An investigation of the frequency of bacteraemia following dental extraction, tooth brushing and chewing

Smoking Impacts Alzheimer's Disease Progression Through Oral Microbiota Modulation

Alzheimer's disease (AD) is an important public health challenge with a limited understanding of its pathogenesis. Smoking is a significant modifiable risk factor for AD progression, and its specific mechanism is often interpreted from a toxicological perspective. However, microbial infections also contribute to AD, with oral microbiota playing a crucial role in its progression. Notably, smoking alters the ecological structure and pathogenicity of the oral microbiota. Currently, there is no systematic review or summary of the relationship between these three factors; thus, understanding this association can help in the development of new treatments. This review summarizes the connections between smoking, AD, and oral microbiota from existing research. It also explores how smoking affects the occurrence and development of AD through oral microbiota, and examines treatments for oral microbiota that delay the progression of AD. Furthermore, this review emphasizes the potential of the oral microbiota to act as a biomarker for AD. Finally, it considers the feasibility of probiotics and oral antibacterial therapy to expand treatment methods for AD.

Laboratory approaches to determining blood culture contamination rates: an ASM Laboratory Practices Subcommittee report

Blood culture contamination (BCC) is the presence of specific commensal and environmental organisms cultivated from a single blood culture set out of a blood culture series and that do not represent true bacteremia. BCC can impact quality of care and lead to negative outcomes, unnecessary antibiotic exposure, prolonged hospital stays, and substantial costs. As part of the laboratory's quality management plan, microbiology laboratory personnel are tasked with monitoring BCC rates, preparing BCC rate reports, and providing feedback to the appropriate committees within their healthcare system. The BCC rate is calculated by the laboratory using pre-set criteria. However, pre-set criteria are not universally defined and depend on the individual institution's patient population and practices. This mini-review provides practical recommendations on elaborating BCC rate reports, the parameters to define for the pre-set criteria, how to collect and interpret the data, and additional analysis to include in a BCC report.

The effects of regular dental scaling on the complications and mortality after stroke: a retrospective cohort study based on a real-world database

BACKGROUND

Previous observational studies have shown that people with dental scaling (DS) had decreased risk of stroke. However, limited information is available on the association between DS and poststroke outcomes. The present study aimed to evaluate the effects of regular DS on the complications and mortality after stroke.

METHODS

We conducted a retrospective cohort study of 49,547 hospitalized stroke patients who received regular DS using 2010-2017 claims data of Taiwan's National Health Insurance. Using a propensity-score matching procedure, we selected 49,547 women without DS for comparison. Multiple logistic regressions were used to calculate the odds ratios (ORs) and 95% confidence intervals (CIs) of poststroke complications and in-hospital mortality associated with regular DS.

RESULTS

Stroke patients with regular DS had significantly lower risks of poststroke pneumonia (OR 0.58, 95% CI 0.54-0.63), septicemia (OR 0.58, 95% CI 0.54-0.63), urinary tract infection (OR 0.68, 95% CI 0.66-0.71), intensive care (OR 0.81, 95% CI 0.78-0.84), and in-hospital mortality (OR 0.66, 95% CI 0.62-0.71) compared with non-DS stroke patients. Stroke patients with regular DS also had shorter hospital stays (p < 0.0001) and less medical expenditures (p < 0.0001) during stroke admission than the control group. Lower rates of poststroke adverse events in patients with regular DS were noted in both sexes, all age groups, and people with various types of stroke.

CONCLUSION

Stroke patients with regular DS showed fewer complications and lower mortality compared with patients had no DS. These findings suggest the urgent need to promote regular DS for this susceptible population of stroke patients.

The oral microbiome, pancreatic cancer and human diversity in the age of precision medicine

Pancreatic cancer is a deadly disease with limited diagnostic and treatment options. Not all populations are affected equally, as disparities exist in pancreatic cancer prevalence, treatment and outcomes. Recently, next-generation sequencing has facilitated a more comprehensive analysis of the human oral microbiome creating opportunity for its application in precision medicine. Oral microbial shifts occur in patients with pancreatic cancer, which may be appreciated years prior to their diagnosis. In addition, pathogenic bacteria common in the oral cavity have been found within pancreatic tumors. Despite these findings, much remains unknown about how or why the oral microbiome differs in patients with pancreatic cancer. As individuals develop, their oral microbiome reflects both their genotype and environmental influences. Genetics, race/ethnicity, smoking, socioeconomics and age affect the composition of the oral microbiota, which may ultimately play a role in pancreatic carcinogenesis. Multiple mechanisms have been proposed to explain the oral dysbiosis found in patients with pancreatic cancer though they have yet to be confirmed. With a better understanding of the interplay between the oral microbiome and pancreatic cancer, improved diagnostic and therapeutic approaches may be implemented to reduce healthcare disparities. Video Abstract.

The impact of a needs-oriented dental prophylaxis program on bacteremia after toothbrushing and systemic inflammation in children, adolescents, and young adults with chronic kidney disease

BACKGROUND

Chronic kidney disease (CKD) still leads to high mortality rates, mainly due to cardiovascular disease. One important influencing factor is persisting low-grade chronic inflammation partly maintained by gingivitis that favors transient bacteremia during daily activities such as toothbrushing.

