Glucose Incorporation by Human Dental Plaque Bacteria

Abstract

The incorporation of ¹⁴C-sugars was measured in dental plaque suspensions (pH 6.8) incubated at 37 °C. The initial rates of incorporation in 0.1 mM glucose, 0.1 mM fructose and 0.05 mM sucrose solutions were 1.21, 0.59 and 0.99 nmol hexose mg wet wt^––1min^-1, respectively. Incorporation of glucose showed saturation kinetics with 1/2 saturation occurring at 41 μM glucose. In suspensions of Streptococcus mitis, 111 saturation was at 25 μM glucose. Uptake of the non-utilisable glucose analogue 2-deoxyglucose was considerably slower than glucose in both plaque and S. mitis suspensions. Incorporation of glucose by S. mitis and plaque took place over a wide pH range and was inhibited in the presence of excess amounts of 2-deoxyglucose, mannose and 5-thioglucose. Inhibition also occurred in the presence of fluoride, sulphydryl reagents, arsenate, azide, proton-conducting uncouplers and the adenosine triphosphatase inhibitor N, N^I-dicyclohexylcarbodiimide. The inhibition studies indicate that glucose transport mechanisms other than phosphoenolpyruvate-dependent phosphotransferase systems are also present in oral bacteria.

Effect of Salivary Lysozyme on Glucose Incorporation and Acid Production in Streptococcus mutans

“…We used this nonmetabolizable glucose analogue in order to study the incorporation of sugar without the complication of further metabolism. The rate of incorporation of l4C-2DG into Streptococcus mitis is less than that of glu cose [Roberts et al, 1981], 2DG is not uti lized by S. mutans and accumulates in the cell as 2DG-6-phosphate [Schachtele and Leung, 1975]. On prolonged incubation with radiolabelled glucose the amount of label inside the cells decreases, presum ably due to transformation into lactic acid [Robertset al, 1981].…”

Effect of Human Lysozyme on 2-Deoxyglucose Uptake by Streptococcus mutans and Other Oral Microorganisms

“…Sugar in corporation at 37°C was measured using a mem brane filter technique [Roberts et al, 1981]. The nonmetabolizable glucose analogue 2DG was used to avoid inaccuracies in sugar uptake due to further metabolism.…”

Pediatric allergy medications: review of currently available formulations

“…Dentists have long been aware of the harmful effects of sugar-containing medicines, first documented nearly 30 years ago 71 , on children's teeth [72][73][74][75] . The European Commission guidelines on excipients in medicines require that syrups containing sugar add a labeling statement that such products 'may be harmful to the teeth' 76 .…”

“…However, these agents may provide unpleasant, and even harmful, adverse effects of their own ( Table 2) 67,[71][72][73][74][75][96][97][98][99] . Nutritive sugar alcohols such as maltitol, mannitol, sorbitol, and xylitol, are US FDA-approved and generally safe and well tolerated in moderation, but excessive intake is associated with gastrointestinal bloating and overt diarrhea because they are poorly absorbed in the small intestine and fermented in the colon [96][97][98] .…”