Real‐time interaction of oral streptococci with human salivary components

Oral streptococci are present in large numbers in dental plaque and several types interact with the enamel salivary pellicle to form a biofilm on tooth surfaces. The respective affinity of individual streptococci for salivary components has an influence on the etiologic properties of oral biofilm in the development of dental caries. We studied real‐time biospecific interactions between oral streptococci and salivary components utilizing biosensor technology to analyze surface plasmon resonance. Streptococcus sanguis and Streptococcus mutans showed significant responses for binding to salivary components, in comparison with other bacteria. Further, the association rates (4.1 × 10^?11/bacterium) and dissociation rate (5.7 ± 0.9 × 10^?3 Second(s)^?1) were higher for S. sanguis than for S. mutans (2.4 × 10^?11 and 2.9 ± 0.8 × 10^?3) and Streptococcus mitis (1.3 × 10^?11 and 3.5 ± 1.3 × 10^?3). However, the association equilibrium constants (8.2 S/bacterium) for S. mutans was 2 times higher in than S. mitis (3.8) and slightly higher than S. sanguis (7.2). These findings may provide useful information regarding the mechanism of early biofilm formation by streptococci on the tooth surface.     

唾液富酷蛋白对致龋细菌粘附的影响

目的：探讨唾液富酪蛋白（statherin）对致龋细菌变形链球菌和血链球菌粘附的影响。方法：用高效疏水色谱分离提纯30名个体唾液富酪蛋白并观察不同浓度唾液富酪蛋白与变开链球菌和血链球菌粘附的关系。结果：唾液富酪蛋白明显促进变形链球菌对羟磷灰石的粘附且其促进作用的大小与其浓度有关（P＜0．05）;而对血链球菌的粘附无明显影响（P＞0．05）。结论：唾液富酪蛋白可促进变形链球粘附于羟磷灰石上。     

Characteristics of accumulation of oral gram-positive bacteria on mucin-conditioned glass surfaces in a model system

Strains of Streptococcus, Actinomyces and Lactobacillus were grown on glass surfaces in semi-defined medium (pH 7.0) with mucin. at a dilution rate of D = 0.1 h⁻¹, in a modified chemostat. The accumulation of cells followed four phases. In phase 1 (0-1 h). cells did not divide on the surfaces and adhesion accounted for rapid accumulation. Phase 2 (1-4 h) comprised adhesion and cell division, and accumulation slowed, cell number doubling times (Cd_t) Streptococcus , 2.7 h to 8.6 h, Actinomyces , 2.3 h to 7.5 h and Lactobacillus , 3.6 h to 3.8 h. Cell division on surfaces accounted for accumulation in phase 3 (4 h to 12 h): Cdt Streptococcus , 1.7 h to 5.2 h. Actinomyces , 2.4 h to 7.5 h and Lactobacillus , 2.2 h to 7.2 h. The biofilm stabilized in Phase 4, Cd₁ 18.5 h to 90.2 h. The numbers (10⁶ colony-forming units per cm²) of cells in stable biofilms were Streptococcus, 4.02 to 5.12, Actinomyces , 12.5 and 34.0 and Lactobacillus, 2.77. Accumulation increased (Cd₁ 0.9 h-2.7 h) when cells were exposed to glucose excess or high dilution rates and phase 2 of accumulation did not occur.     

不同龋敏感人群唾液富酪蛋白对致龋细菌粘附影响的比较

目的比较不同龋敏感人群唾液富酪蛋白(SalivaryStatherin)含量的差别,并观察唾液富酪蛋白对牙菌斑中两种主要细菌(变形链球菌和血链球菌)粘附能力的影响,探讨富酪蛋白与龋病的关系。方法用高效疏水色谱分离提纯唾液富酪蛋白,对比分析15名无龋者(DMFT =0 )及15名高龋者(DMFT≥6 )唾液中富酪蛋白的含量,并用全唾液及提纯的不同浓度的富酪蛋白作为实验性获得性膜成分,观察经放射性同位素3 H -胸腺嘧啶核苷酸(3 H -TDR)标记的变形链球菌和血链球菌对羟磷灰石的粘附情况。结果高龋个体唾液富酪蛋白的浓度明显较无龋者唾液富酪蛋白的浓度低(P <0 .0 5 )。富酪蛋白明显促进变形链球菌对羟磷灰石(Hydroxyapatite,HAP)的粘附且其促进作用的大小与其浓度有关(P <0 .0 5 )。而唾液富酪蛋白对血链球菌的粘附无明显影响(P >0 .0 5 )。不同龋敏感人群相同浓度的唾液富酪蛋白对S .mutans粘附的影响无明显差异(P >0 .0 5 )。结论唾液富酪蛋白的含量具有个体差异性,而且对不同细菌粘附的影响不同,从而可能导致不同个体、不同牙面对龋敏感度不同。     

