Search

Over her near 60‐year career, Mirdza E. (Mitzi) Neiders has served as a teacher, dentist, researcher, mentor, role‐model, friend, and critic for thousands of faculty, students, and patients of the University at Buffalo School of Dental Medicine. One of the first women to serve on the dental school faculty, this article describes her journey and the great impact that she has made on dentistry and her community on the occasion of her retirement. [ABSTRACT FROM AUTHOR]

Nonventilator hospital-associated pneumonia has recently emerged as an important preventable hospital-associated infection, and is a leading cause of healthcare-associated infection. Substantial accumulated evidence links poor oral health with an increased risk of pneumonia, which can be caused by bacterial, viral, or fungal pathogens, each with their own distinct mechanisms of transmission and host susceptibility. These infections are frequently polymicrobial, and often include microbes from biofilms in the oral cavity. Evidence documenting the importance of oral care to prevent nonventilator hospital-associated pneumonia is continuing to emerge. Reduction of oral biofilm in these populations will reduce the numbers of potential respiratory pathogens in the oral secretions that can be aspirated, which in turn can reduce the risk for pneumonia. This review summarizes up-to-date information on the role of oral care in the prevention of nonventilator hospital-associated pneumonia. [ABSTRACT FROM AUTHOR]

Objective: Periodontitis is an inflammatory oral disease that occurs as a result of the damaging effects of the immune response against the subgingival microflora. Among the mechanisms involved, the nucleotide‐binding oligomerization domain, leucine‐rich repeat‐containing proteins family member NLRP3 (NLR family pyrin domain‐containing 3), proposed as the key regulator of macrophage‐induced inflammation, is strongly associated with periodontal disease due to the bacterial activators. This paper aimed to present key general concepts of NLRP3 inflammasome activation and regulation in periodontal disease. Method: A narrative review was conducted in order to depict the current knowledge on the relationship between NLRP3 inflammasome activity and periodontal disease. In vitro and in situ studies were retrieved and commented based on their relevance in the field. Results: The NLRP3 inflammasome activity stimulated by periodontal microbiota drive periodontal disease pathogenesis and progression. This occurs through the release of proinflammatory cytokines IL‐1β, IL‐18, and DAMPs (damage‐associated molecular pattern molecules) following inflammasome activation. Moreover, the tissue expression of NLRP3 is dysregulated by oral microbiota, further exacerbating periodontal inflammation. Conclusion: The review provides new insights into the relationship between the NLRP3 inflammasome activity and periodontal disease pathogenesis, highlighting the roles and regulatory mechanism of inflammatory molecules involved in the disease process. [ABSTRACT FROM AUTHOR]

It is widely accepted that common diseases of the oral cavity, such as gingivitis and periodontitis, are preventable. Based on a large body of scientific evidence, a number of preventive strategies are known to prevent these diseases, but only if routinely implemented. Unfortunately, while most preventive strategies are theoretically simple to understand, they are often difficult to employ in practice at individual and public health levels. This volume of Periodontology 2000 provides the most current information on the state of the science and the evidence base supporting a preventive perspective for the management of periodontal disease, including evidence for proven interventions as well as cutting-edge ideas for potential future interventions. In addition to well-established and scientifically proven approaches (tooth and implant cleansing, topical chemotherapeutics, reduction in risk factors such as tobacco smoking), a number of new ideas are now under investigation, including antioxidant agents, probiotics, vaccines, and slow-release alternative chemotherapeutics. Furthermore, there are new ideas to alter patient behaviors with the aim to improve adherence to preventive strategies. Finally, examples from implementation science and public health are provided that suggest novel approaches to bring new ideas into clinical practice. [ABSTRACT FROM AUTHOR]

The proximity and continuity of the oral cavity and the lower respiratory tract allows the oropharyngeal microbiome to be a major determinant of the lung microbiome. In addition, host-pathogen interactions related to the oropharyngeal microbiome or its metabolites could propagate systemic inflammation or modulate host defense mechanisms that could affect other organs, including the lung. There is increasing appreciation of the pathophysiologic significance of the lung microbiome, not only in the classical infection-related diseases, pneumonia, bronchiectasis, and cystic fibrosis, but also in chronic noninfectious lung diseases, such as chronic obstructive pulmonary disease, asthma, and pulmonary fibrosis. In this review, we will explore the relationship of the oral microbiome with lung diseases, such as pneumonia, chronic obstructive pulmonary disease, asthma, and cystic fibrosis. [ABSTRACT FROM AUTHOR]

Oral biofilm, the cause of dental caries and periodontal diseases, consists of multiple bacterial species. Streptococcus spp. and Veillonella spp. have been reported as to be initial and early colonizers of oral biofilms. Our previous studies showed that Veillonella tobetsuensis may play an important role on the development of S. gordonii biofilms without coaggregation involving extracellular biomolecules. In this study, the effect of a cyclic dipeptide autoinducer from culture supernatants from V. tobetsuensis at late-exponential growth phase on S. gordonii biofilm was examined. The cyclic dipeptide, identified as cyclo (-L-Leu-L-Pro) by gas chromatography/mass spectrometry, inhibited the development of S. gordonii biofilm. Furthermore, cyclo (-L-Leu-L-Pro) appeared not to cause bactericidal effects on planktonic cells of S. gordonii. This is the first report that oral Veillonella produces cyclo (-L-Leu-L-Pro) in their culture supernatants. Moreover, the results of this study suggest that cyclo (-L-Leu-L-Pro) may have an application to inhibit early stage development of oral biofilms. [ABSTRACT FROM AUTHOR]

Background. Mechanical disruption of dental biofilm is critical to maintain periodontal health. Baking soda-containing dentifrices have shown to be potential aids for improving gingival health and maintaining dental biofilm control. Types Of Studies Reviewed. Evidence from classic and contemporary literature is reviewed and summarized in this review. In vitro and in vivo (animal and human, respectively) studies and clinical trials have been analyzed. Conclusions. Some clinical studies demonstrated the benefits of baking soda dentifrices in plaque and gingivitis reduction. Clinical trials with longer follow-up would be useful to confirm the impact of baking soda on gingival health. Practical Implications. Regular dental biofilm control and adjunctive use of baking soda dentifrices in an otherwise healthy and compliant patient may provide success in maintenance of gingival health. [ABSTRACT FROM AUTHOR]

