Glucosyltransferase as a Marker for Caries Activity

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DESCRIPTION: Dental caries involves the interaction of host molecules, bacterial components, dietary substrate and time. Tests for assessing caries activity, and the likelihood of developing new lesions include determination of level of infection by using salivary mutans streptococci and lactobacilli counts [Rogosa, et al., 1951; Duchin and van Houte 1978; Beighton, 1991], determination of aciduric organisms in plaque and saliva [Snyder, 1951; Grainger et al., 1965], and assessment of prior caries activity [Grainger and Nikiforuk, 1960; Stamm, 1993; Hausen, 1997; Powell, 1998; Messer, 2000]. There is a need for a simple, reliable and reproducible test to determine caries in affected individuals, all of which have shortcomings. Glucosyltransferases (Gff, E.C. 2.4.1.5) are the only proven virulence factors in the etiology of Dental caries identified from Streptococcus mutans thus far [DeStoppelaar et al., 1971; Hamada et al., 1984; Tanzer et al., 1985; Yamashita et al., 1993]. Levels of active Gff in saliva correlate with salivary populations of S. mutans [R611a et al., 1983; Scheie et al., 1987; Vacca-Smith et al., 1996b]. Given that Gffs are proven virulence factors in the pathogenesis of Dental caries and are present in whole saliva, it appears prudent to explore the development of a test using the enzyme(s) as a marker(s) for caries. To this end we will test saliva from either caries free children, or children with Early Childhood Caries, for Gff (contributed by both mutans and non-mutans streptococci) by direct enzyme assay. We will also determine the quantity(ies) of GffB, GtfC, and GtID of S. mutans in the subjects' saliva using monoclonal antibodies in an enzyme-linked immunosorbent assay. We will then attempt to correlate the assayed activity of Gff (from both mutans and non-mutan streptococci) with the concentrations of GtfB, GffC and GffD of S. mutans. Finally, we will determine whether we can correlate both the concentrations of GtfB, GtfC, and GffD, and the overall assayed Gff activity in saliva, with the current levels of clinical caries experience of the subjects. If successful in showing, in this first-step cross-sectional pilot study, a correlation between overall Gff activity, or level of individual Gffs in saliva, with caries prevalence, then the way might be open to explore in the future, in a second, longitudinal study, (separate from this application) whether Gtf in saliva can be used as a predictor of future caries development. Our eventual goal (in a future application) is to determine caries risk well before the onset of lesions and to identify those who are caries active short of cavitation or even white spot formation.