METHODS

To examine whether intensive dental prophylaxis can restore oral health, reduce the prevalence of bacteremia and degree of systemic inflammation indicated by CRP levels, we conducted this pilot study examining 30 CKD patients aged 6-26 years, 15 receiving intensive prophylaxis (IP), 15 receiving treatment as usual (TAU) serving as control group. There were three appointments for examination, each 10 ± 1 weeks apart (at baseline, after intervention periods one and two, when TAU also received IP, and the IP group stopped prophylaxis).

RESULTS

The gingival index (GI) in the IP group decreased by 90% (GI 0.09; p=0.001), resulting in almost healthy gingiva. There was no significant change in CRP or prevalence of bacteremia. General prevalence of bacteremia after toothbrushing was 9.5% affecting 7 (26%) of the participants. In three participants, bacteremia dissolved after IP, in one after TAU. Two patients developed bacteremia ≥ 10 weeks after ending IP. We identified eight different bacterial species.

CONCLUSIONS

We were able to show that IP can effectively treat gingivitis. It might be a promising approach to reduce systemic inflammation and subsequently lower premature cardiovascular disease, despite the lack of statistical significance. Future research requires a larger patient cohort to enable matched treatment groups with long-term follow-up and molecular detection methods for bacteremia. A higher resolution version of the Graphical abstract is available as Supplementary information.

Do Periodontal Pathogens or Associated Virulence Factors Have a Deleterious Effect on the Blood-Brain Barrier, Contributing to Alzheimer's Disease?

The central nervous system (CNS) is protected by a highly selective barrier, the blood-brain barrier (BBB), that regulates the exchange and homeostasis of bloodborne molecules, excluding xenobiotics. This barrier forms the first line of defense by prohibiting pathogens from crossing to the CNS. Aging and chronic exposure of the BBB to pathogens renders it permeable, and this may give rise to pathology in the CNS such as Alzheimer's disease (AD). Researchers have linked pathogens associated with periodontitis to neuroinflammation and AD-like pathology in vivo and in vitro. Although the presence of periodontitis-associated bacteria has been linked to AD in several clinical studies as DNA and virulence factors were confirmed in brain samples of human AD subjects, the mechanism by which the bacteria traverse to the brain and potentially influences neuropathology is unknown. In this review, we present current knowledge about the association between periodontitis and AD, the mechanism whereby periodontal pathogens might provoke neuroinflammation and how periodontal pathogens could affect the BBB. We suggest future studies, with emphasis on the use of human in vitro models of cells associated with the BBB to unravel the pathway of entry for these bacteria to the CNS and to reveal the molecular and cellular pathways involved in initiating the AD-like pathology. In conclusion, evidence demonstrate that bacteria associated with periodontitis and their virulence factors are capable of inflecting damage to the BBB and have a role in giving rise to pathology similar to that found in AD.

Evaluation of the Effect of Preoperative Amoxicillin on Bacteremia Associated with Exodontia in Periodontal and Periapical Pathology

AIM

The aim of this study was to evaluate the efficacy of preoperative prophylactic antibiotics of 2 g of oral amoxicillin on bacteremia following extraction of teeth with periodontal and periapical pathology.

MATERIALS AND METHODS

This study was carried out on 160 patients. The patients were divided into four groups of forty patients each: two antibiotic groups, with periodontal and periapical pathology, receiving 2 g of oral amoxicillin preoperatively and two control groups, with periodontal and periapical pathology, receiving no amoxicillin preoperatively. Blood samples were collected before the start of the procedure, intraoperatively, and immediately following extraction of teeth. The collected blood samples were cultured and studied for bacterial growth.

RESULTS

In the control group patients with periodontal pathology, 17 out of 40 blood samples showed growth of Streptococcus viridans along with Staphylococcus epidermidis. In the control group patients with periapical pathology, 14 out of 40 blood samples showed growth of S. viridans and Staphylococcus aureus. No growth was observed in both the groups on prophylactic antibiotics with 2 g of oral amoxicillin.

CONCLUSION

Bacteremia was found in 40% of the control group patients, while there was no bacteremia present in patients with preoperative administration of 2 g of oral amoxicillin.