Background: There is emerging evidence linking diabetes with periodontal disease. Diabetes is a well-recognized risk factor for periodontal disease. Conversely, pro-inflammatory molecules released by periodontally-diseased tissues may enter the circulation to induce insulin resistance. While this association has been demonstrated in adults, there is little information regarding periodontal status in obese children with and without type 2 diabetes (T2D). We hypothesized that children with T2D have higher rates of gingivitis, elevated salivary inflammatory markers, and an altered salivary microbiome compared to children without T2D. Methods: Three pediatric cohorts ages 10–19 years were studied: lean (normal weight—C), obese (Ob), and obese with T2D (T2D). Each subject completed an oral health survey, received a clinical oral examination, and provided unstimulated saliva for measurement of inflammatory markers and microbiome analysis. Results: The diabetes group was less likely to have had a dental visit within the last six months. Body mass index (BMI) Z-scores and waist circumference/height ratios were similar between Ob and T2D cohorts. The number of carious lesions and fillings were similar for all three groups. The gingival index was greater in the T2D group compared to the Ob and C groups. Although salivary microbial diversity was minimal between groups, a few differences in bacterial genus composition were noted. Conclusions: Obese children with T2D show a trend toward poorer oral health compared to normal weight and obese children without T2D. This study characterizes the salivary microbiome of children with and without obesity and T2D. This study supports a modest link between T2D and periodontal inflammation in the pediatric population. [ABSTRACT FROM AUTHOR]

Oral diseases, such as caries and periodontitis, not only have local effects on the dentition and on tooth-supporting tissues but also may impact a number of systemic conditions. Emerging evidence suggests that poor oral health influences the initiation and/or progression of diseases such as atherosclerosis (with sequelae including myocardial infarction and stoke), diabetes mellitus and neurodegenerative diseases (such as Alzheimer's disease, rheumatoid arthritis and others). Aspiration of oropharyngeal (including periodontal) bacteria causes pneumonia, especially in hospitalized patients and the elderly, and may influence the course of chronic obstructive pulmonary disease. This article addresses several pertinent aspects related to the medical implications of periodontal disease in the elderly. There is moderate evidence that improved oral hygiene may help prevent aspiration pneumonia in high-risk patients. For other medical conditions, because of the absence of well-designed randomized clinical trials in elderly patients, no specific guidance can be provided regarding oral hygiene or periodontal interventions that enhance the medical management of older adults. [ABSTRACT FROM AUTHOR]

Abstract: The oral cavity harbors a rich and diverse microflora, which is mostly found within biofilms attached to the various soft- and hard-tissue surfaces. Recent studies using molecular methods have revealed previously unrecognized species within biofilms associated with health and several common oral diseases. These unrecognized species established an under-appreciated diversity within the flora, with new questions to be answered. Information regarding the composition of the oral microbiome associated with oral health, dental caries, periodontal disease, and endodontic infection is briefly reviewed. Recent concepts regarding the potential role of the oral microbiome in several common systemic diseases are also briefly discussed. [Copyright &y& Elsevier]

Investigates the role of a catabolite control protein A gene (ccpA) homolog (regG) in the regulation of amylase binding protein A gene (adpA) expression in Streptococcus gordonii. Effect of carbon catabolite repression on abpA expression; RegG Identification; Effect of regG insertional inactivation on abpA expression; Transcriptional regulation of abpA.

Discusses the twenty-first century improvements in oral medicine. Practice of dentistry in the Middle Ages; Advances in tissue engineering; Vaccines against tooth decay and gum disease; Home care in preventing dental diseases.

A replica-plate assay was used to screen for the interaction of salivary molecules with dental plaque bacteria. Bacterial colonies cultured from supragingival plaque on sheep-blood (SB) agar were replica-plated onto nitrocellulose membranes overlaying SB or mitis-salivarius agar. Membranes with attached colonies were removed and incubated with 125I-amylase or 125I-proline-rich glycoprotein (PRG). Positive interaction us were detected by autoradiography. Only strains of Streptococcus gordonii and Actinomyces viscosusbound amylase, and strains of A. viscosus bound PRG. The results suggest that amylase and PRG bind to selected species of aerobic dental plaque bacteria. [ABSTRACT FROM AUTHOR]

The article focuses on examining the relationship between periodontitis and dyslipidemia, demonstrating a direct association between both diseases. Topics include discussing the limitations of cross-sectional study design in determining the direction and temporality of the association, as well as the methodology used to investigate the relationship between periodontitis and dyslipidemia while considering confounding variables.

The goal of this review is to summarize the results of randomized trials reported since 2010 that assessed the effect of periodontal interventions on at least one systemic outcome in human subjects of any age, gender or ethnicity. Oral outcome measures included gingivitis, pocket depth, clinical attachment loss and/or radiographic bone loss and oral hygiene indices. Studies were excluded if the trial was not completed or if treatment was not randomized. The results suggest that nonsurgical periodontal intervention provided to pregnant women is safe and improves periodontal status without preventing adverse pregnancy outcomes. Nonsurgical periodontal intervention was also found to provide modest improvement in glycemic control in individuals with type 2 diabetes mellitus and periodontitis. Also, improving oral care through mechanical or chemical control of dental-plaque biofilm formation can contribute to the prevention of respiratory infections in differing clinical settings, including hospitals and nursing homes, and in patients with chronic obstructive pulmonary disease. No clinical trials were reported that tested the effect of periodontal interventions on medical outcomes of atherosclerosis, cardiovascular diseases, stroke, rheumatoid arthritis, Alzheimer's disease, chronic kidney disease or malignant neoplasia. [ABSTRACT FROM AUTHOR]

Recently, Veillonella infantium was isolated from tongue biofilm of a Thai child and established as a novel Veillonella species. In this study, a species-specific primer was designed to identify V. infantium on the basis of the sequence of the 70 kDa heat shock protein ( dnaK ) gene of Veillonella infantium JCM 31738 T (= TSD-88 T ). The primer pair generated a specific PCR (Polymerase Chain Reaction) product specific for V. infantium , but not for other oral Veillonella species. This specific primer pair could detect dnaK even from 1 pg of genomic DNA extracted from the V. infantium type strain. To validate the primer pair, a number of strains of Veillonella species were isolated from tongue biofilm of 3 Japanese children, DNA was isolated from each strain, and PCR was performed using species-specific primers. All oral Veillonella species except V. infantium were identified by one-step PCR method reported previously. Four kinds of Veillonella species were detected in these subjects. V. rogosae was detected in all subjects and the most predominant species with an average prevalence of 82%. However, V. infantium was detected in 2 of 3 subjects and it was the second most predominant species of oral Veillonella detected in these subjects with an average prevalence of 9.4%. V. infantium appears to coexist with other oral Veillonella species in tongue biofilm. This species-specific primer pair established in this study could be useful to detect V. infantium and support the study of Veillonella for oral health in the future. [ABSTRACT FROM AUTHOR]

