title: Cariogenic traits in xylitol-resistant and xylitol-sensitive mutans streptococci.
abstract: Long-term xylitol consumption leads to the emergence of xylitol-resistant (X-R) mutans streptococci. The aim of the present study was to compare cariogenic traits in X-R and xylitol-sensitive (X-S) strains. Six strains of mutans streptococci, three X-R and three X-S strains, were studied. Xylitol resistance and sensitivity were confirmed by growth in xylitol-supplemented media. Acid production from glucose or fructose or uptake of xylitol was initiated by adding (14)C-labelled glucose, fructose or xylitol to bacterial suspensions. The resultant metabolites were identified by HPLC. Lactate was the major metabolite from glucose, whether the bacteria were grown in the presence or the absence of xylitol. Lactate production per colony-forming unit was lower in X-S cells than in X-R cells. Fructose was metabolized by both X-R and X-S cells. Both X-R and X-S cells took up xylitol, but xylitol-5-P was detected in X-S cells only. Total polysaccharides were measured through production of C(14)-labelled ethanol-insoluble polymers from [U(14)-C]-sucrose. No difference in polysaccharide production was found between X-R and X-S cells. The present study thus does not support the contention that X-R are less cariogenic than X-S mutans streptococci.
authors.affiliation: Department of Oral Biology, The Faculty of Dentistry, University of Oslo, Oslo, Norway.
authors.forename: S
authors.initials: S
authors.lastname: Assev
authors.forename: S
authors.initials: S
authors.lastname: Stig
authors.forename: A Aa
authors.initials: AA
authors.lastname: Scheie
mesh_terms: D002250:Carbon Radioisotopes; D002327:Cariostatic Agents / Q000378:metabolism / Q000494:pharmacology*; D002851:Chromatography, High Pressure Liquid; D015169:Colony Count, Microbial; D003470:Culture Media; D003731:Dental Caries / Q000382:microbiology*; D024881:Drug Resistance, Bacterial; D005632:Fructose / Q000378:metabolism; D005947:Glucose / Q000378:metabolism; D006801:Humans; D007773:Lactates / Q000378:metabolism; D011108:Polymers; D011135:Polysaccharides, Bacterial / Q000032:analysis / Q000096:biosynthesis; D019275:Radiopharmaceuticals; D012995:Solubility; D013295:Streptococcus mutans / Q000187:drug effects* / Q000254:growth & development; D016986:Streptococcus sobrinus / Q000187:drug effects / Q000254:growth & development; D013395:Sucrose / Q000378:metabolism; D013549:Sweetening Agents / Q000378:metabolism / Q000494:pharmacology*; D014993:Xylitol / Q000378:metabolism / Q000494:pharmacology*
chemical_list: D002250:Carbon Radioisotopes; D002327:Cariostatic Agents; D003470:Culture Media; D007773:Lactates; D011108:Polymers; D011135:Polysaccharides, Bacterial; D019275:Radiopharmaceuticals; D013549:Sweetening Agents; D005632:Fructose; D013395:Sucrose; D005947:Glucose; D014993:Xylitol