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Biomedical subjects

Frank A Scannapieco

Publications and source records attributed to Frank A Scannapieco.

At least 19 recordsLinked to original sources
PubMed2006

Pneumonia in nonambulatory patients. The role of oral bacteria and oral hygiene.

BACKGROUND: Considerable evidence exists to support a relationship between poor oral health, the oral microflora and bacterial pneumonia, especially ventilator-associated pneumonia in institutionalized patients. Teeth or dentures have nonshedding surfaces on which oral biofilms (that is, dental plaque) form that are susceptible to colonization by respiratory pathogens. Subsequent aspiration of respiratory pathogens shed from oral biofilms into the lower airway increases the risk of developing a lung infection. In addition, patients may aspirate inflammatory products from inflamed periodontal tissues into the lower airway, contributing to lung insult. TYPES OF STUDIES REVIEWED: The author reviewed laboratory studies, clinical trials and review articles. CONCLUSIONS: A number of studies have shown that the mouth can be colonized by respiratory pathogens and serve as a reservoir for these organisms. Other studies have demonstrated that oral interventions aimed at controlling or reducing oral biofilms can reduce the risk of pneumonia in high-risk populations. Taken together, the evidence is substantial that improved oral hygiene may prevent pneumonia in vulnerable patients. CLINICAL IMPLICATIONS: Institution of rigorous oral hygiene regimens for hospitalized patients and long-term-care residents may reduce the risk of developing pneumonia.

Aged↗
PubMed2006

Inhibition of proinflammatory activities of major periodontal pathogens by aqueous extracts from elder flower (Sambucus nigra).

BACKGROUND: Prolonged induction of excessive levels of inflammatory mediators contributes to the pathogenesis of chronic disease states, such as periodontitis. It is thus important to develop safe and effective anti-inflammatory strategies for therapeutic reasons. In this study, we determined the ability of aqueous extracts from elder flower (Sambucus nigra) to inhibit the proinflammatory activity of major virulence factors from the periodontal pathogens Porphyromonas gingivalis and Actinobacillus actinomycetemcomitans. METHODS: Monocytes/macrophages or neutrophils were incubated with whole cells of P. gingivalis, A. actinomycetemcomitans, or purified components thereof (lipopolysaccharide and fimbriae) in the absence or presence of elder flower extract and were assayed for cytokine production, integrin activation, or induction of the oxidative burst. RESULTS: The elder flower extract was found to potently inhibit all proinflammatory activities tested. Investigation of the underlying mechanisms revealed that the anti-inflammatory extract inhibited activation of the nuclear transcription factor kappaB and of phosphatidylinositol 3-kinase. CONCLUSION: The elder flower extract displays useful anti-inflammatory properties that could be exploited therapeutically for the control of inflammation in human periodontitis.

Aggregatibacter actinomycetemcomitans↗
PubMed2006

Supragingival plaque may modify the effects of subgingival bacteria on attachment loss.

BACKGROUND: Bacterial interactions in response to local and systemic factors may explain important features of the pathogenesis of periodontal disease. This study evaluates the role of supragingival plaque level on the relationship between subgingival microorganisms and the risk of attachment loss. METHODS: The study population consisted of 386 white women aged 45 years and older who had at least seven teeth. Subgingival plaque samples were taken from the mesio-buccal surface of six maxillary and six mandibular teeth using paper point technique. The samples were pooled, and immunofluorescence microscopy was performed to identify the following target microorganisms: Actinobacillus actinomycetemcomitans (Aa), Tannerella forsythensis (Tf), Campylobacter rectus (Cr), Prevotella intermedia (Pi), Capnocytophaga species (Cs), Porphyromonas gingivalis (Pg), Eubacterium saburreum (Es), and Fusobacterium nucleatum (Fn). The presence or absence of supragingival plaque and clinical attachment loss (CAL) were assessed at the same 12 sites where subgingival plaque samples were taken. The association of each microorganism with CAL was tested using multiple logistic regressions controlling for age, smoking status, and diabetes. Odds ratios (OR) and their 95% confidence intervals (CI) were calculated. RESULTS: At low supragingival plaque levels, only the presence of Pg was significantly associated with CAL (OR: 6.41, 95% CI: 1.30 to 31.70); all remaining microorganisms were also associated with increased but non-significant risk of CAL. At high supragingival plaque levels, the presence of Tf (OR: 2.40, 95% CI: 1.42 to 4.04) and Pg (OR: 3.71, 95% CI: 1.63 to 8.42) was significantly associated with increased risk of attachment loss. By contrast, the presence of Cs (OR: 0.55, 95% CI: 0.30 to 1.01) and Es (OR: 0.35, 95% CI: 0.15 to 0.82) was associated with decreased risk of attachment loss. Fn, Pi, and Cr were not significantly associated with CAL at either low or high supragingival plaque levels. CONCLUSIONS: This study suggests that the association of certain subgingival microorganisms with CAL changes in relation to supragingival plaque levels in older adult women. It also suggests that the overall effect of dental plaque is a function of the balance between pathogenic and other microorganisms that colonize this environment. Therefore, all microorganisms in the biofilm, including those with no apparent association with overt disease and those with negative associations, may play roles in the pathogenesis of periodontal diseases.

