Bacterial and viral pathogens in saliva: disease relationship and infectious risk

Salivary biomarkers: a promising approach for predicting immunotherapy response in head and neck cancers

Head and neck cancers, including cancers of the mouth, throat, voice box, salivary glands, and nose, are a significant global health issue. Radiotherapy and surgery are commonly used treatments. However, due to treatment resistance and disease recurrence, new approaches such as immunotherapy are being explored. Immune checkpoint inhibitors (ICIs) have shown promise, but patient responses vary, necessitating predictive markers to guide appropriate treatment selection. This study investigates the potential of non-invasive biomarkers found in saliva, oral rinses, and tumor-derived exosomes to predict ICI response in head and neck cancer patients. The tumor microenvironment significantly impacts immunotherapy efficacy. Oral biomarkers can provide valuable information on composition, such as immune cell presence and checkpoint expression. Elevated tumor mutation load is also associated with heightened immunogenicity and ICI responsiveness. Furthermore, the oral microbiota may influence treatment outcomes. Current research aims to identify predictive salivary biomarkers. Initial studies indicate that tumor-derived exosomes and miRNAs present in saliva could identify immunosuppressive pathways and predict ICI response. While tissue-based markers like PD-L1 have limitations, combining multiple oral fluid biomarkers could create a robust panel to guide treatment decisions and advance personalized immunotherapy for head and neck cancer patients.

Non-invasive early-stage cancer detection: current methods and future perspectives

This review paper explores the realm of non-invasive methods for early cancer detection. Early identification is crucial for effective therapeutic intervention, and non-invasive techniques have emerged as promising tools to enhance diagnostic accuracy and improve patient outcomes. The paper thoroughly examines the advantages, limitations, and prospects of various non-invasive approaches, including blood tests, non-blood-based tests, and diverse imaging modalities. It discusses the biomarkers found in blood for early-stage cancer detection, specifying the types of cancer associated with each biomarker. The non-blood-based tests focus on components in saliva, urine, and breath for cancer detection, alongside current studies and future perspectives on various cancers. Optical imaging methods covered in this review include fluorescence imaging in the near-infrared (NIR) region, bioluminescence imaging, and Raman spectroscopy for early-stage cancer detection. The review also highlights the pros and cons of ultrasound imaging in early-stage cancer detection. Additionally, the clinical implications of using AI for cancer detection, both present and future, are explored. This paper provides valuable insights for researchers and clinicians working in the field of non-invasive early-stage cancer detection.

Microbial- and host immune cell-derived extracellular vesicles in the pathogenesis and therapy of periodontitis: A narrative review

Periodontitis is a chronic inflammatory disease caused by dysbiotic biofilms and destructive host immune responses. Extracellular vesicles (EVs) are circulating nanoparticles released by microbes and host cells involved in cell-to-cell communication, found in body biofluids, such as saliva and gingival crevicular fluid (GCF). EVs are mainly involved in cell-to-cell communication, and may hold promise for diagnostic and therapeutic purposes. Periodontal research has examined the potential involvement of bacterial- and host-cell-derived EVs in disease pathogenesis, diagnosis, and therapy, but data remains scarce on immune cell- or microbial-derived EVs. In this narrative review, we first provide an overview of the role of microbial and host-derived EVs on disease pathogenesis. Recent studies reveal that Porphyromonas gingivalis and Aggregatibacter actinomycetemcomitans-derived outer membrane vesicles (OMVs) can activate inflammatory cytokine release in host cells, while M1 macrophage EVs may contribute to bone loss. Additionally, we summarised current in vitro and pre-clinical research on the utilisation of immune cell and microbial-derived EVs as potential therapeutic tools in the context of periodontal treatment. Studies indicate that EVs from M2 macrophages and dendritic cells promote bone regeneration in animal models. While bacterial EVs remain underexplored for periodontal therapy, preliminary research suggests that P. gingivalis OMVs hold promise as vaccine candidates. Finally, we acknowledge the current limitations present in the field of translating immune cell derived EVs and microbial derived EVs in periodontology. It is concluded that microbial and host immune cell-derived EVs have a role in periodontitis pathogenesis and hence may be useful for studying disease pathophysiology, and as diagnostic and treatment monitoring biomarkers.

Relationship between oral microbiota and colorectal cancer: A systematic review

This systematic review aims to investigate the microbial basis underlying the association between oral microbiota and colorectal cancer. A comprehensive search was conducted across four databases, encompassing potentially relevant studies published up to April 2024 related to the PECO question: "Is there a differentiation in oral microbial composition between adult patients diagnosed with colorectal cancer compared to healthy patients?". The Newcastle-Ottawa Scale was used to evaluate the quality of the studies included. The level of evidence was assessed through the GRADE (Grading of Recommendations, Assessment, Development and Evaluation) tool. Sixteen studies fulfilled the eligibility criteria. Based on low to moderate evidence profile, high levels of certain subspecies within Firmicutes (such as Streptococcus anginosus, Peptostreptococcus stomatis, S. koreensis, and S. gallolyticus), Prevotella intermedia, Fusobacterium nucleatum, and Neisseria oralis were found to be associated with colorectal cancer. Conversely, certain bacteria (e.g., Lachnospiraceae, F. periodonticum, and P. melaninogenica) could exert a symbiotic protective effect against colorectal cancer. Based on existing evidence, it appears that variations in oral microbiota composition exist among individuals with and without colorectal cancer. However, further research is necessary to determine the mechanisms of oral dysbiosis in colorectal carcinogenesis.

Bacteroides fragilis in saliva: investigating links with ulcerative colitis

BACKGROUND

Ulcerative colitis (UC) is a long-term bowel inflammation of unknown cause. Recent research points to gut microbiota, especially Enterotoxigenic Bacteroides fragilis (ETBF), in UC's development. This study examined the presence of Bacteroides fragilis (B. fragilis) and ETBF in the saliva of UC patients and Healthy Controls (HCs) in Iran.

METHODS

A total of 40 UC patients and 40 healthy controls were included in the study. Saliva samples were collected and analyzed for the presence of B. fragilis and ETBF using real-time polymerase chain reaction (PCR).

RESULTS

B. fragilis was more prevalent in HCs (70%) than UC patients (67.5%), but not significantly (p = 0.809). ETBF was significantly more prevalent in UC patients (50%) than HCs (10%) (p < 0.0001). The mean count of B. fragilis was higher in UC patients, but not significantly (p = 0.47). However, the mean count of ETBF was significantly higher in UC patients (p = 0.000089). In terms of gender, the number of B. fragilis in women was not significant (p = 0.16), but the number of ETBF was significantly higher in women with UC (p = 0.000458). For men, no significant differences were observed.

CONCLUSIONS

The present study suggest a higher prevalence of B. fragilis observed in UC patients compared to HCs. Further research is needed to confirm these findings and explore potential mechanisms underlying this association.

