| 1. |
- Basic, Amina, et al.
(författare)
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The proteins of Fusobacterium spp. involved in hydrogen sulfide production from L-cysteine
- 2017
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Ingår i: Bmc Microbiology. - : Springer Science and Business Media LLC. - 1471-2180. ; 17:61
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Tidskriftsartikel (refereegranskat)abstract
- Background: Hydrogen sulfide (H2S) is a toxic foul-smelling gas produced by subgingival biofilms in patients with periodontal disease and is suggested to be part of the pathogenesis of the disease. We studied the H2S-producing protein expression of bacterial strains associated with periodontal disease. Further, we examined the effect of a cysteine-rich growth environment on the synthesis of intracellular enzymes in F. nucleatum polymorphum ATCC 10953. The proteins were subjected to one-dimensional (1DE) and two-dimensional (2DE) gel electrophoresis An in-gel activity assay was used to detect the H2S-producing enzymes; Sulfide from H2S, produced by the enzymes in the gel, reacted with bismuth forming bismuth sulfide, illustrated as brown bands (1D) or spots (2D) in the gel. The discovered proteins were identified with liquid chromatography - tandem mass spectrometry (LC-MS/MS). Results: Cysteine synthase and proteins involved in the production of the coenzyme pyridoxal 5'phosphate (that catalyzes the production of H2S) were frequently found among the discovered enzymes. Interestingly, a higher expression of H2S-producing enzymes was detected from bacteria incubated without cysteine prior to the experiment. Conclusions: Numerous enzymes, identified as cysteine synthase, were involved in the production of H2S from cysteine and the expression varied among Fusobacterium spp. and strains. No enzymes were detected with the in-gel activity assay among the other periodontitis-associated bacteria tested. The expression of the H2S-producing enzymes was dependent on environmental conditions such as cysteine concentration and pH but less dependent on the presence of serum and hemin.
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| 2. |
- Charyeva, Olga, et al.
(författare)
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Bacterial Biofilm Formation on Resorbing Magnesium Implants
- 2015
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Ingår i: Open Journal of Medical Microbiology. - : Council of scientific & industrial research. - 2165-3372 .- 2165-3380. ; 5:1
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Tidskriftsartikel (refereegranskat)abstract
- Background: Implant-associated infections are a result of bacterial adhesion to an implant surface and subsequent biofilm formation at the implantation site. This study compares different magnesium materials based on their ability to resist bacterial adhesion as well as further biofilm formation. Material and Methods: The surfaces of four magnesium-based materials (Mg2Ag, Mg10Gd, WE43 and 99.99% pure Mg) were characterized using atomic force microscope. In addition, the samples were tested for their ability to resist biofilm formation. Planktonic bacteria of either S. epidermidis or E. faecalis were allowed to adhere to the magnesium surfaces for two hour followed by rinsing and, for S. epidermidis, further incubation of 24, 72 and 168 h was carried out. Results: E. faecalis had a significantly stronger adhesion to all magnesium surfaces compared to S. epidermidis (p = 0.001). Biofilm growth of S. epidermidis was different on various magnesium materials: the amount of bacteria increased up to 72 h but interestingly a significant decrease was seen at 168 h on Mg2Ag and WE43 surfaces. For pure Mg and Mg10Gd the biofilm formation reached plateau at 72 h. Surface characteristics of resorbable magnesium materials were changing over time, and the surface was generally less rough at 168 h compared to earlier time points. No correlation was found between the surface topology and the amount of adherent bacteria. Conclusion: In early stages of biofilm adhesion, no differences between magnesium materials were observed. However, after 72 h Mg2Ag and WE43 had the best ability to suppress S. epidermidis’ biofilm formation. Also, bacterial adhesion to magnesium materials was not dependent on samples’ surface topology.
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| 3. |
- Chavez de Paz, Luis E., et al.