Aged↗
PubMed2005

Environmental influences on Actinobacillus actinomycetemcomitans biofilm formation.

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.

Aggregatibacter actinomycetemcomitans↗
PubMed2005

Systemic effects of periodontal diseases.

A number of studies suggest an association between periodontal disease and cardiovascular disease, pulmonary disease, diabetes,and pregnancy complications. Presently, the data must be regarded as preliminary. Additional large-scale longitudinal epidemiologic and interventional studies are necessary to validate these associations and to determine whether the associations are causal. The goal of this article is to review the history of this concept, describe the biologically plausible circumstances that may underlie these potential associations, and provide a summary of the published literature that supports or refutes them.

Cardiovascular Diseases↗
PubMed2004

Exposure to the dental environment and prevalence of respiratory illness in dental student populations.

OBJECTIVE: To determine if the prevalence of respiratory disease among dental students and dental residents varies with their exposure to the clinical dental environment. METHODS: A detailed questionnaire was administered to 817 students at 3 dental schools. The questionnaire sought information concerning demographic characteristics, school year, exposure to the dental environment and dental procedures, and history of respiratory disease. The data obtained were subjected to bivariate and multiple logistic regression analysis. RESULTS: Respondents reported experiencing the following respiratory conditions during the previous year: asthma (26 cases), bronchitis (11 cases), chronic lung disease (6 cases), pneumonia (5 cases) and streptococcal pharyngitis (50 cases). Bivariate statistical analyses indicated no significant associations between the prevalence of any of the respiratory conditions and year in dental school, except for asthma, for which there was a significantly higher prevalence at 1 school compared to the other 2 schools. When all cases of respiratory disease were combined as a composite variable and subjected to multivariate logistic regression analysis controlling for age, sex, race, dental school, smoking history and alcohol consumption, no statistically significant association was observed between respiratory condition and year in dental school or exposure to the dental environment as a dental patient. CONCLUSION: No association was found between the prevalence of respiratory disease and a student's year in dental school or previous exposure to the dental environment as a patient. These results suggest that exposure to the dental environment does not increase the risk for respiratory infection in healthy dental health care workers.

Air Microbiology↗
PubMed2004

Perceptions of dental schools from within and outside the university.

Perceptions of dental schools held by high-level administrators of their parent institutions and officials in the local community have great potential to influence the future of dental education. The intent of this investigation was to gain a preliminary knowledge of such perceptions at seven institutions in the United States and to use this information to formulate hypotheses that can provide the basis for further targeted investigations that provide evidence useful in decision making and planning processes within dental schools. Interviews with university administrators, executive directors of state dental associations, and state government officials in seven areas of the United States were conducted. The hypotheses drawn from these interviews are: 1) dental schools are generally too insular and need to interact more with their parent institutions and external community; 2) dental schools need to systematically and continually get the message of the value of their services out to the public and political constituencies; and 3) multidisciplinarity and integration with other units are important to university administrators but largely outside the concerns of those external to the university. We suggest that these hypotheses form the basis of subsequent, more targeted, follow-up investigations with the intent of formulating specific recommendations for action.

Administrative Personnel↗
PubMed2004

Periodontal inflammation: from gingivitis to systemic disease?

