Streptococcus mutans cell
- 1. Streptococcus mutans: tooth decay, caries, plaque By:Goua Vang
- 2. Outline General information about S. mutans Biofilm How biofilm form? S. mutans adhere Acid production Affect on tooth Prevention Conclusion
- 3. General information S. mutans appear in the mouth after teeth have erupted as they need solid surfaces to colonize establishment is slow the first two years species most commonly isolated from dental plaque in humans is S. mutans
- 4. General information produce extracellular glucans and adhere to the tooth surfaces S. mutans have been found in the mouth of all populations sampled all over the world Usually, serotype c (Streptococcus mutans) is the dominating serotype One person can have several serotypes
- 5. General information Dental caries is a disease microbial fermentation of dietary carbohydrates leads to localized demineralization and destruction of the teeth prevalence of caries is highest on the occlusal surfaces of first and second molars, and lowest on the lingual surfaces of mandibular teeth
- 6. Biofilm What is a biofim? -biofilm is a complex aggregation of microorganisms growing on a solid substrate characterized by structural heterogeneity, genetic diversity, complex community interactions, and an extracellular matrix of polymeric substances. consist of many species of bacteria living within a matrix
- 7. Biofilm Formation of a biofilm begins with the attachment of free-floating microorganisms to a surface Are usually found on solid substrates submerged in or exposed to some aqueous solution
- 8. How biofilm form? When tooth first erupt -glycoproteins (pellicle) from saliva are absorpted onto the tooth surfaces Bacteria adhere to the pellicle, and the pellicle coats the enamal
- 9. S. mutans adhere The enzyme Glucosyltransferases (GTF) -synthesis of water-soluble and insoluble glucose polymers (glucans) from sucrose three GTFs types -GtfB, GtfC –synthesize primarily insoluble glucan -GtfD –synthesize exclusively water-soluble glucan
- 11. S. mutans adhere GtfB and GtfC are more important than GtfD for attachment All three is required for maximal cariogenesis
- 12. GTFs domain -A carboxyl-terminal region composed of multiple, homologous direct repeat segments +constitutes the glucan-binding domain (GBD) S. mutans adhere
- 13. S. mutans adhere GBD -essential for glucan synthesis but not for sucrase activity N-terminal two-third of the GTFs -is the sucrose-binding domain +where sucrose are hydrolysis
- 15. S. mutans adhere SpaP -major surface antigen that play an important role in saliva-mediated aggregation and adherence
- 16. Acid production
- 17. Acid production What does acid production do? -lower the pH -over time drop in pH lead to tooth demineralization and the development of caries -lower the pH to 3.5
- 18. Acid production How does S. mutans survive? -increase in activity and amounts of F1F0 ATPase and a low pH inducible DNA repair system -shift in total membrane fatty acid composition Low pH -higher proportion of long-chained, monounsaturated fatty acids as compare to pH 7
- 19. Acid production Increase in pH -68% of membrane consisted of C 14:0 plus C 16:0 Decrease in pH -48% C 18:1 plus C 20:1
- 20. Affect on the tooth damages the structures tooth -cause +tooth decay or caivites Untreated can lead -pain -tooth loss -infection -death in severe case
- 21. Affect on the tooth
- 22. Affect on the tooth
- 24. Prevention Brushing -removal of the bacteria, disrupting the biofilm Fluoride -reducing enamel solubility -remineralization of incipient enamel
- 25. Prevention (cont) Sealant -plastic materials applied to fissures as a barrier against microbial attack
- 26. Conclusion Good oral hygiene will keep the microorganism stable, but there is a need to intervene with some cleaning and dental check up annually to prevent further infection.
- 27. References Yau-Wei Tsai a, Jean-Shan Chia b, Yuh-Yuan Shiau a, Hsiu-Chuan Chou a, Yen-Chywan Liaw c;1, Kuo-Long Lou, “Three-dimensional modelling of the catalytic domain of Streptococcus mutans glucosyltransferase GtfB.” FEMS Microbiology Letters 188 (2000) 75-79 Paula J. Crowley, L. Jeannine Brady, Suzanne M. Michalek, and Arnold S. Bleiweis, “Virulrnce of a spsP mutant of Streptococcus mutans in a Gnotobiotic Rat Model.” Infection and Immunity, Mar 1999, p. 1201-1206 Elizabeth M. Fozo and Robert G. Quivey, Jr, “Shife in the membrane fatty acid profile of Streptococcus mutans enhance survival in acidic environments.” Applied and Environment Microbiology, Feb. 2004, p. 929-936 Bing Wang and Howard K. Kuranmitsu, “A pleiotropic regulator, frp, affects exopolysaccgaride synthesis, biofilm formation, and competence development in streptococcus mutans.” Infection and Immunity, Aug. 2006, p. 4581-4589 JEAN-SAN CHIA,* CZAU-SIUNG YANG, AND JEN-YANG CHEN, “Functional Analyses of a Conserved Region inGlucosyltransferases of Streptococcus mutans.” INFECTION AND IMMUNITY, Oct. 1998, p. 4797–4803 KURT M. SCHILLINGt AND WILLIAM H. BOWEN, “Glucans Synthesized In Situ in Experimental Salivary PellicleFunction as Specific Binding Sites for Streptococcus mutans.” INFECTION AND IMMUNITY, Jan. 1992, p. 284-295 Fernanda C. Petersen,1* Lin Tao,2 and Anne A. Scheie1, “DNA Binding-Uptake System: a Link between Cell-to-Cell Communication and Biofilm Formation.” JOURNAL OF BACTERIOLOGY, July 2005, p. 4392–4400 Haitham Hussain,1 Pavel Branny,2 and Elaine Allan1*, “A Eukaryotic-Type Serine/Threonine Protein Kinase Is Required for Biofilm Formation, Genetic Competence, and Acid Resistance.” JOURNAL OF BACTERIOLOGY, Feb. 2006, p. 1628–1632