2,4-Diacetylphloroglucinol Modulates Candida albicans Virulence

Abstract

The dimorphic fungus Candida albicans is one of the most important opportunistic pathogens for humankind. The use of fungicides against Candida could be associated with sub-inhibitory effects, which are referred to as fungal stress responses and are undesirable for the host. In this work, we investigated the antifungal action of 2,4-diacetylphloroglucinol (2,4-DAPG) against Candida albicans ATCC 10231 with a focus on their biofilm-forming ability. We found that 2,4-DAPG was able to reduce the ability of Candida cells to form biofilms, but complete inhibition and eradication effects were not achieved. Furthermore, C. albicans cells in the adherent state were characterized by reduced susceptibility to 2,4-DAPG compared to planktonic cells. The investigation of the mechanisms that could explain the antibiofilm action of 2,4-DAPG revealed a reduction in the cell`s surface hydrophobicity and the inhibition of the yeast-to-hyphae transition. The inhibition of the Candida cells filamentation was accompanied by an increase in the expression of the NRG1 gene, which is a negative regulator of hyphal development. In addition, we microscopically visualized the treated biofilms and revealed numerous channels that were decorated with particles and localized on the hyphae. We assumed that these hyphal structures could be associated with the secretion of aspartyl proteases (Sap). The performed assessments revealed an increase in the activity of Sap, which was accompanied by an increase in the expression of the sap2 and sap4 genes. The antifungal action of 2,4-DAPG is known to be associated with affecting the permeability of cellular structures, which leads to H+ATPase malfunction and the disruption of mitochondrial respiration. The subsequent cytosol acidification and generation of ROS trigger the inhibition of Candida filamentation and activation of Sap production. The introduction of antioxidant Trolox simultaneously with 2,4-DAPG leads to a reduction in Sap production. Collectively, the obtained data indicate new aspects of the interaction of fungal cells with 2,4-DAPG, an antimicrobial metabolite of Pseudomonas spp.

Lipase-Responsive Amphotericin B Loaded PCL Nanoparticles for Antifungal Therapies

“…C. albicans ATCC 10231, an opportunistic pathogen was used in this study due to its lipase-producing activity reported in the literature [ 24 , 25 , 26 , 27 , 28 ]. C. albicans was plated onto potato dextrose agar (Oxoid, ThermoFisher, MA, USA) and incubated overnight at 37 °C.…”

Mar1, an HMG-box protein, regulatesn-alkane adsorption and cell morphology of the dimorphic yeastYarrowia lipolytica

“…In fact, it has been demonstrated that cell surface hydrophobicity is altered by filamentation in Candida tropicalis (50). Several drugs have also been reported to reduce cell surface hydrophobicity and inhibit filamentous growth in C. albicans (51)(52)(53)(54)(55)(56)(57)(58)(59)(60). Therefore, it is possible that there exist mechanisms that simultaneously regulate cell surface hydrophobicity and cell morphology in dimorphic yeasts and that Mar1 is involved in their regulation in Y.…”

A review on mechanisms and prospects of endophytic bacteria in biocontrol of plant pathogenic fungi and their plant growth-promoting activities

“…The selected mutants were subjected to chemical, biochemical, and genetic analyses, and they reported three prime physiological activities relevant to DAPG sensitivity: membrane permeability, ROS regulation, and homeostasis of cells. According to Stepanov et al [ 141 ], the antifungal actions of DAPG include damaging cellular permeability, malfunctioning of H + ATPase, and disturbance of mitochondrial respiration. The primary adverse effects of DAPG are respiration intervention and ATP synthesis, leading to growth inhibition [ 142 ].…”