Objective: The objective of this study is to determine if the presence of dental infection is associated with an increased likelihood of hospital admission following an emergency department (ED) visit among patients diagnosed with pneumonia. We hypothesized that the presence of a dental infection may worsen the clinical symptoms in ED patients diagnosed with pneumonia and are using hospital admission as a marker of worsening clinical severity. Materials and methods: We analyzed the data from the 2008 Nationwide Emergency Department Sample and used Poisson regression with robust estimates of variance to obtain prevalence ratios (PRs) with the appropriate adjustments for complex survey sampling. Results: In the final multivariable model, there was a 19 % increase in the likelihood of hospital admission following an ED visit among pneumonia patients diagnosed with dental infection compared to those without dental infection (PR = 1.19, 95 % CI = 1.11-1.27). In an exploratory multivariable analysis, pneumonia patients diagnosed with dental caries had a 29 % increase in the likelihood of admission compared to those not having dental caries (PR = 1.29, 95 % CI = 1.23-1.34). These findings remained consistent in a subgroup analysis among patients with less clinically severe forms of pneumonia. Conclusions: Dental infections may worsen the clinical symptoms in ED patients with pneumonia increasing their likelihood for hospital admission. Dental caries may be a marker for poor oral hygiene and increased dental plaque rather than serve directly as a source of respiratory pathogens. Clinical relevance: The findings suggest that an increased focus on preventive oral health may reduce the need for admission following an ED visit for patients diagnosed with pneumonia. [ABSTRACT FROM AUTHOR]

Objective: To investigate the association between the severity of periodontitis (exposure) and dyslipidemia (outcome). Methods: This was a cross‐sectional study of users of public health services. Periodontitis was defined using the Center for Disease Prevention and Control and the American Academy of Periodontology criteria. Lipid evaluation used data on systemic biomarkers. Dyslipidemia diagnosis was based on the Guidelines of total cardiovascular risk of the World Health Organization. Weight, height, waist circumference, and blood pressure were measured, and socioeconomic–demographic, lifestyle behavior factors, general and oral health conditions of the participants were collected. Hierarchical and logistic regression analyzes were used to determine the association between the exposures and the outcome. Odds Ratios, unadjusted and adjusted, and 95% confidence intervals were estimated. Results: Of 1,011 individuals examined, 75.17% had dyslipidemia, and 84.17% had periodontitis, 0.2% with mild, 48.56% moderate, and 35.41% severe disease. The association between periodontitis and dyslipidemia was maintained through hierarchical analysis and in the multiple regression modeling, showing that the occurrences of dyslipidemia in the group with periodontitis, and its moderate and severe levels, were, respectively, 14%, 30%, and 16% higher compared with those without periodontitis. Conclusions: The results showed a positive association between moderate and severe periodontitis and dyslipidemia. [ABSTRACT FROM AUTHOR]

Aim To critically appraise recent research into associations between periodontal disease and systemic diseases and conditions specifically respiratory disease, chronic kidney disease, rheumatoid arthritis, cognitive impairment, obesity, metabolic syndrome and cancer. Methods A MEDLINE literature search of papers published between 2002 and April 2012 was conducted. Studies that included periodontitis as an exposure were identified. Cross-sectional epidemiological investigations on large samples, prospective studies and systematic reviews formed the basis of the narrative review. A threshold set for the identification of periodontitis was used to identify those studies that contributed to the conclusions of the review. Results Many of the investigations were cross-sectional secondary analyses of existing data sets in particular the NHANES studies. There were a small number of systematic reviews and prospective studies. There was substantial variability in the definitions of exposure to periodontitis. A small number of studies met the threshold set for periodontitis and supported associations; however, in some of the chronic diseases there were no such studies. There was strong evidence from randomized controlled trials that interventions, which improve oral hygiene have positive effects on the prevention of nosocomial pneumonias. Conclusions There was substantial heterogeneity in the definitions used to identify periodontitis and very few studies met a stringent threshold for periodontitis. Published evidence supports modest associations between periodontitis and some, although not all, of the diseases and conditions reviewed. There is a need to reach a consensus on what constitutes periodontitis for future studies of putative associations with systemic diseases. [ABSTRACT FROM AUTHOR]

α-Amylase-binding streptococci (ABS) are a heterogeneous group of commensal oral bacterial species that comprise a significant proportion of dental plaque microfloras. Salivary α-amylase, one of the most abundant proteins in human saliva, binds to the surface of these bacteria via specific surface-exposed α-amylase-binding proteins. The functional significance of α-amylase-binding proteins in oral colonization by streptococci is important for understanding how salivary components influence oral biofilm formation by these important dental plaque species. This review summarizes the results of an extensive series of studies that have sought to define the molecular basis for α-amylase binding to the surface of the bacterium as well as the biological significance of this phenomenon in dental plaque bioflim formation. [ABSTRACT FROM AUTHOR]

Candida albicans often resides in the oral cavity of healthy humans as a harmless commensal organism. This opportunistic fungus can cause significant disease in critically ill patients, such as those undergoing mechanical ventilation in the intensive care unit (ICU) having compromised local airway defense mechanisms. The goal of this study was to determine the intra- and inter-patient genetic relationship between strains of C. albicans recovered from dental plaque, tracheal secretions, and the lower airway by bronchoalveolar lavage of patients undergoing mechanical ventilation. Three pulsed-field gel electrophoresis (PFGE) typing methods were used to determine the genetic relatedness of the C. albicans strains, including electrophoretic karyotyping (EK) and restriction endonuclease analysis of the genome using SfiI (REAG-S) and BssHII (REAG-B). The C. albicans isolates from dental plaque and tracheo-bronchial sites from the same patient were genetically indistinguishable and retained over time, whereas strains from different patients usually separated into different genotypes. Among the three methods, REAG-B proved to be the most discriminatory method to differentiate isolates. The finding of genetically similar strains from the oral and tracheo-bronchial sites from the same patient supports the notion that the oral cavity may serve as an important source for C. albicans spread to the trachea and lung of mechanically ventilated patients. [ABSTRACT FROM AUTHOR]

El artículo trata la relación de la placa dental y la enfermedad periodontal con la neumonía asociada a la residencia, neumonía intrahospitalaria y neumonía asociada a un respirador. Describe la epidemiología, patogenia y tratamiento de la neumonía. Sugiere que la placa dental y la enfermedad periodontal se asocian con varios tipos de neumonía. Nota que los organismos patógenos respiratorios colonizan la placa dental de los pacientes hospitalizados con enfermedades pulmonares crónicas.

The article offers information on the recent concepts concerning the pathogenesis, risk factors, microbial etiology, epidemiology, diagnosis and treatment of the different types of pneumonia. It discusses the role of dental biofilms and periodontal inflammation on the development of various types of pneumonia including hospital-acquired pneumonia, ventilator-associated pneumonia and home-associated pneumonia.

