Streptoccus mutans
There are over 700 different types of bacteria that live in your mouth – some of them are good for you but others are not.
One species that can cause problems is Streptococcus mutans which grows in biofilms, all over your teeth. When it grows it produces acid that can make your teeth decay. Understanding how Streptococcus mutans forms these biofilms will help us discover ways to prevent tooth decay.
The bacterium Streptococcus mutans is present in the mouth and is a primary player in the progression of dental caries – or tooth decay – especially when it grows in layers, or biofilms over the surface of teeth. This bacterium feeds on the sugars present in your food and produces acids that contribute to tooth decay. Furthermore, in this acid environment species linked to tooth decay, like Streptococcus mutans, have an advantage and become more abundant while other species become rarer. Streptococcus mutans forms biofilms in different ways and understanding this will help develop methods to prevent tooth decay.
The oral bacterium, Streptococcus mutans, grows as biofilms on the tooth surface and is implicated in dental caries, or tooth decay (Levine RS, Rowles SL. 1973, Loesche WJ. 1976). Acid is produced by fermentation of sugars and it is this acid that initiates tooth decay. The lower pH also provides a favourable environment for further growth (Stookey GK. 2008). In fact, under acid stress, there exists a microbial dysbiosis in the mouth as acid-loving species associated with caries (like Streptococcus mutans) are in far larger numbers than species that prefer a higher pH and are not associated with caries.
Further reading about Streptococcus mutans
Levine RS, Rowles SL. 1973. Further studies on the remineralization of human carious dentine in vitro. Arch Oral Biol. 18(11):1351–1356. DOI: 10.1016/0003-9969(73)90108-8.
Loesche WJ. 1976. Chemotherapy of dental plaque infections. Oral Sci Rev. 9:65–107. https://pubmed.ncbi.nlm.nih.gov/1067529/.
Stookey GK. 2008. The effect of saliva on dental caries. J Am Dent Assoc. 139:11S–17S. DOI: 10.14219/jada.archive.2008.0347.
Ooshima T, Matsumura M, Hoshino T, Kawabata S, Sobue S, Fujiwara T. 2001. Contributions of three glycosyltransferases to sucrose-dependent adherence of Streptococcus mutans . J Dent Res. 80(7):1672–1677. DOI: 10.1177/00220345010800071401.
Mishra A, Pandey RK, Manickam N. 2015. The significance of gtf genes in caries expression: a rapid identification of Streptococcus mutans from dental plaque of child patients. J Indian Soc Pedod Prev Dent. 33(2):134–137. DOI: 10.4103/0970-4388.155126.
Decker EM, Klein C, Schwindt D, Von OC. 2014. Metabolic activity of Streptococcus mutans biofilms and gene expression during exposure to xylitol and sucrose. Int J Oral Sci. 6(4):195–204. DOI: 10.1038/ijos.2014.38.
Krzysciak W, Jurczak A, Koscielniak D, Bystrowska B, Skalniak A. 2014. The virulence of Streptococcus mutans and the ability to form biofilms. Eur J Clin Microbiol Infect Dis. 33(4):499–515. DOI: 10.1007/s10096-013-1993-7.
Matsumoto-Nakano M. 2018. Role of Streptococcus mutans surface proteins for biofilm formation. Jpn Dent Sci Rev. 54(1):22–29. DOI: 10.1016/j.jdsr.2017.08.002.
Sato Y, Yamamoto Y, Kizaki H. 1997. Cloning and sequence analysis of the gbpC gene encoding a novel glucan-binding protein of Streptococcus mutans. Infect Immun. 65(2): 668–675. https://doi.org/10.1128/iai.65.2.668-675.1997
Shah DS, Russell RR. 2004. A novel glucan-binding protein with lipase activity from the oral pathogen Streptococcus mutans. Microbiology (Reading, Engl). 150(Pt 6): 1947–1956. DOI: 10.1099/mic.0.26955-0.
Russell MW, Lehner T. 1978. Characterisation of antigens extracted from cells and culture fluids of Streptococcus mutans serotype c. Arch Oral Biol. 23(1):7–15. DOI: 10.1016/0003-9969(78)90047-x.
Russell RB. 1979. Wall-associated protein antigens of Streptococcus mutans. 114(1):109–115. DOI: 10.1099/00221287-114-1-109.
Forester H, Hunter N, Knox KW. 1983. Characteristics of a high molecular weight extracellular protein of Streptococcus mutans. Microbiology. 129(9):2779–2788. DOI: 10.1099/00221287-129-9-2779.
Demuth DR, Lammey MS, Huck M, Lally ET, Malamud D. Comparison of Streptococcus mutans and Streptococcus sanguis receptors for human salivary agglutinin. Microb Pathog. 9(3):199–211. DOI: 10.1016/0882-4010(90)90022-i.
Koga T, Okahashi N, Takahashi I, Kanamoto T, Asakawa H, Iwaki M. 1990. Surface hydrophobicity, adherence, and aggregation of cell surface protein antigen mutants of Streptococcus mutans serotype c. Infect Immun. 58(2): 289–296. https://doi.org/10.1128/iai.58.2.289-296.1990.
Beg AM, Jones MN, Miller-Torbert T, Holt RG. 2002. Binding of Streptococcus mutans to extracellular matrix molecules and fibrinogen. Biochem Biophy Res Commun. 298(1): 75–79. DOI: 10.1016/s0006-291x(02)02390-2.
Abranches J, Miller JH, Martinez AR, Simpson-Haidaris PJ, Burne RA, Lemos JA. 2011. The collagen-binding protein Cnm is required for Streptococcus mutans adherence to and intracellular invasion of human coronary artery endothelial cells. Infect Immun. 79(6):2277–2284. DOI: 10.1128/IAI.00767-10.