An Anaerobic Culture Study to Assess the Prevalence of Porphyromonas gingivalis in Periodontal Disease Incidences Among Adults

Introduction Periodontitis is a complex condition influenced by various factors involving interactions between the host and bacterial plaque. Porphyromonas gingivalis, an anaerobic gram-negative bacterium, is commonly linked with periodontal disease. Aim This study aimed to examine the occurrence of P. gingivalis in individuals diagnosed with chronic periodontitis (CP) compared to those who show no clinical indications of periodontal disease. Methodology Patients diagnosed with CP (including both severe and moderate cases) and individuals without any signs of periodontal disease were recruited for this study. Samples were collected from the gingival pockets using curettes and were subsequently subjected to anaerobic culturing. Results A group of 30 patients, divided into moderate and severe CP, along with 30 healthy individuals serving as controls, were examined. In individuals with CP, P. gingivalis was found in 23 (78%) of cases, while in healthy individuals, the prevalence was 10 (34%). The presence of P. gingivalis was notably higher in those with periodontal diseases compared to healthy subjects, with rates of 23 (78%) vs. 10 (34%), respectively. Conclusion P. gingivalis is frequently found in individuals with periodontal diseases as well as in those without such conditions, albeit in smaller quantities. Consequently, the existence of P. gingivalis raises the probability of developing periodontal disease and may be regarded as a notable potential contributor to its initiation.

Microbiota of Saliva: A Non-invasive Diagnostic Tool

Potential of salivary microbiota as a non-invasive diagnostic tool for various diseases are explained in the present review. Traditional diagnostic methods rely on blood, which has limitations in terms of collection and biomarker specificity. We discuss the concept of normal flora and how disruptions in oral microbiota can be indicative of diseases. Saliva, harboring a diverse microbial community, offers promise as a diagnostic biomarker source for oral and non-oral conditions. We delve into the role of microbial dysbiosis in disease pathogenesis and the prospects of using biological indicators like dysbiosis for diagnosis, prediction, and monitoring. This review also emphasizes the significance of saliva microbiota in advancing early disease detection and timely intervention. We addressed the following research question and objectives: Can the microbiota of saliva serve as a non-invasive diagnostic tool for the early detection and monitoring of both oral and non-oral diseases? To achieve this, we will explore the normal flora of microorganisms in the oral cavity, the impact of microbial dysbiosis, and the potential of using specific pathogenic microorganisms as biomarkers. Additionally, we will investigate the correlation between oral and non-oral diseases by analyzing total saliva or site-specific dental biofilms for signs of symbiosis or dysbiosis. This research seeks to contribute valuable insights into the development of a non-invasive diagnostic approach with broad applications in healthcare.

Mouthguard-Type Wearable Sensor for Monitoring Salivary Turbidity to Assess Oral Hygiene

Salivary turbidity is a promising indicator for evaluating oral hygiene. This study proposed a wearable mouthguard-type sensor for continuous and unconstrained measurement of salivary turbidity. The sensor evaluated turbidity by measuring the light transmittance of saliva with an LED and a phototransistor sealed inside a double-layered mouthguard. The sensor was also embedded with a Bluetooth wireless module, enabling the wireless measurement of turbidity. The mouthguard materials (polyethylene terephthalate-glycol and ethylene-vinyl acetate) and the wavelength of the LED (405 nm) were experimentally determined to achieve high sensitivity in salivary turbidity measurement. The turbidity quantification characteristic of the proposed sensor was evaluated using a turbidity standard solution, and the sensor was capable of turbidity quantification over a wide dynamic range of 1-4000 FTU (formazine turbidity unit), including reported salivary turbidity (400-800 FTU). In vitro turbidity measurement using a saliva sample showed 553 FTU, which is equivalent to the same sample measured with a spectrophotometer (576 FTU). Moreover, in vivo experiments also showed results equivalent to that measured with a spectrophotometer, and wireless measurement of salivary turbidity was realized using the mouthguard-type sensor. Based on these results, the proposed mouthguard-type sensor has promising potential for the unconstrained continuous evaluation of oral hygiene.

Saliva as a potential non-invasive liquid biopsy for early and easy diagnosis/prognosis of head and neck cancer

Head and neck squamous cell carcinomas (HNSCCs) are the most devastating diseases in India and southeast Asia. It is a preventable and curable disease if detected early. Tobacco and alcohol consumption are the two major risk-factors but infection of high-risk HPVs are also associated with development of predominantly oral and oropharyngeal carcinomas. Interestingly, unlike cervical cancer, HPV-induced HNSCCs show good prognosis and better survival in contrast, majority of tobacco-associated HPV-ve HNSCCs are highly aggressive with poor clinical outcome. Biomarker analysis in circulatory body-fluids for early cancer diagnosis, prognosis and treatment monitoring are becoming important in clinical practice. Early diagnosis using non-invasive saliva for oral or other diseases plays an important role in successful treatment and better prognosis. Saliva mirrors the body's state of health as it comes into direct contact with oral lesions and needs no trained manpower to collect, making it a suitable bio-fluid of choice for screening. Saliva can be used to detect not only virus, bacteria and other biomarkers but variety of molecular and genetic markers for an early detection, treatment and monitoring cancer and other diseases. The performance of saliva-based diagnostics are reported to be highly (≥95 %) sensitive and specific indicating the test's ability to correctly identify true positive or negative cases. This review focuses on the potentials of saliva in the early detection of not only HPV or other pathogens but also identification of highly reliable gene mutations, oral-microbiomes, metabolites, salivary cytokines, non-coding RNAs and exosomal miRNAs. It also discusses the importance of saliva as a reliable, cost-effective and an easy alternative to invasive procedures.

Establishment of a consensus protocol to explore the brain pathobiome in patients with mild cognitive impairment and Alzheimer's disease: Research outline and call for collaboration

Microbial infections of the brain can lead to dementia, and for many decades microbial infections have been implicated in Alzheimer's disease (AD) pathology. However, a causal role for infection in AD remains contentious, and the lack of standardized detection methodologies has led to inconsistent detection/identification of microbes in AD brains. There is a need for a consensus methodology; the Alzheimer's Pathobiome Initiative aims to perform comparative molecular analyses of microbes in post mortem brains versus cerebrospinal fluid, blood, olfactory neuroepithelium, oral/nasopharyngeal tissue, bronchoalveolar, urinary, and gut/stool samples. Diverse extraction methodologies, polymerase chain reaction and sequencing techniques, and bioinformatic tools will be evaluated, in addition to direct microbial culture and metabolomic techniques. The goal is to provide a roadmap for detecting infectious agents in patients with mild cognitive impairment or AD. Positive findings would then prompt tailoring of antimicrobial treatments that might attenuate or remit mounting clinical deficits in a subset of patients.

Effectiveness of Herbal, Homeopathic and Conventional Dentifrices on Dental Caries - A Double-Blind Randomised Controlled Trial

PURPOSE

To compare the effectiveness of ayurvedic, homeopathic and conventional dentifrices on plaque and saliva in terms of cariogenic bacteria, salivary pH, and plaque pH.