Objectives: The role of the viridans group of streptococci (Streptococcus oralis) in the prevention of colonization with Streptococcus pneumoniae was investigated in an adenoid organ culture system. Methods: The adenoids from 10 patients who were undergoing adenoidectomy for either hypertrophy or recurrent otitis media were used. Results: Streptococcus oralis Parker and S oralis Booth (two organisms isolated from the nasopharynges of patients undergoing adenoidectomy only and patients undergoing adenoidectomy and bilateral tympanostomy with tubes, respectively) uniformly inhibited both penicillin-sensitive and penicillin-resistant S pneumoniae. Although both strains of S oralis inhibited the growth of both S pneumoniae strains, strain Parker provided more complete inhibition than did strain Booth. Conclusions: The results indicate that some strains of S oralis may inhibit the growth of the most serious pathogens in the nasopharynx. It is therefore possible that colonization of inhibitory strains of viridans streptococci may be used in the nasopharynx as a relatively safe and inexpensive approach to prevention of recurrent otitis media in some children and of recurrent suppurative sinusitis in both children and adults. [ABSTRACT FROM AUTHOR]

Fresh isolates of the oral bacterial pathogen Actinobacillus actinomycetemcomitans exhibit a fimbriated, rough colony phenotype. Evidence suggests that the fimbrial subunit gene flp is part of a cluster of 14 genes (flp to tadG) thought to encode proteins involved in the synthesis, assembly and export of these fimbriae. To determine the transcriptional organization of the 5' terminus of this gene cluster, total RNA from rough and smooth phenotype variants of A. actinomycetemcomitans strain 283 were analysed by RT-PCR. Primers designed to amplify regions spanning gene junctions or multiple genes yielded ampticons at each individual gene junction from flp to tadD for both the rough and smooth variants. Semi-quantitative RT-POR of the rcpA to tadZ amplicon revealed that significantly more mRNA was transcribed from the rough than the smooth variant. Longer amplicons encompassing flp to tadZ(3.9 kb) and tadA to tadD (2·1 kb) were also detected, but only from the rough variant. Rapid amplification of cDNA ends (RACE) was used to identify the 5' end of the mRNA containing flp. Antisense primers located within rcpC, orfB and flp-2 enabled amplification of a RACE product that was subsequently isolated and subcloned into pGEM-T. DNA sequencing indicated that the 5' end of the mRNA was located at a G or T nucleotide -102 to -101 nt upstream of tip. Corresponding σ[sup 70] consensus sequences were located at -10 (TATAAT) and -35 (TTGCAT) relative to the transcription start site. These data confirm that the flp gene cluster is an operon transcribed as a polycistronic message commencing from a G or T nucteotide located in the intergenic region upstream of flp. Promoter function of the lip upstream region was confirmed using a lacZ reporter gene construct transformed into Escherichia coli. RT-POR analysis further suggests that although transcription does occur in both the rough and smooth variants, full-length transcripts are rapidly degraded or are significantly... [ABSTRACT FROM AUTHOR]

The binding of salivary amylase to Streptococcus gordonii has previously been shown to involve a 20-kDa amylase-binding protein (AbpA). S. gordonii also releases an 82-kDa protein into the supernatant that binds amylase. To study this 82-kDa component, proteins were precipitated from bacterial culture supernatants by the addition of acetone or purified amylase. Precipitated proteins were separated by SDS–PAGE and transferred to a sequencing membrane. The P2 kDa band was then sequenced, yielding a 25 N-terminal amino acid sequence, CGFIFGRQLTADGSTMFGPTEDYP. Primers derived from this sequence were used in an inverse PCR strategy to clone the full-length gene from S. gordonii chromosomal DNA. An open reading frame of 1959 bp was noted that encoded a 652 amino acid protein having a predicted molecular mass of 80 kDa. The first 24 amino acid residues were consistent with a hydrophobic signal peptide, followed by a 25 amino acid N-terminal sequence that shared identity (24 of 25 residues) with the amino acid sequence of purified AbpB. The abpB gene from strains of S. gordonii was interrupted by allelic exchange with a 420-bp fragment of the abpB gene linked to an erythromycin cassette. The 82-kDa protein was not detected in supernatants from these mutants. These abpB mutants retained the ability to bind soluble amylase. Thus, AbpA, but not AbpB, appears sufficient to be the major receptor for amylase binding to the streptococcal surface. The role of AbpB in bacterial colonization remains to be elucidated. [Copyright &y& Elsevier]

Objective: This study investigated the association between periodontitis severity (exposure) and metabolic syndrome (MetS - outcome), using two criteria for diagnosis of the outcome, since this relationship remains unexplored. Materials and methods: A case-control study was conducted with 870 individuals: 408 with first MetS diagnosis (cases) and 462 without MetS (controls). Participants' general information was obtained using a questionnaire and laboratory data was collected from medical records. Periodontitis severity criteria followed the Center for Disease Control and Prevention: none, mild, moderate, and severe. Odds ratios (OR) and 95% confidence intervals (95% CI) were determined by logistic regression analysis. Results: Findings showed a positive association between moderate and severe periodontitis and MetS: ORadjusted = 1.64 (95% CI: 1.01 to 2.68) and ORadjusted = 1.94 (95% CI: 1.19 to 3.16), respectively, after adjustment for age, sex, schooling level, smoking habit, and cardiovascular disease. The adjusted measurements showed that among individuals with moderate or severe periodontitis, the probability of having MetS was around two times greater than among those without periodontitis, and that the chance was greater among participants with severe periodontitis than those with moderate periodontitis. Conclusion: An association between the severity of periodontal status and MetS was found, suggesting a possible relationship between the two diseases. Clinical relevance: MetS influences the etiology of cardiovascular diseases, one of the leading causes of mortality worldwide. The findings suggest that the greater the severity of periodontitis, the greater is the association magnitude with MetS. The health professional needs to recognize that the importance of periodontal disease may play in MetS. [ABSTRACT FROM AUTHOR]

It is well established that dental plaque on teeth leads to gingivitis and periodontitis, and that several mechanical and chemical methods of plaque control can prevent gingivitis. The aim of the current review is to summarize and synthesize the available scientific evidence supporting practices for mechanical oral hygiene to prevent periodontal diseases. Evidence for contemporary practices of mechanical oral hygiene to prevent periodontal disease relies on studies of gingivitis patients. General recommendations concerning the ideal oral hygiene devices and procedures are still inconclusive. However, toothbrushing and interdental cleaning remain the mainstays of prevention of periodontal diseases. The primary approach requires individually tailored instruction for implementation of a systematic oral hygiene regimen. [ABSTRACT FROM AUTHOR]

Objective: This study estimated the association between stress and periodontitis. Materials and methods: A cross-sectional study was conducted with a sample of 621 individuals. Information about individuals was obtained through a questionnaire. Stress was evaluated using the Perceived Stress Scale. The diagnosis of periodontitis was based on a complete periodontal examination including clinical attachment level, probing depth, and bleeding on probing. Prevalence ratios (PR), crude and adjusted, and their respective 95% confidence intervals (95%CI) were estimated by Poisson regression analysis. Results: In the final sample, 48.47% (301) of the individuals were classified as having stress, of which, 23.92% (72) had the diagnosis of periodontitis. Association measurements between stress and probing depth ≥ 4 mm (PRadjusted = 1.28, 95%CI [1.04 to 1.58]), stress and clinical attachment level ≥ 5 mm (PRadjusted = 1.15, 95%CI [1.01 to 1.31]), and stress and periodontitis (PRadjusted = 1.36, 95%CI [1.01 to 1.83]) showed that the frequency of these outcomes among those exposed to stress was 15–36% higher than those without the condition of stress, after adjustment for age, sex, schooling level, current smoking habit, pulmonary disease, and body mass index. Conclusions: The findings showed positive association between exposure to stress and the presence of periodontitis, reaffirming the need to prevent and control stress. Clinical relevance: Although there are limitations in this study, the results showed that an association exists between stress and periodontitis, signaling the necessity of a multidisciplinary attention when considering the psychological status in the management of oral and general health conditions of the individual. [ABSTRACT FROM AUTHOR]