Glucosyltransferase production by Streptococcus sanguis Challis and comparison with other oral streptococci

Glucosyltransferase (GTF) activity in batch cultures of Streptococcus sanguis strain Challis in defined medium was maximum at peak growth and declined rapidly on further incubation into stationary phase. Activity was present in spent culture medium and was associated with 2 polypeptides of approximate Mrs 170 kDa (90% of activity) and 155 kDa (about 10% of activity). Other S. sanguis strains produced similar antigenically-related polypeptides but with varying activities, and antibodies to the S. sanguis enzyme did not react with enzymes produced by other species of oral streptococci. Increasing the [Na+] reduced GTF production by S. sanguis strains Challis and NCTC 7865, and by Streptococcus sobrinus, but not by Streptococcus salivarius. Addition of Tween 80 to cultures caused a rapid inhibition of GTF synthesis by strain Challis, but not by strain NCTC 7865. Benzyl alcohol had a slower and less inhibitory effect on GTF production by strain Challis. Tween 80 generally inhibited to varying degrees GTF production by other oral streptococci through in S. sobrinus it was stimulated. The results suggest controls operating on GTF synthesis and secretion by different strains of oral streptococci appear to be diverse.     

Mutans streptococci and lactobacilli in the elderly

The prevalence of salivary mutans streptococci and lactobacilli, salivary flow rate, and the type of dentition were studied in connection with a medical survey of 76-, 81-, and 86-yr-old inhabitants of Helsinki living at home. High bacterial counts were associated with low salivary flow rates. High counts of mutans streptococci (>10⁶ CFU/ml) were found in 68% of wearers of full dentures, as compared with 53% of subjects having natural teeth. High counts of lactobacilli (>10⁶ CFU/ml) were found in 44%) of subjects having removable partial dentures and in 39% of subjects having natural teeth. The bacterial counts correlated neither with medicines taken daily nor with diseases among this population.     

Salivary IgA antibody to oral streptococcal antigens in predentate infants

Salivary IgA antibodies to oral streptococci which colonize the infant oral cavity soon after birth were analyzed in 53 whole salivas of 17 infants who were between three and 27 weeks old. Antibody activities to Streptococcus mitis cells were detected by enzyme linked immunosorbent assay in 78% of the whole salivas by the twelfth week of age. This antibody activity was associated with polymeric IgA as determined after gel filtration of salivas on Superose 6, followed by ELISA. Western blot analyses were used to detect IgA antibodies to Streptococcus mitis and Streptococcus salivarius culture supernatants. Forty one, and 91% of saliva samples contained IgA antibody which reacted in Western blot analyses with S. salivarius and S. mitis culture supernatants, respectively. The youngest infant to show reactive IgA antibody with either oral streptococcal antigen preparation was five week old. Salivary IgA antibody to either bacterial culture supernatant was detected in Western blot only after the isolation of the respective streptococcal species from the oral cavity of these young infants. Some heterogeneity was observed among patterns developed with salivas from different infants. These results suggest that salivary IgA antibody responses may be induced by oral colonization (S. mitis, S. salivarius) by the end of the first month of life.     

Association of salivary immunoglobulin A antibody and initial mutans streptococcal infection

We explored the relationship between mutans streptococcal infection and the development of salivary IgA antibody during initial colonization. Repetitive swabbing ( n = 292) of the teeth of 33 children revealed that 45% became infected with mutans streptococci between 13 and 36 months of age. In contrast, mutans streptococci could not be detected in 18 children whose last sample was taken at 39–81 months of age (median age=62 months). During the period of mutans streptococcal infectivity, immunoglobulin A (IgA) antibody to several mutans streptococcal antigens appeared in most children, whether or not infection had been demonstrated. Robust responses to mutans streptococcal components occurred during or shortly after, but not before the period of mutans streptococcal infectivity. No consistent differences were observed among the summarized patterns of response of infected and uninfected groups of children, although the IgA Western blot patterns of individual subjects were often quite distinct. For example, sets of siblings, who would be presumed to be challenged with similar maternal mutans streptococcal clonotypes, were shown to develop qualitatively different salivary IgA responses to mutans streptococcal components. These results support a discrete period for mutans streptococcal infection and may suggest that the level of maternal infection is a factor in the success of infection of the child during this period. The data also suggest that exposure to mutans streptococci is a sufficient condition for robust mucosal IgA responses to mutans streptococcal antigens during the period of infectivity and that these responses may be different, even among siblings.     

