A IIIman protein is involved in the transport of glucose,mannose and fructose by oral streptococci

We show in this article that the transport of glucose, mannose and fructose by the phosphoenolpyruvate: mannose phosphotransferase system of oral streptococci requires the participation of a protein component that we have called III_man. This protein was purified from Streptococcus salivarius by chromatography on DEAE-cellulose, DEAE-TSK, hydroxyapatite, and Dyematrex Green A. The purified protein migrated as a 38,900 molecular weight protein on a sodium dodecyl sulfate polyacrylamide gel. However, electrophoretic analysis of phosphoproteins and Western blot experiments indicated the presence in membrane-free cellular extracts of S. salivarius of 2 different forms of III_man having molecular weights of 38,900 and 35,200. The presence of the high-molecular-weight form of III_man was observed by immunodiffusion. Western blot and phosphorylation by [³²]PEP in S. salivarius, Streptococcus mutans, Streptococcus sobrinus, and Streptococcus lactis but not in Streptococcus faecium, Staphylococcus aureus, Bacillus subtilis and Lactobacillus casei. Antibodies directed against the III_man of S. salivarius did not react with the III_man of Escherichia coli.     

纳米非晶金刚石膜改善义齿基托表面变形链球菌黏附量的研究

目的:观察比较义齿基托材料镀用纳米非晶金刚石薄膜前后,表面变形链球菌黏附量变化情况,探索纳米非晶金刚石薄膜镀用义齿树脂基托表面后的抗菌可能性。方法:采用热凝牙托材料制作30mm×10mm×2mm标准试件30个。按不同粗糙度(280目、600目、1200目)分成3组,每组10个。相同粗糙度的10个试件再分成2组,每组5个,一组试件双面镀用纳米非晶金刚石薄膜作为实验组,一组不作处理作为对照组。结果:3组不同粗糙度试件实验组及对照组均存在变形链球菌黏附,实验组少于对照组,两者差异有显著性(1200目P<0.05;600及280目P<0.01);不论实验组还是对照组试件表面变形链球菌黏附量均随粗糙度增大而增多(P<0.05),实验组增多趋势相对较小。结论:纳米非晶金刚石薄膜能够改善义齿树脂基托表面的变形链球菌黏附量,具有部分抑菌功能。     

Antibacterial treatment needed for severe early childhood caries

OBJECTIVES: To assess the effects of a single 10% povidone iodine application as an adjunct to extensive surgical procedures in the clinical treatment of children with early childhood caries. METHODS: Twenty-two children scheduled for dental treatment under general anesthesia were randomized into either an intervention group (10% povidone iodine), or a control group (phosphate buffered saline). Either povidone iodine or phosphate buffered saline was applied to teeth and soft tissues after prophylaxis and all operative dental procedures, followed by 1.23% acidulated phosphate fluoride gel. Saliva samples taken at baseline, and after 1 hour, 3 weeks and 3 months were assayed for mutans streptococci, lactobacilli and total viable bacteria. Caries lesions were recorded at baseline and at one year. RESULTS: Mutans streptococci and lactobacilli levels in the povidone iodine group were significantly reduced relative to baseline at 1 hour, 3 weeks and 3 months. At one year at least 60% of subjects had new caries lesions in each group, and there was no significant difference in caries increment between the two groups. CONCLUSIONS: Even prophylaxis, fluoride gel application and complete surgical treatment of caries at baseline were insufficient to prevent new caries in over 60% of the patients in these high caries risk infants. Although the one-time treatment with povidone iodine reduced mutans streptococci and lactobacilli levels for up to 3 months this therapy failed to additionally reduce future caries formation over one year, indicating that repeated antibacterial treatments will be needed to control high levels of cariogenic bacteria.     

冠心病人口腔龈下菌斑中血链球菌、中间普氏菌的比较研究

目的:探讨口腔龈下菌斑中血链球菌、中间普氏菌与冠心病的关系。方法:检查与记录60例研究对象(冠心病组与对照组各30例)的牙龈指数(GI)、菌斑指数(PLI)、牙周袋探诊深度(PD)。应用生化法检测两组研究对象龈下菌斑中的血链球菌数,并用定性随机引物酶链反应法对两组研究对象龈下菌斑中的中间普氏菌进行了鉴定。结果:冠心病组的PD、PLI和龈下菌斑中的血链球菌数及中间普氏菌检出率明显高于对照组(P(0.05)。结论:冠心病组的牙周健康状况相对更差,与冠心病有关的口腔细菌除血链球菌外,龈下菌斑中的中间普氏菌也与冠心病的发病关系密切。     

Effect of a dentifrice containing the peptide of streptococcal antigen I/II on the adherence of mutans streptococcus

Objective

Antigen I/II of mutans streptococcus (MS) is a surface protein, which binds to salivary receptors. The objective of this study was to study the effect of a peptide corresponding to residues 1025-1044 of antigen I/II and a dentifrice containing peptide on the adherence of MS.