There has been a resurgence of interest in recent years in the systemic effects of oral infections such as periodontal diseases. The study of the various means by which periodontal infections and inflammation may influence a variety of systemic conditions is collectively referred to as periodontal medicine. The periodontium responds to tooth-borne biofilm (dental plaque) by the process of inflammation. Dental biofilms release a variety of biologically active products, such as bacterial lipopolysaccharides (endotoxins), chemotactic peptides, protein toxins, and organic acids. These molecules stimulate the host to produce a variety of responses, among them the production and release of potent agents known as cytokines. These include interleukin-1 beta, interleukin-8, prostaglandins, and tumor necrosis factor-alpha. There is a spectrum of periodontal response to these molecules, from mild gingivitis to severe destructive periodontitis. These and other host products and responses may influence a variety of important disease pathways, including atherosclerosis, mucosal inflammation, and premature parturition. The purpose of this article is to review the possible biological pathways by which periodontal diseases may influence these disease processes.

Animals↗
PubMed2003

Molecular analysis of bacterial flora associated with chronically inflamed maxillary sinuses.

Chronic maxillary sinusitis is a chronic inflammatory condition in which the role of microbial infection remains undefined. Bacteria have been isolated from chronically inflamed sinuses; however, their role in the chronicity of inflammation is unknown. The objective of this study was to determine whether bacteria are present in clinical samples from chronic maxillary sinusitis and to assess the diversity of the flora present. Washes and/or tissue samples from endoscopic sinus surgery on 11 patients with chronic maxillary sinusitis were subjected to PCR amplification of bacterial 16S rDNA using three universal primer pairs, followed by cloning and sequencing. The samples were also assessed for the presence of bacteria and fungi by conventional culture methods. Viable bacteria and/or bacterial 16S rDNA were detected from maxillary sinus samples of five of the 11 patients examined (45 %). Three sinus samples were positive by both PCR and culture methods, one was positive only by PCR, and one only by culture. Thirteen bacterial species were identified: Abiotrophia defectiva, Enterococcus avium, Eubacterium sp., Granulicatella elegans, Neisseria sp., Prevotella sp., Pseudomonas aeruginosa, Serratia marcescens, Staphylococcus aureus, Stenotrophomonas maltophilia, Streptococcus gordonii, Streptococcus mitis/Streptococcus oralis and Streptococcus sp. Fungi were not detected. In one patient Streptococcus mitis/Streptococcus oralis, and in another patient Pseudomonas aeruginosa, were detected from both the sinus and the oral cavity using species-specific PCR primers. These results suggest that both aerobic and anaerobic bacteria can be detected in nearly half of chronic maxillary sinusitis cases.

Bacteria↗
PubMed2003

Transcriptional analysis of the 5' terminus of the flp fimbrial gene cluster from Actinobacillus actinomycetemcomitans.

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 amplicons at each individual gene junction from flp to tadD for both the rough and smooth variants. Semi-quantitative RT-PCR 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 flp. Corresponding sigma(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 nucleotide located in the intergenic region upstream of flp. Promoter function of the flp upstream region was confirmed using a lacZ reporter gene construct transformed into Escherichia coli. RT-PCR analysis further suggests that although transcription does occur in both the rough and smooth variants, full-length transcripts are rapidly degraded or are significantly downregulated in the smooth variant.

5' Untranslated Regions↗
PubMed2003

Associations between periodontal disease and risk for atherosclerosis, cardiovascular disease, and stroke. A systematic review.