Investigation of the relationship between periodontal and systemic inflammation in children with Sickle Cell Disease: A case- control study

Periodontal diseases are chronic inflammatory diseases and tissue destruction increases with oxidative stress in periodontal tissues. Periodontal diseases are associated with systemic diseases such as diabetes, cardio-vascular diseases and rheumatoid arthritis by means of systemic inflammation. Sickle cell disease (SCD) is a chronic inflammatory disease in which vaso-occlusive crisis and endothelial dysfunction are present. It is not known whether the chronic systemic inflammation seen in SCD affect periodontal tissues. The aim of this study was to investigate the relationship between periodontal and systemic inflammation in children with SCD. Forty-three children with SCD and 43 healthy children were included in the study. Physical, dental and periodontal statuses were examined, blood and saliva samples were taken. Levels of pro-inflammatory and oxidative stress mediators in serum and saliva were evaluated. The periodontal findings of the groups were similar. The majority of the subjects in both groups had gingival inflammation. In SCD group, significantly higher serum high sensitive C-reactive protein (Hs-CRP), interleukin (IL)-6, IL-8, tumor necrosis factor (TNF)-α, total oxidant status (TOS), nitric oxide (NO) and salivary IL-6 were observed (p < 0.05). There were positive correlations between salivary IL-6 levels and serum Hs-CRP levels (r = 0.303, p < 0.05). In addition; it was determined that salivary IL-6, TNF-α and NO levels were increased 3-6 times in children with a history of painful crisis or acute chest syndrome compared to children who had never had a painful crisis or acute chest syndrome. Although, observed oral health status was similar in both groups, salivary cytokine levels were increased in children with SCD. The higher salivary cytokine levels may be associated with chronic systemic inflammation and vaso-occlusion observed in children with SCD.

Effect of Receiving Dental Treatment on mortality among nursing facility residents

AIM

To assess the association between receipt of different types of dental procedures and mortality among nursing home residents.

METHODS AND RESULTS

Between June 2006 and March 2008, 535 nursing home residents received a health screening assessment and were offered comprehensive dental care. Death certificate data were obtained in September 2013 and multivariable regression models were generated to assess the effect of dental procedures delivered after the screening assessment on mortality, adjusting for demographic and health-related covariates. Residents had a mean age of 85.2 years at baseline and approximately 30% were edentulous. About two-thirds received at least one dental procedure, and about 88% had died, between the screening date and the end of follow-up. Among dentate residents, after adjustment for relevant covariates, for each one-unit increase in the number of intervals during which they received at least one preventive dental procedure there was a 13% decrease in mortality (HR = 0.87, 95% CI = 0.78-0.98) at any given time, while for prosthetic dental procedures there was a 16% decrease in mortality (HR = 0.84, 95% CI = 0.72-0.97). Among edentulous residents, only prosthetic procedures were analyzed, and they were not significantly associated with mortality.

CONCLUSION

Among dentate institutionalized elderly, receipt of preventive or prosthetic dental procedures was associated with decreased mortality.

Medicolegal Causation Investigation of Bacterial Endocarditis Associated with an Oral Surgery Practice Using the INFERENCE Approach

Investigating causation is a primary goal in forensic/legal medicine, aiming to establish the connection between an unlawful/negligent act and an adverse outcome. In malpractice litigation involving a healthcare-associated infection due to a failure of infection prevention and control practices, the medicolegal causal analysis needs to quantify the individual causal probabilities to meet the evidentiary requirements of the court. In this paper, we present the investigation of the most probable cause of bacterial endocarditis in a patient who underwent an invasive procedure at a dental/oral surgical practice where an outbreak of bacterial endocarditis had already been identified by the state Department of Health. We assessed the probability that the patient’s endocarditis was part of the outbreak versus that it was an unrelated sporadic infection using the INFERENCE (Integration of Forensic Epidemiology and the Rigorous Evaluation of Causation Elements) approach to medicolegal causation analysis. This paper describes the step-by-step application of the INFERENCE approach to demonstrate its utility in quantifying the probability of causation. The use of INFERENCE provides the court with an evidence-based, transparent, and reliable guide to determine liability, causation, and damages.

Culturable and Non-Culturable Blood Microbiota of Healthy Individuals

Next-generation sequencing (NGS) and metagenomics revolutionized our capacity for analysis and identification of the microbial communities in complex samples. The existence of a blood microbiome in healthy individuals has been confirmed by sequencing, but some researchers suspect that this is a cell-free circulating DNA in blood, while others have had isolated a limited number of bacterial and fungal species by culture. It is not clear what part of the blood microbiota could be resuscitated and cultured. Here, we quantitatively measured the culturable part of blood microbiota of healthy individuals by testing a medium supplemented with a high concentration of vitamin K (1 mg/mL) and culturing at 43 °C for 24 h. We applied targeted sequencing of 16S rDNA and internal transcribed spacer (ITS) markers on cultured and non-cultured blood samples from 28 healthy individuals. Dominant bacterial phyla among non-cultured samples were Proteobacteria 92.97%, Firmicutes 2.18%, Actinobacteria 1.74% and Planctomycetes 1.55%, while among cultured samples Proteobacteria were 47.83%, Firmicutes 25.85%, Actinobacteria 16.42%, Bacteroidetes 3.48%, Cyanobacteria 2.74%, and Fusobacteria 1.53%. Fungi phyla Basidiomycota, Ascomycota, and unidentified fungi were 65.08%, 17.72%, and 17.2% respectively among non-cultured samples, while among cultured samples they were 58.08%, 21.72%, and 20.2% respectively. In cultured and non-cultured samples we identified 241 OTUs belonging to 40 bacterial orders comprising 66 families and 105 genera. Fungal biodiversity accounted for 272 OTUs distributed in 61 orders, 105 families, and 133 genera. Bacterial orders that remained non-cultured, compared to blood microbiota isolated from fresh blood collection, were Sphingomonadales, Rhizobiales, and Rhodospirillales. Species of orders Bacillales, Lactobacillales, and Corynebacteriales showed the best cultivability. Fungi orders Tremellales, Polyporales, and Filobasidiales were mostly unculturable. Species of fungi orders Pleosporales, Saccharomycetales, and Helotiales were among the culturable ones. In this study, we quantified the capacity of a specific medium applied for culturing of blood microbiota in healthy individuals. Other culturing conditions and media should be tested for optimization and better characterization of blood microbiota in healthy and diseased individuals.

