Incidence of bacteremia after chewing, tooth brushing and scaling in individuals with periodontal inflammation

Biological Safe Gold Nanoparticle-Modified Dental Aligner Prevents the Porphyromonas gingivalis Biofilm Formation

Oral microbiology could directly influence overall health. Porphyromonas gingivalis (P. gingivalis) is a highly pathogenic bacterium that causes periodontitis and other related systematic diseases, including Alzheimer's disease. Orthodontic devices (e.g., invisalign aligner) is commonly used in populations with periodontitis who are also at a high risk of systematic diseases. In this study, newly explored antibacterial 4,6-diamino-2-pyrimidinethiol-modified gold nanoparticles (AuDAPT) were coated onto aligners. The coated aligners showed favorable antibacterial activity against P. gingivalis. In the presence of the coated aligner, the number of planktonic cells was decreased, and biofilm formation was prevented. This material also showed favorable biocompatibility in vivo and in vitro. This study reveals a new method for treating oral P. gingivalis by coating aligners with AuDAPT, which has typical advantages compared to other treatments for both periodontitis and related systematic diseases.

Further evidence on the relationship between abdominal aortic aneurysm and periodontitis: A cross-sectional study

BACKGROUND

Periodontitis is a chronic inflammatory disease characterized by Gram-negative bacteria responsible for the degradation of tissues surrounding tooth. Moreover, periopathogens can invade the bloodstream, disseminate and promote cardiovascular disease, such as the link between Porphyromonas gingivalis and atherosclerosis. The aim of this study was to explore the relationship between the severity of periodontitis and of abdominal aortic aneurysm (AAA).

METHODS

This cross-sectional study compared patients with stable AAA (n = 30) and patients with unstable AAA (n = 31) based on aortic diameter, growth rate, and eligibility for surgical intervention. Periodontal clinical parameters were recorded as well as the Periodontal Inflamed Surface Area and the Periodontal Index for Risk of Infectiousness (PIRI). Microbiological analyses were performed on saliva and supragingival and subgingival plaque. Quantification of Tannerella forsythia (Tf), Porphyromonas gingivalis (Pg), Aggregatibacter actinomycetemcomitans (Aa), Fusobacterium nucleatum (Fn), and Prevotella intermedia (Pi) was done by quantitative polymerase chain reaction.

RESULTS

The two AAA groups were homogeneous for age, sex, and most risk factors except hypertension and chronic obstructive pulmonary disease. Periodontal parameters were comparable but the proportion of patients with high PIRI scores was greater in those with unstable AAA (51.6% versus 23.3%). The probing depth (PD) and the proportion of PD >6 mm were positively correlated with AAA size and thrombus volume. Several associations were found between periopathogens such as Pg and AAA diameters and volumes, but no difference could be evidenced between stable and unstable AAA groups.

CONCLUSIONS

Periodontitis was highly prevalent in both stable and unstable AAA patients. Severe and progressive periodontitis (stage IV and grade C) tended to be more frequent in the group of patients with unstable AAA. Moreover, Pg was observed in all the samples (saliva, supragingival, and subgingival plaque) and was correlated with AAA diameters and volumes. The study evidenced potential relationships between periodontitis severity and size of AAA.

Periodontal Disease and Periodontal Disease-Related Bacteria Involved in the Pathogenesis of Alzheimer's Disease

Alzheimer’s disease (AD) is the most common cause of dementia, and it exhibits pathological properties such as deposition of extracellular amyloid β (Aβ) and abnormally phosphorylated Tau in nerve cells and a decrease of synapses. Conventionally, drugs targeting Aβ and its related molecules have been developed on the basis of the amyloid cascade hypothesis, but sufficient effects on the disease have not been obtained in past clinical trials. On the other hand, it has been pointed out that chronic inflammation and microbial infection in the brain may be involved in the pathogenesis of AD. Recently, attention has been focused on the relationship between the periodontopathic bacterium Porphylomonas gingivalis and AD. P. gingivalis and its toxins have been detected in autopsy brain tissues from patients with AD. In addition, pathological conditions of AD are formed or exacerbated in mice infected with P. gingivalis. Compounds that target the toxins of P. gingivalis ameliorate the pathogenesis of AD triggered by P. gingivalis infection. These findings indicate that the pathological condition of AD may be regulated by controlling the bacteria in the oral cavity and the body. In the current aging society, the importance of oral and periodontal care for preventing the onset of AD will increase.

Improved oral hygiene is associated with decreased risk of new-onset diabetes: a nationwide population-based cohort study

AIMS/HYPOTHESIS

Inflammation plays an important role in the development of diabetes, a major global health problem. Periodontal disease is also common in the general population. Because periodontal disease and poor oral hygiene can provoke transient bacteraemia and systemic inflammation, we hypothesised that periodontal disease and oral hygiene indicators would be associated with the occurrence of new-onset diabetes.

METHODS

In this study we analysed data collected between 2003 and 2006 on 188,013 subjects from the National Health Insurance System-Health Screening Cohort (NHIS-HEALS) in Korea who had no missing data for demographics, past medical history, oral hygiene indicators or laboratory findings. The presence of periodontal disease was defined on the basis of a modified version of ICD-10 codes (Korean Classification of Disease, sixth edition), if claims for treatment for acute periodontitis (K052), chronic periodontitis (K053) and periodontosis (K054) were made more than two times by a dentist, or if, according to medical records, subjects received treatment by a dentist for periodontal disease with ICD-10 codes K052, K053 or K054. Oral hygiene behaviours (number of tooth brushings, a dental visit for any reason and professional dental cleaning) were collected as self-reported data of dental health check-ups. Number of missing teeth was ascertained by dentists during oral health examination. The incidence of new-onset diabetes was defined according to ICD-10 codes E10-E14. The criterial included at least one claim per year for both visiting an outpatient clinic and admission accompanying prescription records for any glucose-lowering agent, or was based on a fasting plasma glucose ≥7 mmol/l from NHIS-HEALS.

RESULTS

Of the included subjects, 17.5% had periodontal disease. After a median follow-up of 10.0 years, diabetes developed in 31,545 (event rate: 16.1%, 95% CI 15.9%, 16.3%) subjects. In multivariable models, after adjusting for demographics, regular exercise, alcohol consumption, smoking status, vascular risk factors, history of malignancy and laboratory findings, the presence of periodontal disease (HR 1.09, 95% CI 1.07, 1.12, p < 0.001) and number of missing teeth (≥15 teeth) remained positively associated with occurrence of new-onset diabetes (HR 1.21, 95% CI 1.09, 1.33, p < 0.001, p for trend <0.001). Frequent tooth brushing (≥3 times/day) was negatively associated with occurrence of new-onset diabetes (HR 0.92, 95% CI 0.89, 0.95, p < 0.001, p for trend <0.001).

CONCLUSIONS/INTERPRETATION

Frequent tooth brushing may be an attenuating factor and the presence of periodontal disease and an increased number of missing teeth may be augmenting factors for the occurrence of new-onset diabetes. Improving oral hygiene may be associated with a decreased risk of occurrence of new-onset diabetes.