MATERIALS AND METHODS

This double-blinded, parallel-group, randomised controlled trial was performed at Saveetha Dental College and Hospitals, Chennai, India. The participants comprised healthy adults possessing more than 20 permanent natural teeth and having a Decayed Missing and Filled Teeth (DMFT) score, plaque index score, and gingival index score less than or equal to 2. There were 3 intervention groups: 1: herbal dentifrice (Dabur Meswak); 2: homeopathic dentifrice (Gum Forte gel); 3: fluoride dentifrice (Colgate Total). The outcome measures were as follows: plaque and saliva samples were evaluated for pH; colony counts of Streptococcus mutans and Lactobacillus at baseline, 14 and 28 days of follow-up. One-way and repeated measures ANOVA, Wilcoxon signed-rank and Kruskal Wallis tests were used to compare the mean differences of plaque and salivary pH and plaque and salivary S. mutans and Lactobacillus counts at baseline, 14 and 28 days.

RESULTS

The mean S. mutans and Lactobacillus counts in plaque and saliva decreased statistically significantly in all treatment groups at the 28-day follow-up. Mean plaque pH was not statistically significantly different at the 14-day follow-up (p-value = 0.16). On the 28th day, group 1 (7.64 ± 0.20) showed the highest increase in plaque pH followed by group 2 (7.39 ± 0.25) and group 3 (7.27 ± 0.19), which was found to be statistically significant. No statistically significant difference in mean salivary pH was observed between the three groups at the different time points.

CONCLUSION

This study reveals that the herbal dentifrice tested here was effective in reducing cariogenic bacterial count and increasing the plaque pH, thereby warranting the usage of the same.

Viscoelasticity enhances collective motion of bacteria

Bacteria form human and animal microbiota. They are the leading causes of many infections and constitute an important class of active matter. Concentrated bacterial suspensions exhibit large-scale turbulent-like locomotion and swarming. While the collective behavior of bacteria in Newtonian fluids is relatively well understood, many fundamental questions remain open for complex fluids. Here, we report on the collective bacterial motion in a representative biological non-Newtonian viscoelastic environment exemplified by mucus. Experiments are performed with synthetic porcine gastric mucus, natural cow cervical mucus, and a Newtonian-like polymer solution. We have found that an increase in mucin concentration and, correspondingly, an increase in the suspension's elasticity monotonously increases the length scale of collective bacterial locomotion. On the contrary, this length remains practically unchanged in Newtonian polymer solution in a wide range of concentrations. The experimental observations are supported by computational modeling. Our results provide insight into how viscoelasticity affects the spatiotemporal organization of bacterial active matter. They also expand our understanding of bacterial colonization of mucosal surfaces and the onset of antibiotic resistance due to swarming.

Salivary and fecal microbiota: potential new biomarkers for early screening of colorectal polyps

Objective

Gut microbiota plays an important role in colorectal cancer (CRC) pathogenesis through microbes and their metabolites, while oral pathogens are the major components of CRC-associated microbes. Multiple studies have identified gut and fecal microbiome-derived biomarkers for precursors lesions of CRC detection. However, few studies have used salivary samples to predict colorectal polyps. Therefore, in order to find new noninvasive colorectal polyp biomarkers, we searched into the differences in fecal and salivary microbiota between patients with colorectal polyps and healthy controls.

Methods

In this case-control study, we collected salivary and fecal samples from 33 patients with colorectal polyps (CP) and 22 healthy controls (HC) between May 2021 and November 2022. All samples were sequenced using full-length 16S rRNA sequencing and compared with the Nucleotide Sequence Database. The salivary and fecal microbiota signature of colorectal polyps was established by alpha and beta diversity, Linear discriminant analysis Effect Size (LEfSe) and random forest model analysis. In addition, the possibility of microbiota in identifying colorectal polyps was assessed by Receiver Operating Characteristic Curve (ROC).

Results

In comparison to the HC group, the CP group's microbial diversity increased in saliva and decreased in feces (p < 0.05), but there was no significantly difference in microbiota richness (p > 0.05). The principal coordinate analysis revealed significant differences in β-diversity of salivary and fecal microbiota between the CP and HC groups. Moreover, LEfSe analysis at the species level identified Porphyromonas gingivalis, Fusobacterium nucleatum, Leptotrichia wadei, Prevotella intermedia, and Megasphaera micronuciformis as the major contributors to the salivary microbiota, and Ruminococcus gnavus, Bacteroides ovatus, Parabacteroides distasonis, Citrobacter freundii, and Clostridium symbiosum to the fecal microbiota of patients with polyps. Salivary and fecal bacterial biomarkers showed Area Under ROC Curve of 0.8167 and 0.8051, respectively, which determined the potential of diagnostic markers in distinguishing patients with colorectal polyps from controls, and it increased to 0.8217 when salivary and fecal biomarkers were combined.

Conclusion

The composition and diversity of the salivary and fecal microbiota were significantly different in colorectal polyp patients compared to healthy controls, with an increased abundance of harmful bacteria and a decreased abundance of beneficial bacteria. A promising non-invasive tool for the detection of colorectal polyps can be provided by potential biomarkers based on the microbiota of the saliva and feces.

Ten-year prevalence of acute hospital ENT infections and the impact of COVID: A large population study

BACKGROUND

Acute ear, nose and throat (ENT) infections were the commonest referrals from accident and emergency to ENT services. The referral rate changed dramatically with season, year, national outbreaks and during the COVID pandemic.

METHOD

Retrospective longitudinal study of the epidemiology of seven acute ENT infections in secondary care over 10 years. A mixed city and rural population of over 650 000 in central England was studied. The risk factors for each wave of infection during the surge of infection were sought. A statistical analysis of their significance was undertaken. This included analysis and correlation of group A-beta haemolytic streptococcus (GABHS) in hospital and community. Seasonal variations, hospital admissions and the impact of the COVID were analysed.

RESULTS

There were 16 883 reported cases of the seven index ENT infections during the 10-year period. Great seasonal and year-to-year variations were recorded. There was an incremental rise in 2018. Spring had the highest season of acute ENT infections. An outbreak of GABHS was noted in the community in 2014. The mean duration of hospital admission was 1.5 days. There was no statistical ethnic or gender predominance. A dramatically lower number of acute ENT infections were recorded during the COVID-19 pandemic, and this continued after lifting of lockdown restrictions.

CONCLUSION

A resurgence in scarlet fever directly and indirectly contributed to an incremental rise in acute ENT infections in the following years. Both hospital and community B-haemolytic cultures have declined during the COVID-19 pandemic due to a reduction in infections as opposed to reduced case ascertainment.

Oral Bacterial Microbiota in Digestive Cancer Patients: A Systematic Review

The relation between the gut microbiota and human health is increasingly recognized. Recently, some evidence suggested that dysbiosis of the oral microbiota may be involved in the development of digestive cancers. A systematic review was conducted according to the PRISMA guidelines to investigate the association between the oral microbiota and digestive cancers. Several databases including Medline, Scopus, and Embase were searched by three independent reviewers, without date restriction. Over a total of 1654 records initially identified, 28 studies (2 prospective cohort studies and 26 case-controls) were selected. They investigated oral microbiota composition in patients with esophageal squamous cell carcinoma (n = 5), gastric cancer (n = 5), colorectal cancer (n = 9), liver carcinoma (n = 2), and pancreatic cancer (n = 7). In most of the studies, oral microbiota composition was found to be different between digestive cancer patients and controls. Particularly, oral microbiota dysbiosis and specific bacteria, such as Fusobacterium nucleatum and Porphyromonas gingivalis, appeared to be associated with colorectal cancers. Current evidence suggests that differences exist in oral microbiota composition between patients with and without digestive cancers. Further studies are required to investigate and validate oral-gut microbial transmission patterns and their role in digestive cancer carcinogenesis.

