Effect of nicotine on the adherence and gene expression of selected oral microorganisms / Shan Gunasegar
The ability of microbes to adhere on tooth surfaces coated with salivary pellicle lead to the formation of biofilm. Some environment risk factor such as smoking, poor oral hygiene and diet can contribute to the formation of plaque on tooth surface. The aim of this study was to investigate the eff...
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| Format: | Thesis |
| Published: |
2017
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| Subjects: | |
| Online Access: | http://studentsrepo.um.edu.my/10417/4/shan.pdf http://studentsrepo.um.edu.my/10417/ |
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| Summary: | The ability of microbes to adhere on tooth surfaces coated with salivary pellicle lead to
the formation of biofilm. Some environment risk factor such as smoking, poor oral
hygiene and diet can contribute to the formation of plaque on tooth surface. The aim of
this study was to investigate the effect of nicotine on the antimicrobial, adherence
capacity, expression of adherence-associated genes and extracellular polysaccharide
(EPS) and micro-colonies formation of selected oral microorganisms; Streptococcus
sanguinis, Streptococcus mutans, Candida albicans and Candida parapsilosis. Growth
profiles were carried out to determine the survival rate of the selected oral microbes in
different concentration of nicotine (1, 2, 4 and 8 mg/ml). The relative number of viable
microbial cells was estimated using viable plate count enumeration method and biofilm
growth was quantified using crystal violet assay. Cell surface hydrophobicity and the cell
aggregation were also studied. The regulations of selected genes associated with
adherence were evaluated quantitatively and qualitatively by using real time and reserve
transcription-polymerase chain reaction. In addition, the structure of EPS and biofilm
maximum depth upon exposure with nicotine were analysed using confocal laser scanning
microscope (CLSM). The results indicated that nicotine enhanced the growth of oral
candida and bacteria in both planktonic and biofilm cells. Cell surface hydrophobicity and
the expression of hyphal wall protein 1 (HWP1) and agglutinin-like sequences 3 (ALS3)
of C. albicans and C. parapsilosis were found to increase in relative to the nicotine
concentrations used. We also found that nicotine could increase the expression of
Streptococcus sp. adherence-associated genes such as surface protein antigen (spaP),
glucosyltransferase (gtfB), and glucan binding protein B (gbpB). Interestingly, the
iv
thickness of biofilm was increased as the nicotine concentration increases. The data
concluded that nicotine can promote the growth of S. sanguinis, S. mutans, C. albicans
and C. parapsilosis and influences its adherence on the plastic wells which mimic tooth
surfaces. The findings of the study may have implications in improving and providing
better healthcare for heavy smokers to reduce dental biofilm. In addition, the overall
outcomes of this research may be applied to smoking cessation measures in smokers and
aid in providing guidelines for control and preventive measures of dental biofilm
associated oral diseases. |
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