Atrial fibrillation and cardiac arrhythmia associated with acute dental infection: A systematic literature review and case report

OBJECTIVES

This paper outlines how oral diseases such as periodontitis and periapical periodontitis may be linked to cardiovascular disease, atrial fibrillation and cardiac arrhythmia. We undertake a systematic review of the literature focused on acute dental infection and types of cardiac arrhythmia and also describe an illustrative case where an acute dental infection diagnosed as periapical periodontitis was associated with the occurrence of atrial fibrillation.

METHODS

An electronic search was undertaken using MEDLINE and SCOPUS from 01 Jan 1970 to 30 June 2020. We also undertook manual searches using forward and backward citation chasing. Inclusion criteria were any primary research studies investigating any acute dental infection, with outcomes of cardiac arrhythmia or atrial fibrillation.

RESULTS

Over the last fifty years, only two low-quality studies have been investigated in this area. Our illustrative case involved a 58 year-old who was diagnosed with an acute dental infection from an upper canine tooth who then developed atrial fibrillation.

CONCLUSIONS

Based on the biological plausibility of a link between acute dental infection and types of cardiac arrhythmia such as atrial fibrillation, together with the case report presented, it is evident that further study in this area is needed. If there are possible cardiovascular consequences for patients suffering from acute dental infection, then this will have implications for healthcare staff since they can integrate professional advice relating to oral health with cardiovascular disease and atrial fibrillation. Screening programmes situated in dental settings can facilitate early intervention and prevention producing benefits for patients and savings to the health system.

Optimization of treatment and prevention of generalized periodontal diseases with the use of transgingival photoactived disinfection

The aim of the study is to develop protocols for the treatment and prevention of generalized periodontal disease using a nozzle that designed for transgingival photosensitizer activation. Methods. Analysis of available variants of irradiation nozzles for photoactivated disinfection. Circuit design and construction of authors’ irradiation nozzle for transgingival photosensitizer activation. Results. Based on the analysis of data, there was developed a nozzle design that allows treating periodontium areas within 4-6 teeth, evenly distributes the required power of laser radiation, and can be used in hard-to-reach areas of the oral cavity. Based on the above calculations, a nozzle for transgingival photosensitizer activation was created (jointly with Fotonika Plus, PE). To optimize the PAD procedure, there was created a protocol of transgingival photoactivated disinfection to be applied at the stage of professional oral hygiene, using the created irradiation nozzle NOU-9 of authors’ design, and diode 2 W laser LIKA-surgeon with a wavelength of 660 nm. The result is the accelerated procedure of transgingival photoactivated disinfection. Conclusions. The development of photoactivated disinfection technology allows supplementing the traditional treatment of generalized periodontal diseases. Studies of non-invasive, transgingival method of photosensitizer activation have recently become popular. This, in turn, carries a lower probability of cross-infection and less traumatization of periodontal tissues during the manipulation. The use of PAD cannot lead to resistance of the microflora in contrast to pharmacological antibacterial preparations. Carrying out PAD does not require any complex manual skills, the purchase of expensive equipment, provides an opportunity for widespread introduction of technology. The use of the therapeutic complex and protocols of PAD that were developed can significantly reduce the duration of the procedure, resulting in improved comfort for both the doctor and the patient. The NOU-9 irradiation nozzle allows reaching hard-to-reach areas of the oral cavity, distributing laser radiation efficiently and evenly on periodontal tissues. The LIKA-surgeon 2 W laser with a wavelength of 660 nm provides the operating parameters required to activate the photosensitizer. Due to low-intensity radiation, it is possible to enhance regenerative processes in the periodontium after traumatic intervention. Clinical studies on the antibacterial efficacy of the technology are ongoing

Methicillin-Resistant Staphylococcus aureus in the Oral Cavity: Implications for Antibiotic Prophylaxis and Surveillance

The oral cavity harbors a multitude of commensal flora, which may constitute a repository of antibiotic resistance determinants. In the oral cavity, bacteria form biofilms, and this facilitates the acquisition of antibiotic resistance genes through horizontal gene transfer. Recent reports indicate high methicillin-resistant Staphylococcus aureus (MRSA) carriage rates in the oral cavity. Establishment of MRSA in the mouth could be enhanced by the wide usage of antibiotic prophylaxis among at-risk dental procedure candidates. These changes in MRSA epidemiology have important implications for MRSA preventive strategies, clinical practice, as well as the methodological approaches to carriage studies of the organism.