A New Specimen for Syphilis Diagnosis: Evidence by High Loads of Treponema pallidum DNA in Saliva

BACKGROUND

DNA from many pathogens can be detected in saliva. However, the presence and quantity of Treponema pallidum DNA in patients with syphilis in saliva is unknown.

METHODS

234 patients with syphilis with different stages and 30 volunteers were enrolled. Paired saliva and plasma samples were collected from all participants. Consecutive saliva samples from 9 patients were collected every 4 hours following treatment. Treponema pallidum DNA in samples was determined by nested polymerase chain reaction (PCR) and droplet digital PCR targeting polA and Tpp47.

RESULTS

Treponema pallidum DNA detection rates in saliva and plasma were 31.0% (9/29) and 51.7% (15/29) in primary syphilis (P = .11), 87.5% (63/72) and 61.1% (44/72) in secondary syphilis (P < .001), 25.6% (21/82) and 8.5% (7/82) in latent syphilis (P = .004), and 21.6% (11/51) and 5.9% (3/51) in symptomatic neurosyphilis (P = .021), respectively. Median (range) loads of Tpp47 and polA in saliva were 627 (0-101 200) and 726 (0-117 260) copies/mL, respectively, for patients with syphilis. In plasma, however, loads of Tpp47 and polA were low: medians (range) of 0 (0-149.6) and 0 (0-176) copies/mL, respectively. Loads of T. pallidum DNA in saliva during treatment fluctuated downward; the clearance time was positively correlated with the loads of T. pallidum DNA before treatment.

CONCLUSIONS

Collection of saliva is noninvasive and convenient. The high loads of T. pallidum DNA in saliva and reduction after treatment indicated that saliva can be not only a diagnostic fluid for syphilis but also an indicator of therapeutic effectiveness.

Direct detection of SARS-CoV-2 antisense and sense genomic RNA in human saliva by semi-autonomous fluorescence in situ hybridization: A proxy for contagiousness?

Saliva is a matrix which may act as a vector for pathogen transmission and may serve as a possible proxy for SARS-CoV-2 contagiousness. Therefore, the possibility of detection of intracellular SARS-CoV-2 in saliva by means of fluorescence in situ hybridization is tested, utilizing probes targeting the antisense or sense genomic RNA of SARS-CoV-2. This method was applied in a pilot study with saliva samples collected from healthy persons and those presenting with mild or moderate COVID-19 symptoms. In all participants, saliva appeared a suitable matrix for the detection of SARS-CoV-2. Among the healthy, mild COVID-19-symptomatic and moderate COVID-19-symptomatic persons, 0%, 90% and 100% tested positive for SARS-CoV-2, respectively. Moreover, the procedure allows for simultaneous measurement of viral load ('presence', sense genomic SARS-CoV-2 RNA) and viral replication ('activity', antisense genomic SARS-CoV-2 RNA) and may yield qualitative results. In addition, the visualization of DNA in the cells in saliva provides an additional cytological context to the validity and interpretability of the test results. The method described in this pilot study may be a valuable diagnostic tool for detection of SARS-CoV-2, distinguishing between 'presence' (viral load) and 'activity' (viral replication) of the virus. Moreover, the method potentially gives more information about possible contagiousness.

Supercritical fluid extraction-supercritical fluid chromatography of saliva: Single-quadrupole mass spectrometry monitoring of caffeine for gastric emptying studies†

Saliva is an attractive sampling matrix for measuring various endogenous and exogeneous substances but requires sample treatment prior to chromatographic analysis. Exploiting supercritical CO₂ for both extraction and chromatography simplifies sample preparation, reduces organic solvent consumption, and minimizes exposure to potentially infectious samples, but has not yet been applied to oral fluid. Here, we demonstrate the feasibility and benefits of online supercritical fluid extraction coupled to supercritical fluid chromatography and single-quadrupole mass spectrometry for monitoring the model salivary tracer caffeine. A comparison of ¹³ C- and ³² S-labeled internal standards with external standard calibration confirmed the superiority of stable isotope-labeled caffeine over nonanalogous internal standards. As proof of concept, the validated method was applied to saliva from a magnetic resonance imaging study of gastric emptying. After administration of 35 mg caffeine via ice capsule, salivary levels correlated with magnetic resonance imaging data, corroborating caffeine's usefulness as tracer of gastric emptying (R²  = 0.945). In contrast to off-line methods, online quantification required only minute amounts of organic solvents and a single manual operation prior to online bioanalysis of saliva, thus demonstrating the usefulness of CO₂ -based extraction and separation techniques for potentially infective biomatrices.

Legionnaires' disease in dental offices: Quantifying aerosol risks to dental workers and patients

Legionella pneumophila is an opportunistic bacterial respiratory pathogen that is one of the leading causes of drinking water outbreaks in the United States. Dental offices pose a potential risk for inhalation or aspiration of L. pneumophila due to the high surface area to volume ratio of dental unit water lines-a feature that is conducive to biofilm growth. This is coupled with the use of high-pressure water devices (e.g., ultrasonic scalers) that produce fine aerosols within the breathing zone. Prior research confirms that L. pneumophila occurs in dental unit water lines, but the associated human health risks have not been assessed. We aimed to: (1) synthesize the evidence for transmission and management of Legionnaires' disease in dental offices; (2) create a quantitative modeling framework for predicting associated L. pneumophila infection risk; and (3) highlight influential parameters and research gaps requiring further study. We reviewed outbreaks, management guidance, and exposure studies and used these data to parameterize a quantitative microbial risk assessment (QMRA) model for L. pneumophila in dental applications. Probabilities of infection for dental hygienists and patients were assessed on a per-exposure and annual basis. We also assessed the impact of varying ventilation rates and the use of personal protective equipment (PPE). Following an instrument purge (i.e., flush) and with a ventilation rate of 1.2 air changes per hour, the median per-exposure probability of infection for dental hygienists and patients exceeded a 1-in-10,000 infection risk benchmark. Per-exposure risks for workers during a purge and annual risks for workers wearing N95 masks did not exceed the benchmark. Increasing air change rates in the treatment room from 1.2 to 10 would achieve an ∼85% risk reduction, while utilization of N95 respirators would reduce risks by ∼95%. The concentration of L. pneumophila in dental unit water lines was a dominant parameter in the model and driver of risk. Future risk assessment efforts and refinement of microbiological control protocols would benefit from expanded occurrence datasets for L. pneumophila in dental applications.

