Accessible sialic acid content of oral epithelial cells from healthy and gingivitis subjects

Exploration of correlation of oral hygiene and condition with influenza infection

Influenza viruses are known to be infected through epithelial cells of the upper respiratory tract. The oral cavity is in close anatomical proximity to the upper respiratory tract, and it is conceivable that the viruses could pass through the oral cavity and infect to the upper respiratory tract. Several researchers have suggested that colonization of certain pathogenic bacteria such as Staphylococcus aureus or Streptococcus pneumoniae might affect the risk of influenza viral disease, indicating that oral hygiene and/or condition might play an important role in respiratory viral infection. Therefore, the purpose of this study was to investigate whether an oral hygiene/condition might impact influenza infection. We conducted a retrospective observational study of Japanese citizens' regional cohort (N = 2,904) consisting of National Health Insurance beneficiaries who underwent annual health/dental examination with data entries in the Kokuho database (KDB). Trained dentists checked the oral hygiene/condition, and saliva specimens were examined using the LION dental saliva multi-test (SMT) kit. Influenza infection was identified from the diagnosis recorded in the KDB. The correlations between influenza infection and oral hygiene, dryness of the mouth, or various salivary test results were examined by a multivariate analysis adjusting for confounding factors such as gender, age, recent smoking, alcohol drinking, BMI, HbA1c, RBC for influenza infection. The logistic regression model showed that age significantly correlated with influenza infection. In addition, oral hygiene status had a nearly significant impact on influenza infection (p = 0.061), whereby, the subjects with poor oral hygiene had a higher risk of influenza infection than those with good oral hygiene (odds ratio: 1.63, 95% confidence interval: 0.89-2.95). Further, the prevalence of influenza infection was lower in the subjects with saliva weakly acidic and/or containing higher protein level. The results of this study suggested that the maintenance of oral health conditions might be one of the pivotal factors for preventing and reducing influenza infection.

Glycan cross-feeding supports mutualism between Fusobacterium and the vaginal microbiota

Women with bacterial vaginosis (BV), an imbalance of the vaginal microbiome, are more likely to be colonized by potential pathogens such as Fusobacterium nucleatum, a bacterium linked with intrauterine infection and preterm birth. However, the conditions and mechanisms supporting pathogen colonization during vaginal dysbiosis remain obscure. We demonstrate that sialidase activity, a diagnostic feature of BV, promoted F. nucleatum foraging and growth on mammalian sialoglycans, a nutrient resource that was otherwise inaccessible because of the lack of endogenous F. nucleatum sialidase. In mice with sialidase-producing vaginal microbiotas, mutant F. nucleatum unable to consume sialic acids was impaired in vaginal colonization. These experiments in mice also led to the discovery that F. nucleatum may also “give back” to the community by reinforcing sialidase activity, a biochemical feature of human dysbiosis. Using human vaginal bacterial communities, we show that F. nucleatum supported robust outgrowth of Gardnerella vaginalis, a major sialidase producer and one of the most abundant organisms in BV. These results illustrate that mutually beneficial relationships between vaginal bacteria support pathogen colonization and may help maintain features of dysbiosis. These findings challenge the simplistic dogma that the mere absence of “healthy” lactobacilli is the sole mechanism that creates a permissive environment for pathogens during vaginal dysbiosis. Given the ubiquity of F. nucleatum in the human mouth, these studies also suggest a possible mechanism underlying links between vaginal dysbiosis and oral sex.

Bacterial mutualism involving the prominent oral bacterium Fusobacterium nucleatum may drive vaginal dysbiosis in women and could help to explain the clinical correlations between vaginal dysbiosis and oral sex.

Estimation of Sialic Acid and IL10 Levels in Stage 1 and 2 Periodontitis Patients

Objective

The role of biomarkers in staging and grading periodontal disease has become detrimental in relation to the overall treatment plan. This study aimed at evaluating and comparing the role of sialic acid and IL10 in the early and moderate stages of periodontitis.

Materials and Methods

Patients were selected according to the assessment of pocket depth and radiographic bone loss. Bone loss was calculated as <15% for stage 1 and 15–33% for stage 2. Salivary samples were collected using spit technique 2 hrs post consumption of food. The unstimulated saliva was collected in a sterile graduated container every minute for 5–8 minutes. IL10 estimation was done using ELISA, and sialic acid estimation was done using the diphenylamine method. The variables for the three groups were assessed using ANOVA, and intragroup comparisons for quantitative data were evaluated using the post hoc Bonferroni test (P < 0.05).

