| 1. |
- Bikker, Floris J., et al.
(författare)
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Phytosphingosine Prevents the Formation of Young Salivary Biofilms in vitro
- 2018
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Ingår i: Caries Research. - : S. Karger. - 0008-6568 .- 1421-976X. ; 52:1-2, s. 7-13
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Tidskriftsartikel (refereegranskat)abstract
- Dental biofilms are formed in a multistep process that is initiated by the adhesion of oral bacteria to the dental hard surface. As dental biofilms are associated with oral diseases their control is necessary in order to maintain oral health. Recently, it was revealed that phytosphingosine (PHS)-treated hydroxyapatite discs showed anti-adhesive activity in a static in vitro biofilm model against Streptococcus mutans. The goal of the present study was to further unravel the anti-adhesive and anti-biofilm properties of PHS in both static and dynamic in vitro biofilm models against a full salivary inoculum. After 3 h under static conditions, bacterial adherence on PHS-treated cover glass slides was reduced by 60% compared to the untreated surface. After 6 and 24 h under static conditions, no significant differences in bacterial adherence were observed between PHS-treated and untreated cover glass slides. However, under dynamic conditions, i.e., the presence of shear forces, virtually no bacterial adherence was observed for up to 16 h on PHS-coated surfaces. Besides, PHS showed a strong bactericidal activity on salivary biofilms. Treatment of a 3- and 6-h statically grown biofilm resulted in a 99 and 94% reduction of viable cells, respectively, which was effectuated within minutes. In principle, these anti-adherence and anti-biofilm properties make PHS a promising candidate ingredient for use in oral care products aimed at oral microbial control. (C) 2017 S. Karger AG, Basel
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| 2. |
- Neilands, Jessica, et al.
(författare)
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Parvimonas micra stimulates expression of gingipains from Porphyromonas gingivalis in multi-species communities
- 2019
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Ingår i: Anaerobe. - : Elsevier. - 1075-9964 .- 1095-8274. ; 55, s. 54-60
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Tidskriftsartikel (refereegranskat)abstract
- Dental biofilms are complex ecosystems containing many bacterial species that live in mutualistic relationships. These interactions can profoundly affect the virulence properties of the community. In this study we investigated how the production of gingipains, virulence factors from Porphyromonas gingivalis important in periodontal disease, was affected by other commonly found members of the sub-gingival microbiome. To mimic the subgingival microbiome, multispecies consortia (P. gingivalis, Fusobacterium nucleatum, Actinomyces naeslundii, Streptococus oralis, Streptococcus mitis, Streptococcus gordonii and Streptococcus cristatus, with or without Parvimonas micra) as well as dual species consortia (P. gingivalis with P. micra, S. oralis or F. nucleatum) were constructed and maintained anaerobically in 10% serum for up to seven days. The number of P. gingivalis was determined by plating on Brucella agar and the gingipain specific fluorogenic substrate BikKam-10 was used to investigate gingipain activity. The effect of secreted products from P. micra on gingipain activity was investigated by adding supernatants from P. micra to P. gingivalis cultures. The most prominent secreted proteins in the supernatant were identified using mass spectrometry. P. gingivalis was unable to grow in serum, either alone or in the presence of S. oralis or F. nucleatum. In contrast, with P. micra growth was significantly enhanced and this was associated with an increase in gingipain activity. In the multi-species consortia, the presence of P. micra caused a 13-fold increase in gingipain activity. Exposure of P. gingivalis to supernatants from P. micra for 24 hours caused a 3-fold increase in gingipain activity. This effect was reduced by 43% after heat-treatment of the supernatant. Two dimensional gel electrophoresis revealed that several of the most prominent proteins in the P. micra supernatant were glycolytic enzymes. The results from this study suggests that gingipains are produced in response to a P. micra derived signaling molecule that is most likely a protein. This is the first time it has been shown that P. micra can affect P. gingivalis virulence properties. This is likely to be of significance for the development of be of periodontitis since these two microorganisms are often found together in the subgingival biofilm.
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| 3. |
- Valentijn-Benz, Marianne, et al.
(författare)
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Sphingoid Bases Inhibit Acid-Induced Demineralization of Hydroxyapatite
- 2015
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Ingår i: Caries Research. - : S. Karger. - 0008-6568 .- 1421-976X. ; 49:1, s. 9-17
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Tidskriftsartikel (refereegranskat)abstract
- Calcium hydroxyapatite (HAp), the main constituent of dental enamel, is inherently susceptible to the etching and dissolving action of acids, resulting in tooth decay such as dental caries and dental erosion. Since the prevalence of erosive wear is gradually increasing, there is urgent need for agents that protect the enamel against erosive attacks. In the present study we studied in vitro the anti-erosive effects of a number of sphingolipids and sphingoid bases, which form the backbone of sphingolipids. Pretreatment of HAp discs with sphingosine, phytosphingosine (PHS), PHS phosphate and sphinganine significantly protected these against acid-induced demineralization by 80 ± 17%, 78 ± 17%, 78 ± 7% and 81 ± 8%, respectively (p < 0.001). On the other hand, sphingomyelin, acetyl PHS, octanoyl PHS and stearoyl PHS had no anti-erosive effects. Atomic force measurement revealed that HAp discs treated with PHS were almost completely and homogeneously covered by patches of PHS. This suggests that PHS and other sphingoid bases form layers on the surface of HAp, which act as diffusion barriers against H+ ions. In principle, these anti-erosive properties make PHS and related sphingosines promising and attractive candidates as ingredients in oral care products.
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