Oral lichen planus: a microbiologist point of view

Oral lichen planus (OLP) is a chronic disease of uncertain etiology, although it is generally considered as an immune-mediated disease that affects the mucous membranes and even the skin and nails. Over the years, this disease was attributed to a variety of causes, including different types of microorganisms. This review analyzes the present state of the art of the disease, from a microbiological point of view, while considering whether or not the possibility of a microbial origin for the disease can be supported. From the evidence presented here, OLP should be considered an immunological disease, as it was initially proposed, as opposed to an illness of microbiological origin. The different microorganisms so far described as putative disease-causing agents do not fulfill Koch’s postulates; they are, actually, not the cause, but a result of the disease that provides the right circumstances for microbial colonization. This means that, at this stage, and unless new data becomes available, no microorganism can be envisaged as the causative agent of lichen planus.

Prevalence and correlates of spitting on police officers: New risks in the COVID era

OBJECTIVES

Spitting is an occupational hazard of police work with increased risk due to the COVID-19 pandemic. We sought to calculate the prevalence of spitting on police officers in use of force incidents, as well as the demographic and situational factors associated with spitting.

METHODS

Data on spitting were compiled from more than 10,000 use of force incidents occurring at 81 agencies in eight different states in the US.

RESULTS

Spitting occurred in 3.6% of cases. Female and younger subjects and those using drugs and/or alcohol are more likely to spit on officers. Spitting is more likely to occur in incidents of longer duration, when officers use less force relative to subject resistance, when subjects are assaultive or engage in self-harm, and when subjects are hobbled.

CONCLUSIONS

Spitting on officers is common and may now constitute a significant work hazard. Implications for police practice are discussed.

An innovative risk-scoring system of dental procedures and safety protocols in the COVID-19 era

BACKGROUND

The aim of this paper is to assess an innovative risk score for common dental procedures, based on the most recent contaminant SARS-CoV-2. After scoring the level of infection risk, safety procedures, advice and personal protective equipment (PPE) are recommended for the dental team in each dental practice.

METHODS

The authors of this research analysed 42 common dental procedures on the basis of known transmission risks. In increasing order, many consider the parameters leading to different risk scores for the dental team and patients for each procedure to be: direct contact with saliva (score 1), direct contact with blood (score 2), production of low levels of spray/aerosol via air-water syringes (score 3), the production of high levels of spray/aerosol from rotating, ultrasound and piezoelectric tools (score 4); and the duration of the procedure, which may increase the risk of procedures producing droplets and aerosols.

RESULTS

Using this innovative risk-scoring system, the authors classified the different dental procedures according to low, medium or high risk: low (1-3), medium (4-5), high (≥ 6). A safety protocol for each procedure was thereafter matched with the calculated risk level.

CONCLUSIONS

The innovative risk-scoring system presented in this research permits the reclassification of dental procedures according to the infection risk level. Consequently, specific procedures, previously considered as entry level, will now merit revision. This paper also highlighted an effective and routine clinical tool for general dentists and oral medicine practitioners.

Intraoral human herpes viruses detectable by PCR in majority of patients

OBJECTIVES

To identify factors which influence the intraoral prevalence of human herpes viruses (HHVs) using mucosal swabs, saliva samples and qPCR analysis.

METHODOLOGY

In this cross-sectional observational study, matched saliva and oral swabs were collected from a total of 115 subjects: 70 immunocompetent subjects with no mucosal abnormalities, 22 with mucosal abnormalities and 23 therapeutically immunocompromised individuals. Extracted DNA was analysed by multiplex qPCR for detection and quantification of HHVs 1-6.

RESULTS

At least one human herpes virus was detected in 77.1% of immunocompetent individuals with no mucosal abnormalities, with EBV the most commonly detected at 61.4%. HHV-6 was detected in 17.1%, HSV-1 in 4.3% and CMV in 1.1%. Detection was higher in saliva than in oral swabs. There was no detection of HSV-2 or VZV. Neither presence of oral mucosal abnormality nor therapeutic immunocompromise was related to increased detection of human herpes virus.

CONCLUSION

Commensal detection rates of EBV are high, and caution in clinical correlation of positive detection is warranted. Commensal CMV rates are low, and detection is likely to be clinically relevant. This study presents a comprehensive commensal detection rate of HHVs 1-6 by qPCR in saliva and swabs.

From conifers to cognition: Microbes, brain and behavior

A diversity of bacteria, protozoans and viruses ("endozoites") were recently uncovered within healthy tissues including the human brain. By contrast, it was already recognized a century ago that healthy plants tissues contain abundant endogenous microbes ("endophytes"). Taking endophytes as an informative precedent, we overview the nature, prevalence, and role of endozoites in mammalian tissues, centrally focusing on the brain, concluding that endozoites are ubiquitous in diverse tissues. These passengers often remain subclinical, but they are not silent. We address their routes of entry, mechanisms of persistence, tissue specificity, and potential to cause long-term behavioral changes and/or immunosuppression in mammals, where rabies virus is the exemplar. We extend the discussion to Herpesviridae, Coronaviridae, and Toxoplasma, as well as to diverse bacteria and yeasts, and debate the advantages and disadvantages that endozoite infection might afford to the host and to the ecosystem. We provide a clinical perspective in which endozoites are implicated in neurodegenerative disease, anxiety/depression, and schizophrenia. We conclude that endozoites are instrumental in the delicate balance between health and disease, including age-related brain disease, and that endozoites have played an important role in the evolution of brain function and human behavior.

Neutrophil gelatinase associated lipocalin a biomarker for bacterial-induced pharyngeal infection-A pilot study

OBJECTIVES

Neutrophil gelatinase associated lipocalin (NGAL) is secreted from activated neutrophil granulocytes and is considered an acute phase protein. The aim of this pilot study was to determine whether the NGAL concentration in saliva increases in response to a bacterial throat infection and identify pitfalls, which shall be taken into account in a protocol in a larger hypothesis testing study.

METHODS

Saliva samples for measurement of NGAL concentration where obtained from cases with an acute throat infection (n = 21) and controls (n = 24). Among cases, plasma NGAL, plasma CRP, and whole blood leukocytes, were measured as well.

RESULTS

There was no significant difference in NGAL saliva concentration between cases and controls overall (p = .31). For both cases and controls, the saliva NGAL concentration decreased significantly after cleansing the mouth with tap water (cases p = .01; controls p = .01). Among cases, a significant positive correlation between saliva NGAL concentrations before mouth cleansing and plasma CRP concentrations (p = .001) was observed. Blood neutrophil granulocyte count presented a nonsignificant positive correlation to saliva NGAL (p = .07).

CONCLUSION

We could not demonstrate a simple association between the salivary NGAL concentration and pharyngeal bacterial infection. Furthermore, the salivary NGAL concentrations were higher among some controls than cases, suggesting that cofounders for example, periodontitis, uneven salivary dilution level, or other exogenous factors affect salivary NGAL content.

Periodontal disease and detection of human herpesviruses in saliva and gingival crevicular fluid of chronic kidney disease patients

BACKGROUND

Patients with chronic kidney disease (CKD) have inability to maintain the normal levels of protein metabolism products, blood pressure and hematocrit. Periodontal disease involves an inflammatory destructive process. Identification of opportunistic viruses is extremely important as they are associated with co-morbidities. The objective of this study was to analyse the presence of human herpesviruses in saliva and gingival crevicular fluid (GCF) from patients with CKD.