Interaction between surface protein antigens of Streptococcus mutans and human salivary components

The potential involvement of surface antigens (Ags) I/II and III of Streptococcus mutans in its adherence to salivary pellicle-coated tooth surfaces was investigated. The binding of radiolabelled Ag I/II to hydroxyapatite was increased by pretreating the mineral with human parotid saliva, and binding was maintained in the continuous presence of saliva. Binding of Ag III to hydroxyapatite was inhibited by pretreatment with, or in the presence of, saliva. Various aminohexoses, and also tris, inhibited the binding of Ag I/II. When Ags I/II and III were tested for their ability to bind to salivary components separated by SDS gel electrophoresis, several proteins capable of binding Ag I/II were identified, notably 2 proteins of apparent relative molecular mass 28,000 and 38,000. Analysis of these proteins, isolated by micro-preparative electrophoresis, indicated high proportions of proline, glycine, and glutamic acid, and overall compositions similar to basic proline-rich salivary proteins.     

口腔链球菌对白假丝酵母菌的拮抗作用

目的 观测3种口腔链球菌对白假丝酵母菌的生长有无抑制作用.方法 采用直接点种法、反点种菌落计数法和液体共培养法观测口腔变异链球菌、血链球菌、唾液链球菌对白假丝酵母菌的拮抗作用.结果 1)直接点种法中各组均未观察到清晰的抑菌圈;2)唾液链球菌软琼脂上的白假丝酵母菌菌落数较对照组减少(P<0.05);3)活菌与白假丝酵母菌...     

Oral glucose clearance in subjects with high or low salivary levels of Streptococcus mutans and lactobacili

Abstract — The ability to eliminate sugar from the oral cavity was studied in subjects with high or low numbers of salivary Streptococcus mutans and lactobacilli. The glucose concentration in saliva was determined after consumption of biscuits using the Gloxtest, and the logarithms of the glucose values were plotted against time. The sugar clearance time was measured where the slope of the plot intersected with a glucose level of I mg/ml. Subjects with a high level of S, mutans had a significantly longer clearance time than subjects with a low level. More salivary lactobacilli were found in a subject group- with a long sugar clearance time than in a group with a fast clearance rate.     

Immunoglobulin A reaction to oral streptococci in saliva of subjects with different combinations of caries and levels of mutans streptococci

The aim of this study, performed in Bangkok, was to study whether a particular salivary immunoglobulin A (IgA) antibody profile against mutans streptococci could be related to the absence or presence of caries. A group of 12-year-old individuals representing various combinations of mutans streptococci levels and caries experience was selected. Whole saliva stimulated by paraffin-chewing was collected, and the children were investigated for decayed, missing and filled surfaces (DMFS) and teeth (DMFT), following WHO criteria and methods, at baseline and after 2 years. The total amount of salivary IgA was determined by an immunobead enzyme-linked immunosorbent assay, and SDS-PAGE and Western blot analysis was performed using sonicated antigens of Streptococcus mutans and Streptococcus sobrinus strains and, as a control, a Streptococcus parasanguis strain. The results showed that Thai children with low caries prevalence had more distinct immunoblot bands to antigens from mutans streptococci than did the high-caries children. A similar picture was not seen for S. parasanguis. On the whole, the Thai children also showed fewer bands than usual Swedish saliva samples from comparable age groups. The complexity of the relationship between dental caries and IgA in saliva is highlighted.     

Interference of oral hygiene products with an adhesion-based assay of salivary mutans streptococci

Abstract – The effect of several oral hygiene products on an adhesion-based assay for salivary mutans streptococci (Dentocult-SM Strip Mutans) was studied in three women. The mutans streptococci levels were recorded for up to 24 h after a 1-min rinse with the product. The chlorhexidine (0.05%) and stanno-amine fluoride solutions (corresponding 0.025% F) interfered selectively with the adhesion-based assay. No such effect was observed for a polyvidoneiodine solution (10 μg/ml) or two toothpastes containing either sodium lauryl sulfate or amine fluorides. The results indicate that antimicrobial agents showing retention in the oral cavity may interfere for several hours after their use with adhesion-based assays of salivary mutans streptococci.     

