KG performed the chemical analyses. GK performed the bioinformatic and phylogenetic analyses. LB and JC participated in drafting the

manuscript and revising it critically. All authors read and approved the final manuscript.”
“Background Candida spp. are the fourth most common cause of nosocomial bloodstream infections [1], and Candida albicans accounts for approximately Quisinostat ic50 50% of cases of candidemia [2]. Frequently, candidemia is associated with C. albicans colonization of indwelling devices, such as catheters, endotracheal tubes, and pacemakers [3–6]. In fact, C. albicans is the most common fungus in biofilms formed on medical devices [7]. Biofilm formation is a complex, multicellular process, consisting of cell adhesion, growth, morphogenic switching between yeast and filamentous states, and quorum sensing [8, 9]. Adhesion of C. albicans cells to materials or host cells is a prerequisite for biofilm formation, and cell-cell interactions may be important

in the hierarchical organization of cells within the biofilm [6]. Moreover, biofilm formation of C. albicans is governed by a tightly woven gene network composed of six transcription regulators and their target genes [10]. The zinc finger transcription factor BCR1 and its target genes, ALS1, ALS3, HWP1, and ECE1, play an important role, especially in the process of adhesion [11–13]. ACY-738 Human serum (HS) is a complex medium composed of proteins, lipids, and small molecules. The interaction of C. albicans with serum has been of long-standing interest in the field

of fungal pathogenesis. Because Candida spp. can form biofilms on intravenous GPX6 catheters and other inserted medical devices that may come into contact with blood, serum is regarded as an external cue to trigger biofilm formation. Yuthika et al.[14] reported that 3% human serum can promote the formation of C. albicans biofilms. However, other researches revealed that serum can inhibit biofilm formation in some bacteria. Another study showed that human serum and fetal bovine serum (FBS) inhibit biofilm formation in Staphylococcus selleck chemicals llc aureus[15], and Hammond et al.[16] found that adult bovine serum (ABS) or adult human serum (AHS) also inhibits P. aeruginosa biofilm formation on plastic surfaces, including intravenous catheters. Some studies revealed the ability of serum components to prevent the formation of bacterial biofilms. It was reported that bovine serum albumin (BSA) caused a significant decrease in biofilm development [16]. Abraham et al. indicated that a low molecular weight component of human serum inhibits biofilm formation in Staphylococcus aureus[15]. In addition, one component of innate immunity also prevents bacterial biofilm development [17]. Therefore, our hypothesis is that the positive effect of human serum on Candida albicans biofilm formation may be due to many factors, so it is necessary to study the related molecular mechanism. Results The C.