METHODS

One hundred and thirty one individuals were divided depending on the stage of CKD: Group 1 (clearance of creatinine > 75 mL/min) patients with no renal disease (n = 24); Group 2 (clearance of creatinine of 11-75 mL/min) patients with renal disease (n = 67); Group 3 (clearance of creatinine < 10 mL/min) patients on hemodialysis (n = 40). The parameters of periodontal disease were evaluated. The viral detection was assessed by PCR.

RESULTS

considering the three groups, the prevalence of herpes simplex virus 1 (HSV-1) were 9% in saliva and 5% in GCF; Epstein-Barr virus 36% in saliva and 39% in GCF; human cytomegalovirus (HCMV) 11% in GCF; varicella zoster virus 6% in saliva and 3% in GCF; of human herpesvirus-6 (HHV-6) 6% in saliva and 2% in GCF; and HHV-7 44% in saliva and 8% in GCF. Of these patients, 46.48% presented with severe periodontitis. A statistically significant association between HSV-1 and HCMV was found in hemodialysis patients and severe periodontitis was also more frequent among them.

CONCLUSION

These findings show the importance of evaluating the periodontal disease and detecting herpesviruses in patients with CKD as the inflammatory process observed in these clinical conditions may worsen the course of both periodontal disease and CKD.

Oral Microbiota as Promising Diagnostic Biomarkers for Gastrointestinal Cancer: A Systematic Review

Emerging evidence has shown the potential of oral microbiota as a noninvasive diagnostic tool in gastrointestinal (GI) cancer. PubMed, Web of Science, and Embase were systematically searched for eligible studies published until May 31, 2019. Of the 17 included studies published between 2011 and 2019, five kinds of GI cancer, including colorectal cancer (n=6), pancreatic cancer (n=5), gastric cancer (n=4), esophageal cancer (n=2) and liver cancer (n=1), were reported. Generally, the diagnostic performance of the multi-bacteria model for GI cancer was strong with the best area under the receiver operator characteristic curve (AUC) exceeding 0.90, but only one study had a validation phase. Pathogens involved in periodontal disease, such as Porphyromonas gingivalis and Tannerella forsythia, were linked to various kinds of GI cancer. Besides, more oral bacteria significantly differed between cases with upper digestive cancer and healthy controls when compared to colorectal cancer (the most common form of lower digestive cancer), probably indicating a different mechanism due to anatomical and physiological differences in the digestive tract. Oral microbiota changes were associated with risk of various kinds of GI cancer, which could be considered as a potential tool for early prediction and prevention of GI cancer, but validation based on a large population, reproducible protocols for oral microbiota research and oral-gut microbiota transmission patterns are required to be resolved in further studies.

Comparing the Effectiveness of Probiotic, Green Tea, and Chlorhexidine- and Fluoride-containing Dentifrices on Oral Microbial Flora: A Double-blind, Randomized Clinical Trial

Introduction:

Oral cavity harbors wide variety of microorganisms; these are considered crucial for the dental caries initiation and progression. Plaque-induced caries is a local disease; therefore, dentifrices are the most ideal vehicle for the daily delivery of antibacterial agents. In recent years, alternatives to fluorides such as green tea, probiotic, and chlorhexidine (CHX) toothpastes have been proposed to possess antiplaque and anticariogenic properties.

Aim:

To compare the effectiveness of probiotic, green tea, and CHX- and fluoride-containing dentifrices on oral microbial flora.

Materials and Methods:

A double-blinded, parallel group, randomized controlled clinical trial was conducted among healthy adults. Fifty-two individuals were randomly allocated to four groups (n = 13): Group I – green tea dentifrice, Group II – fluoridated dentifrice, Group III – CHX dentifrice, and Group IV – probiotic dentifrice. Plaque and saliva samples were evaluated for Streptococcus mutans and Lactobacillus at baseline and 15^th and 30^th days of follow-up. Paired t-test and one-way ANOVA were used to compare the mean differences of plaque and salivary S. mutans counts at two and three time periods. Wilcoxon signed-rank and Kruskal–Wallis tests were used to compare the mean Lactobacillus count in plaque and saliva samples at two and three time periods, respectively.

Results:

The mean S. mutans and Lactobacillus counts in plaque and saliva samples were significantly reduced by all the treatment groups at the 30^th day of follow-up. However, Group III showed the highest reduction and was found to be statistically significant (P < 0.05).

Conclusion:

All the four groups exhibited antimicrobial activity by bringing about a significant reduction in the mean S. mutans and Lactobacillus colony counts at the 30^th day of follow-up. Among all the preventive modalities, Group III (CHX dentifrice) showed better results compared to other groups.

Periodontal herpesvirus morbidity and treatment

Four billion individuals worldwide have a history of periodontitis, with the poorest people in society most affected. Periodontitis can lead to unsightly drifting of teeth and tooth loss that may interfere with the wellbeing of daily living and has also been linked to at least 57 medical diseases and disabilities. The etiology of severe periodontitis includes active herpesviruses, specific bacterial pathogens, and destructive immune responses, but herpesviruses seem to be the major pathogenic determinant. Periodontal herpesviruses that disseminate via the systemic circulation to nonoral sites may represent a major link between periodontitis and systemic diseases. Current treatment of periodontitis focuses almost exclusively on bacterial biofilm and will require revision. Periodontal therapy that targets both herpesviruses and bacterial pathogens can provide long-term clinical improvement and potentially reduces the risk of systemic diseases. Molecular diagnostic tests for periodontal pathogens may enable early microbial identification and preemptive therapy. This review details an efficient and reliable anti-infective treatment of severe periodontitis that can be carried out in minimal time with minimal cost.

Molecular tools for preventing and improving diagnosis of peri-implant diseases

Peri-implantitis is an inflammatory disease of tissues surrounding osseointegrated dental implants. Inflammation affecting soft and hard peri-implant tissues can cause alveolar bone resorption and subsequent implant loss. Clinical surveillance and early diagnosis are of paramount importance to reduce clinical failures and improve implant survival. Current diagnosis of implants is based on clinical and radiological signs. Molecular tests are an emerging diagnostic methodology, which potentially can help to detect and prevent early peri-implantitis and monitor the efficacy of therapy as well. A plethora of potential biomarkers are potentially available to support the clinical diagnosis of peri-implantitis. However, conflicting diagnostic conclusions have been reached, probably related to weak statistical results due to limited sample size or disease heterogeneity. The present paper reviews candidate diagnostic biomarkers for peri-implantitis, including infective agents, genetic susceptibility factors, and key proteins related to inflammation and tissue remodeling.

Comparing bacterial, fungal, and human cell concentrations with rapid adenosine triphosphate measurements for indicating microbial surface contamination

BACKGROUND

The goal of this study was to test for associations between adenosine triphosphate (ATP) content and microbial concentrations on desk surfaces in school classrooms.