Comparative Microbiological and Whole-Genome Analysis of Staphylococcus aureus Populations in the Oro-Nasal Cavities, Skin and Diabetic Foot Ulcers of Patients With Type 2 Diabetes Reveals a Possible Oro-Nasal Reservoir for Ulcer Infection

Patients with type 2 diabetes are at higher risk for periodontal disease and diabetic foot ulcer infections (DFUIs), the latter of which are predominantly caused by staphylococcal bacteria. Staphylococci have also been detected in the mouth, nose and gums (the oro-nasal cavity) of patients with periodontal disease and can move between the mouth and nose. The present study investigated if the oro-nasal cavity and/or periodontal pockets (PPs) in diseased gum tissue can provide a microbial reservoir for DFUIs. Eighteen patients with type 2 diabetes and at least three natural teeth (13 patients with ulcers and 5 patients without ulcers) underwent non-invasive microbiological sampling of PP, oro-nasal, skin and ulcer sites. Staphylococci were recovered using selective chromogenic agar, definitively identified and subjected to DNA microarray profiling, whole-genome sequencing and core-genome multilocus sequence typing (cgMLST). Staphylococcus aureus and Staphylococcus epidermidis were recovered from both the oro-nasal and ulcer sites of 6/13 and 5/13 patients with ulcers, respectively. Molecular typing based on the staphylococcal protein A (spa) gene and DNA microarray profiling indicated that for each patient investigated, S. aureus strains from oro-nasal and ulcer sites were identical. Comparative cgMLST confirmed that isolates from multiple anatomical sites of each individual investigated grouped into closely related, patient-distinct clusters (Clusters 1-7). Isolates belonging to the same cluster exhibited an average of 2.9 allelic differences (range 0-11). In contrast, reference genomes downloaded from GenBank selected as representatives of each sequence type identified in the present study exhibited an average of 227 allelic differences from the most closely related isolate within each cluster.

Current trends and new developments in HIV research and periodontal diseases

With the advent of combined antiretroviral therapies, the face of HIV infection has changed dramatically from a disease with almost certain mortality from serious comorbidities, to a manageable chronic condition with an extended lifespan. In this paper we present the more recent investigations into the epidemiology, microbiology, and pathogenesis of periodontal diseases in patients with HIV, and the effects of combined antiretroviral therapies on the incidence and progression of these diseases both in adults and perinatally infected children. In addition, comparisons and potential interactions between the HIV-associated microbiome, host responses, and pathogenesis in the oral cavity with the gastrointestinal tract and other areas of the body are presented. Also, the effects of HIV and combined antiretroviral therapies on comorbidities such as hyposalivation, dementia, and osteoporosis on periodontal disease progression are discussed.

Periodontal treatment and peripheral arterial disease severity – a retrospective analysis of health insurance claims data

Summary: Background: Although epidemiological data suggest an association between periodontitis (PD) and peripheral arterial disease (PAD), it is currently unclear whether treatment of PD influences the severity of PAD. Patients and methods: Whether periodontal treatment is associated with PAD disease severity was examined by analysing health insurance claims data of patients insured by the German health insurance fund, BARMER, between January 1, 2012 and December 31, 2016. The presence of PAD was determined in individuals using International Classification of Diseases (ICD) 10th revision codes for intermittent claudication (IC) or chronic limb threatening ischaemia (CLTI). Treatment of PD was assessed by adequate ambulatory coding for non-surgical and surgical treatment of PD. Multivariate logistic regression analysis was performed to evaluate the association between PAD stages and periodontal treatment, adjusted for diabetes, age and sex. Results: The study cohort included 70,944 hospitalized patients with a diagnosis of symptomatic PAD (54.99 % women, 49.05 % IC). Among these patients, 3,567 (5.03 %) had received prior treatment for PD by supra- or sub-gingival debridement. PAD patients who had received periodontal treatment showed a lower proportion of CLTI (28.76 % among treated vs. 52.12 % among non-treated). Using multivariable regression methods, exhibiting a CLTI (vs. IC) was associated with not being treated for PD (Odds Ratio 1.97, 95 %–CI 1.83–2.13) after adjustment for age, gender, and diabetes. Conclusions: In this large-scale retrospective analysis of health insurance claims data comprising hospitalized symptomatic PAD patients, treatment of PD was associated with PAD disease severity independent of age, gender and diabetes. A potential benefit of periodontal treatment in relation to PAD will have to be determined in further prospective studies.

Role of oral pathogens in the pathogenesis of intracranial aneurysm: review of existing evidence and potential mechanisms

Degeneration of intracranial aneurysm wall is under active research and recent studies indicate an increased risk of rupture of intracranial aneurysm among patients with periodontal diseases. In addition, oral bacterial DNA has been identified from wall samples of ruptured and unruptured aneurysms. These novel findings led us to evaluate if oral diseases could predispose to pathological changes seen on intracranial aneurysm walls eventually leading to subarachnoid hemorrhage. The aim of this review is to consider mechanisms on the relationship between periodontitis and aneurysm rupture, focusing on recent evidence.

Cardiologists' and cardiovascular surgeons' attitudes toward managing endodontic infections and oral health in patients with cardiovascular diseases

Objective: A relationship between dentists and medical doctors should be encouraged to reduce cardiovascular risk in cardiac patients with dental infection. The aim of this study was to evaluate the attitudes of cardiologists and cardiovascular surgeons (cardiac specialists) toward managing endodontic infections and oral health in patients with cardiovascular diseases (CVDs).Methods: A survey of 16 questions assessing knowledge of endodontic infection, dental examination, timing of endodontic treatment, and antibiotic prophylaxis was sent to cardiac specialists in Turkey. The participants' responses were compared by means of the chi-square test (p ≤ 0.05).Results: Responses were received from 444 (44.71%) participants. Of all participants, 91.4% agreed that endodontic infections are important diseases that should be treated. Cardiac patients were referred to a dentist by 66.6% of the cardiologists and 80.3% of the cardiovascular surgeons (p = 0.002). Almost all participants (97.3%) believed that the heart health of cardiac patients with endodontic infections could be negatively affected by this infection.Conclusion: Although there is not yet any conclusive evidence on whether the presence of an endodontic infection may have an impact on CVDs, this study showed that most cardiac specialists attached importance to endodontic infections.

Comparative Microbiological and Whole-Genome Analysis of Staphylococcus aureus Populations in the Oro-Nasal Cavities, Skin and Diabetic Foot Ulcers of Patients With Type 2 Diabetes Reveals a Possible Oro-Nasal Reservoir for Ulcer Infection

Patients with type 2 diabetes are at higher risk for periodontal disease and diabetic foot ulcer infections (DFUIs), the latter of which are predominantly caused by staphylococcal bacteria. Staphylococci have also been detected in the mouth, nose and gums (the oro-nasal cavity) of patients with periodontal disease and can move between the mouth and nose. The present study investigated if the oro-nasal cavity and/or periodontal pockets (PPs) in diseased gum tissue can provide a microbial reservoir for DFUIs. Eighteen patients with type 2 diabetes and at least three natural teeth (13 patients with ulcers and 5 patients without ulcers) underwent non-invasive microbiological sampling of PP, oro-nasal, skin and ulcer sites. Staphylococci were recovered using selective chromogenic agar, definitively identified and subjected to DNA microarray profiling, whole-genome sequencing and core-genome multilocus sequence typing (cgMLST). Staphylococcus aureus and Staphylococcus epidermidis were recovered from both the oro-nasal and ulcer sites of 6/13 and 5/13 patients with ulcers, respectively. Molecular typing based on the staphylococcal protein A (spa) gene and DNA microarray profiling indicated that for each patient investigated, S. aureus strains from oro-nasal and ulcer sites were identical. Comparative cgMLST confirmed that isolates from multiple anatomical sites of each individual investigated grouped into closely related, patient-distinct clusters (Clusters 1-7). Isolates belonging to the same cluster exhibited an average of 2.9 allelic differences (range 0-11). In contrast, reference genomes downloaded from GenBank selected as representatives of each sequence type identified in the present study exhibited an average of 227 allelic differences from the most closely related isolate within each cluster.

