Comparison of Saccharomyces cerevisiae strains of clinical and nonclinical origin by molecular typing and determination of putative virulence traits

Abstract

Saccharomyces cerevisiae strains of clinical and nonclinical origin were compared by pulse field gel electrophoresis. Complete separation between strains of clinical origin and food strains by their chromosome length polymorphism was not obtained even though there was a tendency for the clinical and food strains to cluster separately. All the investigated strains, except for one food strain, were able to grow at temperatures ≥37 °C but not at 42 °C. Great strain variations were observed in pseudohyphal growth and invasiveness, but the characters were not linked to strains of clinical origin. The adhesion capacities of the yeast strains to a human intestinal epithelial cell line (Caco-2) in response to different nutritional availabilities were determined, as were the effects of the strains on the transepithelial electrical resistance (TER) across polarized monolayers of Caco-2 cells. The yeast strains displayed very low adhesion capacities to Caco-2 cells (0.6–6.2%), and no significant difference was observed between the strains of clinical and nonclinical origin. Both S. cerevisiae strains of clinical and non-clinical origin increased the TER of polarized monolayers of Caco-2 cells. Based on the results obtained in this study, no specific virulence factor was found that clearly separated the strains of clinical origin from the strains of nonclinical origin. On the contrary, all investigated strains of S. cerevisiae were found to strengthen the epithelial barrier function.

Gene Transcription and Virulence Potential ofListeria monocytogenesStrains After Exposure to Acidic and NaCl Stress

“…The Caco-2 cells were propagated and maintained as previously described (Klingberg et al, 2008). For the experiments, 1 mL of Caco-2 cells (2.5Â10 5 cells=mL) was seeded in 24-well tissue culture plates (Nunc, Roskilde, Denmark) and incubated at 378C in a humidified atmosphere of 5% CO 2 and 95% air until monolayers were developed (72 h).…”

Diversity and antifungal susceptibility of yeasts isolated by multiple-tube fermentation from three freshwater lakes in Brazil

“…One isolate of S. cerevisiae was resistant to amphotericin B and two were resistant to itraconazole. Recent reports about the involvement of S. cerevisiae in superficial and life-threatening systemic diseases (Munoz et al 2005;de Llanos et al 2006a,b) suggest that this yeast can be pathogenic under certain circumstances due to its ability to proliferate, persist and disseminate in the body and invade different organs (de Llanos et al 2006a;Klingberg et al 2008). The presence of yeast species which are known to be involved in human mycoses and additionally display high resistance to the antifungal drugs tested here is a serious concern for the people who use these aquatic environments for recreational purposes.…”

Significance of Fermented Food in Nutrition and Food Science

“…Several in vitro and in vivo studies have shown that polyphenols such as flavonoids have antioxidative and immunomodulatory actions. The high content of polyphenols might therefore be at responsible for the bioactive effects of Regulat [18]. The trial was to identify a suitable marker that could be used to obtain significant insight into the complex network of immune function, inflammation, and the redox state and the impact of Regulat as well as fermented foods in healthy subjects [17].…”