(författare)
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Strains of Enterococcus faecalis differ in their ability to coexist in biofilms with other root canal bacteria
- 2015
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Ingår i: International Endodontic Journal. - : Wiley. - 0143-2885 .- 1365-2591. ; 48:10, s. 916-925
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Tidskriftsartikel (refereegranskat)abstract
- AimTo investigate the relationship between protease production and the ability of Enterococcus faecalis strains to coexist in biofilms with other bacteria commonly recovered from infected root canals. MethodologyBiofilms with bacteria in mono-, dual- and four-species communities were developed in flow chambers. The organisms used were Lactobacillus salivarius, Streptococcus gordonii and Actinomyces naeslundii and E.faecalis strains, GUL1 and OG1RF. Biovolume and species distribution were examined using 16S rRNA fluorescence insitu hybridization in combination with confocal microscopy and image analysis. The full proteome of the E.faecalis strains was studied using two-dimensional gel electrophoresis. Spots of interest were identified using tandem mass spectroscopy and quantified using Delta 2D software. ResultsAll bacteria formed biofilms and an anova analysis revealed that the biofilm biomass increased significantly (P0.01) between 6 and 24h. L.salivarius, S.gordonii and A.naeslundii formed mutualistic biofilm communities, and this pattern was unchanged when E.faecalis GUL1 was included in the consortium. However, with OG1RF, L.salivarius and S.gordonii were outcompeted in a 24-h biofilm. Proteomic analysis revealed that OG1RF secreted higher levels of proteases, GelE (P=0.02) and SprE (P=0.002) and a previously unidentified serine protease (P=0.05), than GUL1. ConclusionsDifferent strains of E.faecalis can interact synergistically or antagonistically with a consortium of root canal bacteria. A possible mechanism underlying this, as well as potential differences in virulence, is production of different levels of proteases, which can cause detachment of neighbouring bacteria and tissue damage.
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| 4. |
- Lima, Bruno P, et al.
(författare)
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Streptococcus gordonii type I lipoteichoic acid contributes to surface protein biogenesis
- 2019
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Ingår i: mSphere. - : American Society for Microbiology. - 2379-5042. ; 4:6
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Tidskriftsartikel (refereegranskat)abstract
- Lipoteichoic acid (LTA) is an abundant polymer of the Gram-positive bacterial cell envelope and is essential for many species. Whereas the exact function of LTA has not been elucidated, loss of LTA in some species affects hydrophobicity, biofilm formation, and cell division. Using a viable LTA-deficient strain of the human oral commensal Streptococcus gordonii, we demonstrated that LTA plays an important role in surface protein presentation. Cell wall fractions derived from the wild-type and LTA-deficient strains of S. gordonii were analyzed using label-free mass spectroscopy. Comparisons showed that the abundances of many proteins differed, including (i) SspA, SspB, and S. gordonii 0707 (SGO_0707) (biofilm formation); (ii) FtsE (cell division); (iii) Pbp1a and Pbp2a (cell wall biosynthesis and remodeling); and (iv) DegP (envelope stress response). These changes in cell surface protein presentation appear to explain our observations of altered cell envelope homeostasis, biofilm formation, and adhesion to eukaryotic cells, without affecting binding and coaggregation with other bacterial species, and provide insight into the phenotypes revealed by the loss of LTA in other species of Gram-positive bacteria. We also characterized the chemical structure of the LTA expressed by S. gordonii Similarly to Streptococcus suis, S. gordonii produced a complex type I LTA, decorated with multiple d-alanylations and glycosylations. Hence, the S. gordonii LTA appears to orchestrate expression and presentation of cell surface-associated proteins and functions.IMPORTANCE Discovered over a half-century ago, lipoteichoic acid (LTA) is an abundant polymer found on the surface of Gram-positive bacteria. Although LTA is essential for the survival of many Gram-positive species, knowledge of how LTA contributes to bacterial physiology has remained elusive. Recently, LTA-deficient strains have been generated in some Gram-positive species, including the human oral commensal Streptococcus gordonii The significance of our research is that we utilized an LTA-deficient strain of S. gordonii to address why LTA is physiologically important to Gram-positive bacteria. We demonstrate that in S. gordonii, LTA plays an important role in the presentation of many cell surface-associated proteins, contributing to cell envelope homeostasis, cell-to-cell interactions in biofilms, and adhesion to eukaryotic cells. These data may broadly reflect a physiological role of LTA in Gram-positive bacteria.