BACKGROUND: Recent studies implicate exposure to systemic conditions involving chronic inflammation, including chronic periodontitis, in the etiology of atherosclerosis. RATIONALE: A systematic review of the literature was conducted to assess the association between chronic inflammatory periodontal disease and atherosclerosis. FOCUSED QUESTION: Does periodontal disease influence the initiation/progression of atherosclerosis and, therefore, cardiovascular disease (CVD), stroke, and peripheral vascular disease (PVD)? SEARCH PROTOCOL: MEDLINE, pre-MEDLINE, MEDLINE Daily Update, and the Cochrane Controlled Trials Register were searched to identify human studies that related variables associated with atherosclerosis to periodontal disease. Searches were made for papers published from 1966 through March 2002. INCLUSION CRITERIA: Published randomized controlled clinical trials (RCTs), longitudinal, cohort, and case-control studies were included. Study participants included those with atherosclerosis, myocardial infarction (MI), stroke, or PVD. Oral conditions included periodontal disease. EXCLUSION CRITERIA: Only studies on humans were included. DATA COLLECTION AND ANALYSIS: Because the studies used different oral assessment measures, it was not possible to perform a meta-analysis of the data reported. Weighted mean differences, relative risks, or odds ratios were compared for cohort studies. MAIN RESULTS: 1. Of the initial 1,526 studies identified, 31 (including 8 case-control and 18 cross-sectional reports) were included in the analysis. Taken together, most of the literature supports a modest association between periodontal disease and atherosclerosis. However, data reported in several studies do not show this association. 2. The absence of a standard definition and measures for periodontal disease complicates interpretation of results, as do potential confounding risk factors common to both conditions. REVIEWERS' CONCLUSIONS: 1. Periodontal disease may be modestly associated with atherosclerosis, MI, and CVD. 2. Additional large-scale longitudinal epidemiologic and intervention studies are necessary to validate this association and to determine causality.

Arteriosclerosis↗
PubMed2003

Associations between periodontal disease and risk for nosocomial bacterial pneumonia and chronic obstructive pulmonary disease. A systematic review.

BACKGROUND: Several recent studies provide evidence that the oral cavity may influence the initiation and/or the progression of lung diseases such as pneumonia and chronic obstructive pulmonary disease (COPD). RATIONALE: Studies have shown that poor oral hygiene and periodontal disease may foster colonization of the oropharyngeal region by respiratory pathogens, particularly in hospital or nursing home patients. If aspirated, these pathogens can cause pneumonia, one of the most common respiratory infections, especially in institutionalized subjects. Other cross-sectional epidemiologic studies point to an association between periodontal disease and COPD. This systematic review examines the literature to determine if interventions that improve oral hygiene reduce the rate of pneumonia in high-risk populations. FOCUSED QUESTION: Do periodontal diseases or other indicators of poor oral health influence the initiation/progression of pneumonia or other lung diseases? SEARCH PROTOCOL: MEDLINE, pre-MEDLINE, MEDLINE Daily Update, and the Cochrane Controlled Trials Register were searched to identify published studies that related variables associated with pneumonia and other lung disease to periodontal disease. Searches were performed for articles published in English from 1966 through March 2002. INCLUSION CRITERIA: Randomized controlled clinical trials (RCTs), longitudinal, cohort, and case-control studies were included. Study populations included patients with any form of pneumonia or chronic obstructive pulmonary disease (COPD) and periodontal disease, as measured by assessments of gingival inflammation, probing depth, clinical attachment level, and/or radiographic bone loss, or oral hygiene indices. EXCLUSION CRITERIA: Limited to studies of humans. DATA COLLECTION AND ANALYSIS: The summary statistics used to analyze the RCTs included weighted mean differences in rates of disease between control and intervention groups. For cohort studies that measured differences in rates of disease between groups with and without oral disease, weighted mean differences, relative risks, or odds ratios were compared. A meta-analysis was performed on the 5 intervention studies to determine the relationship between oral hygiene intervention and rate of pneumonia in institutionalized patients. MAIN RESULTS: Of the initial 1,688 studies identified, 36 satisfied all inclusion criteria and were read. Of these, 21 (11 case-control and cohort studies [study population 1,413] and 9 RCTs [study population 1,759]) were included in the analysis. 1. A variety of oral interventions improving oral hygiene through mechanical and/or topical chemical disinfection or antibiotics reduced the incidence of nosocomial pneumonia by an average of 40%. 2. Several studies demonstrated a potential association between periodontal disease and COPD. REVIEWERS' CONCLUSIONS: 1. Oral colonization by respiratory pathogens, fostered by poor oral hygiene and periodontal diseases, appears to be associated with nosocomial pneumonia. 2. Additional large-scale RCTs are warranted to provide the medical community with further evidence to institute effective oral hygiene procedures in high-risk patients to prevent nosocomial pneumonia. 3. The results associating periodontal disease and COPD are preliminary and large-scale longitudinal and epidemiologic and RCTs are needed.

