Streptococcus mutans

Taxobox
color = lightgrey
name = "Streptococcus mutans"

---

image_width = 240px
image_caption = Gram stain of "S. mutans" in thioglycollate broth culture.
regnum = Bacteria
phylum = Firmicutes
classis = Cocci
ordo = Lactobacillales
familia = Streptococcaceae
genus = "Streptococcus"
species = "S. mutans"
binomial = "Streptococcus mutans"
binomial_authority = Clarke 1924

"Streptococcus mutans" is a Gram-positive, facultatively anaerobic bacteria commonly found in the human oral cavity and is a significant contributor to tooth decay.cite book | author = Ryan KJ; Ray CG (editors) | title = Sherris Medical Microbiology | edition = 4th ed. | publisher = McGraw Hill | year = 2004 | id = ISBN 0-8385-8529-9 ] cite book | author = Loesche WJ | title = Microbiology of Dental Decay and Periodontal Disease. "In:" Baron's Medical Microbiology "(Baron S "et al", eds.)| edition = 4th ed. | publisher = Univ of Texas Medical Branch | year = 1996 | id = [http://www.ncbi.nlm.nih.gov/books/bv.fcgi?rid=mmed.chapter.5326 (via NCBI Bookshelf)] ISBN 0-9631172-1-1 ] The microbe was first described by Clarke in 1924.cite journal | author = Clarke, JK| title = On the bacterial factor in the etiology of dental caries | journal = Brit J Exp Pathol| year = 1924 | volume = 5| pages = 141–7 | url= ]

Role in tooth decay

Along with "S. sobrinus", "S. mutans" plays a major role in tooth decay, metabolizing sucrose to lactic acid. 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 that help for better adhesion to the surface of teeth. Sucrose is utilized by "S. mutans" to produce a sticky, extracellular, dextran-based polysaccharide that allows them to 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.

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.cite book | author = Madigan M; Martinko J (editors). | title = Brock Biology of Microorganisms | edition = 11th ed. | publisher = Prentice Hall | year = 2005 | id = ISBN 0-13-144329-1 ] 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.cite journal |last=Klein |first=J.P. |authorlink= |coauthors=Scholler, M. |year=1998 |month=December |title= Recent Advances in the Development of a Streptococcus mutans Vaccine|journal=European Journal of Epidemiology |volume=4 |issue=4 |pages=419-425 |id= |url=http://links.jstor.org/sici?sici=0393-2990%28198812%294%3A4%3C419%3ARAITDO%3E2.0.CO%3B2-A |accessdate=2007-05-15|quote= ] Recently, proteins involved in the colonization of teeth by "S. mutans" have been shown to produce antibodies that inhibit the cariogenic process.cite book |chapterurl=http://www.horizonpress.com/oral2|author=Hajishengallis G and Russell M W|year=2008|chapter=Molecular Approaches to Vaccination against Oral Infections|title=Molecular Oral Microbiology|publisher=Caister Academic Press|id= [http://www.horizonpress.com/oral2 ISBN 978-1-904455-24-0] ]

ee also

* "Streptococcus viridans"
*Mutacin 1140
* Oral microbiology

References

External links

* [http://www.mchoralhealth.org/OpenWide/mod1_2.htm MCHoralhealth.org]