Objective: To conduct a systematic review and meta‐analysis to evaluate the recent scientific literature addressing the association between periodontitis and asthma, chronic obstructive pulmonary disease (COPD), and pneumonia. Materials and Methods: The search for studies was carried out using MEDLINE/PubMed, EMBASE, Lilacs, Web of Science, Scopus, and SciELO databases, including the gray literature (ProQuest). Reference lists of selected articles were also searched. Studies having varying epidemiological designs assessing the association between periodontitis and respiratory diseases in human subjects were eligible for inclusion. Three independent reviewers performed the selection of articles and data extraction. Fixed and random effects meta‐analysis were performed for the calculation of the association measurements (Odds Ratio—OR) and 95% confidence intervals (95% CI). Results: A total of 3,234 records were identified in the database search, with only 13 studies meeting the eligibility criteria and 10 studies contributed data for meta‐analysis. Using a random effects models periodontitis was associated with asthma: ORadjusted: 3.54 (95% CI: 2.47–5.07), I2 = 0%; with COPD: OR adjusted: 1.78 (95% CI: 1.04–3.05), I2 = 37.9%; and with pneumonia: OR adjusted: 3.21 (95% CI: 1.997–5.17), I2 = 0%. Conclusions: The main findings of this systematic review validated an association between periodontitis and asthma, COPD and pneumonia. [ABSTRACT FROM AUTHOR]

Objective: To evaluate the association between periodontitis and severe asthma, with participants in treatment for severe asthma, controlled by therapy. Methods: A case–control investigation was performed to compare 130 adults with severe asthma with 130 without asthma. Individuals with periodontitis were those with ≥4 teeth with ≥1 site with probing depth ≥4 mm, clinical attachment level ≥3 mm, and bleeding upon probing at the same site. Severe asthma diagnosis was based on Global Initiative for Asthma criteria. Results: Association between exposure to periodontitis and severe asthma was found: ORcrude = 2.98 (95% CI: 1.74–5.11). When confounders were considered, the association between exposure to periodontitis and severe asthma was maintained: ORadjusted = 3.01–3.25. Individuals with periodontitis had about a threefold increased risk of severe asthma than those without periodontitis. Frequency of periodontitis in participants with severe asthma was greater than that of those without asthma (46.6% vs 22.3%, p ≤ .05). Conclusions: Association between periodontitis and severe asthma was observed. Further investigation is required to determine the direction of this relationship. It may be causal, but it may also be a consequence of the immunopathological process that characterizes asthma, or else, consequence of the medication used for treatment. [ABSTRACT FROM AUTHOR]

Objective: This study aims to conduct a systematic review to determine the prevalence of halitosis in adolescents and adults. Methods: Electronic searches were performed using four different databases without restrictions: PubMed, Scopus, Web of Science, and SciELO. Population-based observational studies that provided data about the prevalence of halitosis in adolescents and adults were included. Additionally, meta-analyses, meta-regression, and sensitivity analyses were conducted to synthesize the evidence. Results: A total of 584 articles were initially found and considered for title and abstract evaluation. Thirteen articles met inclusion criteria. The combined prevalence of halitosis was found to be 31.8% (95% CI 24.6-39.0%). Methodological aspects such as the year of publication and the socioeconomic status of the country where the study was conducted seemed to influence the prevalence of halitosis. Conclusions: Our results demonstrated that the estimated prevalence of halitosis was 31.8%, with high heterogeneity between studies. The results suggest a worldwide trend towards a rise in halitosis prevalence. Clinical relevance: Given the high prevalence of halitosis and its complex etiology, dental professionals should be aware of their roles in halitosis prevention and treatment. [ABSTRACT FROM AUTHOR]

Poor oral hygiene often leads to chronic diseases such as periodontitis and dental caries resulting in substantial economic costs and diminished quality of life in not only adults but also in children. In this study, the salivary microbiome was characterized in a group of children stratified by the Simplified Oral Hygiene Index (OHI-S). Illumina MiSeq high-throughput sequencing based on the 16S rRNA was utilized to analyze 90 salivary samples (24 Good, 31 Moderate and 35 Poor oral hygiene) from a cohort of Thai children. A total of 38,521 OTUs (Operational Taxonomic Units) with a 97% similarity were characterized in all of the salivary samples. Twenty taxonomic groups (Seventeen genera, two families and one class; Streptococcus, Veillonella, Gemellaceae, Prevotella, Rothia, Porphyromonas, Granulicatella, Actinomyces, TM-7-3, Leptotrichia, Haemophilus, Selenomonas, Neisseria, Megasphaera, Capnocytophaga, Oribacterium, Abiotrophia, Lachnospiraceae, Peptostreptococcus, and Atopobium) were found in all subjects and constituted 94.5–96.5% of the microbiome. Of these twenty genera, the proportion of Streptococcus decreased while Veillonella increased with poor oral hygiene status (P < 0.05). Furthermore, an unassigned species of Veillonella, Veillonella dispar and Veillonella parvula tended to be elevated in the Poor oral hygiene group. This is the first study demonstrating an important association between increase of Veillonella and poor oral hygiene status in children. However, further studies are required to identify the majority of Veillonella at species level in salivary microbiome of the Poor oral hygiene group. [ABSTRACT FROM AUTHOR]

Background: Successful commensal bacteria have evolved to maintain colonization in challenging environments. The oral viridans streptococci are pioneer colonizers of dental plaque biofilm. Some of these bacteria have adapted to life in the oral cavity by binding salivary a-amylase, which hydrolyzes dietary starch, thus providing a source of nutrition. Oral streptococcal species bind a-amylase by expressing a variety of amylase-binding proteins (ABPs). Here we determine the genotypic basis of amylase binding where proteins of diverse size and function share a common phenotype. Results: ABPs were detected in culture supernatants of 27 of 59 strains representing 13 oral Streptococcus species screened using the amylase-ligand binding assay. N-terminal sequences from ABPs of diverse size were obtained from 18 strains representing six oral streptococcal species. Genome sequencing and BLAST searches using N-terminal sequences, protein size, and key words identified the gene associated with each ABP. Among the sequenced ABPs, 14 matched amylase-binding protein A (AbpA), 6 matched amylase-binding protein B (AbpB), and 11 unique ABPs were identified as peptidoglycan-binding, glutamine ABC-type transporter, hypothetical, or choline-binding proteins. Alignment and phylogenetic analyses performed to ascertain evolutionary relationships revealed that ABPs cluster into at least six distinct, unrelated families (AbpA, AbpB, and four novel ABPs) with no phylogenetic evidence that one group evolved from another, and no single ancestral gene found within each group. AbpA-like sequences can be divided into five subgroups based on the N-terminal sequences. Comparative genomics focusing on the abpA gene locus provides evidence of horizontal gene transfer. Conclusion: The acquisition of an ABP by oral streptococci provides an interesting example of adaptive evolution. [ABSTRACT FROM AUTHOR]