Impact of dental clearance on total joint arthroplasty: A systematic review

Many orthopedic surgeons require that their patients obtain dental clearance before elective total joint arthroplasty (TJA). However, there is no consensus substantiating the practice. To this end, a systematic review on the prevalence of dental pathology in TJA patients, risk factors for failing dental screening, and impact of dental evaluations was performed. Literature was sourced from PubMed and Scopus databases. Six papers were sourced from the initial search, one study was extracted from the references of the original six manuscripts, and one new publication was retrieved from a second search conducted after the first. The prevalence of dental pathology ranged from 8.8% to 29.4% across studies. Two of four papers reported lower than average or improvements in post-operative infection with pre-operative dental evaluations while two found no such association. There is insufficient evidence to support universal dental clearance before TJA.

Repeated Porphyromonas gingivalis W83 exposure leads to release pro-inflammatory cytokynes and angiotensin II in coronary artery endothelial cells

The role of Porphyromonas gingivalis (P. gingivalis) or its virulence factors, including lipopolysaccharide (LPS) not only has been related with periodontitis but also with endothelial dysfunction, a key mechanism involved in the genesis of atherosclerosis and hypertension that involving systemic inflammatory markers as angiotensin II (Ang II) and cytokines. This study compares the effect of repeated and unique exposures of P. gingivalis W83 LPS and live bacteria on the production and expression of inflammatory mediators and vasoconstrictor molecules with Ang II. Human coronary artery endothelial cells (HCAEC) were stimulated with purified LPS of P. gingivalis (1.0, 3.5 or 7.0 μg/mL) or serial dilutions of live bacteria (MOI 1: 100 - 1:0,1) at a single or repeated exposure for a time of 24 h. mRNA expression levels of AGTR1, AGTR2, IL-8, IL-1β and MCP-1 were determined by RT-qPCR, and IL-6, MCP-1, IL-8, IL-1β and GM-CSF levels were measured by flow cytometry, ELISA determined Ang II levels. Live bacteria in a single dose increased mRNA levels of AGTR1, and repeated doses increased mRNA levels of IL-8 and IL-1β (p < 0.05). Repeated exposure of live-P. gingivalis induced significant production IL-6, MCP-1 and GM-CSF (p < 0.05). Moreover, these MCP-1, IL-6 and GM-CSF levels were greater than in cells treated with single exposure (p < 0.05), The expression of AGTR1 and production of Ang II induced by live-P. gingivalis W83 showed a vasomotor effect of whole bacteria in HCAEC more than LPS. In conclusion, the findings of this study suggest that repeated exposure of P. gingivalis in HCAEC induces the activation of proinflammatory and vasoconstrictor molecules that lead to endothelial dysfunction being a key mechanism of the onset and progression of arterial hypertension and atherosclerosis.

Molecular characterisation of the synovial fluid microbiome in rheumatoid arthritis patients and healthy control subjects

METHODS

The presence and identity of bacterial and fungal DNA in the synovial fluid of rheumatoid arthritis (RA) patients and healthy control subjects was investigated through amplification and sequencing of the bacterial 16S rRNA gene and fungal internal transcribed spacer region 2 respectively. Synovial fluid concentrations of the cytokines IL-6, IL-17A, IL22 and IL-23 were determined by ELISA.

RESULTS

Bacterial 16S rRNA genes were detected in 87.5% RA patients, and all healthy control subjects. At the phylum level, the microbiome was predominated by Proteobacteria (Control = 83.5%, RA = 79.3%) and Firmicutes (Control = 16.1%, RA = 20.3%), and to a much lesser extent, Actinobacteria (Control = 0.2%, RA = 0.3%) and Bacteroidetes (Control = 0.1%, RA = 0.1%). Fungal DNA was identified in 75% RA samples, and 88.8% healthy controls. At the phylum level, synovial fluid was predominated by members of the Basidiomycota (Control = 53.9%, RA = 46.9%) and Ascomycota (Control = 35.1%, RA = 50.8%) phyla. Statistical analysis revealed key taxa that were differentially present or abundant dependent on disease status.

CONCLUSIONS

This study reports the presence of a synovial fluid microbiome, and determines that this is modulated by disease status (RA) as are other classical microbiome niches.

Significance of oral health in adult patients with congenital heart disease

Due to improved diagnosis and treatment life expectancy of patients with congenital heart disease is steadily increasing resulting in a growing portion of adult patients. When entering, adulthood patients commonly show a shift in their specific needs for medical care. Since the treatment is mostly not curative many patients have life-long cardiovascular anomalies, among others, entailing high risk for the development of infective endocarditis. Several oral diseases, i.e., caries, apical periodontitis and periodontitis show a very high overall prevalence. These entities are primarily initiated by bacterial infections. Hence, they cause an inherent risk for bacteremia and subsequently for infective endocarditis in patients with congenital heart disease during professional dental care and various daily activities. Conversely congenital heart disease seems to be inevitably associated with considerable impairment of oral health resulting in a tight interrelation between both entities. Different preventive strategies are available to address the elevated risk for infective endocarditis due to oral diseases in patients with congenital heart disease during professional dental care and routine daily activities. This review delineates the current evidence regarding the issue of oral health in adult patients with congenital heart disease.

Awareness of oral health in adults with congenital heart disease

Background

Poor oral health is known to be a risk factor for infective endocarditis (IE) and acquired cardiovascular disease. Many patients with congenital heart disease (CHD) are at risk for developing IE. Excellent oral health is deemed essential to prevent IE, a potentially life-threatening condition, and therefore is important in adults with congenital heart defects (ACHD). As data on oral heath in ACHD are scarce, the current study aims to assess the prevalence of caries among ACHD and the knowledge of patients about oral health as a risk factor for IE and cardiovascular disease.

Methods

A cross-sectional study included ACHD who subsequently presented at the German Heart Center Munich. The participants completed a questionnaire assessing oral health and risk awareness. Additionally, as an indicator of caries prevalence, a dentist documented the DMFT index (sum of decayed, missing and filled teeth).

Results

The median age of the 112 participants was 31.5 (range, 18-77) years. Forty-three patients (38%) were unaware of a correlation between oral health and heart disease. Twelve participants (11%) did not know about poor oral health being a risk factor for cardiovascular diseases. Less than half of the surveyed patients knew the term endocarditis. An additional twelve patients (11%) reported caveats against dental treatment because of their CHD. In twenty-three patients (21%), caries was found at the dentine level. The mean DMFT index, representing caries prevalence, was 7.91 (±6.54). There was no correlation between the Bethesda criteria of CHD and the DMFT index (P=0.69). The DMFT index was higher in patients at high risk for IE (P<0.01). However, this difference in the caries score was mainly due to more extracted and filled teeth in the high-risk patients for IE, whereas the number of decayed teeth did not differ significantly (P=0.09).

Conclusions

The awareness of the importance of optimized oral health in ACHD needs to be improved.

Streptococcus mutans isolated from a 4-year-old girl diagnosed with infective endocarditis

Objectives

Infective endocarditis (IE) has an extremely high fatality rate. In this study, we isolated a strain of Streptococcus mutans, which we called HM, from the blood drawn from a 4-year-old girl diagnosed with IE. We aimed to fully type the HM strain and investigate its biological properties, including its virulence with respect to IE.

Material and methods

A 16S rRNA phylogenetic tree and glucosyltransferase gene sequences were used to type HM. Serotyping was performed using the Ouchterlony method. Morphological observations were made using phase contrast and electron microscopy. Fibrinogen adhesion and biofilm formation were investigated to examine the tissue colonization properties of HM, whereas its bodily origin was determined from its fingerprinting pattern.

Results

The isolated strain was S. mutans serotype e. However, its morphology was observed to be short chains, unlike that of the NCTC 10449 reference strain. Fibrinogen adhesion and biofilm formation were more apparent than in NCTC 10449. The fingerprinting pattern showed that HM came from the patient's saliva.

Conclusions

HM differs from NCTC 10449 in its higher fibrinogen affinity. HM was also found to be derived from the oral cavity. These results highlight the importance of good oral hygiene for the prevention of IE in children.