Orthodontics in patients with significant medical co-morbidities

A wide variety of patients with medical co-morbidities may present to general orthodontic practice. It is important for the treating clinician to have a general understanding of key medical conditions that may impact upon the treatment and management options. This clinical supplement provides a treatment-focused summative update for the orthodontist regarding significant medical co-morbidities, their general prevalence and an exploration of potential impacts upon orthodontic treatment. This review also discusses the significance of key medications and provides suggestions for the safe provision of orthodontic treatment.

The Role of the Microbiome in Driving RA-Related Autoimmunity

Once referred to as "normal commensal flora" the human microbiome plays an integral role between health and disease. The host mucosal surface replete with a multitude of immune cells is a vast arena constantly sensing and responding to antigen presentation and microbial by-products. It is this key role that may allow the microbiome to prime or protect the host from autoimmune disease. Rheumatoid arthritis (RA) is a chronic, disabling inflammatory condition characterized by a complex multifactorial etiology. The presence of certain genetic markers has been proven to increase susceptibility to RA however it does not guarantee disease development. Given low concordance rates demonstrated in monozygotic twin studies there is a clear implication for the involvement of external players in RA pathogenesis. Since the historical description of rheumatoid factor, numerous additional autoantibodies have been described in the sera of RA patients. The presence of anti-cyclic citrullinated protein antibody is now a standard test, and is associated with a more severe disease course. Interestingly these antibodies are detectable in patient's sera long before the clinical signs of RA occur. The production of autoantibodies is driven by the lack of tolerance of the immune system, and how tolerance is broken is a crucial question for understanding RA development. Here we review current literature on the role of the microbiome in RA development including periodontal, gut and lung mucosa, with particular focus on proposed mechanisms of host microbiome interactions. We discuss the use of Mendelian randomization to assign causality to the microbiome and present considerations for future studies.

Molecular Characterization of Circulating Microbiome Signatures in Rheumatoid Arthritis

Rheumatoid Arthritis (RA) has been increasingly associated with perturbations to the microbial communities that reside in and on the body (the microbiome), in both human and animal studies. To date, such studies have mainly focused on the microbial communities that inhabit the gut and oral cavity. Mounting evidence suggests that microbial DNA can be detected in the blood circulation using a range of molecular methods. This DNA may represent an untapped pool of biomarkers that have the potential to report on changes to the microbiome of distant sites (e.g., example, the gut and oral cavity). To this end, through amplification and sequencing of the bacterial 16S rRNA variable region four, we evaluated the presence and identity of microbial DNA in blood samples obtained from RA patients (both prior to and 3 months following the instigation of treatment) in comparison to a small number of healthy control subjects and samples obtained from patients with ankylosing spondylitis (AS) and psoriatic arthritis (PA). Bacterial-derived DNA was identified in the majority of our patient samples. Taxonomic classification revealed that the microbiome community in RA was distinct from AS, PA, and the healthy state. Through analysis of paired patient samples obtained prior to and 3 months following treatment (V0 vs. V3), we found the microbiome to be modulated by treatment, and in many cases, this shift reduced the distance between these samples and the healthy control samples, suggesting a partial normalization following treatment in some patients. This effect was especially evident in seronegative arthritis patients. Herein, we provide further evidence for the existence of a blood microbiome in health and identify specific taxa modulated in disease and following treatment. These blood-derived signatures may have significant utility as disease biomarkers and suggest this area warrants further investigation.

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.

Calibrated interdental brushing for the prevention of periodontal pathogens infection in young adults - a randomized controlled clinical trial

Periodontal disease is clearly correlated with systemic disease. The presence of periodontal pathogens in interdental spaces in young, healthy adults is a strong indicator of the need to introduce daily interdental prophylaxis. Twenty-five subjects (aged 18–35 years), diagnosticated clinically as periodontally healthy, were enrolled in this study. One hundred interdental sites were included. Among these sites, 50 “test” sites were cleaned daily with calibrated interdental brushes (IDBs), whereas the other 50 sites were not cleaned and considered “controls”. The interdental biofilm at these interdental sites was collected at the beginning of the study (basal) and at 1 week, 2 weeks, 3 weeks, 4 weeks, and 3 months. Real-time polymerase chain reaction (PCR) methodology was used to quantify (i) 19 periodontal bacteria, including Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, and (ii) total bacteria. In the test sites, the quantity of total bacteria decreased over time with the use of IDBs. The bacteria from the red and orange Socransky complexes, which are associated with periodontal disease, significantly decreased in the test sites but not in the control sites. Bacteria from the yellow, and purple Socransky complexes, which are associated with periodontal health, increased significantly in both groups whereas bacteria from the blue Socransky complex increased significantly only in the test sites. Furthermore, at basal, 66% of test sites and 68% of control sites bled during interdental brushing. These percentages decreased by 85% in 3 months for the test sites and by 27% in the control sites. In conclusion, the daily use of calibrated IDBs can reduce periodontal pathogens, reestablish symbiotic microbiota and, decrease interdental inflammation in interdental sites of healthy young adults.

