures 1B, J, S). In fact, the adhesion of this strain to 96 wells plate was between 2 to 4-fold weaker than others tested bacterial strains (data not shown). This effect may be due to small amount of adhesion proteins on E. faecalis ATCC 29212 strain.