METHODS

ATP bioluminescence and quantitative polymerase chain reaction (qPCR) techniques were employed to measure total bacterial, fungal, and human cell concentrations on 66 high-traffic desks spread across 9 schools: 3 in Connecticut (CT) and 6 in Oklahoma (OK). In CT, 6 samples were taken from each desk, 1 precleaning and 5 postcleaning (after 30 minutes, 1 day, 3 days, 7 days, and 21 days). In OK, samples were taken immediately before and after cleaning each desk.

RESULTS

Based on simple linear regression analyses, ATP values were good predictors of microbial concentrations (r = 0.8, P = .003) in both CT school postcleaning samples and OK pre- and postcleaning samples (r = 0.7, P = .00002). However, biomass reductions measured after cleaning were 1.5-2 times greater when measured by ATP than by qPCR (P = .007).

CONCLUSIONS

Overall, ATP bioluminescence measurements correlate with qPCR-based surface measurements on school desks but may overestimate the physical removal of bacteria and fungi due to cleaning.

Microbial species associated with dental caries found in saliva and in situ after use of self-ligating and conventional brackets

Objectives

Enamel demineralization is among the main topics of interest in the orthodontic field. Self-ligating brackets have been regarded as advantageous in this aspect. The aim of this study was to evaluate the break homeostasis in the oral environment and the levels of microorganisms associated with dental caries among the different types of brackets.

Material and Methods

Twenty patients received two self-ligating brackets: In-Ovation^®R, SmartClip^TM, and one conventional Gemini^TM. Saliva was collected before bonding (S0), 30 (S1) and 60 (S2) days after bonding. One sample of each bracket was removed at 30 and 60 days for the in situ analysis. Checkerboard DNA-DNA Hybridization was employed to evaluate the levels of microbial species as-sociated with dental caries. Data were evaluated by nonparametric Friedman and Wilcoxon tests at 5% significance level.

Results

The salivary levels of L. casei (p=0.033), S. sobrinus (p=0.011), and S. sanguinis (p=0.004) increased in S1. The in situ analyses showed alteration in S. mutans (p=0.047), whose highest levels were observed to the In-Ovation^®R.

Conclusions

The orthodontic appliances break the salivary homeostasis of microorganisms involved in dental caries. The contamination pattern was different between self-ligating and conventional brackets. The In-Ovation^®R presented worse performance considering the levels of cariogenic bacterial species.

Microbial Degradation of Forensic Samples of Biological Origin: Potential Threat to Human DNA Typing

Forensic biology is a sub-discipline of biological science with an amalgam of other branches of science used in the criminal justice system. Any nucleated cell/tissue harbouring DNA, either live or dead, can be used as forensic exhibits, a source of investigation through DNA typing. These biological materials of human origin are rich source of proteins, carbohydrates, lipids, trace elements as well as water and, thus, provide a virtuous milieu for the growth of microbes. The obstinate microbial growth augments the degradation process and is amplified with the passage of time and improper storage of the biological materials. Degradation of these biological materials carriages a huge challenge in the downstream processes of forensic DNA typing technique, such as short tandem repeats (STR) DNA typing. Microbial degradation yields improper or no PCR amplification, heterozygous peak imbalance, DNA contamination from non-human sources, degradation of DNA by microbial by-products, etc. Consequently, the most precise STR DNA typing technique is nullified and definite opinion can be hardly given with degraded forensic exhibits. Thus, suitable precautionary measures should be taken for proper storage and processing of the biological exhibits to minimize their decaying process by micro-organisms.

Cytokine Levels and Human Herpesviruses in Saliva from Clinical Periodontal Healthy Subjects with Peri-Implantitis: A Case-Control Study

This study evaluated the presence of cytokines (IL-1β, IL-2, IL-4, IL-6, MCP-1, MIP-1α, MIP-1β, and TNF-α) and human herpesvirus (HSV1, HSV2, EBV, CMV, VZV, HHV6, HHV7, and HHV8) in saliva samples taken from subjects with and without peri-implantitis. Forty-two periodontally healthy subjects were divided according to peri-implant condition: healthy and peri-implantitis groups. The clinical parameters as probing depth, clinical attachment level, plaque index, gingival bleeding, bleeding on probing, and suppuration were evaluated. For cytokine detection, multiplex analysis was performed, and PCR assay was used to identify herpesviruses. No significant differences were found in cytokine levels between groups (p > 0.05). The presence of herpesvirus was 1.97-fold higher in patients with peri-implantitis (odds ratio, CI 0.52-7.49). The association of the presence or absence of herpesvirus with the salivary markers was statistically significant for MIP-1β (p = 0.0087) and TNF-α (p = 0.0437) only in the peri-implantitis group. The presence of herpesviruses in patients with peri-implantitis suggests the development of a proinflammatory environment, which is characterized by increased expression of MIP-1β and TNF-α in saliva.

Decreased oral Epstein-Barr virus DNA loads in patients with nasopharyngeal carcinoma in Southern China: A case-control and a family-based study

The link of nasopharyngeal carcinoma (NPC) with Epstein-Barr virus (EBV) has been established for decades. Although an abnormal high level of EBV sero-antibody spectrum and cell-free circulating EBV DNA loads were exhibited in NPC patients, oral EBV DNA loads, which are primarily responsible for the EBV transmission, has not been previously studied in NPC patients. We conducted an epidemiological study to measure the oral EBV loads, viral components, and the relationship with the serum antibody titers in a large case-control population (968 cases and 1656 controls) and a family-based population (91 cases and 165 unaffected family members). EBV DNA loads were detected by quantitative PCR approach targeting the BamHI-W region. Although a large individualized variation existed, we still observed a decreased oral EBV DNA loads in the population of NPC patients compared to that of healthy controls (ORs were 1.00, 0.69, 0.62, 0.33 classified by the quartiles of viral loads, Ptrend  < .001) and family members. In contrast, the elevated levels of oral EBV loads were present in asymptomatic males and elders, suggesting a different important source for EBV transmission. Notably, oral EBV loads were inversely associated with serum antibody titers of VCA-IgA, EA-IgA (All Ptrend  < .001) in the cases but not in the controls. Our study provides the first epidemiological data of oral EBV loads and viral components in NPC patients and controls in the highest risk area of Southern China, indicating that NPC status is unlikely to be an important determinant of EBV transmission.

Periodontitis: facts, fallacies and the future

This volume of Periodontology 2000 represents the 25th anniversary of the Journal, and uses the occasion to assess important advancements in periodontology over the past quarter-century as well as the hurdles that remain. Periodontitis is defined by pathologic loss of the periodontal ligament and alveolar bone. The disease involves complex dynamic interactions among active herpesviruses, specific bacterial pathogens and destructive immune responses. Periodontal diagnostics is currently based on clinical rather than etiologic criteria, and provides limited therapeutic guidance. Periodontal causative treatment consists of scaling, antiseptic rinses and occasionally systemic antibiotics, and surgical intervention has been de-emphasized, except perhaps for the most advanced types of periodontitis. Plastic surgical therapy includes soft-tissue grafting to cover exposed root surfaces and bone grafting to provide support for implants. Dental implants are used to replace severely diseased or missing teeth, but implant overuse is of concern. The utility of laser treatment for periodontitis remains unresolved. Host modulation and risk-factor modification therapies may benefit select patient groups. Patient self-care is a critical part of periodontal health care, and twice-weekly oral rinsing with 0.10-0.25% sodium hypochlorite constitutes a valuable adjunct to conventional anti-plaque and anti-gingivitis treatments. A link between periodontal herpesviruses and systemic diseases is a strong biological plausibility. In summary, research during the past 25 years has significantly changed our concepts of periodontitis pathobiology and has produced more-effective and less-costly therapeutic options.

