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- Leffler, Hakon, et al.
(författare)
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Strategies for studying bacterial adhesion in Vivo
- 1995. - C
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Ingår i: Adhesion of Microbial Pathogens. - 0076-6879. ; 253, s. 206-220
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Bokkapitel (refereegranskat)abstract
- The ultimate goal of studies on microbial adhesion is to understand what molecular interactions between the host and microbe occur in vivo and the impact of these interactions on disease processes. With this goal in mind, the problem can be approached at four levels. At the biochemical level, the host receptors at the relevant colonization site are identified; at the cell biology level, consequences of bacterial binding to host epithelial cells are studied in cell culture; at the physiological level, the consequences of bacterial binding are studied in experimental animals or humans; and at the population level, the consequences of receptor binding for colonization are studied by epidemiological methods. This chapter provides an example of studies at each level and discusses the implications for what might occur in vivo.
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- Signoretto, Caterina, et al.
(författare)
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Effects of mushroom and chicory extracts on the shape, physiology and proteome of the cariogenic bacterium Streptococcus mutans.
- 2013
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Ingår i: BMC complementary and alternative medicine. - : Springer Science and Business Media LLC. - 1472-6882. ; 13
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Tidskriftsartikel (refereegranskat)abstract
- Background: Dental caries is an infectious disease which results from the acidic demineralisation of the tooth enamel and dentine as a consequence of the dental plaque (a microbial biofilm) accumulation. Research showed that several foods contain some components with antibacterial and antiplaque activity. Previous studies indicated antimicrobial and antiplaque activities in a low-molecular-mass (LMM) fraction of extracts from either an edible mushroom (Lentinus edodes) or from Italian red chicory (Cichorium intybus). Methods: We have evaluated the antimicrobial mode of action of these fractions on Streptococcus mutans, the etiological agent of human dental caries. The effects on shape, macromolecular syntheses and cell proteome were analysed. Results: The best antimicrobial activity has been displayed by the LMM mushroom extract with a bacteriostatic effect. At the MIC of both extracts DNA synthesis was the main macromolecular synthesis inhibited, RNA synthesis was less inhibited than that of DNA and protein synthesis was inhibited only by roughly 50%. The partial inhibition of protein synthesis is compatible with the observed significant increase in cell mass. The increase in these parameters is linked to the morphological alteration with transition from cocci of the untreated control to elongated cells. Interestingly, these modifications were also observed at sub-MIC concentrations. Finally, membrane and cytosol proteome analysis was conducted under LMM mushroom extract treatment in comparison with untreated S. mutans cells. Significant changes were observed for 31 membrane proteins and 20 of the cytosol fractions. The possible role of the changed proteins is discussed. Conclusions: This report has shown an antibiotic-like mode of action of mushroom and chicory extracts as demonstrated by induced morphogenetic effects and inhibition of specific macromolecular synthesis. This feature as well as the safe use of this extract as result of its natural origin render the LMM both mushroom and chicory extracts suitable for the formulation into products for daily oral hygiene such as mouthwashes or toothpastes.
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- Signoretto, Caterina, et al.
(författare)
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The anti-adhesive mode of action of a purified mushroom (Lentinus edodes) extract with anticaries and antigingivitis properties in two oral bacterial phatogens
- 2014
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Ingår i: BMC Complementary and Alternative Medicine. - : Springer Science and Business Media LLC. - 1472-6882. ; 14:75
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Tidskriftsartikel (refereegranskat)abstract
- Abstract Background In previous works we have shown that a low-molecular-mass (LMM) fraction from mushroom (Lentinus edodes) homogenate interferes with binding of Streptococcus mutans to hydroxyapatite and Prevotella intermedia to gingival cells. Additionally, inhibition of biofilm formation of both odonto- and periodonto-pathogenic bacteria and detachment from preformed biofilms have been described for this compound. Further purification of mushroom extract has been recently achieved and a sub-fraction (i.e. # 5) has been identified as containing the majority of the mentioned biological activities. The aim of this study was to characterise the bacterial receptors for the purified mushroom sub-fraction #5 in order to better elucidate the mode of action of this compound when interfering with bacterial adhesion to host surfaces or with bacteria-bacteria interactions in the biofilm state. Methods Candidate bacterial molecules to act as target of this compound were bacterial surface molecules involved in cell adhesion and biofilm formation, and, thus, we have considered cell wall associated proteins (CWPs), teichoic acid (TA) and lipoteichoic acid (LTA) of S. mutans, and outer membrane proteins (OMPs) and lipopolysaccharide (LPS) of P. intermedia. Results Fifteen S. mutans CWPs and TA were capable of binding sub-fraction #5, while LTA did not. As far as P. intermedia is concerned, we show that five OMPs interact with sub-fraction # 5. Capacity of binding to P. intermedia LPS was also studied but in this case negative results were obtained. Conclusions Binding sub-fraction # 5 to surface molecules of S. mutans or P. intermedia may result in inactivation of their physiological functions. As a whole, these results indicate, at molecular level, the bacterial surface alterations affecting adhesion and biofim formation. For these antimicrobial properties, the compound may find use in daily oral hygiene.
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