Results

On comparing sialic acid levels among the three groups, stage 2 showed the highest mean (8.61) compared with the other two groups and was highly significant (P < 0.001). On the contrary, IL10 when compared to stage 1 and 2 periodontitis revealed insignificant change.

Conclusion

The value of IL10 was higher as patients progressed from health to periodontitis.

Effect of Non-Surgical Periodontal Therapy on the Serum Sialic Acid Levels in Diabetic Patients with Periodontitis

Sialic acid (SA), a family of acetylated derivatives of neuraminic acid, an acute phase reactant by itself. It usually occurs as a terminal component at the non-reducing end of carbohydrate chains of glycoproteins and glycolipids. SA participates in multiple physiological functions, such as cell-to-cell interactions, cell migration and proliferation. Diabetes mellitus (DM) is a chronic metabolic disorder characterized by rise in blood glucose level. Periodontitis is a chronic inflammatory disease of the periodontal tissue, leading to destruction of bone surrounding the tooth and ultimately tooth loss. There is a two way relationship between diabetes mellitus and periodontitis. Periodontitis is the sixth complication of diabetes along with retinopathy, nephropathy, neuropathy, macrovascular disease, and altered wound healing. Inflammatory mediators like interleukin-6 and tumor necrosis factor-alpha produced during periodontal inflammation can interfere with the actions of insulin receptors and worsen the glycemic control of diabetic patients. Periodontitis is a major cause of tooth loss, affecting over 300 million people and bacteria associated with periodontitis are also linked with systemic problems like endocarditis, atherosclerosis. Recent work has highlighted a major role for the host sugar sialic acid in the biofilm physiology and host-pathogen interactions of T. forsithya, a key periodontal pathogen. There exists a need for a biomarker, for early detection of disease evolution and more robust therapy efficacy measurements. Serum sialic acids were estimated in Indian population by diphenylamine method and Thiobarbituric acid method. The average values were 68 ± 2.6 mg percent by DPA method and 56 ± 5 mg percent by TBA (thiobarbituric acid assay) method. Age and sex showed no influence on serum sialic acid level. Objectives of the present study was to compare (TSSA) level in healthy subjects, subjects with (CMP) with and without (NIDDM) and its effect on non-surgical periodontal therapy. In the present study, the participants were divided into three groups: Group A, B and C. Group A consists of systemically healthy subjects, Group B consists of subjects with (CMP) while Group C consists of subjects with (CMP) with (NIDDM) and results of this study indicated that, at baseline, there were significant differences between Group A, B and Group C with respect to all the clinical parameters, including (GI), (OHI-S), (PPD), (CAL), (TSSA) and (HbA1c) levels. Thus (TSSA) level could be considered as novel biomarker in the progression of periodontal disease and diabetic status. Periodontitis could be considered as a potential, modifiable, and independent risk factor for the development of diabetes. Early detection of elevated (TSSA) level may help in interpreting the progression of periodontitis, risk of development of diabetes mellitus in future and also to prevent complications.

Determination of sialic acid levels by using surface-enhanced Raman spectroscopy in periodontitis and gingivitis

OBJECTIVES

To compare the sialic acid (SA) levels in saliva among periodontitis-affected, gingivitis and control patients.

METHODS

The study involved 93 subjects. The participants were divided into three groups: (1) 30 subjects without periodontal disease (control group); (2) 30 subjects with gingivitis; and (3) 33 subjects with periodontitis. The oral parameters examined were as follows: (a) Simplified Oral Hygiene Index; (b) Calculus Index; (c) Gingival Index; (d) probing pocket depth; and (e) level of epithelial attachment. SA levels in saliva were measured by means of surface-enhanced Raman spectroscopy (SERS). This method has demonstrated the capacity to detect extremely low concentrations of molecules. The spectrum was calibrated using analytical reagent SA.

RESULTS

The obtained median values for SA concentrations were 5.98, 7.32, and 17.12 mg/dl for control, gingivitis, and periodontitis patients, respectively.

CONCLUSIONS

Our measurements by SERS corroborate that in periodontitis-affected patients, the SA concentration is larger than their concentrations in either control or gingivitis patients. This confirms previous reports and opens the possibility of using SERS as a diagnostic tool.

Estimation of salivary and serum total sialic Acid levels in periodontal health and disease

BACKGROUND

Chronic gingivitis and periodontitis are inflammatory diseases. An important function of host sialic acid is to regulate innate immunity. The aim of the study was to assess the concentration of Total sialic acid (TSA) in saliva and serum and also to find out their association if any, in periodontal health and disease.