Psoriasis Patients Suffer From Worse Periodontal Status-A Meta-Analysis

Background and Objective: Patients with psoriasis have a significantly elevated risk of periodontitis compared with the nonpsoriasis controls. However, the data regarding the difference in the periodontal health status of the psoriasis patients and the nonpsoriasis controls are limited and inconsistent; hence, a specialized meta-analysis that quantitatively compared the periodontal status between the psoriasis and nonpsoriasis subjects by evaluating the related clinical periodontal indexes was needed. The aim of this meta-analysis was to quantitatively evaluate whether the periodontal status of psoriasis patients is worse than that of nonpsoriasis subjects.

Methods: We searched PubMed and EMBASE for all eligible studies that compared the periodontal status between psoriasis patients and nonpsoriasis subjects. The studies were screened based on pre-established inclusion criteria. After extracting the available periodontal indexes from the included studies, the weighted mean difference (WMD) with 95% confidence intervals (CIs) was calculated by pooling the mean and standard deviations (SD) of each index.

Results: In total, 8 studies, including 812 psoriasis patients and 772 nonpsoriasis subjects, were included in our meta-analysis, and the publication dates ranged from 2013 to 2019; eight periodontal indexes were analyzed. The WMD (95% CIs) for each index were: bleeding on probing (%), 9.188 (4.046–14.330, P < 0.001); probing depth (mm), 0.524 (0.183–0.865, P = 0.003); clinical attachment loss (mm), 0.408 (0.051–0.765, P = 0.025); plaque index, 0.186 (−0.170 to 0.543, P = 0.306); gingival index, 0.458 (−0.413 to 1.328, P = 0.303), remaining teeth, −1.709 (−2.106 to −1.312, P < 0.001); missing teeth, 1.130 (0.275–1.985, P = 0.010); the level of alveolar bone loss (mm), 0.400 (0.102–0.698, P = 0.008).

Conclusion: In summary, our meta-analysis revealed that psoriasis patients suffer from worse periodontal health than do nonpsoriasis subjects, mainly characterized by worse gingival inflammation, more alveolar bone loss, fewer remaining teeth and more missing teeth. Considering the limitations of this meta-analysis, more high-quality and well-designed studies are needed to validate our conclusions in the future.

Linkage of Periodontitis and Rheumatoid Arthritis: Current Evidence and Potential Biological Interactions

The association between rheumatoid arthritis (RA) and periodontal disease (PD) has been the focus of numerous investigations driven by their common pathological features. RA is an autoimmune disease characterized by chronic inflammation, the production of anti-citrullinated proteins antibodies (ACPA) leading to synovial joint inflammation and destruction. PD is a chronic inflammatory condition associated with a dysbiotic microbial biofilm affecting the supporting tissues around the teeth leading to the destruction of mineralized and non-mineralized connective tissues. Chronic inflammation associated with both RA and PD is similar in the predominant adaptive immune phenotype, in the imbalance between pro- and anti-inflammatory cytokines and in the role of smoking and genetic background as risk factors. Structural damage that occurs in consequence of chronic inflammation is the ultimate cause of loss of function and disability observed with the progression of RA and PD. Interestingly, the periodontal pathogen Porphyromonas gingivalis has been implicated in the generation of ACPA in RA patients, suggesting a direct biological intersection between PD and RA. However, more studies are warranted to confirm this link, elucidate potential mechanisms involved, and ascertain temporal associations between RA and PD. This review is mainly focused on recent clinical and translational research intends to discuss and provide an overview of the relationship between RA and PD, exploring the similarities in the immune-pathological aspects and the possible mechanisms linking the development and progression of both diseases. In addition, the current available treatments targeting both RA and PD were revised.

Identification of Virulence-Associated Properties by Comparative Genome Analysis of Streptococcus pneumoniae, S. pseudopneumoniae, S. mitis, Three S. oralis Subspecies, and S. infantis

Streptococcus pneumoniae is one of the most important human pathogens but is closely related to Streptococcus mitis, with which humans live in harmony. The fact that the two species evolved from a common ancestor provides a unique basis for studies of both infection-associated properties and properties important for harmonious coexistence with the host. By detailed comparisons of genomes of the two species and other related streptococci, we identified 224 genes associated with virulence and 25 genes unique to the mutualistic species. The exclusive presence of the virulence factors in S. pneumoniae enhances their potential as vaccine components, as a direct impact on beneficial members of the commensal microbiota can be excluded. Successful adaptation of S. mitis and other commensal streptococci to a harmonious relationship with the host relied on genetic stability and properties facilitating life in biofilms.

From a common ancestor, Streptococcus pneumoniae and Streptococcus mitis evolved in parallel into one of the most important pathogens and a mutualistic colonizer of humans, respectively. This evolutionary scenario provides a unique basis for studies of both infection-associated properties and properties important for harmonious coexistence with the host. We performed detailed comparisons of 60 genomes of S. pneumoniae, S. mitis, Streptococcus pseudopneumoniae, the three Streptococcus oralis subspecies oralis, tigurinus, and dentisani, and Streptococcus infantis. Nonfunctional remnants of ancestral genes in both S. pneumoniae and in S. mitis support the evolutionary model and the concept that evolutionary changes on both sides were required to reach their present relationship to the host. Confirmed by screening of >7,500 genomes, we identified 224 genes associated with virulence. The striking difference to commensal streptococci was the diversity of regulatory mechanisms, including regulation of capsule production, a significantly larger arsenal of enzymes involved in carbohydrate hydrolysis, and proteins known to interfere with innate immune factors. The exclusive presence of the virulence factors in S. pneumoniae enhances their potential as vaccine components, as a direct impact on beneficial members of the commensal microbiota can be excluded. In addition to loss of these virulence-associated genes, adaptation of S. mitis to a mutualistic relationship with the host apparently required preservation or acquisition of 25 genes lost or absent from S. pneumoniae. Successful adaptation of S. mitis and other commensal streptococci to a harmonious relationship with the host relied on genetic stability and properties facilitating life in biofilms.

The Prevention of Infections in Older Adults: Oral Health

The oral cavity is exposed to the external environment and from a very young age is colonized by infectious agents. Under certain circumstances including poor oral hygiene, dry mouth, trauma, and the use of antibiotics, oral infections can occur. They can result in damage to the oral cavity including teeth and their support structures. Oral infections can also lead to the extension of infection into surrounding tissues and to systemic infections. Chronic oral infection is a recognized risk factor for heart disease. Older adults are at high risk for oral infections and associated complications. Tooth loss, for which infection is the most significant cause, leads to cosmetic changes and a decreased ability to masticate certain foods that can lead to malnutrition. Chronic oral infections and the manipulation of teeth and supporting structures can lead to the hematogenous spread of infection including the infection of artificial joints and endocardial implants. Good oral hygiene, the use of fluoride, regular dental care, and the appropriate use of antibiotics can all reduce oral infections and their associated complications. J Am Geriatr Soc 68:411-416, 2020.

Oral Health in Adults with Congenital Heart Disease

Oral bacteria and odontogenic oral infections are responsible for a high portion of cases with infective endocarditis. Hence, oral health in patients with congenital heart disease (CHD) gains particular importance. This case-control study compared the oral health status in 112 adults with CHD and 168 healthy control subjects. In addition, the patient group was stratified according to the complexity of the heart defect and the recommendation for antibiotic prophylaxis during invasive dental procedures. Considering caries experience, a significantly lower mean DMFT (decayed missing filled teeth) score (7.91 ± 6.63 vs. 13.6 ± 8.15; p < 0.0001) was found in patients with CHD compared to healthy controls. Healthy controls had a higher average number of decayed teeth (0.33 ± 0.76 vs. 1.76 ± 2.61; p < 0.0001). In female subjects a significant lower relative amount of teeth with apical periodontitis was found among CHD patients (3.4% ± 0.9%) as compared to healthy controls (5.6% ± 1.9%) (p = 0.053). Regarding periodontal health, patients with CHD had lower rate of sulcus bleeding (0.32 ± 0.65 vs. 0.71 ± 0.60; p < 0.0001) and less alveolar bone loss than heart healthy individuals (% root length: multi rooted teeth: 8.97 ± 10.64 vs. 23.22 ± 20.70; p < 0.0001; single rooted teeth: 5.59 ± 6.25 vs. 17.30 ± 17.17; p = 0.003). On the contrary, CHD patients presented with higher amount of plaque in comparison to healthy controls (Quigley & Hein index: 2.22 ± 0.67 vs. 1.25 ± 0.72; p < 0.0001). Based on the current results, it can be concluded that adults with CHD have better oral health than heart healthy individuals.