Oral streptococcal colonization of infants

The objective of this study was to determine the prevalence and proportions of different streptococcal species among the streptococcal flora during infancy. A total of 60 oral samples were collected by oral swabbing of the buccal mucosa and alveolar ridges of 18 infants before tooth eruption and from buccal and lingual surfaces of teeth after tooth eruption. A total of 549 isolates on mitis salivarius agar were speciated, principally by recently revised biochemical criteria of Kilian et al. Streptococcus mitis biovar 1 predominated, both in prevalence (89%) and proportion of oral streptococci recovered in each sample (median = 87% of streptococcal flora). Streptococcus salivarius was also prevalent (94%) but generally represented a small percentage of the total streptococcal flora (median = 3%). Streptococcus oralis and Streptococcus anginosus strains were detected in approximately one third of predentate and dentate infants in the first year of life. Streptococcus sanguis strains were not detected before tooth eruption, but could be detected in 7/14 of the infants with teeth. Thus, S. mitis constitutes the major component of the initially colonizing streptococcal microbiota of the young infant.     

Identification of oral mitis group streptococci by arbitrarily primed polymerase chain reaction

"Mitis group" streptococci are commensal but may play some role in dental caries, septicemia or endocarditis. Rapid genotypic identification would aid studies of dental plaque ecology, or diagnostic use. AP-PCR with 58 unpaired arbitrary primers was used to characterize 7 Streptococcus gordonii, 11 Streptococcus sanguis, 2 Streptococcus crista, 5 Streptococcus parasanguis, 18 Streptococcus oralis, and 36 Streptococcus mitis (22 biovar 1 and 14 biovar 2). S. parasanguis 16S rRNA variable region primer RR2 produced species-specific bands with all S. gordonii and S. sanguis. Human V beta 1 T-cell receptor primer 434 yielded concordant genotypic identification of all phenotypically defined S. crista and S. parasanguis, 83% of S. oralis, and 74% of S. mitis biovar 1. Amplicon patterns for S. mitis biovar 2 were heterogeneous. Findings suggest that primers RR2 and 434 in succession will allow rapid identification of genotypic groups corresponding closely to mitis group species established by phenotype.     

Effect of antimicrobial mouthrinses on salivary microflora in healthy subjects

Abstract – The antibacterial effects of chlorhexidine and an oxygen releasing agent on the salivary microflora were evaluated in healthy subjects in two separate experiments: 1) mouthrinsing on a single occasion and 2) mouthrinsing two or four times a day for 1 wk. Both experiments were performed in a cross-over study, and each subject was randomly tested for both rinsing agents and a saline control. The total bacterial number and some selected bacterial genera were followed in saliva samples taken prior to (zero-samples) and on three occasions after the rinsing or rinsing period. The reduction of the total bacterial number by mouthrinsing two or four times a day for 1 wk with chlorhexidine was statistically significant and lasted for over 4 h. After rinsing with chlorhexidine on one single occasion the reduction of the microflora was statistically significant and of the same magnitude as after rinsing two or four times daily for 1 wk. Although statistically significant reduction was obtained, the significant biologic effect of antimicrobial agents may be questioned. The number of Strep, mutans was dramatically reduced with chlorhexidine in some subjects and this reduction lasted for over 1 wk. The oxygen releasing agent did not reduce salivary flora significantly when rinsing took place two or four times daily for 1 wk.     

Determination and identification of antibiotic-resistant oral streptococci isolated from active dental infections in adults

Objective: To determine and identify antibiotic-resistant bacteria (ARB) of oral streptococci from active dental infections in adults and its association with age and gender.

Material and methods: This cross-sectional study included 59 subjects from 18 to 62 years old. Ninety-eighth samples obtained from the subjects were cultivated in agar plates containing antibiotics amoxicillin/clavulanic acid (A-CA), clindamycin, and moxifloxacin (concentrations of 16, 32 or 64 µg/ml). PCR assay was performed to identify bacterial species.

Results: The bacterial species that showed more antibiotic-resistance (AR) was S. mutans (45.9%), followed by S. gordonii (21.6%), S. oralis (17.6%), S. sanguinis (9.5%), S. salivarius (5.4%) and S. sobrinus (0%). Moreover, clindamycin (59.4%) showed the highest frequency of AR. Moxifloxacin and A-CA showed an susceptibility >99.1%, while clindamycin showed the lowest efficacy (93.3%); there was a significant statistically difference (p?p?Conclusions: Clindamycin was the antibiotic with the highest frequency of ARB and lower bactericidal effect. Moxifloxacin and A-CA showed the highest efficacy and the lowest ARB frequency. Streptococcus mutans was the bacterial specie that showed an increased frequency of AR.     

变异链球菌对人唾液腺细胞系免疫球蛋白受体影响的初步研究

目的:观察变异链球菌(S.mutans)对人唾液腺细胞系(HSG)中多聚免疫球蛋白受体(Pigr)表达的影响.方法:用免疫荧光染色验证细胞系来源与Pigr在HSG中的表达.将对数生长中期的S.mutans水热灭活后与HSG细胞共培养,CCK-8法观察细胞增殖,qPCR与Western blot检测S.mutans对Pi...