In the bloodstream, C. albicans is exposed to the innate immune defenses. As a part of human innate immune system, serum and its components show different degrees of protection against systemic candidiasis. In this study, the natural proliferation condition of C. albicans was monitored continuously by a Live Cell Movie Analyzer. C. albicans cells in HS moved with Brownian motion in the initial selleck stage of culture, then failed adhere to the surface of polystyrene plates. This indicates

that C. albicans may remain in a suspended status at the early period of entering the blood stream. Previous studies showed that free-flowing C. albicans can be rapidly cleared from the blood [19]. We determined that human serum facilitates the removal of C. albicans by inhibiting the adhesion of C. albicans on the surface of the endothelial cells. C. albicans possesses virulence factors that are needed to establish candidiasis that are involved in the many steps of this complicated process,

such as adhesion, phenotypic switching, morphogenesis, and biofilm learn more formation [20]. Some factors in the bloodstream, such as temperature and serum, facilitate the filamentation of C. albicans[21–23]. It is reported that filamentation is favorable for C. albicans adhesion and biofilm formation [24, 25]. However, filamentation failed to offset the biofilm formation inhibition caused by the HS-induced adhesion defect, as demonstrated in our study. We also investigated the effect of serum on germ tube formation in C. albicans. Our results LY2835219 research buy showed that the science rate of germ tube formation is high in HS medium, but compared with the control group, germ

tube formation in the experimental group was delayed in the initial stage of culture (within 90 min). This may be one of the reasons for HS-induced adhesion inhibition. Based on these results, we also think that RPMI 1640 medium may be a more suitable medium than human serum to conduct germ tube testing in C. albicans. In the initial stage of biofilm culture (the adhesion period), low serum concentrations suppressed C. albicans biofilm formation. However, the serum had no effect on pre-adhered biofilms (90 min), even if the serum was in a very high concentration. Thus, we concluded that serum may inhibit biofilm formation by preventing the adhesion of C. albicans, in consensus with previous studies [15, 16]. Recent studies showed that addition of as little as 3% human serum to media can promote C. albicans biofilm formation [14], contrary to our results. This may be explained by the use of different materials, such as serum, culture medium, strains, adhesive medium, and so on. It has been reported that IgG, LL-37, transferrin and lactoferrin, at concentrations close to those found in vivo, can reduce the capacity of C. albicans and bacteria to adhere to polystyrene [17, 26–28].