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Systemic infections caused by pathogenic Candida species pose a significant threat to public health in the past decades due to increasing resistance to existing antifungal drugs. Given this scenario, probiotics have been suggested as an alternative approach for managing Candida infections. Hence, the purpose of this study was to evaluate whether probiotic yeast Saccharomyces boulardii co-aggregate with Candida spp. as well as to determine their auto-aggregation ability in dependence on temperature (28 °C, 37 °C, 42 °C) and pH (4.5, 7.0, 8.5) after 5 h and 24 h. Our results revealed that the aggregation of tested yeasts was lower in the first 5 h but increased significantly after 24 h. All strains were able to auto-aggregate in different degrees ranging from 47.46 to 95.95% assessed at 24 h of incubation. Among them the highest auto-aggregation values had C. albicans and C. krusei strains followed by probiotic strain S. boulardii, while the less were observed in C. glabrata strains. In addition, co-aggregation between probiotic and Candida strains was strain-specific. It was evident that S. boulardii significantly inhibited the aggregation of C. albicans ATCC 10261, C. krusei ATCC 6258, and C. glabrata ZIM 2369. However, in C. glabrata ZIM 2382, the aggregation was even enhanced. Temperature and pH also affected the ability to aggregate in a different way only after 5 h of incubation, with the highest cell aggregation evidenced at temperature 37 °C in most cases and pH 4.5. These findings may be of importance when trying to establish probiotic use against pathogenic Candida species. [ABSTRACT FROM AUTHOR]

The aim of this study was to assess the potential of bacteria Escherichia coli ATCC 35218, Pseudomonas aeruginosa ATCC 27853, Staphylococcus aureus ATCC 25923 and yeast Pichia membranifaciens ZIM 2417 to adhere to wooden surfaces such as poplar (Populus sp.), Norway spruce (Picea abies), European beech (Fagus sylvatica), beech coated with the commercial Belinka oil food contact and disinfectant P3-oxonia active 150, and investigate their survival on the beech wood surface under different relative humidities (RH; 65%, 75%, 85%, 98%) and temperatures (10 °C, 20 °C, 27 °C/37 °C). To extend the research goals, the scanning electron microscopy (SEM) analysis was also performed. The adhesion was determined by the number of colony-forming units per mm2 of sample (CFU/mm2). Results showed that all tested bacteria and yeast were able to adhere to the wooden surfaces, although differences were observed according to strains and type of wood. It was evident that number of adhered cells of S. aureus was lower on spruce (3.62 × 103 CFU/mm2) compared to poplar and beech (1.09 × 105 and 2.11 × 104 CFU/mm2, respectively). Furthermore, oil and disinfectant promoted the adhesion of P. aeruginosa (155.93 and 130.50%, respectively) on the beech surfaces, while they had a strong inhibitory effect on the other tested microorganisms E. coli (87.44 and 88.44%, respectively), S. aureus (91.24 and 96.80%, respectively) and P. membranifaciens (92.45 and 87.24%, respectively). These findings are consistent with SEM micrographs. The current data also indicated that relative humidity and temperature significantly affected the adhesion of tested bacteria and yeast. The highest degree of adhesion was observed at a relative humidity of 98% and temperature of 20 and 37 °C for bacteria, or 20 and 27 °C for yeast. Thus, the knowledge of how these microorganisms adhere to wooden surfaces and which factors affect this phenomenon proves to be of great importance in order to avoid their colonization. [ABSTRACT FROM AUTHOR]