Streptococcus gordonii, a primary colonizer of the tooth surface, interacts with salivary α-amylase via amylase-binding protein A (AbpA). This enzyme hydrolyzes starch to glucose, maltose, and maltodextrins that can be utilized by various oral bacteria for nutrition. Microarray studies demonstrated that AbpA modulates gene expression in response to amylase, suggesting that the amylase-streptococcal interaction may function in ways other than nutrition. The goal of this study was to explore the role of AbpA in gene regulation through comparative transcriptional profiling of wild-type KS1 and AbpA- mutant KS1ΩabpA under various environmental conditions. A portion of the total RNA isolated from mid-log-phase cells grown in 5% CO2 in (i) complex medium with or without amylase, (ii) defined medium (DM) containing 0.8% glucose with/without amylase, and (iii) DM containing 0.2% glucose and amylase with or without starch was reverse transcribed to cDNA and the rest used for RNA sequencing. Changes in the expression of selected genes were validated by quantitative reverse transcription-PCR. Maltodextrin-associated genes, fatty acid synthesis genes and competence genes were differentially expressed in a medium-dependent manner. Genes in another cluster containing a putative histidine kinase/response regulator, peptide methionine sulfoxide reductase, thioredoxin protein, lipoprotein, and cytochrome c-type protein were downregulated in KS1ΩabpA under all of the environmental conditions tested. Thus, AbpA appears to modulate genes associated with maltodextrin utilization/transport and fatty acid synthesis. Importantly, in all growth conditions AbpA was associated with increased expression of a potential two-component signaling system associated with genes involved in reducing oxidative stress, suggesting a role in signal transduction and stress tolerance. [ABSTRACT FROM AUTHOR]

Recent studies suggest that periodontal disease and type 2 diabetes mellitus are bi-directionally associated. Identification of a molecular signature for periodontitis using unbiased metabolic profiling could allow identification of biomarkers to assist in the diagnosis and monitoring of both diabetes and periodontal disease. This cross-sectional study identified plasma and salivary metabolic products associated with periodontitis and/or diabetes in order to discover biomarkers that may differentiate or demonstrate an interaction of these diseases. Saliva and plasma samples were analyzed from 161 diabetic and non-diabetic human subjects with a healthy periodontium, gingivitis and periodontitis. Metabolite profiling was performed using Metabolon's platform technology. A total of 772 metabolites were found in plasma and 475 in saliva. Diabetics had significantly higher levels of glucose and α-hydroxybutyrate, the established markers of diabetes, for all periodontal groups of subjects. Comparison of healthy, gingivitis and periodontitis saliva samples within the non-diabetic group confirmed findings from previous studies that included increased levels of markers of cellular energetic stress, increased purine degradation and glutathione metabolism through increased levels of oxidized glutathione and cysteine-glutathione disulfide, markers of oxidative stress, including increased purine degradation metabolites (e.g. guanosine and inosine), increased amino acid levels suggesting protein degradation, and increased ω-3 (docosapentaenoate) and ω-6 fatty acid (linoleate and arachidonate) signatures. Differences in saliva between diabetic and non-diabetic cohorts showed altered signatures of carbohydrate, lipid and oxidative stress exist in the diabetic samples. Global untargeted metabolic profiling of human saliva in diabetics replicated the metabolite signature of periodontal disease progression in non-diabetic patients and revealed unique metabolic signatures associated with periodontal disease in diabetics. The metabolites identified in this study that discriminated the periodontal groups may be useful for developing diagnostics and therapeutics tailored to the diabetic population. [ABSTRACT FROM AUTHOR]

Abstract: Pseudomonas aeruginosa is an important opportunistic bacterial pathogen, causing infections of respiratory and other organ systems in immunocompromised hosts that may invade and proliferate in mucosal epithelial cells to induce apoptosis. Previous studies suggest that oral bacteria, especially gram-negative periodontal pathogens, may enhance P. aeruginosa invasion into respiratory epithelial cells to augment tissue destruction. In this study, we investigated the effect of the periodontopathogen Porphyromonas gingivalis on P. aeruginosa-induced epithelial cell apoptosis. P. gingivalis invasion transiently inhibited P. aeruginosa-induced apoptosis in respiratory epithelial cells via the signal transducer and activator of transcription 3 (STAT3) signaling pathway. The activated STAT3 up-regulated the downstream anti-apoptotic moleculars survivin and B-cell leukemia-2 (bcl-2). This process was accompanied by down-regulation of pro-apoptosis molecular Bcl-2-associated death promoter (bad) and caspase-3 activity inhibition. In addition, the activation of the STAT3 pathway was affected by P. gingivalis in a dose-dependent manner. Finally, co-invasion of P. aeruginosa and P. gingivalis led to greater cell death compared with P. aeruginosa challenge alone. These results suggest that regulation of P. aeruginosa-induced apoptosis by P. gingivalis contributes to the pathogenesis of respiratory disease. Interference with this process may provide a potential therapeutic strategy for the treatment and prevention of respiratory disease. [Copyright &y& Elsevier]

Summary: Background: Estimating attributable mortality of ventilator-associated pneumonia has been hampered by confounding factors, small sample sizes, and the difficulty of doing relevant subgroup analyses. We estimated the attributable mortality using the individual original patient data of published randomised trials of ventilator-associated pneumonia prevention. Methods: We identified relevant studies through systematic review. We analysed individual patient data in a one-stage meta-analytical approach (in which we defined attributable mortality as the ratio between the relative risk reductions [RRR] of mortality and ventilator-associated pneumonia) and in competing risk analyses. Predefined subgroups included surgical, trauma, and medical patients, and patients with different categories of severity of illness scores. Findings: Individual patient data were available for 6284 patients from 24 trials. The overall attributable mortality was 13%, with higher mortality rates in surgical patients and patients with mid-range severity scores at admission (ie, acute physiology and chronic health evaluation score [APACHE] 20–29 and simplified acute physiology score [SAPS 2] 35–58). Attributable mortality was close to zero in trauma, medical patients, and patients with low or high severity of illness scores. Competing risk analyses could be done for 5162 patients from 19 studies, and the overall daily hazard for intensive care unit (ICU) mortality after ventilator-associated pneumonia was 1·13 (95% CI 0·98–1·31). The overall daily risk of discharge after ventilator-associated pneumonia was 0·74 (0·68–0·80), leading to an overall cumulative risk for dying in the ICU of 2·20 (1·91–2·54). Highest cumulative risks for dying from ventilator-associated pneumonia were noted for surgical patients (2·97, 95% CI 2·24–3·94) and patients with mid-range severity scores at admission (ie, cumulative risks of 2·49 [1·81–3·44] for patients with APACHE scores of 20–29 and 2·72 [1·95–3·78] for those with SAPS 2 scores of 35–58). Interpretation: The overall attributable mortality of ventilator-associated pneumonia is 13%, with higher rates for surgical patients and patients with a mid-range severity score at admission. Attributable mortality is mainly caused by prolonged exposure to the risk of dying due to increased length of ICU stay. Funding: None. [ABSTRACT FROM AUTHOR]

