Influence of Culture Media on Biofilm Formation byCandidaSpecies and Response of Sessile Cells to Antifungals and Oxidative Stress

Abstract

The aims of the study were to evaluate the influence of culture media on biofilm formation by C. albicans, C. glabrata, C. krusei, and C. parapsilosis and to investigate the responses of sessile cells to antifungals and reactive oxygen species (ROS) as compared to planktonic cells. For biofilm formation, the Candida species were grown at different periods of time in YP or YNB media supplemented or not with 0.2 or 2% glucose. Sessile and planktonic cells were exposed to increasing concentrations of antifungals, H2O2, menadione or silver nanoparticles (AgNPs). Biofilms were observed by scanning electron microscopy (SEM) and quantified by the XTT assay. C. albicans formed biofilms preferentially in YPD containing 2% glucose (YPD/2%), C. glabrata in glucose-free YNB or supplemented with 0.2% glucose (YNB/0.2%), while C. krusei and C. parapsilosis preferred YP, YPD/0.2%, and YPD/2%. Interestingly, only C. albicans produced an exopolymeric matrix. This is the first report dealing with the in vitro effect of the culture medium and glucose on the formation of biofilms in four Candida species as well as the resistance of sessile cells to antifungals, AgNPs, and ROS. Our results suggest that candidiasis in vivo is a multifactorial and complex process where the nutritional conditions, the human immune system, and the adaptability of the pathogen should be considered altogether to provide an effective treatment of the patient.

Culture media profoundly affect Candida albicans and Candida tropicalis growth, adhesion and biofilm development

“…Despite burgeoning data of the effect of varying culture media on candidal growth (Serrano-Fujarte et al 2015), adhesion and biofilm development in laboratory settings there is no consensus recommendation to date, for a specific, choice medium suitable for in vitro biofilm experiments. Therefore, we investigated the effect of three different culture media on the growth, adhesion and biofilm formation of C. albicans and C. tropicalis , and their mixed biofilms using the microtiter plate system.…”

Biosynthesis of micro‐ and nanocrystals of Pb (II), Hg (II) and Cd (II) sulfides in four Candida species: a comparative study of in vivo and in vitro approaches

“…Altogether, these tests show that the four species of Candida are able to withstand 1.0 mM of Pb 2+ , Cd 2+ or Hg 2+ for 90 min. Although all Candida species are able to grow at a concentration of 1.0 mM of any of the three metals evaluated, the ability of any Candida species to withstand a higher concentration of these metals will depend on the adaptability of each of these yeasts to the different physiological niches in order to survive in the host (Serrano‐Fujarte et al ., ). In this regard, each species of Candida was reported to respond differentially whether they were in the presence of different azole antifungals or in the presence of different reactive oxygen species (ROS; Cuellar‐Cruz et al ., ; Ramirez‐Quijas et al ., ; Serrano‐Fujarte et al ., ).…”

Interactions between Candida albicans and Candida glabrata in biofilms: Influence of the strain type, culture medium and glucose supplementation

“…These results are in line with SEM observations (Figure ), which show structural differences between biofilms of these species. While C. glabrata biofilms are only composed of yeasts and produce lower amount of exopolymeric material, biofilms of C. albicans present intermixed composition (yeasts of higher diameter, pseudohyphae and hyphae), what promotes a higher CV absorption when compared with C. glabrata which, in turn, results in higher absorbance values. Similarly, the amount of biofilm biomass of C. albicans 324LA/94 was higher than that originated by C. albicans ATCC 10231, under all experimental conditions, and SEM observations clearly show a higher number of hyphae for biofilms of C. albicans 324LA/94 when compared with the reference strain (Figure A, D, G, J and M).…”