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| 5. |
- Ljunggren, Stefan, 1988-, et al.
(författare)
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Modified lipoproteins in periodontitis : a link to cardiovascular disease?
- 2019
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Ingår i: Bioscience Reports. - : Portland Press. - 0144-8463 .- 1573-4935. ; 39:3
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Tidskriftsartikel (refereegranskat)abstract
- There is a strong association between periodontal disease and atherosclerotic cardiovascular disorders. A key event in the development of atherosclerosis is accumulation of modified lipoproteins within the arterial wall. We hypothesize that patients with periodontitis have an altered lipoprotein profile towards an atherogenic form. Therefore, this study aims at identifying modifications of plasma lipoproteins in periodontitis. Lipoproteins from ten female patients with periodontitis and gender- and age-matched healthy controls were isolated by density-gradient-ultracentrifugation. Proteins were separated by two-dimensional gel-electrophoresis and identified by map-matching or by nano-liquid chromatography followed by mass spectrometry. ApoA-I methionine oxidation, Oxyblot, total antioxidant capacity and a multiplex of 71 inflammation-related plasma proteins were assessed.Reduced levels of apoJ, phospholipid transfer protein, apoF, complement C3, paraoxonase 3 and increased levels of alpha-1-antichymotrypsin, apoA-II, apoC-III were found in HDL from the patients. In LDL/VLDL, the levels of apoL-1 and platelet-activating factor acetylhydrolase as well as apo-B fragments were increased. Methionine oxidation of apoA-I was increased in HDL and showed a relationship with periodontal parameters. Alpha-1 antitrypsin and alpha-2-HS glycoprotein were oxidised in LDL/VLDL and antioxidant capacity was increased in the patient group. 17 inflammation-related proteins were important for group separation with the highest discriminating proteins identified as IL-21, Fractalkine, IL-17F, IL-7, IL-1RA and IL-2.Patients with periodontitis have an altered plasma lipoprotein profile, defined by altered protein levels as well as posttranslational and other structural modifications towards an atherogenic form, which supports a role of modified plasma lipoproteins as central in the link between periodontal and cardiovascular disease (CVD).
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| 6. |
- Neilands, Jessica, et al.
(författare)
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Bacterial profiles and proteolytic activity in peri-implantitis versus healthy sitesBacterial profiles and proteolytic activity in peri-implantitis versus healthy sites
- 2015
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Ingår i: Anaerobe. - : Academic Press. - 1075-9964 .- 1095-8274. ; 35, s. 28-34
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Tidskriftsartikel (refereegranskat)abstract
- Peri-implantitis is a biofilm-induced destructive inflammatory process that, over time, results in loss of supporting bone around an osseointegrated dental implant. Biofilms at peri-implantitis sites have been reported to be dominated by Gram-negative anaerobic rods with a proteolytic metabolism such as, Fusobacterium, Porphyromonas, Prevotella and Tannerella, as well as anaerobic Gram-positive cocci. In this study, we hypothesized that protease activity is instrumental in driving bone destruction and we therefore compared the microbial composition and level of protease activity in samples of peri-implant biofluid (PIBF) from 25 healthy subjects (H group) and 25 subjects with peri-implantitis (PI group). Microbial composition was investigated using culture techniques and protease activity was determined using a FITC-labelled casein substrate. The microbial composition was highly variable in subjects both in the H and PI groups but one prominent difference was the prevalence of Porphyromonas/Prevotella and anaerobic Gram positive cocci which was significantly higher in the PI than in the H group. A subgroup of subjects with peri-implantitis displayed a high level of protease activity in the PIBF compared to healthy subjects. However, this activity could not be related to the presence of specific bacterial species. We propose that a high level of protease activity may be a predictive factor for disease progression in peri-implantitis. Further longitudinal studies are however required to determine whether assessment of protease activity could serve as a useful method to identify patients at risk for progressive tissue destruction.