Multiplexing arrays increase the throughput and decrease sample requirements for studies employing multiple biomarkers. The goal of this project was to examine the performance of Multiplex arrays for measuring multiple protein biomarkers in saliva and serum. Specimens from the OsteoPerio ancillary study of the Women’s Health Initiative Observational Study were used. Participants required the presence of at least 6 teeth and were excluded based on active cancer and certain bone issues but were not selected on any specific condition. Quality control (QC) samples were created from pooled serum and saliva. Twenty protein markers were measured on five multiplexing array panels. Sample pretreatment conditions were optimized for each panel. Recovery, lower limit of quantification (LLOQ) and imprecision were determined for each analyte. Statistical adjustment at the plate level was used to reduce imprecision estimates and increase the number of usable observations. Sample pre-treatment improved recovery estimates for many analytes. The LLOQ for each analyte agreed with manufacturer specifications except for MMP-1 and MMP-2 which were significantly higher than reported. Following batch adjustment, 17 of 20 biomarkers in serum and 9 of 20 biomarkers in saliva demonstrated acceptable precision, defined as <20% coefficient of variation (<25% at LLOQ). The percentage of cohort samples having levels within the reportable range for each analyte varied from 10% to 100%. The ratio of levels in saliva to serum varied from 1∶100 to 28∶1. Correlations between saliva and serum were of moderate positive magnitude and significant for CRP, MMP-2, insulin, adiponectin, GM-CSF and IL-5. Multiplex arrays exhibit high levels of analytical imprecision, particularly at the batch level. Careful sample pre-treatment can enhance recovery and reduce imprecision. Following statistical adjustments to reduce batch effects, we identified biomarkers that are of acceptable quality in serum and to a lesser degree in saliva using Multiplex arrays. [ABSTRACT FROM AUTHOR]

Streptococcus gordonii, an important primary colonizer of dental plaque biofilm, specifically binds to salivary amylase via the surface-associated amylase-binding protein A (AbpA). We hypothesized that a function of amylase binding to S. gordonii may be to modulate the expression of chromosomal genes, which could influence bacterial survival and persistence in the oral cavity. Gene expression profiling by microarray analysis was performed to detect genes in S. gordonii strain CH1 that were differentially expressed in response to the binding of purified human salivary amylase versus exposure to purified heat-denatured amylase. Selected genes found to be differentially expressed were validated by quantitative reverse transcription-PCR (qRT-PCR). Five genes from the fatty acid synthesis (FAS) cluster were highly (10- to 35-fold) upregulated in S. gordonii CH1 cells treated with native amylase relative to those treated with denatured amylase. An abpA-deficient strain of S. gordonii exposed to amylase failed to show a response in FAS gene expression similar to that observed in the parental strain. Predicted phenotypic effects of amylase binding to S. gordonii strain CH1 (associated with increased expression of FAS genes, leading to changes in fatty acid synthesis) were noted; these included increased bacterial growth, survival at low pH, and resistance to triclosan. These changes were not observed in the amylase-exposed abpA-deficient strain, suggesting a role for AbpA in the amylase-induced phenotype. These results provide evidence that the binding of salivary amylase elicits a differential gene response in S. gordonii, resulting in a phenotypic adjustment that is potentially advantageous for bacterial survival in the oral environment. [ABSTRACT FROM AUTHOR]

Abstract: Pseudomonas aeruginosa is an important opportunistic bacterial pathogen, causing infections of the respiratory and other organ systems in susceptible hosts. P. aeruginosa infection is initiated by adhesion to and invasion of mucosal epithelial cells. The failure of host defenses to eliminate P. aeruginosa from mucosal surfaces results in P. aeruginosa proliferation, sometimes followed by overt infection and tissue destruction. There is growing evidence that associates poor oral health and respiratory infection. An in vitro model system for bacterial invasion of respiratory epithelial cells was used to investigate the influence of oral bacteria on P. aeruginosa epithelial cell invasion. Oral pathogens including Porphyromonas gingivalis, Fusobacterium nucleatum and Aggregatibacter (Actinobacillus) actinomycetemcomitans increased invasion of P. aeruginosa into HEp-2 cells from one- to threefold. In contrast, non-pathogenic oral bacteria such as Actinomyces naeslundii and Streptococcus gordonii showed no significant influence on P. aeruginosa invasion. P. aeruginosa together with oral bacteria stimulated greater cytokine production from HEp-2 cells than did P. aeruginosa alone. P. aeruginosa in combination with periodontal pathogens also increased apoptosis of HEp-2 cells and induced elevated caspase-3 activity. These results suggest that oral bacteria, especially periodontal pathogens, may foster P. aeruginosa invasion into respiratory epithelial cells to enhance host cell cytokine release and apoptosis. [Copyright &y& Elsevier]

Background. Ventilator-associated pneumonia (VAP) is a leading cause of morbidity and mortality in patients hospitalized in intensive care units. Recent studies suggest that dental plaque biofilms serve as a reservoir for respiratory pathogens. The goal of this study was to determine the genetic relationship between strains of respiratory pathogens first isolated from the oral cavity and later isolated from bronchoalveolar lavage fluid from the same patient undergoing mechanical ventilation with suspected VAP. Methods. Plaque and tracheal secretion samples were obtained on the day of hospital admission and every other day thereafter until discharge from the intensive care unit from 100 patients who underwent mechanical ventilation. Bronchoalveolar lavage was performed for 30 patients with suspected VAP. Pulse-field gel electrophoresis and multilocus sequence typing were used to determine the genetic relatedness of strains obtained from oral, tracheal, and bronchoalveolar lavage samples. Results. Isolates of Staphylococcus aureus, Pseudomonas aeruginosa, Acinetobacter species, and enteric species recovered from plaque from most patients were indistinguishable from isolates recovered from bronchoalveolar lavage fluid (i.e., had >95% similarity of pulse-field gel electrophoresis patterns). Nearly one-half of the Pseudomonas strains showed identical genetic profiles between patients, which suggested a common environmental source of infection. Conclusions. Respiratory pathogens isolated from the lung are often genetically indistinguishable from strains of the same species isolated from the oral cavity in patients who receive mechanical ventilation who are admitted to the hospital from the community. Thus, dental plaque serves as an important reservoir for respiratory pathogens in patients who undergo mechanical ventilation. [ABSTRACT FROM AUTHOR]

