This Article Full Text (PDF) References Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Saved Citations Download to citation manager Request Permissions Request Reprints Add to My Marked Citations Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Citing Articles via Scopus Google Scholar Articles by Trahan, L. Articles by Breton, R. Search for Related Content PubMed PubMed Citation Articles by Trahan, L. Articles by Breton, R. Pubmed/NCBI databases Compound via MeSH Substance via MeSH Hazardous Substances DB FRUCTOSE GLUCOSE SUCROSE Social Bookmarking                         What's this?

Emergence of Multiple Xylitol-resistant (Fructose PTS-) Mutants from Human Isolates of Mutans Streptococci during Growth on Dietary Sugars in the Presence of Xylitol

Groupe de Recherche en Ecologie Buccale, Faculte de medecine dentaire, Universite Laval, Quebec, Canada G1K 7P4

G. Bourgeau

Groupe de Recherche en Ecologie Buccale, Faculte de medecine dentaire, Universite Laval, Quebec, Canada G1K 7P4

R. Breton

Groupe de Recherche en Ecologie Buccale, Faculte de medecine dentaire, Universite Laval, Quebec, Canada G1K 7P4

The growth inhibition of mutans streptococci is one of the proposed mechanisms of action of xylitol, a caries-preventive natural carbohydrate sweetener. Xylitol is taken up and accumulated as non-metabolizable, toxic xylitol phosphate via a constitutive fructose PTS, and selects, during in vitro growth at the expense of glucose, for natural xylitol-resistant mutants that lack constitutive fructose PTS activity. Since long-term xylitol consumption leads to the emergence of xylitol-resistant mutans populations in humans in an oral environment containing sugars of dietary origin, we wanted to test the hypothesis that xylitol-resistant cells could be selected from mutans streptococci strains during in vitro growth on fructose, sucrose, or lactose. Three laboratory strains and three fresh mutans streptococcal isolates were repeatedly transferred in trypticase-yeast extract medium supplemented with glucose, fructose, sucrose, or lactose in the presence and absence of xylitol. Depending on the growth sugar, the presence of xylitol resulted in the selection of xylitol-resistant populations for several of the six strains tested, but not necessarily in the presence of all four sugars. All six strains rapidly became xylitol-resistant when grown on glucose in the presence of xylitol. All three fresh isolates became xylitol-resistant after 9 to 16 transfers in the presence of fructose or sucrose plus xylitol, while none of the laboratory strains became xylitol-resistant after 16 transfers in the presence of these sugars. The growth rates of 12 xylitol-resistant mutants in the presence of eight sugars suggested the existence of various types of xylitol-resistant mutants. The data partially explain the occurrence of xylitol-resistant mutans populations in long-term xylitol consumers and suggest a mechanism consistent with a selection process. Since various preliminary results suggest that xylitol-resistant natural mutants may be less virulent and less cariogenic than their parent strains, this selection process may alter, for the better, the mutans streptococci population of the plaque and play a role in the caries-preventive action of xylitol.

Key Words: xylitol • Streptococcus mutans • dental caries • laboratory strains • clinical isolates

Journal of Dental Research, Vol. 75, No. 11, 1892-1900 (1996)
DOI: 10.1177/00220345960750111201


CiteULike    Complore    Connotea    Del.icio.us    Digg    Reddit    Technorati    Twitter    What's this?

This article has been cited by other articles:

				A. Deshpande and A. R. Jadad The impact of polyol-containing chewing gums on dental caries: A systematic review of original randomized controlled trials and observational studies J Am Dent Assoc, December 1, 2008; 139(12): 1602 - 1614. [Abstract] [Full Text] [PDF]

				P.P. Hujoel, K.K. Makinen, C.A. Bennett, K.P. Isotupa, P.J. Isokangas, P. Allen, and P.-L. Makinen The Optimum Time to Initiate Habitual Xylitol Gum-chewing for Obtaining Long-term Caries Prevention Journal of Dental Research, March 1, 1999; 78(3): 797 - 803. [Abstract] [PDF]

				P. F. Wright Xylitol Sugar and Acute Otitis Media Pediatrics, October 1, 1998; 102(4): 971 - 972. [Full Text] [PDF]