An understanding of adherence ability is crucial in many areas, for example, in research on biofi... more An understanding of adherence ability is crucial in many areas, for example, in research on biofilms, evaluation of probiotics or in biotechnology. In all these analyses, the reproducible washing is very important in the prevention of false results. During washing, the force, direction of the flow, position of the pipette tip, number of washing cycles, type of washing solution and the way of removing the washing solution can be sources of inappropriate stress to attached cells. To overcome these problems, we here propose the use of high mass density solutions as flotation agents. As the density of bacteria is lower than that of the flotation solutions, nonattached or weakly attached bacteria are moved to the surface due to hydrostatic force. Caesium chloride, ammonium nitrate and sodium diatrizoate solutions, which are commonly used as FAs, were compared with a standard method of rinsing. Several concentrations of agents were used to investigate the optimal concentration and influence of hydrostatic pressure on adhered micro-organisms. We show that flotation is a rapid method for distinguishing between adhered and weakly attached or loosed cells with reproducible results. Due to its range of possible mass density concentration, the best FA was shown to be caesium chloride. This is the first study that suggests using flotation agents to separate planktonic from adhered bacteria. When a high-density solution is used, buoyancy of bacteria ensures their segregation in the solution. Flotation agents could be used instead of washing procedure, which is inaccurate and hardly reproducible. High-density flotation agents could be used for more precise evaluation of bacterial adherence in many assays, such as research of biofilms or evaluation of probiotics.
Prebiotics are generally considered to promote the function or viability of probiotics via their ... more Prebiotics are generally considered to promote the function or viability of probiotics via their fermentation, but their effect on the adherence of probiotics is still unclear. In this study, we examined the effect of 4 commercially available prebiotics [Orafti GR, Orafti P95, and Orafti Synergy (Beneo GmbH, Mannheim, Germany), and Vivinal (Friesland Foods Domo, Amersfoort, the Netherlands)] and 3 simple saccharides (glucose, galactose, and lactose) on the adherence of 5 probiotic type strains, 2 lactococci starter cultures, and 5 potential dairy probiotic strains from the Culture Collection of Dairy Microorganisms (Tábor, Czech Republic). Adherence was tested in microtiter plates on the following types of substrate: polystyrene alone and polystyrene coated with either porcine mucus or cocultures of the human colon cell lines Caco2 and HT29-MXT (1:9 ratio of HT29-MXT:Caco2). Adherence was evaluated as a change in fluorescence in the well of a microtiter plate. The most commonly observed effect (with a few exceptions) of prebiotics was decreased adherence of the tested strains observed on all types of substrate. The tested saccharides, which are part of the residual compounds of the used prebiotics, had a very similar effect-eliciting a decrease in adherence ability in the majority of the probiotic strains.
Neurodegenerative Protein Misfolding Diseases (PMDs), such as Alzheimer's (AD), Parkinson's (PD) ... more Neurodegenerative Protein Misfolding Diseases (PMDs), such as Alzheimer's (AD), Parkinson's (PD) and prion diseases, are generally difficult to diagnose before irreversible damage to the central nervous system damage has occurred. Detection of the misfolded proteins that ultimately lead to these conditions offers a means for providing early detection and diagnosis of this class of disease. In this review, we discuss recent developments surrounding protein misfolding diseases with emphasis on the cytotoxic oligomers implicated in their aetiology. We also discuss the relationship of misfolded proteins with biological membranes. Finally , we discuss how far techniques for providing early diagnoses for PMDs have advanced and describe promising clinical approaches. We conclude that antibodies with specificity towards oligomeric species of AD and PD and lectins with specificity for particular glycosylation, show promise. However, it is not clear which approach may yield a reliable clinical test first. Relevance for patients: Individuals suffering from protein misfolding diseases will likely benefit form earlier, less-or even non-invasive diagnosis techniques. The current state and possible future directions for these are subject of this review.