Abstract: Objectives: The authors review the biologic characteristics of the oral mucosa. In addition, the authors report a contemporary harvesting technique of the oral mucosa for urethral transplantation, using biologically sound principles, modified by current literature. Methods: We reviewed pertinent English literature from January 1966 through January 1, 2007 regarding the biologic properties of the oral mucosa. Results: The oral mucosa is made up of a thick, nonkeratinized, squamous cell epithelium, overlying a thin lamina propia. It hosts a number of microorganisms, yet, the tissue''s inflammatory response to these organisms is minimal. There are multiple immunologic processes intrinsic to the oral mucosa that makes it impervious to native oral flora colonization. Histologic studies have demonstrated that the oral mucosa is highly compatible with the urethral recipient site, at times being indistinguishable from the surrounding tissue. The harvesting surgeon should closely inspect the oral mucosa for any abnormalities prior to considering harvest. Wound healing in the oral mucosa is ameliorated by sound surgical principles, yet is mediated by biologic processes beyond the surgeon''s control. When harvesting oral mucosa, the surgeon is advised to stay well away from pertinent anatomic landmarks to defer any aesthetic or functional defect to the donor site. Conclusions: Success of the oral mucosa graft for urethral surgery can be partially attributed to the tissue''s biologic properties. When harvesting the tissue, anatomic landmarks should be considered to provide the best possible treatment for the patient while minimizing morbidity to the donor site. [Copyright &y& Elsevier]

This cross-sectional study evaluated the association between radiographic evidence of alveolar bone loss and the concentration of host-derived bone resorptive factors (interleukin-1 beta, tumor necrosis factor-alpha, interleukin-6, prostaglandin-E2), and markers of bone turnover [pyridinoline cross-linked carboxyterminal telopeptide of type I collagen (ICTP), osteocalcin, osteonectin] in stimulated human whole saliva collected from 110 untreated dental patients. Alveolar bone loss scores for each patient were derived from radiographic examination. Variables positively associated with increased bone loss score were: age, current smoking, use of bisphosphonate drugs, and salivary interleukin-1beta levels above the median. Salivary osteonectin levels above the median were associated with a decreased bone loss score. Additional in vitro studies were carried out to determine the fate of interleukin-1beta, interleukin-6 and tumor necrosis factor-alpha added to whole and parotid saliva. All cytokines added to saliva were detected in significantly lower concentrations than when added to buffer alone. Protease inhibitors added to saliva did not prevent the reduction in detection of biomarkers. Variation in time of incubation, repeated cycles of freezing and thawing, or exposure to dimethylsulfoxide did not appreciably affect the measurement of cytokines in saliva. These results suggest that detection of biomarkers by conventional immunoassays may underestimate the actual quantity of molecules in saliva. [ABSTRACT FROM AUTHOR]

Background: Glucosyltransferases (Gtfs), enzymes that produce extracellular glucans from dietary sucrose, contribute to dental plaque formation by Streptococcus gordonii and Streptococcus mutans. The alpha-amylase-binding protein A (AbpA) of S. gordonii, an early colonizing bacterium in dental plaque, interacts with salivary amylase and may influence dental plaque formation by this organism. We examined the interaction of amylase and recombinant AbpA (rAbpA), together with Gtfs of S. gordonii and S. mutans. Results: The addition of salivary alpha-amylase to culture supernatants of S. gordonii precipitated a protein complex containing amylase, AbpA, amylase-binding protein B (AbpB), and the glucosyltransferase produced by S. gordonii (Gtf-G). rAbpA was expressed from an inducible plasmid, purified from Escherichia coli and characterized. Purified rAbpA, along with purified amylase, interacted with and precipitated Gtfs from culture supernatants of both S. gordonii and S. mutans. The presence of amylase and/or rAbpA increased both the sucrase and transferase component activities of S. mutans Gtf-B. Enzyme-linked immunosorbent assay (ELISA) using anti-Gtf-B antibody verified the interaction of rAbpA and amylase with Gtf-B. A S. gordonii abpAdeficient mutant showed greater biofilm growth under static conditions than wild-type in the presence of sucrose. Interestingly, biofilm formation by every strain was inhibited in the presence of saliva. Conclusion: The results suggest that an extracellular protein network of AbpA-amylase-Gtf may influence the ecology of oral biofilms, likely during initial phases of colonization. [ABSTRACT FROM AUTHOR]

Fresh clinical isolates of the periodontal pathogen Actinobacillus actinomycetemcomitans have an adherent, rough colony morphology that transforms into a minimally adherent, smooth colony phenotype during successive in vitro passage. The objectives of this study were: (1) to compare biofilm formation of the rough (RVs) and smooth variants (SVs) of several strains of A. actinomycetemcomitans grown under various environmental conditions and (2) to examine the dynamics of biofilm formation. A microtitre plate biofilm assay was used to evaluate biofilm formation of strains grown in broth with modified salt concentration and pH, and to evaluate the effect of pre-conditioning films. Scanning electron microscopy (SEM) was used to monitor microscopic changes in morphology. Dynamics of biofilm formation were measured in a flowcell monitored by confocal microscopy. The RVs generally produced greater biofilm than the SVs. However, medium-dependent differences in biofilm formation were evident for some rough/smooth pairs. The RVs were more tolerant to changes in salt and pH, and more resistant to chlorhexidine than the SVs. Horse serum virtually eliminated, and saliva significantly reduced, biofilm formation by the SVs in contrast to the RVs. SEM revealed no alteration in morphology with change of environment. In a flowcell, the RVs produced towers of microcolonies anchored by a small contact area, whereas the SVs produced an open architecture of reduced height. After 7 days in a flowcell, the rough to smooth phenotype transition could be demonstrated. In conclusion, strain, growth medium and conditioning film all affect biofilm formation. The RVs produce biofilms of unique architecture that may serve to protect the bacterium from environmental perturbations. [Copyright &y& Elsevier]

Investigates the role of the viridians group streptococci in the prevention of colonization in adenoid culture system. Use of adenoids undergoing adenoidectomy for hypertrophy or otitis media; Inhibition of colonization by streptococcus oralis Parker; Colonization with potential pathogens by S oralis.

MyPro is a software pipeline for high-quality prokaryotic genome assembly and annotation. It was validated on 18 oral streptococcal strains to produce submission-ready, annotated draft genomes. MyPro installed as a virtual machine and supported by updated databases will enable biologists to perform quality prokaryotic genome assembly and annotation with ease. [ABSTRACT FROM AUTHOR]