Methods

The peptide was synthesized and included into dentifrice. Anti-adherence experiments of the peptide and a dentifrice containing it were processed in vitro and in vivo.

Results

The results showed that the adherence of MS to hydroxyapatite was inhibited by synthetic antigen I/II peptide and also by a dentifrice containing the peptide in vitro. The numbers of MS in plaque from subjects treated with dentifrices containing the peptide for 1 month was significantly reduced compared to baseline (log 3.11 ± 0.80 vs log 4.09 ± 0.90, P < 0.01), whereas the control group showed no reduction.

Conclusion

The adherence of MS to hydroxyapatite was inhibited by both a synthetic peptide and a dentifrice containing the peptide. The peptide dentifrice produced a significant reduction of MS in dental plaque in vivo.     

老年人高龋患者牙菌斑变形链球菌临床分离株产酸能力的研究

目的：探讨老年人不同龋敏感者口腔中变形链球菌（血清C型）的临床分离株产酸能力的差异。方法：收集老年人高龋患者、无龋者牙菌斑变形链球菌临床分离株（血清C型），比较细菌产酸能力，并与国际参考菌株比较。结果：老年人高龋患者口腔中分离出的变形链球菌临床分离株产酸能力明显高于无龋者口腔中分离出的变形链球菌临床分离株，与国际参考菌株却无明显地统计学差异。同时我们研究也发现，在老年人高龋患者同一个体的口腔中变形链球菌的临床分离株产酸能力存在明显差异。结论：老年人高龋者口腔中变形链球菌（血清C型）临床分离株的高致龋性与其携带有产酸能力强的菌株有关。     

老年人高龋患者牙菌斑中变形链球菌临床分离株合成胞外多糖能力的研究

目的；探讨老年人高龋患者牙菌斑中变形链球菌（血清C型）临床分离株合成胞外多糖能力。方法：收集老年人高龋患者、无龋者牙菌斑中变形链球菌（血清C型），检测合成胞外多糖能力，并与国际参考菌株比较。结果：老年人高龋患者牙菌斑中分离出的变形链球菌临床分离株合成胞外多糖能力明显高于无龋组。同时研究发现，在老年人高龋患者同一个体牙菌斑中，不同基因型变形链球菌临床分离株合成胞外多糖的能力仔任差异，在无龋者牙菌斑中发现没有这一现象。结论：老年人高龋患者牙菌斑中变形链球菌（血清C型）临床分离株合成胞外多糖能力强的菌株与龋病的发生密切有关。     

溶菌酶抑菌作用的实验研究

溶菌酶（Ｌｙｓｏｚｙｍｅ，ＬＺＭ）抑菌作用实验证实溶菌酶对溶壁小球菌具有溶菌作用，并证实１２烷基磺酸钠存在时，溶菌酶对变形链球菌表现出不溶菌现象，这与表面活性剂１２烷基磺酸钠是溶菌酶的抑制剂相符合     

变形链球菌活性氧代谢的酶学基础

目的 :观察不同培养条件下变形链球菌代谢产生活性氧的情况 ,研究变形链球菌活性氧代谢的酶学基础 ,探讨变形链球菌活性氧代谢产物对菌斑微生态的作用。方法 :采用化学发光法检测变形链球菌培养液中超氧化物歧化酶 (superoxidedismutase ,SOD)含量 ;采用电子自旋捕捉法检测不同培养条件下变形链球菌产生活性氧的情况及还原型尼克酰胺腺嘌呤二核苷酸 (nicotinamideadeninedinucleotidereduced ,NADH)对次黄嘌呤—黄嘌呤氧化酶体系和Fe —H2 O2 体系产生活性氧的影响。结果 :在生理盐水培养条件下 ,变形链球菌培养液中能检测到特征性的二甲基吡咯氮氧化物 (dimethylpyridineN -oxide ,DMPO) -O2 ·和DMPO -OH·的电子自旋共振 (elec tronspinresonance ,ESR)信号 ;外源性糖使变形链球菌培养过程中产生的特征性ESR信号增强 ;美兰则使ESR信号消失 ;NADH使得次黄嘌呤—黄嘌呤氧化酶体系和Fe —H2 O2 体系的ESR信号明显减弱甚至消失 ;在变形链球菌培养液中检测到SOD。结论 :不同培养条件下变形链球菌代谢产生O2 ·和OH·的量不同 ,NADH氧化酶催化的反应可能是变形链球菌产生活性氧的主要来源。