Dental treatment and recommended management in patients at risk of infective endocarditis

Infective endocarditis (IF) is found in high-risk groups with congenital or acquired cardiac defects. It is caused by episodes of short bacteraemia. The magnitude and duration of bacteraemia caused by dental procedures are decreased by using antibiotic prophylaxis (AP). The aim of this study is to describe and discuss all clinical implications related to IF and dental procedures, and AP before invasive dental procedures. Maintenance of optimal oral health and hygiene is more important than AP in decreasing the risk of IF. Routine daily activities are associated with a similar risk of bacteraemia. It is estimated that antibiotics use in dentistry may represent up to 10% of total antibiotics use, and the risk of developing bacterial resistance should be taken into account.

Inherited nongenetic influences on the gut microbiome and immune system

The gut microbiome and the immune system codevelop around the time of birth, well after genetic information has been passed from the parents to the offspring. Each of these "organ systems" displays plasticity. The immune system can mount highly specific adaptive responses to newly encountered antigens, and the gut microbiota is affected by changes in the environment. Despite this plasticity, there is a growing appreciation that these organ systems, once established, are remarkably stable. In health, the immune system rapidly mounts responses to infections, and once cleared, resolves inflammatory responses to return to homeostasis. However, a skewed immune system, such as seen in allergy, does not easily return to homeostasis. Allergic responses are often seen to multiple antigens. Likewise, a dysbiotic gut microbiota is seen in multiple diseases. Attempts to reset the gut microbiota as a therapy for disease have met with varied success. Therefore, how these codeveloping "organ systems" become established is a central question relevant to our overall health. Recent observations suggest that maternal factors encountered both in utero and after birth can directly or indirectly impact the development of the offspring's gut microbiome and immune system. Here, we discuss how these nongenetic maternal influences can have long-term effects on the progeny's health.

Does chlorhexidine reduce bacteremia following tooth extraction? A systematic review and meta-analysis

Background and aims

Scientific evidence is not clear regarding the use of antimicrobial mouth rinse before dental extraction to reduce bacteremia. We tested the null hypothesis that there would be no difference in the incidence of bacteremia following dental extractions in patients treated with or without chlorhexidine.

Material and methods

We conducted a meta-analysis following the recommendations proposed by PRISMA Preferred Reporting Items for Systematic Reviews and Meta-Analyses. The data sources Pubmed, Cochrane, Web of Science, Science Direct, Scopus, and Ovid MD were searched until April 30, 2017. (chlorhexidine) AND (bacteremia OR bacteraemia) AND (extraction OR removal) were used as key words in a free-text search. Published meeting abstracts were searched. The references of each article were reviewed. We only included randomized controlled clinical trials. There were no restrictions regarding language or date of publication. The outcome measure was the incidence of the bacteremia measured within the first ten minutes post-extraction. Two reviewers independently undertook the risk of bias assessment and data extraction. A fixed-effects inverse variance weighted meta-analysis was conducted.

Results

Out of 18 studies, eight eligible trials with 523 participants were selected, 267 in the experimental group and 256 in the control group: risk ratio = 0.882 (95% confidence interval 0.799 to 0.975; p = 0.014), heterogeneity I² = 13.07%, and p = 0.33. The number needed to treat was 16 (95% CI 7-Infinity).

Conclusions

Approximately 12% of bacteremia cases can be prevented if a population is exposed to chlorhexidine. CRD42016046586.

Relationship between Dental Procedures and Shunt Infections in Hydrocephalic Patients: A Narrative Review

Oral physicians frequently encounter medically compromised patients in their everyday practice and a sizable number of these patients are in urgent need of specialized care. One such medically specialized category is that of patients suffering from hydrocephalus. A large number of medical reports and citations in support of surgical care of the hydrocephalic disorder are available in literature. However, reports on dental studies offer contradictory statements on the relationship between hydrocephalic shunts and oral manoeuvres. The present narrative review aims to delineate the historical journey of the association between shunt infections and dental procedures, decode the existing controversies and provide updated information on antibiotic prophylaxis prior dental treatment for hydrocephalic patients.

Bacteremia after supragingival scaling and dental extraction: Culture and molecular analyses

OBJECTIVE

To study the incidence and magnitude of bacteremia after dental extraction and supragingival scaling.

SUBJECTS AND METHODS

Blood samples were taken before and 5 and 30 min after dental extraction and supragingival scaling from individuals at high (n = 44) or negligible risk (n = 51) for infective endocarditis. The former received prophylactic antibiotic therapy. Samples were subjected to aerobic and anaerobic culture and quantitative real-time polymerase chain reaction to determine the incidence of bacteremia and total bacterial levels.

RESULTS

Patients who did not receive prophylactic antibiotic therapy had a higher incidence of positive blood cultures (30% 5 min after extraction) than patients who received prophylactic antibiotic therapy (0% 5 min after extraction; p < .01). Molecular analysis did not reveal significant differences in the incidence or magnitude of bacteremia between the two patient groups either 5 or 30 min after each of the procedures evaluated. Extraction was associated with higher incidence of bacteremia than supragingival scaling by blood culture (p = .03) and molecular analysis (p = .05).