Distal Consequences of Oral Inflammation

Periodontitis is an incredibly prevalent chronic inflammatory disease, which results in the destruction of tooth supporting structures. However, in addition to causing tooth and alveolar bone loss, this oral inflammatory disease has been shown to contribute to disease states and inflammatory pathology at sites distant from the oral cavity. Epidemiological and experimental studies have linked periodontitis to the development and/or exacerbation of a plethora of other chronic diseases ranging from rheumatoid arthritis to Alzheimer's disease. Such studies highlight how the inflammatory status of the oral cavity can have a profound impact on systemic health. In this review we discuss the disease states impacted by periodontitis and explore potential mechanisms whereby oral inflammation could promote loss of homeostasis at distant sites.

The impact of the oral cavity in febrile neutropenia and infectious complications in patients treated with myelosuppressive chemotherapy

Febrile neutropenia (FN) is an inflammatory response causing fever that may develop during cancer therapy-induced neutropenia. FN may herald life-threatening infectious complications and should therefore be considered a medical emergency. Patients presenting with FN are routinely subjected to careful history taking and physical examination including X-rays and microbiological evaluations. Nevertheless, an infection is documented clinically in only 20-30% of cases, whereas a causative microbial pathogen is not identified in over 70% of FN cases. The oral cavity is generally only visually inspected. Although it is recognized that ulcerative oral mucositis may be involved in the development of FN, the contribution of infections of the periodontium, the dentition, and salivary glands may be underestimated. These infections can be easily overlooked, as symptoms and signs of inflammation may be limited or absent during neutropenia. This narrative review is aimed to inform the clinician on the potential role of the oral cavity as a potential source in the development of FN. Areas for future research directed to advancing optimal management strategies are discussed.

Alzheimer's disease and symbiotic microbiota: an evolutionary medicine perspective

Microorganisms resident in our bodies participate in a variety of regulatory and pathogenic processes. Here, we describe how etiological pathways implicated in Alzheimer's disease (AD) may be regulated or disturbed by symbiotic microbial activity. Furthermore, the composition of symbiotic microbes has changed dramatically across human history alongside the rise of agriculturalism, industrialization, and globalization. We postulate that each of these lifestyle transitions engendered progressive depletion of microbial diversity and enhancement of virulence, thereby enhancing AD risk pathways. It is likely that the human life span extended into the eighth decade tens of thousands of years ago, yet little is known about premodern geriatric epidemiology. We propose that microbiota of the gut, oral cavity, nasal cavity, and brain may modulate AD pathogenesis, and that changes in the microbial composition of these body regions across history suggest escalation of AD risk. Dysbiosis may promote immunoregulatory dysfunction due to inadequate education of the immune system, chronic inflammation, and epithelial barrier permeability. Subsequently, proinflammatory agents-and occasionally microbes-may infiltrate the brain and promote AD pathogenic processes. APOE genotypes appear to moderate the effect of dysbiosis on AD risk. Elucidating the effect of symbiotic microbiota on AD pathogenesis could contribute to basic and translational research.

Multiplex polymerase chain reaction for detection of bacteremia during dental extraction

AIM

Incidence of transient bacteremia following dental extractions ranges 30%-70% among adults and 58%-100% in children. This study aims to assess the multiplex polymerase chain reaction (PCR) technique in detection of transient bacteremia during dental extraction.

METHODS

Twenty volunteers for dental extraction entered the study. Blood samples were taken at baseline and 30 seconds and 15 minutes after extraction. Five types of bacteria were selected, namely Streptococcus mutans, S. salivarius, S. sanguinis, Enterococcus faecalis and Lactobacillus. Blood samples were evaluated by microbial culture and multiplex PCR.

RESULTS

Blood culture showed rates of 0%, 80% and 25% for bacteremia before, during and after dental extraction, respectively. A significant difference was observed between baseline and during extraction. Using PCR, bacteremia was deemed 20%, 100% and 30% before, during and after extraction, respectively, and a significant difference was witnessed between the baseline and during extraction. The highest incidence was at the 30-second mark after extraction, and the most prevalent type of bacteria was S. mutans.

CONCLUSIONS

Multiplex PCR can be used to determine bacterial diversity with high accuracy during occurrence of bacteremia. Therefore, in cases where positive blood cultures only indicate the presence of one species, we recommend the use of this method to detect more diverse bacteria types.

COL4A2 in the tissue-specific extracellular matrix plays important role on osteogenic differentiation of periodontal ligament stem cells

Periodontal ligament stem cells (PDLSCs) can repair alveolar bone defects in periodontitis in a microenvironment context-dependent manner. This study aimed to determine whether different extracellular matrices (ECMs) exert diverse effects on osteogenic differentiation of PDLSCs and accurately control alveolar bone defect repair. Methods: The characteristics of PDLSCs and bone marrow mesenchymal stem cells (BMSCs) with respect to surface markers and multi-differentiation ability were determined. Then, we prepared periodontal ligament cells (PDLCs)-derived and bone marrow cells (BMCs)-derived ECMs (P-ECM and B-ECM) and the related decellularized ECMs (dECMs). Transmission electron microscopy (TEM), scanning electron microscopy (SEM), atomic force microscopy (AFM), and protein mass spectrometry were used to distinguish the ECMs. The expression of Type IV collagen A2 (COL4A2) in the ECMs was inhibited by siRNA or activated by lentiviral transduction of relevant cells. The stemness, proliferation, and differentiation of PDLSCs were determined in vitro in different dECMs. For the in vivo analysis, different dECMs under the regulation of COL4A2 mixed with PDLSCs and Bio-Oss bone powder were subcutaneously implanted into immunocompromised mice or in defects in rat alveolar bone. The repair effects were identified by histological or immunohistochemical staining and micro-CT. Results: B-dECM exhibited more compact fibers than P-dECM, as revealed by TEM, SEM, and AFM. Protein mass spectrometry showed that COL4A2 was significantly increased in B-dECM compared with P-dECM. PDLSCs displayed stronger proliferation, stemness, and osteogenic differentiation ability when cultured on B-dECM than P-dECM. Interestingly, B-dECM enhanced the osteogenic differentiation of PDLSCs to a greater extent than P-dECM both in vitro and in vivo, whereas downregulation of COL4A2 in B-dECM showed the opposite results. Furthermore, the classical Wnt/β-catenin pathway was found to play an important role in the negative regulation of osteogenesis through COL4A2, confirmed by experiments with the Wnt inhibitor DKK-1 and the Wnt activator Wnt3a. Conclusion: These findings indicate that COL4A2 in the ECM promotes osteogenic differentiation of PDLSCs through negative regulation of the Wnt/β-catenin pathway, which can be used as a potential therapeutic strategy to repair bone defects.

The oral microbiome - friend or foe?