Consensus↗
PubMed2003

Periodontal disease as a risk factor for adverse pregnancy outcomes. A systematic review.

BACKGROUND: Recent studies have implicated a variety of infections, including periodontal diseases, as risk factors for adverse pregnancy outcomes such as prematurity and low birth weight. RATIONALE: A number of studies have shown that bacterial vaginosis is related to preterm and/or low birth weight (PT/LBW), which continues to be a significant cause of infant morbidity and mortality. It is also possible that other infectious processes, including periodontal diseases, contribute to PT/LBW. This systematic review examines the literature to determine the possible relationship between PT/LBW and periodontal diseases. FOCUSED QUESTION: Does prevention/control of periodontal disease as compared to controls have an impact on the initiation/progression of adverse pregnancy outcomes? SEARCH PROTOCOL: MEDLINE, pre-MEDLINE, MEDLINE Daily Update, and the Cochrane Oral Controlled Trials Register were searched to identify published studies that related variables associated with PT/LBW and periodontal disease. Searches were performed for articles published through October 2002. INCLUSION CRITERIA: Randomized controlled clinical trials (RCTs), case-control, and cohort studies were included. Study populations included mothers, with or without periodontal disease, who gave birth to preterm and/or mature infants. The interventions considered included all forms of periodontal therapy. EXCLUSION CRITERIA: Only studies on humans were included. DATA COLLECTION AND ANALYSIS: Due to study heterogeneity, meta-analysis was not possible. MAIN RESULTS: 1. Of the over 660 studies identified, 12 (6 case-control, 3 cross-sectional and longitudinal, and 3 intervention) met inclusion and exclusion criteria and were included in the analysis. 2. While several studies implicated periodontal disease as a risk factor for PT/LBW, few assessed the impact of the prevention and treatment of periodontal disease on outcomes. 3. Several epidemiologic studies did not support periodontal disease as a risk factor for PT/LBW. REVIEWERS' CONCLUSIONS: 1. Periodontal disease may be a risk factor for PT/LBW. 2. Additional longitudinal, epidemiologic, and interventional studies are needed to validate this association and to determine whether it is causal. 3. It is not yet clear whether periodontal diseases play a causal role in adverse pregnancy outcomes. 4. Preliminary evidence to date suggests that periodontal intervention may reduce adverse pregnancy outcomes.

Consensus↗
PubMed2002

Identification and analysis of the amylase-binding protein B (AbpB) and gene (abpB) from Streptococcus gordonii.

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.

Amino Acid Sequence↗
PubMed1998

Identification and analysis of a gene (abpA) encoding a major amylase-binding protein in Streptococcus gordonii.

Oral streptococci such as Streptococcus gordonii bind the abundant salivary enzyme alpha-amylase. This interaction may be important in dental plaque formation and metabolism, thus contributing to the initiation and progression of dental caries and periodontal disease, the two most common plaque-mediated diseases. The conjugative transposon Tn916 was used to insertionally inactivate gene(s) essential to the expression of amylase-binding components of S. gordonii Challis, and a mutant deficient in amylase-binding (Challis Tn1) was identified. While wild-type strains of S. gordonii released both 20 kDa and 82 kDa amylase-binding proteins into culture supernatants, Challis Tn1 expressed the 82 kDa but not the 20 kDa protein. The 20 kDa amylase-binding protein was isolated from culture supernatants of S. gordonii Challis by hydroxyapatite chromatography. A partially purified, functionally active 20 kDa protein was sequenced from blots, and the N-terminal sequence obtained was found to be DEP(A)TDAAT(R)NND. A novel strategy, based on the single-specific-primer polymerase chain reaction technique, enabled the gene inactivated by Tn916 to be cloned. Analysis of the resultant nucleotide sequence revealed an open reading frame of 585 bp, designated amylase-binding protein A (abpA), encoding a protein of 20 kDa (AbpA), immediately downstream from the insertion site of Tn916. This protein possessed a potential signal peptide followed by a region having identity with the N-terminal sequence of the 20 kDa amylase-binding protein. These results demonstrate the role of the 20 kDa protein in the binding of amylase to S. gordonii. Knowledge of the nature of amylase-binding proteins may provide a better understanding of the role of these proteins in the colonization of S. gordonii in the oral cavity.

Amino Acid Sequence↗