MATERIALS AND METHODS

A total of 90 subjects were clinically examined and distributed into three groups (n=30) according to the periodontal status namely healthy, chronic gingivitis and chronic periodontitis.Clinical measurements including probing depth, clinical attachment level, gingival index, oral hygeine index were recorded .TSA concentration was determined in saliva and serum of all subjects.

RESULTS

In healthy group the mean salivary TSA level was 39.05mg/dl ±6.35(p<0.0001), mean serum TSA level was 49.75 mg/dl ± 4.87 (p<0.0001). In the chronic gingivitis group the mean salivary TSA level was 68.23 mg/dl ± 2.71 (p<0.0001), mean serum TSA level was 65.65 mg/dl ±3.56 (p<0.0001). In the chronic periodontitis group the mean salivary TSA was 81.33 mg/dl ±3.94 (p<0.0001), mean serum TSA level was 75.98 mg/dl ±3.58 (p<0.0001).

CONCLUSION

The present data indicates that salivary & serum TSA levels can differentiate between chronic periodontitis patients and normal individuals. Thus it can be used as an adjunct to diagnose, monitor response to therapy, to determine the current periodontal disease status and to assess the treatment outcomes.

Effectiveness of oral hygiene interventions against oral and oropharyngeal reservoirs of aerobic and facultatively anaerobic gram-negative bacilli

BACKGROUND

Aerobic and facultatively anaerobic gram-negative bacilli (AGNB) are opportunistic pathogens and continue to cause a large number of hospital-acquired infections. AGNB residing in the oral cavity and oropharynx have been linked to nosocomial pneumonia and septicemia. Although AGNB are not considered members of the normal oral and oropharyngeal flora, medically compromised patients have been demonstrated to be susceptible to AGNB colonization.

METHODS

A literature search was conducted to retrieve articles that evaluated the effectiveness of oral hygiene interventions in reducing the oral and oropharyngeal carriage of AGNB in medically compromised patients.

RESULTS

Few studies have documented the use of mechanical oral hygiene interventions alone against AGNB. Although a number of studies have employed oral hygiene interventions complemented by antiseptic agents such as chlorhexidine and povidone iodine, there appears to be a discrepancy between their in vitro and in vivo effectiveness.

CONCLUSION

With the recognition of the oral cavity and oropharynx as a reservoir of AGNB and the recent emergence of multidrug and pandrug resistance in hospital settings, there is a pressing need for additional high-quality randomized controlled trials to determine which oral hygiene interventions or combination of interventions are most effective in eliminating or reducing AGNB carriage.

Molecular and genetic analyses of Actinomyces spp

Members of the genus Actinomyces are predominant primary colonizers of the oral cavity and play an important role in initiating plaque development. These bacteria have evolved unique mechanisms that favor colonization and persistence in this micro-environment. The expression of cell-surface fimbriae is correlated with the ability of these bacteria to adhere to specific receptors on the tooth and mucosal surfaces, and to interact with other plaque bacteria. The elaboration of sialidase is thought to enhance fimbriae-mediated adherence by unmasking the fimbrial receptors on mammalian cells. The presence of certain cell-associated or extracellular enzymes, including those involved in sucrose or urea metabolism, may provide the means for these bacteria to thrive under conditions when other growth nutrients are not available. Moreover, these enzyme activities may influence the distribution of other plaque bacteria and promote selection for Actinomyces spp. in certain ecological niches. The recent development of a genetic transfer system for Actinomyces spp. has allowed for studies the results of which demonstrate the existence of multiple genes involved in fimbriae synthesis and function, and facilitated the construction of allelic replacement mutants at each gene locus. Analyses of these mutants have revealed a direct correlation between the synthesis of assembled fimbriae and the observed adherence properties. Further genetic analysis of the various enzyme activities detected from strains of Actinomyces should allow for an assessment of the role of these components in microbial ecology, and their contribution to the overall success of Actinomyces spp. as a primary colonizer and a key player in oral health and disease.

Saliva-bacterium interactions in oral microbial ecology

Saliva is thought to have a significant impact on the colonization of microorganisms in the oral cavity. Salivary components may participate in this process by one of four general mechanisms: binding to microorganisms to facilitate their clearance from the oral cavity, serving as receptors in oral pellicles for microbial adhesion to host surfaces, inhibiting microbial growth or mediating microbial killing, and serving as microbial nutritional substrates. This article reviews information pertinent to the molecular interaction of salivary components with bacteria (primarily the oral streptococci and Actinomyces) and explores the implications of these interactions for oral bacterial colonization and dental plaque formation. Knowledge of the molecular mechanisms controlling bacterial colonization of the oral cavity may suggest methods to prevent not only dental plaque formation but also serious medical infections that may follow microbial colonization of the oral cavity.