The microbiome and the human body constitute an integrated superorganism, which is the result of millions of years of coevolution with mutual adaptation and functional integration, and confers significant benefits for both parties. This evolutionary process has resulted in a highly diverse oral microbiome, which covers the full spectrum of acidogenic, aciduric, inflammatory, and anti-inflammatory properties. The relative proportions of members of the microbiome are affected by factors associated with modern life, such as general diet patterns, sugar consumption, tobacco smoking, oral hygiene, use of antibiotics and other antimicrobials, and vaccines. A perturbed balance in the oral microbiome may result in caries, periodontal disease, or candidiasis, and oral bacteria passively transferred to normally sterile parts of the body may cause extra-oral infections. Nevertheless, it should never be our goal to eliminate the oral microbiome, but rather we have to develop ways to re-establish a harmonious coexistence that is lost because of the modern lifestyle. With regard to oral diseases, this goal can normally be achieved by optimal oral hygiene, exposure to fluoride, reduction of sucrose consumption, stimulation of our innate immune defense, smoking cessation, and control of diabetes.

Mediators between oral dysbiosis and cardiovascular diseases

Clinical periodontitis is associated with an increased risk for cardiovascular diseases (CVDs) through systemic inflammation as the etiopathogenic link. Whether the oral microbiota, especially its quality, quantity, serology, and virulence factors, plays a role in atherogenesis is not clarified. Patients with periodontitis are exposed to bacteria and their products, which have access to the circulation directly through inflamed oral tissues and indirectly (via saliva) through the gastrointestinal tract, resulting in systemic inflammatory and immunologic responses. Periodontitis is associated with persistent endotoxemia, which has been identified as a notable cardiometabolic risk factor. The serology of bacterial biomarkers for oral dysbiosis is associated with an increased risk for subclinical atherosclerosis, prevalent and future coronary artery disease, and incident and recurrent stroke. In addition to species-specific antibodies, the immunologic response includes persistent, cross-reactive, proatherogenic antibodies against host-derived antigens. Periodontitis may affect lipoprotein metabolism at all levels, and all lipoprotein classes are affected. Periodontitis or its bacterial signatures may be involved not only in increased storage of proatherogenic lipids but also in attenuation of the anti-atherogenic processes, thereby putatively increasing the net risk of atherosclerosis. In this review we summarize possible molecular mediators between the dysbiotic oral microbiota and atherosclerotic processes.

The Healthy Human Blood Microbiome: Fact or Fiction?

The blood that flows perpetually through our veins and arteries performs numerous functions essential to our survival. Besides distributing oxygen, this vast circulatory system facilitates nutrient transport, deters infection and dispenses heat throughout our bodies. Since human blood has traditionally been considered to be an entirely sterile environment, comprising only blood-cells, platelets and plasma, the detection of microbes in blood was consistently interpreted as an indication of infection. However, although a contentious concept, evidence for the existence of a healthy human blood-microbiome is steadily accumulating. While the origins, identities and functions of these unanticipated micro-organisms remain to be elucidated, information on blood-borne microbial phylogeny is gradually increasing. Given recent advances in microbial-hematology, we review current literature concerning the composition and origin of the human blood-microbiome, focusing on bacteria and their role in the configuration of both the diseased and healthy human blood-microbiomes. Specifically, we explore the ways in which dysbiosis in the supposedly innocuous blood-borne bacterial microbiome may stimulate pathogenesis. In addition to exploring the relationship between blood-borne bacteria and the development of complex disorders, we also address the matter of contamination, citing the influence of contaminants on the interpretation of blood-derived microbial datasets and urging the routine analysis of laboratory controls to ascertain the taxonomic and metabolic characteristics of environmentally-derived contaminant-taxa.

The role of serum lipoxin A4 levels in the association between periodontal disease and metabolic syndrome

Purpose

An unresolved inflammatory state contributes to the pathogenesis of periodontal disease and metabolic syndrome (MetS). Therefore, the purpose of this study was to evaluate the role of lipoxin A4 (LXA4), a proresolving lipid mediator, in the association between periodontal disease and MetS.

Methods

Sixty-seven patients with MetS and 65 patients without MetS were included in the study. Sociodemographic information was obtained via a questionnaire, and detailed medical diagnoses were made. Periodontal parameters (plaque index [PI], gingival index [GI], probing pocket depth [PD], and clinical attachment level [CAL]) and metabolic parameters were measured, and serum LXA4 levels were determined. The associations among MetS, periodontal parameters, and serum LX levels were evaluated by adjusted multivariate linear regression analyses.

Results

Patients with MetS were older and had a higher body mass index than patients without MetS. Periodontal parameters (PI, GI, PD, and CAL) were higher in patients with MetS than in those without MetS. Serum LXA4 levels were higher in patients without MetS. Multivariate linear regression analysis indicated a positive association between MetS and periodontal parameters (PD and CAL). Negative associations were established between MetS and LXA4 levels, and between LXA4 and periodontal parameters (PI, PD, and CAL).

Conclusions

The presence of higher values of periodontal parameters in patients with MetS and the negative relationship of LXA4 with MetS and periodontal disease may support the protective role of proresolving lipid mediators in the association between periodontal disease and MetS.

The influence of vitamin D supplementation on local and systemic inflammatory markers in periodontitis patients: A pilot study

OBJECTIVES

Vitamin D deficiency/insufficiency is a worldwide public health issue that has been linked to numerous inflammatory disorders, including periodontitis. There is increasing support for a role for adequate vitamin D levels in overall health. Populations with darker skin color have a higher prevalence of vitamin D deficiency/insufficiency and periodontitis. The purpose of this small pilot study was to investigate the influence of 12 weeks of 25(OH)D vitamin D supplementation (VDS) on mediators of systemic inflammation in dark-skinned, periodontitis patients.

MATERIALS AND METHODS

A total of 23 patients with moderate to severe periodontitis were randomly assigned to the vitamin D group or placebo group and received intensive single visit scaling and root planning to elicit a systemic inflammatory response.

RESULTS

Vitamin D supplementation increased serum 25(OH)D levels approximately 2-fold over baseline levels; moreover, VDS group had reduced peripheral blood CD3 and CD3+CD8+ cytotoxic T lymphocyte (CTLs) counts and reduced pro-inflammatory salivary cytokines. In contrast, VDS group had higher levels of the autophagy-related proteins and other proteins crucial for anti-microbial autophagy in whole blood PBMCs.

CONCLUSION

In conclusion, VDS has multiple benefits for reducing systemic inflammation and promoting induction of autophagy-related proteins related to anti-microbial functions.

Streptococcus salivarius Prosthetic Joint Infection following Dental Cleaning despite Antibiotic Prophylaxis

We present the case of a 92-year-old man with septic arthritis of a prosthetic hip joint due to Streptococcus salivarius one week following a high-risk dental procedure despite preprocedure amoxicillin. S. salivarius is a commensal bacterium of the human oral mucosa that is an uncommon cause of bacteremia. S. salivarius has previously been described as a causative agent of infective endocarditis and spontaneous bacterial peritonitis but was only recently recognized as a cause of prosthetic joint infection. This case highlights the potential pathogenicity of a common commensal bacteria and the questionable utility of prophylactic antibiotics before dental procedures to prevent periprosthetic joint infections.

