Fungistatic Action of N-Acetylcysteine on Candida albicans Biofilms and Its Interaction with Antifungal Agents

Abstract

Therapies targeted to fungal biofilms, mainly against the matrix, and therapies that do not induce microbial resistance are relevant. N-acetylcysteine (NAC), a mucolytic agent, has shown antimicrobial action. This study evaluated the effect of NAC against fluconazole-susceptible (CaS) and -resistant (CaR) Candida albicans. The susceptibility of planktonic cultures to NAC, the effect of NAC on biofilms and their matrix, the interaction of NAC with antifungal agents, and confocal microscopy were evaluated. Data were analyzed descriptively and by the ANOVA/Welch and Tukey/Gomes–Howell tests. The minimum inhibitory concentration (MIC) of NAC was 25 mg/mL for both strains. NAC significantly reduced the viability of both fungal strains. Concentrations higher than the MIC (100 and 50 mg/mL) reduced the viability and the biomass. NAC at 12.5 mg/mL increased the fungal viability. NAC also reduced the soluble components of the biofilm matrix, and showed synergism with caspofungin against planktonic cultures of CaS, but not against biofilms. Confocal images demonstrated that NAC reduced the biofilm thickness and the fluorescence intensity of most fluorochromes used. High concentrations of NAC had similar fungistatic effects against both strains, while a low concentration showed the opposite result. The antibiofilm action of NAC was due to its fungistatic action.

Multiple surface interaction mechanisms direct the anchoring, co-aggregation and formation of dual-species biofilm between Candida albicans and Helicobacter pylori

“…It has been suggested that abundant cell wall proteins are interconnected by disulfide bridges, e.g., protein Pga59 and Pga62 which are GPI cell wall protein with cysteine residues, in addition, Pga59 and Pga62 are expressed to much higher levels in biofilms than in planktonic cultures [59] and they are required for cell wall integrity [58] . The above is consistent with the observations about effect of N-acethylcysteine on C. albicans biofilms [68] , [69] . In general, anti-biofilm activity of N-acethylcysteine is based on the breaking of disulfide [68] , [69] .…”

“…The above is consistent with the observations about effect of N-acethylcysteine on C. albicans biofilms [68] , [69] . In general, anti-biofilm activity of N-acethylcysteine is based on the breaking of disulfide [68] , [69] . But in term of amino acid composition, it has been determined that the content of thiolated amino acids, i.e., cysteine and tyrosine, forming the wall cell are 2.7 and 3.4%, respectively [60] .…”

Antimicrobial Activity of Curcumin in Nanoformulations: A Comprehensive Review

“…These problems are a challenge for humanity, especially when considering that the development of new drugs demands time and money. Thus, the repurposing of existing medications and alternative therapies, such as natural substances, has been investigated [5][6][7].…”

DNase enhances photodynamic therapy against fluconazole‐resistant Candida albicans biofilms

“…These results corroborate those of previous studies that showed that DNase reduced WSP levels (Flemming et al, 2007; Martins et al, 2012; Panariello et al, 2019). The manana‐glucan complex (MGCx), present in the ECM of C. albicans biofilms, is formed via the interaction of WSPs (α‐mannans) and ASPs (β‐glucans) (Nunes et al, 2020; Panariello et al, 2017). The stability of these polysaccharides is responsible for maintaining the integrity of the MGCx, and the interactions in this complex are responsible for the antifungal resistance of biofilms (Perezous et al, 2005).…”