Browsing by Author "Kristoff, Sylvie N."

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    Streptococcus mutans Binding to Collagen and Fibrinogen in Nicotine
    (Office of the Vice Chancellor for Research, 2015-04-17) Kristoff, Sylvie N.; Gomez, Grace; Gregory, Richard L.
    Introduction: Our overall goal is to find the mechanism for atherosclerosis. Smokers have increased incidence of atherosclerosis. Atherosclerosis occurs when there is a build up of plaque in the arteries. There is evidence that Streptococcus mutans help cause this blockage. We have already proven that S. mutans produces more biofilm in certain concentrations of nicotine. Also, we have found that nicotine upregulates S. mutans binding to proteins in certain concentrations; other labs have also demonstrated this. The intent of this study was to evaluate the binding of S. mutans to both collagen type I and fibrinogen, which are both proteins that are already present on the surface of endothelial cells lining arteries. Methods: S. mutans UA159 was cultured in 0.00-4.00 mg/mL nicotine. The cells were killed in formaldehyde and then coated with biotin. The proteins studied were plated (1 ug/ml) on 96-well microtiter plates. In order to block the empty spaces that the protein did not bind to, 1% BSA in sodium bicarbonate buffer was added to the plate. Each nicotine dilution of S. mutans was added to the plate and the amount of binding was assessed. Extra-avidin HRP and OPD were added to the plate and the intensity was measured at an absorbance of 490 nm using a spectrophotometer. Results: The intensity was directly related to the number of cells bound to the proteins. There was a significant increase in S. mutans binding when compared to the baseline for both collagen type I and fibrinogen. The binding was highest when S. mutans were cultured in 2 and 4 mg/mL nicotine. Conclusions: The data collected suggests that collagen type I and fibrinogen contribute to the mechanism of atherosclerosis. When S. mutans are cultured in moderately high concentrations of nicotine, more binding of the bacteria to these proteins occurs.
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    Streptococcus mutans Binding to Collagen, Fibrinogen, Fibronectin, and Laminin
    (Office of the Vice Chancellor for Research, 2016-04-08) Kristoff, Sylvie N.; Gregory, Richard L.
    Introduction: Streptococcus mutans, nicotine, and certain proteins may be involved in a complicated mechanism that contributes to atherosclerosis. Build up of arterial plaque causes atherosclerosis. Arterial plaque is mainly composed of fat, cholesterol, and calcium. When plaque builds up in the arteries, a clot or blockage can occur and may cause an occlusion. Objective: S. mutans grows in oral biofilm and causes dental caries. These bacteria enter the blood stream from mucosal breaks in the oral cavity. There is evidence that S. mutans binds to endothelial cell surface proteins lining arterial surfaces. An increased incidence of S. mutans in arterial plaque seems to have a direct relationship with atherosclerosis. From preliminary research, there was a strong indication that increased S. mutans biofilm formation is caused by nicotine. The number of binding proteins on nicotine-treated S. mutans cell surface increases as well. In addition, results demonstrated that S. mutans binds to collagen type I, fibrinogen, fibronectin, and laminin, which are proteins found on endothelial cells. Methods: To investigate protein binding, S. mutans UA159 was cultured in 0, 0.25, 0.50, 1.0, 2.0, and 4.0 mg/ml of nicotine and their ability to bind to human collagen type I, fibrinogen, fibronectin and laminin was assessed using an ELISA assay. Results: S. mutans significantly bound to collagen type I and fibrinogen when cultured in 2 and 4 mg/ml nicotine. S. mutans significantly bound to laminin when the bacterium was grown in 1, 2, and 4 mg/ml. The binding of S. mutans to fibronectin varied when cultured in different concentrations of nicotine. Conclusion: From the results, it can be concluded that S. mutans UA159 binds to collagen type I, fibrinogen, fibronectin, and laminin. This indicates that S. mutans and the proteins studied are very likely to be part of the mechanism that leads to atherosclerosis.