Treponema denticola enolase contributes to the production of antibodies against ENO1 but not to the progression of periodontitis

Autoantibodies against alpha-enolase (ENO1) are often detected in various infectious and autoimmune diseases. Anti-ENO1 antibody titers were reported to be associated with the severity of periodontitis in patients with rheumatoid arthritis. Because the enolase of the periodontal pathogen Treponema denticola (TdEno) has the highest homology with ENO1 among the enolases of human-associated bacteria, we hypothesized that anti-ENO1 autoantibodies produced during the immune response to TdEno may contribute to the progression of periodontitis and tested it in human and mouse systems. In human subjects with healthy periodontium or chronic periodontitis, a strong positive correlation between the levels of anti-TdEno and anti-ENO1 antibodies was observed. In addition, the purified anti-TdEno antibodies recognized ENO1 as well as TdEno in a dot blot, confirming the cross-reactivity between TdEno and ENO1. However, anti-ENO1 antibody titers were not associated with the severity of periodontitis. To further investigate the role of TdEno in the production of anti-ENO1 antibodies and the progression of periodontitis, mice received an oral gavage of P. gingivalis alone, subcutaneous immunization with TdEno alone, or both P. gingivalis oral gavage and TdEno immunization. Immunization with TdEno induced not only anti-TdEno but also anti-mouse Eno1 (mEno1) antibodies and increased the expression of TNFα in the gingival tissues. However, alveolar bone loss was not increased by TdEno immunization. In conclusion, autoreactive anti-ENO1/mEno1 antibodies that are produced as byproducts during the antibody response to TdEno play a minimal role in the progression of periodontitis in the absence of rheumatoid arthritis.

Periodontitis and gingival bleeding associate with intracranial aneurysms and risk of aneurysmal subarachnoid hemorrhage

Oral bacteria DNA has been found in intracranial aneurysms (IA) and a high prevalence of periodontitis was reported in IA patients. We investigated whether periodontitis associates with IA formation and aneurysmal subarachnoid hemorrhage (aSAH). First, we compared in a case-control setting the prevalence of periodontal disease in IA patients (42 unruptured IA, 34 ruptured IA) and in age- and gender-matched controls (n = 70) from the same geographical area (Health 2000 Survey, BRIF8901). Next, we investigated whether periodontitis at baseline associated with aSAH in a 13-year follow-up study of 5170 Health 2000 Survey participants. Follow-up data was obtained from national hospital discharge and cause of death registries. Univariate analysis, logistic regression, and Cox-regression were used. Periodontitis (≥ 4mm gingival pocket) and severe periodontitis (≥ 6mm gingival pocket) were found in 92% and 49% of IA patients respectively and associated with IAs (OR 5.3, 95%CI 1.1–25.9, p < 0.000 and OR 6.3, 95%CI 1.3–31.4, p < 0.001, respectively). Gingival bleeding had an even stronger association, especially if detected in 4–6 teeth sextants (OR 34.4, 95%CI 4.2–281.3). Severe periodontitis in ≥ 3 teeth or gingival bleeding in 4–6 teeth sextants at baseline increased the risk of aSAH during follow-up (HR 22.5, 95%CI 3.6–139.5, p = 0.001 and HR 8.3, 95%CI 1.5–46.1, p = 0.015, respectively). Association of periodontitis and gingival bleeding with risk of IA development and aSAH was independent of gender, smoking status, hypertension, or alcohol abuse. Periodontitis and gingival bleeding associate with increased risk for IA formation and eventual aSAH. Further epidemiological and mechanistic studies are indicated.

Long-term Association of Periodontitis With Decreased Kidney Function

RATIONALE & OBJECTIVE

Previous studies have yielded inconclusive findings regarding the relationship between periodontitis and kidney function. We sought to investigate whether periodontitis is associated with subsequent decreases in kidney function (reductions in estimated glomerular filtration rate [eGFR] and increased urinary albumin-creatinine ratio [UACR]) in the general population.

STUDY DESIGN

Population-based cohort study.

SETTING & PARTICIPANTS

We used baseline and 11-year follow-up data from 2,297 and 1,512 adult participants, respectively, in the Study of Health in Pomerania (SHIP). Age range was limited to 20 to 59 years to avoid the potential influence of tooth loss.

EXPOSURES

Periodontal status defined by periodontal pocket probing depth (PPD) and clinical attachment level. Mean levels and the percentage of sites ≥ 3mm was determined for either all sites (PPD) or interproximal sites (clinical attachment level). All PPDs≥4mm were summed to calculate the total PPD.

OUTCOMES

GFR estimated from serum creatinine and serum cystatin C (eGFRcr-cys). Moderately increased albuminuria defined as UACR>30mg/g.

ANALYTICAL APPROACH

Adjusted linear and logistic mixed regression models.

RESULTS

At baseline and follow-up, average eGFRcr-cys was 118.3 and 105.0mL/min/1.73m2, respectively. Using mixed models, no consistently significant associations between periodontitis variables and eGFRcr-cys were detected. Long-term changes in UACR were inconsistently associated with periodontitis measures. After imputation of missing data, associations were either attenuated or no longer detectable.

LIMITATIONS

Because periodontal assessments were performed using a partial recording protocol, periodontal disease severity estimates might have been underestimated, resulting in attenuated effect estimates.

CONCLUSIONS

We found no consistent evidence for an association between periodontitis and decreased kidney function. In contrast to previous studies, these results do not support the hypothesis that periodontitis is an important risk factor for chronic kidney disease.

Infectious Aneurysm Caused by Citrobacter koseri in an Immunocompetent Patient

Citrobacter species can cause severe infection in immunocompetent patients. A 78-year-old man visited our hospital because he had had a fever lasting one day each month for the past 3 months. Antibiotics were initiated for suspected bronchial pneumonia, but the C-reactive protein level remained high. Contrast-enhanced computed tomography revealed saccular brachiocephalic artery aneurysm. Citrobacter koseri was isolated from a blood culture, and he was diagnosed with infectious brachiocephalic artery aneurysm. He underwent endovascular aneurysm repair after one month of intravenous cefepime and metronidazole. We herein report for the first time an immunocompetent patient with infectious aneurysm caused by C. koseri periodontal infection.

Bacteremia after professional mechanical plaque removal in patients with chronic periodontitis

OBJECTIVE

The aim of this study was to investigate the characteristics of bacteremia caused by professional mechanical plaque removal (PMPR) in two groups of patients with generalized moderate chronic periodontitis.

MATERIALS AND METHODS

Venous blood samples were taken at multiple time points for one hour following PMPR in fifty patients with generalized moderate chronic periodontitis. Subjects consisted of two groups, one group was receiving supportive periodontal therapy (SPT, n = 25) and the other group was receiving initial periodontal therapy (IPT, n = 25). Blood samples were processed and analyzed for cultivable microflora. Pertinent clinical parameters were recorded for each patient in both groups.

RESULTS

Bacteremia was detected in 10 of 25 SPT and 8 of 25 IPT patients (p = 0.796). In both groups, the prevalence of bacteremia was dependent on the time of blood sampling and varied in magnitude between <10²  CFU/ml and 10⁶  CFU/ml. Sixteen different bacterial species were identified in both groups, mostly Actinomyces naeslundii (SPT n = 3, IPT n = 4) and Streptococcus spp. (SPT n = 6, IPT n = 2). In regression models, Grade II furcation involvement (p = 0.004) and Gingival Bleeding Index (p = 0.036) had affected the occurrence of bacteremia but in the SPT group only.

CONCLUSION

Professional mechanical plaque removal was associated with bacteremia regardless of whether a patient was receiving SPT or IPT.

