Effect of quorum sensing molecules and natamycin on biofilms of Candida tropicalis and other yeasts isolated from industrial juice filtration membranes

Abstract

Aims Cells limit the cell number of dense biofilms by releasing self‐inhibitory molecules. Here, we aim to assess the effectiveness of yeast quorum sensing (QS) molecules and the antifungal agent natamycin against yeast biofilms of strains commonly isolated from fruit juice ultrafiltration membranes. Methods and Results Yeast QS molecules, such as tyrosol, 2‐phenylethanol and farnesol, were detected by solvent extraction and HS‐SPME GC‐MS in Candida tropicalis cultures. The effect of QS molecules on mono‐ and multispecies biofilms formed by Rhodotorula mucilaginosa, C. tropicalis, Candida krusei and Candida kefyr was evaluated by plate count and epifluorescence microscopy. Farnesol caused a decrease in cell number and disrupted mono‐ and multispecies yeast biofilms during adhesion (0·6 mmol l−1). 2‐phenyl ethanol 1·2 mmol l−1 stimulated biofilm density and increased cell number in both mono‐ and multispecies biofilms, while tyrosol did not show effects when tested against C. tropicalis biofilms (0·05–1·2 mmol l−1). Natamycin caused a strong decrease in cell number and disruption of biofilm structure in C. tropicalis biofilms at high concentrations (0·3–1·2 mmol l−1). The combination of farnesol 0·6 mmol l−1 and natamycin at 0·01 mmol l−1, the maximum concentration of natamycin accepted for direct addition into fruit juices, effectively reduced cell counts and disrupted the structure of C. tropicalis biofilms. Conclusion Farnesol 0·6 mmol l−1 significantly increased the inhibition exerted by natamycin 0·01 mmol l−1 (~5 ppm) reducing biofilm development from juice on stainless steel surfaces. Significance and Impact of the Study These results support the use of QS molecules as biofilm inhibitors in beverages and would certainly inspire the design of novel preservative and cleaning products for the food industry based on combinatory approaches.

In vitro and in vivo Effect of Exogenous Farnesol Exposure Against Candida auris

“…Farnesol is a fungal quorum-sensing molecule that inhibits yeast-to-hyphae transition and promotes reverse morphogenesis in C. albicans (Hornby et al, 2001). Based on recent studies, farnesol acts synergistically with several antifungal agents against C. albicans, Candida glabrata, Candida tropicalis as well as against Candida parapsilosis planktonic cells and/or biofilms (Katragkou et al, 2015;Kovács et al, 2016;Monteiro et al, 2017;Agustín et al, 2019), thus it has been proposed as a potential adjuvant therapeutic agent. In addition, its therapeutic potential has already been confirmed against C. albicans in murine models of mucosal infection (Hisajima et al, 2008;Bozó et al, 2016).…”

Pathogenesis and Clinical Relevance of Candida Biofilms in Vulvovaginal Candidiasis

“…C. nivariensis was reported for the first time in Canary Islands, Spain, and at present, it seems to widely distributed worldwide. Inhibition of quorum sensing molecules with natamycin against C. tropicalis haven been used successfully by researchers (Agustín et al, 2019). However, the number of cases is low possibly due to the impossible phenotypic identification of C. glabrata (Aznar-Marin et al, 2016).…”

Farnesol and Tyrosol: Secondary Metabolites with a Crucial quorum-sensing Role in Candida Biofilm Development

“…Far amplified the inhibition exerted by natamycin, which reduced the biofilm formation, growth and expansion, from juice on stainless steel surfaces. This has highlighted the possibility of using Far in the food industry (or other QSM) [66]. In biofilms treated with higher concentrations of Far, the addition of Tyr resulted in biofilms containing the majority of cells in the yeast form, Tyr could not counteract the effects of higher concentrations of Far [3] and presumably, the effects of Far predominate [11].…”