Browsing by Subject "oral bacteria"

Now showing 1 - 4 of 4
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    Effects of casein phosphopeptide-amorphous calcium phosphate crème on nicotine-induced Streptococcus mutans biofilm in vitro
    (Springer, 2020) Alawadhi, Naser B.; Lippert, Frank; Gregory, Richard L.; Biomedical Sciences and Comprehensive Care, School of Dentistry
    Objectives The aim of this study was to test the effects of casein phosphopeptide-amorphous calcium phosphate (CPP-ACP) crème, or MI Paste™ (MIP), on nicotine-induced Streptococcus mutans biofilm. The experiment utilized S. mutans biofilm assays with varying concentrations of nicotine and MIP aqueous concentrate levels. First hand exposure to nicotine has been demonstrated to significantly increase S. mutans biofilm formation, while the active component, CPP-ACP, in MIP has been shown to reduce S. mutans biofilm formation. Materials and methods A 24-h culture of S. mutans UA159 in microtiter plates were treated with varying nicotine concentrations (0–32 mg/ml) in Tryptic Soy Broth supplemented with 1% sucrose (TSBS) with or without MIP aqueous concentrate. A spectrophotometer was used to determine total growth absorbance and planktonic growth. The microtiter plate wells were washed, fixed, and stained with crystal violet dye and the absorbance measured to determine biofilm formation. Results The presence of MIP aqueous concentrate inhibits nicotine-induced S. mutans biofilm formation at different concentrations of nicotine (0–32 mg/ml). Conclusion The results demonstrated nicotine-induced S. mutans biofilm formation is decreased in the presence of MIP. This provides further evidence about the cariostatic properties of CPP-ACP, the active soluble ingredient in the MIP, and reconfirms the harmful effects of nicotine. Clinical significance Smokers may gain dual benefits from the use of MIP, as a remineralization agent and as a cariostatic agent, by inhibiting nicotine-induced S. mutans biofilm formation.
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    Evaluating the Effect of Fulvic Acid on Oral Bacteria and Cancerous Oral Cells
    (Office of the Vice Chancellor for Research, 2014-04-11) Witcher, Phillip; Gregory, Richard L.; Windsor, L. Jack
    Shilajit is a homeopathic treatment used by local inhabitants of India and Pakistan. It may have specific components that inhibit the formation of cavities and the growth of cancer cells. This experiment analyzed the effects of fulvic acid, an active component of shilajit, on the growth of oral bacteria and squamous cell carcinoma. The effect of fulvic acid was evaluated on early Streptococcus mutans (S. mutans) biofilm formation and established S. mutans biofilm by treating each group with different concentrations of fulvic acid for 24 hours in sterile 96-well flat-bottom microtiter plates. S. mutans was used because it is a common cause of dental caries. The optical density (OD) of the S. mutans biofilm was measured after crystal violet staining using a SpectraMax190; greater growth correlated to greater OD. It was determined that fulvic acid inhibits the growth of newly forming S. mutans biofilm at fulvic acid concentrations greater than 1.25% (vol. %) and established S. mutans biofilm at fulvic acid concentrations greater than 5% (vol. %). To evaluate the effect of fulvic acid on squamous cell carcinoma (SCC-25) cells, six-well plates seeded with SCC-25 cells (1*105 cells/well) were exposed to different concentrations of fulvic acid (buffered to a pH of 7.5) for 72 hours. The cytotoxicity and cell proliferation were measured using a cytotoxicity detection kit and a water soluble tetrazolium kit (Roche Applied Science), respectively. It was determined that fulvic acid inhibits the growth of SCC-25 cells at concentrations of fulvic acid above 2% (volume %). The effects of fulvic acid (0.5%) on matrix metalloproteinase expression and collagen degradation ability of SCC-25 cells is being analyzed. The suppressive mechanisms observed by fulvic acid on both S. mutans and SCC-25 cells could improve overall oral health.
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    INTERACTIONS OF HUMAN ENDOTHELIAL CELLS WITH STREPTOCOCCUS MUTANS
    (Office of the Vice Chancellor for Research, 2012-04-13) Rodenbeck, Jessica; Gregory, Richard l.; al-Shibani, Nouf; Windsor, L. Jack
    Streptococcus mutans (S. mutans) is the major etiological agent for den-tal caries. Nicotine is the addictive ingredient present in tobacco and has been shown to affect the growth and metabolism of oral bacteria, specifically S. mutans. Cigarette smoke condensate (CSC) contains all the chemicals present in cigarette smoke. Dissolvable tobacco products are new tobacco products that do not require one to light up, but may still harm oral tissues. This project examines the effects of S. mutans exposed to these chemicals on human endothelial cells in terms of cytotoxicity and cytokine/growth fac-tor expression. S. mutans treated with these tobacco components are hy-pothesized to increase the expression of pro-inflammatory cytokines/growth factors from endothelial as compared to the controls. S. mutans was grown with each of the reagents for eight hours and then the bacterial cells and su-pernatants separated. Protein assays were used to determine the protein amounts of the cells and in the supernatant. The cytotoxicity of each will be determined by lactate dehydrogenase (LDH) assays. Non-toxic amounts of the bacterial cells and supernatants will then be used to treat endothelial cells for three days before the conditioned media collected and analyzed by cytokine/growth factor protein arrays. The protein assays showed that the protein levels were lower in tobacco treated cells, while the supernatants showed similar protein concentrations throughout. It is hypothesized that the treated bacteria cell will increase cy-tokines/growth factors that increase inflammation and lead to vascular issues.
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    Nicotine-Treated Fusobacterium nucleatum Binding to Collagen, Fibrinogen, and Fibronectin
    (Office of the Vice Chancellor for Research, 2016-04-08) Beshay, Y.S.; Gregory, R.L.
    Fusobacterium nucleatum, a gram-negative anaerobic bacterium found in dental plaque, causes periodontal diseases. Smoking is one of the risk factors that can increase periodontal problems and atherosclerosis. Atherosclerosis is initiated by oral bacteria (i.e., F. nucleatum) binding to surface proteins of endothelial cells, such as collagen, fibrinogen, and fibronectin. The main objective for this study was to test the binding of F. nucleatum to collagen, fibrinogen, and fibronectin under the effect of different concentrations of nicotine. F. nucleatum was grown overnight in brain-heart infusion (BHI) supplemented with yeast extract and 5% vitamin-K/hemin. Biofilm was grown for 48 hours in 0, 0.25, 0.5, 1, and 2 mg/mL of nicotine. Then, the biofilm cells were labeled with biotin 3-sulfo-N-hydroxy-succinimide ester sodium salt and fixed with 10% formaldehyde. A binding assay was conducted by coating a high-binding 96-well microtiter plate with 1 μg/mL of collagen, fibrinogen, or fibronectin. The plate was incubated overnight and blocked with 1% Bovine Serum Albumin (BSA), followed by the biotinylated and nicotine-treated F. nucleatum cells. ExtrAvidin-Peroxidase and OPD Peroxidase Substrate was used to visualize the binding. Optical density (OD) was measured with a spectrophotometer at 490 nm. Collagen, fibrinogen, and fibronectin binding assays demonstrated significantly higher absorbance with 2 mg/mL nicotine-treated F. nucleatum cells compared to untreated cells. The results indicated that an increase in nicotine concentration leads to an increase in F. nucleatum binding to collagen, fibrinogen, and fibronectin. This means that smokers may have an increased risk for atherosclerosis. Supported by Life-Health and Sciences Internship (LHSI).