The efficacy of KSL on a wide range of microorganisms has been established [31–33], as well as its ability to disrupt oral biofilm growth [34]. KSL-W, a recently synthesized KSL analogue, was shown to display LY294002 purchase improved stability in simulated oral and gastric conditions with in vitro preserved antimicrobial activity [30]. Furthermore, combined with sub-inhibitory concentrations of benzalkonium chloride, a known cationic surface-active agent [35], KSL was shown

to significantly promote bacterial biofilm susceptibility. We also recently demonstrated that KSL-W had a selective effect on C. albicans growth, while exhibiting no toxic effect on epithelial cells [36]. As this KSL-W analogue displays a wide range of microbicidal activities, effectively kills bacteria, controls biofilm formation, and destroys intact biofilms, we hypothesized that KSL-W may also possess antifungal potential. Our goal was thus to investigate the ability of KSL-W to inhibit C. albicans growth and transition from blastospore to hyphal form. The action of KSL-W on biofilm formation/disruption was also assessed. Finally, we examined the effect of KSL-W on various see more C. albicans genes involved in its

growth, transition, and virulence. Results Antimicrobial peptide KSL-W reduced C. albicans growth and transition from blastospore to hyphal form C. albicans cultures were incubated with KSL-W for 5, 10, and 15 h to determine whether this antimicrobial peptide had any adverse effect on C. albicans growth. As shown in Figure 1, KSL-W significantly reduced C. albicans proliferation. After 5 h of contact with KSL-W, the growth inhibition of C. albicans was between 30 and 80%, depending on the concentration of KSL-W used (Figure 1A). After 10 h of contact with KSL-W, growth inhibition was significant, beginning at 25 μg/ml (Figure 1B). At later culture periods, C. albicans growth TCL continued to be significantly affected by the presence of KSL-W (Figure 1C). Indeed, with 25 μg/ml of KSL-W, C. albicans growth was almost half that in the controls (non-treated C. albicans cultures), and with 100 μg/ml of KSL-W, C. albicans growth was reduced by almost 60%. It is

interesting to note that KSL-W in as low as 25 μg/ml was effective at both the early and late culture periods. Figure 1 KSL-W inhibited C. albicans growth. The yeast was cultured in Sabouraud supplemented medium with or without KSL-W at various concentrations. The cultures were maintained for 5, 10, and 15 h at 37°C, after which time an MTT assay was performed for each culture condition. The growth was plotted as means ± SD of the absorbance at 550 nm. (A) C. albicans growth with KSL-W for 5 h; (B) C. albicans growth with KSL-W for 10 h; and (C) C. albicans growth with KSL-W for 15 h. The levels of significance for C. albicans growth in the presence or not of KSL-W or amphotericin B (10 μg/ml) were considered significant at P < 0 · 05. As KSL-W contributed to C.