Molecular and Functional Analysis of the Type IV Pilus Gene Cluster in Streptococcus sanguinis SK36

Streptococcus sanguinis, dominant in the oral microbiome, is the only known streptococcal species possessing a pil gene cluster for the biosynthesis of type IV pili (Tfp). Although this cluster is commonly present in the genome of S. sanguinis, most of the strains do not express Tfp-mediated twitching motility. Thus, this study was designed to investigate the biological functions encoded by the cluster in the twitching-negative strain S. sanguinis SK36. We found that the cluster was transcribed as an operon, with three promoters located 5' to the cluster and one in the intergenic region between SSA_2307 and SSA_2305. Studies using promoter-cat fusion strains revealed that the transcription of the cluster was mainly driven by the distal 5' promoter, which is located more than 800 bases 5' to the first gene of the cluster, SSA_2318. Optimal expression of the cluster occurred at the early stationary growth phase in a CcpA-dependent manner, although a CcpA-binding consensus is absent in the promoter region. Expression of the cluster resulted in a short hairlike surface structure under transmission electron microscopy. Deletion of the putative pilin genes (SSA_2313 to SSA_2315) abolished the biosynthesis of this structure and significantly reduced the adherence of SK36 to HeLa and SCC-4 cells. Mutations in the pil genes downregulated biofilm formation by S. sanguinis SK36. Taken together, the results demonstrate that Tfp of SK36 are important for host cell adherence, but not for motility, and that expression of the pil cluster is subject to complex regulation.IMPORTANCE The proteins and assembly machinery of the type IV pili (Tfp) are conserved throughout bacteria and archaea, and yet the function of this surface structure differs from species to species and even from strain to strain. As seen in Streptococcus sanguinis SK36, the expression of the Tfp gene cluster results in a hairlike surface structure that is much shorter than the typical Tfp. This pilus is essential for the adherence of SK36 but is not involved in motility. Being a member of the highly diverse dental biofilm, perhaps S. sanguinis could more effectively utilize this structure to adhere to host cells and to interact with other microbes within the same niche.

The relationship of diabetes, periodontitis and cardiovascular disease

Cardiovascular complications in diabetic patients comprise of interaction between traditional and non-traditional risk factors. This interaction is thought to play role in four-times increment of cardiovascular mortality risk in diabetic patients, compared to non-diabetics. Chronic inflammation is known to be one of atherosclerosis non-traditional risk factor and has a role on every phase of atherogenesis. Periodontitis is the most common cause of chronic inflammation in diabetic patient. Both periodontitis and diabetes have detrimental effect on each other in terms of alveolar bone destruction and poor metabolic control, by continuous inflammatory mediator activation. Defect of bacteria elimination ability and monocyte hyper-responsiveness in diabetic patients leads to persistent elevation of systemic inflammatory mediators. This process give rise to prolonged and augmented exposure to inflammatory cytokines. This exposure interacts with traditional risk factor could lead to initiation of endothelial dysfunction, the first phase of atherogenesis.

Antibiotic Prophylaxis for Dental Treatment in Patients with Immunodeficiency

Routine antibacterial prophylaxis is recommended before dental procedures in select patient populations. Currently, no guidelines are in place for routine prophylaxis before dental procedures in patients with primary immunodeficiency diseases. We review risk factors and provide recommendations on routine dental care and antibacterial prophylaxis in patients with primary immunodeficiency diseases.

Multi-Method Characterization of the Human Circulating Microbiome

The term microbiome describes the genetic material encoding the various microbial populations that inhabit our body. Whilst colonization of various body niches (e.g., the gut) by dynamic communities of microorganisms is now universally accepted, the existence of microbial populations in other "classically sterile" locations, including the blood, is a relatively new concept. The presence of bacteria-specific DNA in the blood has been reported in the literature for some time, yet the true origin of this is still the subject of much deliberation. The aim of this study was to investigate the phenomenon of a "blood microbiome" by providing a comprehensive description of bacterially derived nucleic acids using a range of complementary molecular and classical microbiological techniques. For this purpose we utilized a set of plasma samples from healthy subjects (n = 5) and asthmatic subjects (n = 5). DNA-level analyses involved the amplification and sequencing of the 16S rRNA gene. RNA-level analyses were based upon the de novo assembly of unmapped mRNA reads and subsequent taxonomic identification. Molecular studies were complemented by viability data from classical aerobic and anaerobic microbial culture experiments. At the phylum level, the blood microbiome was predominated by Proteobacteria, Actinobacteria, Firmicutes, and Bacteroidetes. The key phyla detected were consistent irrespective of molecular method (DNA vs. RNA), and consistent with the results of other published studies. In silico comparison of our data with that of the Human Microbiome Project revealed that members of the blood microbiome were most likely to have originated from the oral or skin communities. To our surprise, aerobic and anaerobic cultures were positive in eight of out the ten donor samples investigated, and we reflect upon their source. Our data provide further evidence of a core blood microbiome, and provide insight into the potential source of the bacterial DNA/RNA detected in the blood. Further, data reveal the importance of robust experimental procedures, and identify areas for future consideration.

Porphyromonas gingivalis in Alzheimer's disease brains: Evidence for disease causation and treatment with small-molecule inhibitors

Porphyromonas gingivalis, the keystone pathogen in chronic periodontitis, was identified in the brain of Alzheimer's disease patients. Toxic proteases from the bacterium called gingipains were also identified in the brain of Alzheimer's patients, and levels correlated with tau and ubiquitin pathology. Oral P. gingivalis infection in mice resulted in brain colonization and increased production of Aβ_1-42, a component of amyloid plaques. Further, gingipains were neurotoxic in vivo and in vitro, exerting detrimental effects on tau, a protein needed for normal neuronal function. To block this neurotoxicity, we designed and synthesized small-molecule inhibitors targeting gingipains. Gingipain inhibition reduced the bacterial load of an established P. gingivalis brain infection, blocked Aβ_1-42 production, reduced neuroinflammation, and rescued neurons in the hippocampus. These data suggest that gingipain inhibitors could be valuable for treating P. gingivalis brain colonization and neurodegeneration in Alzheimer's disease.

Tooth loss and dementia: An oro-neural connection. A cross-sectional study

Background:

Recent cross-sectional studies have suggested that chronic inflammation resulting due to gingival and periodontal diseases may have potential reversible risk factors for dementia. Recently, cognition, memory deficit, and along with the behavioral defect have been considered as characteristics of dementia. Age is one of the main factors which is also known to be associated with dementia. The aim of the present study was to establish the correlation between tooth loss and diagnosis of cognitive impairment/dementia in elderly patients.

Materials and Methods:

A cross-sectional study, comprising of 300 patients (Age: 50–80 years), was conducted. For the assessment of cognitive impairment/dementia, Mini-Mental Status Examination (MMSE) was conducted. All the results were analyzed using the Chi-square and Kruskal–Wallis ANOVA test.

Results:

Number of teeth was found to be directly associated with MMSE. Less number of teeth was associated with lower MMSE score, irrespective of gender. The level of statistical significance was found to be P < 0.001. Factors, such as socioeconomic status, school education, and marital status, were found to have a statistically significant impact on the dementia scale.

Conclusion:

The current study found a significant association between tooth loss and cognitive impairment. Along with age factors such as socioeconomic status, education, and marital status were also found to have a direct or indirect impact on dementia. More prospective studies and clinical trials are required to be conducted to confirm the observations of this study.

Detection and quantification of Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans in bacteremia induced by interdental brushing in periodontally healthy and periodontitis patients

OBJECTIVE

This study was aimed to compare the presence and amounts of bacteremia induced by interdental brushing in periodontally healthy (H) and periodontitis (P) individuals using culture based (direct culture [DC]) and molecular based techniques (real-time quantitative polymerase chain reaction [qPCR]) in a cross-sectional study model.

MATERIALS AND METHODS

After a full mouth periodontal evaluation, blood samples were taken before and 1 min after professionally-administered interdental brushing. These samples were analyzed by DC and qPCR, targeting Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans. Subgingival samples were also collected and analyzed. Student t-test, chi-squar tests and correlations were used for analyzing the data.

RESULTS

Thirty individuals per group were included. P. gingivalis and A. actinomycetemcomitans were detected with qPCR methods, but not with DC. At baseline, bacteremia was observed in 5 P patients (16.7%) and in 2 H individuals (6.6%) (p = 0.421). After interdental brushing, bacteremia was only observed in 2 P patients (6.6%) (p = 0.901). A positive correlation between subgingival and blood levels of A. actinomycetemcomitans was observed (r = 0.3; p = 0.013).

CONCLUSION

Bacteremia related to A. actinomycetemcomitans and P. gingivalis did not significantly increase after a single session of use of interdental brushes.