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Streptococcus mutans
Introduction
Overview
Overview
Streptococcus mutans is a Gram-positive, facultatively anaerobic bacteria commonly found in the human oral cavity and is a significant contributor to tooth decay.[1][2] The microbe was first described by Clarke in 1924.[3]
Role in tooth decay
Role in tooth decay
Along with S. sobrinus, S. mutans plays a major role in tooth decay, metabolizing sucrose to lactic acid.[2] The acidic environment created in the mouth by this process is what causes the highly mineralized tooth enamel to be vulnerable to decay. S. mutans is one of a few specialized organisms equipped with receptors for adhesion to the surface of teeth. Sucrose is utilized by S. mutans to produce a sticky, extracellular, dextran-based polysaccharide that allows them to each other forming plaque. S. mutans produces dextran via the enzyme dextransucrase (a hexosyltransferase) using sucrose as a substrate in the following reaction:
- n sucrose → (glucose)n + n fructose
Sucrose is the only sugar that S. mutans can use to form this sticky polysaccharide.[1]
Conversely, many other sugars—glucose, fructose, lactose—can be digested by S. mutans, but they produce lactic acid as an end product. It is the combination of plaque and acid that leads to dental decay.[4] Due to the role the S. mutans plays in tooth decay, there have been many attempts to make a vaccine for the organism. So far, such vaccines have not been successful in humans.[5]
References
References
- ↑ 1.0 1.1 Ryan KJ; Ray CG (editors) (2004). Sherris Medical Microbiology (4th ed. ed.). McGraw Hill. ISBN 0-8385-8529-9.
- ↑ 2.0 2.1 Loesche WJ (1996). Microbiology of Dental Decay and Periodontal Disease. In: Baron’s Medical Microbiology (Baron S et al, eds.) (4th ed. ed.). Univ of Texas Medical Branch. (via NCBI Bookshelf) ISBN 0-9631172-1-1.
- ↑ Clarke, JK (1924). “On the bacterial factor in the etiology of dental caries”. Brit J Exp Pathol. 5: 141&ndash, 7.
- ↑ Madigan M; Martinko J (editors). (2005). Brock Biology of Microorganisms (11th ed. ed.). Prentice Hall. ISBN 0-13-144329-1.
- ↑ Klein, J.P. (1998). “Recent Advances in the Development of a Streptococcus mutans Vaccine”. European Journal of Epidemiology. 4 (4): 419–425. Retrieved 2007-05-15. Unknown parameter
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