Culture Supernatant of Enterococcus faecalis Promotes the Hyphal Morphogenesis and Biofilm Formation of Candida albicans

Abstract

(1) Background: Enterococcus faecalis and Candida albicans are often isolated from infected root canals. The interaction between these two species is not clear enough. Therefore, the objective of this study was to investigate the effect of E. faecalis on the biofilm formation, hyphal morphogenesis and virulence gene expression of C. albicans. (2) Methods: We used the culture supernatant of E. faecalis (CSE) to treat the biofilms of C. albicans. Then, crystal violet staining and colony-forming unit (CFU) counting were performed to evaluate biofilm biomass. Scanning electron microscopy (SEM) and confocal laser scanning microscope (CLSM) were applied to observe fungal morphology. Subsequently, exopolymeric substances (EPS) production, cellular surface hydrophobicity (CSH) and adhesion force of biofilms were investigated by CLSM, water–hydrocarbon two-phase assay and atomic force microscopy (AFM), respectively. Finally, the expression of C. albicans virulence genes (ALS1, ALS3, HWP1 and EFG1) were measured by RT-qPCR assay. (3) Results: The exposure of CSE promoted the biofilm formation and hyphal morphogenesis of C. albicans, increased the EPS production, CSH and adhesion force of C. albicans biofilms, and increased the expression level of EFG1. (4) Conclusions: Our data indicated that CSE promoted the hyphal morphogenesis and biofilm formation of C. albicans.

Evaluation of extracellular polymeric substances matrix volume, surface roughness and bacterial adhesion property of oral biofilm

“…EPS is considered as the major component of a biofilm, which can comprise between 50% and 90% of the total organic matter in biofilms. 7 In this study, the 3D architecture and volume of EPS in oral multispecies biofilms were visualized and quantified using specific fluorescent probes and CLSM, which is widely accepted as a methodology that allows examination of the 3D structure of biofilms without disrupting its architectural integrity. 18 , 19 , 20 Theoretically, the increasement of the biofilm matrix (e.g., EPS), which serves as a physical or chemical diffusion barrier, may prevent antibiotics from penetrating the biofilm during biofilm formation.…”

“… 5 , 6 Although CLSM was recently used to observe EPS production of Candida albicans biofilms, there was no study to quantitatively investigate the EPS production and visualize 3D structure of EPS in oral multispecies biofilms at different stages. 7 The development of biofilms is an ongoing, dynamic process. Biofilms are regarded as mature from 3 weeks onward in terms of their structural development (e.g., the thickness remained relatively unchanged), while 1-week-old biofilm is considered to be young.…”

Catalase produced by Candida albicans protects Streptococcus mutans from H 2 O 2 stress—one more piece in the cross-kingdom synergism puzzle

“…Biofilm matrices of cross-kingdom biofilms are often more robust, as seen with dual-species biofilms of C. albicans and multiple bacteria, including Enterococcus faecalis , Staphylococcus epidermidis, S. aureus, and S. mutans ( 11 , 44 – 46 ). These robust matrices create diffusion barriers against environmental stressors.…”

Staphylococcus aureus wraps around Candida albicans and synergistically escapes from Neutrophil extracellular traps

“…The fabrication process for SEM specimens was derived from preceding research ( 52 ). Primary neutrophils were also incubated in 24-well plates with C. albicans , S. aureus or mixed-species at specified MOIs.…”