CONCLUSIONS

Molecular methods revealed that dental extraction and supragingival scaling were associated with similar incidence of bacteremia in groups receiving or not prophylactic antibiotic therapy. However, blood culture revealed that antibiotic therapy reduced viable cultivable bacteria in the bloodstream in the extraction group.

Is antibiotic prophylaxis to prevent infective endocarditis worthwhile?

Infective endocarditis (IE) is a rare condition which is associated with considerable morbidity and mortality. Almost 100 years ago, the links between endocarditis and procedures, particularly dental procedures, were postulated. Over 50 years ago the first guidelines recommending antibiotic prophylaxis (AP), with the aim of preventing IE developing after procedures, were proposed. However, there has only ever been circumstantial evidence in humans that AP prevents IE. The rarity of IE has made a randomised controlled clinical trial impractical to date. This article outlines the history of AP and reviews the evidence base for the use of AP to prevent IE.

Assessment of periodontitis and its role in viridans streptococcal bacteremia and infective endocarditis

OBJECTIVES

To evaluate the role of periodontitis in viridans group streptococci (VGS) bacteremia and infective endocarditis (IE).

METHODS

A total of 200 subjects including two groups. Group A- 34 subjects undergoing tooth extraction with periodontitis, 46 subjects undergoing tooth extraction without periodontitis and 40 healthy controls. Group B: 40 confirmed cases of IE (17 with and 23 without periodontitis) and 40 healthy controls. Subgingival plaque and blood samples were obtained and processed by standard procedures.

RESULTS

A total of 53 blood samples (66.25%) yielded positive cultures after tooth extraction. The relationship between the presence of periodontitis and a positive blood culture was significantly higher (p=0.05) for tooth extraction cases with periodontitis (79.40%) than tooth extraction cases without periodontitis (56.50%). Periodontitis was observed in 42.5% of IE cases. Out of the 40 patients of IE, the blood samples yielded 40 different isolates, majority were viridans streptococci 15 (37.5%) and staphylococci nine (22.5%). No statistically significant difference was observed between the subgingival plaque and blood isolates of periodontitis in both the groups, indicating similarity of biotypes of viridans streptococci isolated from the blood and the subgingival plaque. Similarity was also observed between the antibiogram profiles of viridans streptococci from both the groups.

CONCLUSIONS

Periodontitis enhances viridans streptococcal bacteremia and may be a potential risk factor for IE.

PKC, ERK/p38 MAP kinases and NF-κB targeted signalling play a role in the expression and release of IL-1β and CXCL8 in Porphyromonas gingivalis-infected THP1 cells

Porphyromonas gingivalis is a keystone pathogen in periodontitis and is gaining importance in cardiovascular pathogenesis. Protease-activated receptors (PARs), toll-like receptors (TLRs) and nucleotide-binding oligomerization domain (NOD) on monocytes recognize the structural components on P. gingivalis, inducing inflammatory intermediates. Here, we elucidate the modulation of PARs, TLRs, NODs, and the role of MAPK and NF-κB in IL-1β and CXCL8 release. THP1 cells were stimulated with P. gingivalis wild-type W50 and its isogenic gingipain mutants: Rgp mutant E8 and Kgp mutant K1A. We observed modulation of PARs, TLRs, NOD, IL-1β and CXCL8 expression by P. gingivalis. Gingipains hydrolyse IL-1β and CXCL8, which is more evident for IL-1β accumulation at 24 h. Inhibition of PKC (protein kinase C), p38 and ERK (extracellular signal-regulated kinases) partially reduced P. gingivalis-induced IL-1β at 6 h, whereas PKC and ERK reduced CXCL8 at both 6 and 24 h. Following NF-κB inhibition, P. gingivalis-induced IL-1β and CXCL8 were completely suppressed to basal levels. Overall, TLRs, PARs and NOD possibly act in synergy with PKC, MAPK ERK/p38 and NF-κB in P. gingivalis-induced IL-1β and CXCL8 release from THP1 cells. These pro-inflammatory cytokines could affect leucocytes in circulation and exacerbate other vascular inflammatory conditions such as atherosclerosis.

Bacteremia Associated With Oral Surgery: A Review

OBJECTIVES

Bacterial (infective) endocarditis, a microbial infection of the endocardium surfaces after bacteremia, causes significant morbidity and mortality. Recent epidemiologic studies have reported a prevalence of 2-8 cases per 100,000 individuals per year, with the highest incidence in those aged 70-80 years and those living in developed countries. We systematically reviewed the literature on several critical aspects regarding the development of bacteremia after oral surgery. The purpose of this work is to assess the controversy regarding antibiotic prophylaxis before oral surgery.

MATERIALS AND METHODS

Publications between 1976 and 2015 were included. Clinical studies focusing on oral surgery as the underlying cause were included.