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| 7. |
- 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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| 8. |
- Ohlin, Acke, et al.
(författare)
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Titanium granules pre-treated with hydrogen peroxide inhibit growth of bacteria associated with post-operative infections in spine surgery
- 2018
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Ingår i: European Spine Journal. - : Springer Science and Business Media LLC. - 0940-6719 .- 1432-0932. ; 27:10, s. 2463-2468
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Tidskriftsartikel (refereegranskat)abstract
- © 2018 The Author(s) Purpose: Post-operative infections are relatively common after posterior spine surgery, and there are several observations reflecting different infection complications related to various metals implanted. Here, we selected an array of different bacterial species that are often found in infections associated with orthopaedic implants and tested for inhibition by hydrogen peroxide-treated titanium (Ti-peroxy). Methods: To study the possibility of using Ti-peroxy as an antimicrobial prophylaxis, we developed a protocol for standardized susceptibility testing of bacteria. Results: Importantly, we found that the resulting Ti-peroxy was highly antimicrobial against all aerobic species tested, among others, Staphylococcus aureus and Pseudomonas aeruginosa. Proteus mirabilis was slightly more resistant than, for example, Klebsiella pneumoniae and enterococci. In contrast, anaerobic bacteria Cutibacterium acnes and Parvimonas micra were equally susceptible compared to staphylococci. Conclusions: Our findings suggest that the Ti-peroxy is a promising perioperative antimicrobial strategy that may be highly effective for prevention of post-operative infections. We therefore suggest application of hydrogen peroxide to implants prior to implantation. Graphical abstract: These slides can be retrieved under Electronic supplementary material.[Figure not available: see fulltext.]
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| 9. |
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| 10. |
- Rabe, Per, et al.
(författare)
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Effect of fluoride and chlorhexidine digluconate mouthrinses on plaque biofilms
- 2015
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Ingår i: The Open Dentistry Journal. - : Bentham eBooks. - 1874-2106. ; 9, s. 106-111
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Tidskriftsartikel (refereegranskat)abstract
- Objective. To develop a model in which to investigate the architecture of plaque biofilms formed on enamel surfaces in vivo and to compare the effects of anti-microbial agents of relevance for caries on biofilm vitality. Materials and Methodology : Enamel discs mounted on healing abutments in the pre-molar region were worn by three subjects for 7 days. Control discs were removed before subjects rinsed with 0.1% chlorhexidine digluconate (CHX) or 0.2% sodium fluoride (NaF) for 1 minute. Biofilms were stained with Baclight Live/Dead and z-stacks of images created using confocal scanning laser micoscopy. The levels of vital and dead/damaged bacteria in the biofilms, assessed as the proportion of green and red pixels respectively, were analysed using ImageTrak(®) software. Results : The subjects showed individual differences in biofilm architecture. The thickness of the biofilms varied from 28-96µm although cell density was always the greatest in the middle layers. In control biofilms, the overall levels of vitality were high (71-98%) especially in the area closest to the enamel interface. Rinsing with either CHX or NaF caused a similar reduction in overall vitality. CHX exerted an effect throughout the biofilm, particularly on the surface of cell clusters whereas NaF caused cell damage/death mainly in the middle to lower biofilm layers. Conclusion : We describe a model that allows the formation of mature, undisturbed oral biofilms on human enamel surfaces in vivo and show that CHX and NaF have a similar effect on overall vitality but differ in their sites of action.
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