Sealed cariogenic bacteria are deprived from dietary carbohydrate, but could be provided with nutrients by pulpal fluids, with adaptive strain-specific activities being possible. We investigated survival and metabolic activity of the cariogenic bacteria Streptococcus sobrinus, Actinomyces naeslundii and Lactobacillus rhamnosus in different carbohydrate-limited media without carbon source (CLM), or containing glucose (CLM-G), albumin (CLM-A), or α1-acid glycoprotein (CLM-AGP) in vitro. Bacterial metabolite concentrations (lactate, pyruvate, oxaloacetate, citrate, acetate, formate, ethanol, acetoin) after 20 and 4 hours incubation, and bacterial numbers (CFU) after 24 hours incubation were analyzed using multivariate-analysis-of-variance (MANOVA). The medium (p = 0.02/MANOVA), strain and incubation-time (both p < 0.001) had significant impact on metabolite concentrations. Bacteria secreted mainly lactate (80.3 µg/10⁶ bacteria S. sobrinus) and acetate (54.5 µg/10⁶ bacteria A. naeslundii). Nearly all metabolites were produced in higher concentrations in S. sobrinus than in A. naeslundii or L. rhamnosus (p < 0.05/HSD). Metabolite concentration was significantly higher in CLM-G than in other media for most metabolites (p < 0.05). L. rhamnosus showed significantly lower survival than S. sobrinus and A. naeslundii (p < 0.05/HSD) regardless of the media, while S. sobrinus and A. naeslundii showed medium-specific survival. Survival of carbon starvation was strain- and medium-specific. Sustained organic acid production was found for all strains and media.

封闭的致龋细菌缺乏饮食中的碳水化合物，但可以通过牙髓液提供营养，并且可能具有适应性的菌株特异性活性。我们研究了生龋细菌的存活和代谢活性远缘链球菌，放线菌属naeslundii和鼠李糖乳杆菌在不同碳水化合物限制媒体无碳源（CLM），或含有葡萄糖（CLM-G），白蛋白（CLM-A），或α1-酸性糖蛋白（CLM-AGP）的体外。孵育20和4小时后，细菌代谢物浓度（乳酸，丙酮酸，草酰乙酸，柠檬酸盐，乙酸盐，甲酸盐，乙醇，乙酰丙酮）和孵育24小时后的细菌数（CFU）均采用多变量分析。培养基（p = 0.02 / MANOVA），菌株和孵育时间（p <0.001）均对代谢物浓度有显着影响。主要分泌细菌乳酸（80.3微克/ 10 ⁶细菌远缘链球菌）和醋酸（54.5微克/ 10 ⁶细菌氏放线菌）。几乎所有的代谢物在更高的浓度产生的远缘链球菌比氏放线菌或鼠李糖乳杆菌（p <0.05 / HSD）。对于大多数代谢物，CLM-G中的代谢物浓度显着高于其他培养基（p <0.05）。不论培养基如何，鼠李糖乳杆菌的存活率均显着低于沙门氏菌和内德氏杆菌（p <0.05 / HSD），而沙门氏菌和内德氏菌则显示中等特异性的存活率。碳饥饿的存活是菌株特异性和培养基特异性的。发现所有菌株和培养基的持续有机酸产量。