RESULTS

Among the 32 clinical studies reviewed, 3564 cases, accounting for 12,839 blood cultures, were evaluated. In 10 of these studies, amoxicillin usefulness was studied. Antimicrobial prophylaxis before an invasive dental procedure does not prevent bacteremia, although it can decrease both its magnitude and its persistence.

CONCLUSIONS

The highly conflicting data and conclusions of the analyzed work highlight the need for new approaches to the study of bacteremia that would provide reliable evidence and thus appropriate prophylactic and therapeutic standards. Many reports have explored the occurrence of bacteremia after dental procedures, but the results have been conflicting.

Frequent Dental Scaling Is Associated with a Reduced Risk of Periprosthetic Infection following Total Knee Arthroplasty: A Nationwide Population-Based Nested Case-Control Study

Oral bacteremia has been presumed to be an important risk factor for total knee arthroplasty (TKA) infection. We aimed to investigate whether dental scaling could reduce the risk of TKA infection. A nested case-control study was conducted to compare 1,291 TKA patients who underwent resection arthroplasty for infected TKA and 5,004 matched controls without infection in the TKA cohort of Taiwan’s National Health Insurance Research Database (NHIRD). The frequency of dental scaling was analyzed. Multiple conditional logistic regression was used to assess the frequency of dental scaling and the risk of TKA infection. The percentage of patients who received dental scaling was higher in the control group than in the TKA infection group. The risk for TKA infection was 20% lower for patients who received dental scaling at least once within a 3-year period than for patients who never received dental scaling. Moreover, the risk of TKA infection was reduced by 31% among patients who underwent more frequent dental scaling (5–6 times within 3 years). Frequent and regular dental scaling is associated with a reduced risk of TKA infection.

Comparison of independent and dependent culture methods for the detection of transient bacteremia in diabetic subjects with chronic periodontitis

INTRODUCTION

Oral-derived bacteremia may occur after several dental procedures and routine daily activities. Some conditions of the oral cavity may favor episodes of bacteremia. This would be the case of patients with diabetes mellitus and periodontitis, who exhibit exacerbated gingival inflammation and may be more prone to developing oral-derived bacteremia. 

OBJECTIVE

To compare the effectiveness of an independent culture method (quantitative real-time PCR- qCR) and the most commonly used method (BacT-ALERT 3D®) for the diagnosis of bacteremia. 

MATERIALS AND METHODS

Blood samples were drawn from subjects with type 2 diabetes mellitus and chronic periodontitis before and after apple chewing. Samples were processed by an automated blood culture system (BacT-ALERT 3D®) monitored for 15 days with suitable subculture of positive cultures. In parallel, whole DNA from blood samples was purified using a commercial kit and screened by qPCR using a universal primer set of16S rDNA for bacteria detection. 

RESULTS

Blood cultures taken before apple chewing were shown to be negative by the two diagnostic methods. After chewing, two samples (11%) showed bacterial growth by BacT-ALERT 3D® whereas qPCR did not detect the presence of bacteria in any sample. 

CONCLUSIONS

qPCR did not show greater effectiveness than the BacT-ALERT 3D® in the detection of bacteremia of oral origin.

Population-based epidemiology and microbiology of community-onset bloodstream infections

Bloodstream infection (BSI) is a major cause of infectious disease morbidity and mortality worldwide. While a positive blood culture is mandatory for establishment of the presence of a BSI, there are a number of determinants that must be considered for establishment of this entity. Community-onset BSIs are those that occur in outpatients or are first identified <48 h after admission to hospital, and they may be subclassified further as health care associated, when they occur in patients with significant prior health care exposure, or community associated, in other cases. The most common causes of community-onset BSI include Escherichia coli, Staphylococcus aureus, and Streptococcus pneumoniae. Antimicrobial-resistant organisms, including methicillin-resistant Staphylococcus aureus and extended-spectrum β-lactamase/metallo-β-lactamase/carbapenemase-producing Enterobacteriaceae, have emerged as important etiologies of community-onset BSI.

The oxidative stress product carboxyethylpyrrole potentiates TLR2/TLR1 inflammatory signaling in macrophages

Oxidative stress is key in the pathogenesis of several diseases including age-related macular degeneration (AMD), atherosclerosis, diabetes, and Alzheimer's disease. It has previously been established that a lipid peroxidation product, carboxyethylpyrrole (CEP), accumulates in the retinas of AMD patients. Retinal infiltrating macrophages also accumulate in the retinas of both AMD patients and in a murine model of AMD. We therefore investigated the ability of CEP-adducts to activate innate immune signaling in murine bone-marrow derived macrophages (BMDMs). We found that CEP specifically synergizes with low-dose TLR2-agonists (but not agonists for other TLRs) to induce production of inflammatory cytokines. Moreover, CEP selectively augments TLR2/TLR1-signaling instead of TLR2/TLR6-signaling. These studies uncover a novel synergistic inflammatory relationship between an endogenously produced oxidation molecule and a pathogen-derived product, which may have implications in the AMD disease process and other oxidative stress-driven pathologies.