An understanding of adherence ability is crucial in many areas, for example, in research on biofi... more An understanding of adherence ability is crucial in many areas, for example, in research on biofilms, evaluation of probiotics or in biotechnology. In all these analyses, the reproducible washing is very important in the prevention of false results. During washing, the force, direction of the flow, position of the pipette tip, number of washing cycles, type of washing solution and the way of removing the washing solution can be sources of inappropriate stress to attached cells. To overcome these problems, we here propose the use of high mass density solutions as flotation agents. As the density of bacteria is lower than that of the flotation solutions, nonattached or weakly attached bacteria are moved to the surface due to hydrostatic force. Caesium chloride, ammonium nitrate and sodium diatrizoate solutions, which are commonly used as FAs, were compared with a standard method of rinsing. Several concentrations of agents were used to investigate the optimal concentration and influence of hydrostatic pressure on adhered micro-organisms. We show that flotation is a rapid method for distinguishing between adhered and weakly attached or loosed cells with reproducible results. Due to its range of possible mass density concentration, the best FA was shown to be caesium chloride. This is the first study that suggests using flotation agents to separate planktonic from adhered bacteria. When a high-density solution is used, buoyancy of bacteria ensures their segregation in the solution. Flotation agents could be used instead of washing procedure, which is inaccurate and hardly reproducible. High-density flotation agents could be used for more precise evaluation of bacterial adherence in many assays, such as research of biofilms or evaluation of probiotics.
Prebiotics are generally considered to promote the function or viability of probiotics via their ... more Prebiotics are generally considered to promote the function or viability of probiotics via their fermentation, but their effect on the adherence of probiotics is still unclear. In this study, we examined the effect of 4 commercially available prebiotics [Orafti GR, Orafti P95, and Orafti Synergy (Beneo GmbH, Mannheim, Germany), and Vivinal (Friesland Foods Domo, Amersfoort, the Netherlands)] and 3 simple saccharides (glucose, galactose, and lactose) on the adherence of 5 probiotic type strains, 2 lactococci starter cultures, and 5 potential dairy probiotic strains from the Culture Collection of Dairy Microorganisms (Tábor, Czech Republic). Adherence was tested in microtiter plates on the following types of substrate: polystyrene alone and polystyrene coated with either porcine mucus or cocultures of the human colon cell lines Caco2 and HT29-MXT (1:9 ratio of HT29-MXT:Caco2). Adherence was evaluated as a change in fluorescence in the well of a microtiter plate. The most commonly observed effect (with a few exceptions) of prebiotics was decreased adherence of the tested strains observed on all types of substrate. The tested saccharides, which are part of the residual compounds of the used prebiotics, had a very similar effect-eliciting a decrease in adherence ability in the majority of the probiotic strains.
Neurodegenerative Protein Misfolding Diseases (PMDs), such as Alzheimer's (AD), Parkinson's (PD) ... more Neurodegenerative Protein Misfolding Diseases (PMDs), such as Alzheimer's (AD), Parkinson's (PD) and prion diseases, are generally difficult to diagnose before irreversible damage to the central nervous system damage has occurred. Detection of the misfolded proteins that ultimately lead to these conditions offers a means for providing early detection and diagnosis of this class of disease. In this review, we discuss recent developments surrounding protein misfolding diseases with emphasis on the cytotoxic oligomers implicated in their aetiology. We also discuss the relationship of misfolded proteins with biological membranes. Finally , we discuss how far techniques for providing early diagnoses for PMDs have advanced and describe promising clinical approaches. We conclude that antibodies with specificity towards oligomeric species of AD and PD and lectins with specificity for particular glycosylation, show promise. However, it is not clear which approach may yield a reliable clinical test first. Relevance for patients: Individuals suffering from protein misfolding diseases will likely benefit form earlier, less-or even non-invasive diagnosis techniques. The current state and possible future directions for these are subject of this review.
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