Effect of preparation method and storage period on the stability of saliva DNA

Saliva is an attractive source for oral microbial detection and quantification since sampling is non-invasive and rapid.

OBJECTIVES

To determine whether different saliva preparation methods or preservation time periods affect DNA stability.

METHODS

Saliva samples from 4 healthy adult volunteers were processed to obtain 3 different preparations: whole saliva, and after centrifugation pellet and supernatant. Purified DNA (MasterPure™) from each sample was divided into 4 aliquots, one for immediate analysis and 3 (stored at -80°C) for later analyses after 1 week and 2 and 6 months. DNA concentrations and qPCR based quantities of Porphyromonas gingivalis, Prevotella intermedia, Parvimonas micra, Fusobacterium nucleatum, Filifactor alocis and Streptococcus mutans were determined.

RESULTS

DNA concentration did not decrease (P>0.05) during the 6-month period in any sample. Mean (SE) DNA concentrations (ng/μl) in whole saliva were 152.2 (51.2) and 147.8 (50) at day 0 and 6 months, respectively. Similarly, the values for pellet were 134.9 (42.5) and 133.6 (42.9), and for supernatant, 11 (1.9) and 8.9 (2.3), the difference being significant (P<0.001) between supernatant and whole saliva or pellet. The quantities of most bacterial species found at day 0 remained stable over the 6-month period in all saliva preparations. In supernatant, species quantities were lower (P<0.05) than in whole saliva or pellet.

CONCLUSIONS

DNA concentrations were comparable between whole saliva and pellet, suggesting that either of them can be used for DNA-based analyses. Our results also demonstrated that DNA extracted from saliva can be preserved at -80°C for at least 6 months without decrease in DNA concentration.

Rapid Chair-Side Test for Detection of Porphyromonas gingivalis

Porphyromonas gingivalis is a keystone pathogen of chronic periodontitis, and its intraoral levels have been shown to predict disease progression (activity). An accurate and sensitive chair-side (point of care) test to determine disease activity is critical for early intervention and clinical management of disease. This study aimed to develop a rapid, chair-side, saliva-based detection of P. gingivalis. Monoclonal antibodies (mAbs) to the A1-adhesin domain of the P. gingivalis RgpA-Kgp proteinase-adhesin complex were screened by enzyme-linked immunosorbent assay and microbial flow cytometry, with 2 mAbs shown to recognize all laboratory and clinical strains tested, without significantly cross-reacting with other oral bacteria tested. With these mAbs, an immunochromatographic device was produced and shown in preclinical studies to detect, in inoculated saliva, all P. gingivalis laboratory strains and clinical isolates tested. The device was able to detect ≥1 × 10⁵ P. gingivalis cells/mL. In a patient age- and sex-matched control clinical cohort, P. gingivalis levels in saliva-as measured by real-time polymerase chain reaction-positively correlated with P. gingivalis levels in subgingival plaque ( r = 0.819, P < 0.01) and clinical parameters of disease ( r = 0.633, P < 0.01). A positive device result strongly correlated with P. gingivalis levels >1 × 10⁵ cells/mL in saliva ( r = 0.778, P < 0.001) and subgingival plaque ( r = 0.715, P < 0.001) with sensitivity, specificity, positive/negative predictive values, and accuracy levels of 95.0%, 93.3%, 90.5%, 96.6%, and 94.0%, respectively. The device result also positively correlated ( r = 0.695, P < 0.01) with disease severity as measured by probing depth. Detection of P. gingivalis in saliva was found to be rapid, taking 3 min from sample collection.

Putative periodontopathic bacteria and herpesviruses in pregnant women: a case-control study

Little is known about herpesvirus and putative periodontopathic bacteria in maternal chronic periodontitis. The present case-control study aimed to explore the potential relationship between putative periodontopathic bacteria and herpesviruses in maternal chronic periodontitis.Saliva samples were collected from 36 pregnant women with chronic periodontitis (cases) and 36 pregnant women with healthy periodontal status (controls). Six putative periodontopathic bacteria (Porphyromonas gingivalis [Pg], Aggregatibacer actinomycetemcomitans [Aa], Fusobacterium nucleatum [Fn], Prevotella intermedia [Pi], Tannerella forsythia [Tf], and Treponema denticola [Td]) and three herpesviruses (Epstein-Barr virus [EBV], human cytomegalovirus [HCMV], and herpes simplex virus [HSV]) were detected. Socio-demographic data and oral health related behaviors, and salivary estradiol and progesterone levels were also collected. The results showed no significant differences in socio-demographic background, oral health related behaviors, and salivary estradiol and progesterone levels between the two groups (all P > 0.05). The detection rates of included periodontopathic microorganisms were not significantly different between the two groups (all P > 0.05), but the coinfection rate of EBV and Pg was significantly higher in the case group than in the control group (P = 0.028). EBV and Pg coinfection may promote the development of chronic periodontitis among pregnant women.

Salivary pathogen and serum antibody to assess the progression of chronic periodontitis: a 24-mo prospective multicenter cohort study

BACKGROUND AND OBJECTIVE

A diagnosis of periodontitis progression is presently limited to clinical parameters such as attachment loss and radiographic imaging. The aim of this multicenter study was to monitor disease progression in patients with chronic periodontitis during a 24-mo follow-up program and to evaluate the amount of bacteria in saliva and corresponding IgG titers in serum for determining the diagnostic usefulness of each in indicating disease progression and stability.

MATERIAL AND METHODS

A total of 163 patients with chronic periodontitis who received trimonthly follow-up care were observed for 24 mo. The clinical parameters and salivary content of Porphyromonas gingivalis, Prevotella intermedia and Aggregatibacter actinomycetemcomitans were assessed using the modified Invader PLUS assay, and the corresponding serum IgG titers were measured using ELISA. The changes through 24 mo were analyzed using cut-off values calculated for each factor. One-way ANOVA or Fisher's exact test was used to perform between-group comparison for the data collected. Diagnostic values were calculated using Fisher's exact test.

RESULTS

Of the 124 individuals who completed the 24-mo monitoring phase, 62 exhibited periodontitis progression, whereas 62 demonstrated stable disease. Seven patients withdrew because of acute periodontal abscess. The ratio of P. gingivalis to total bacteria and the combination of P. gingivalis counts and IgG titers against P. gingivalis were significantly related to the progression of periodontitis. The combination of P. gingivalis ratio and P. gingivalis IgG titers was significantly associated with the progression of periodontitis (p = 0.001, sensitivity = 0.339, specificity = 0.790).

CONCLUSIONS

It is suggested that the combination of P. gingivalis ratio in saliva and serum IgG titers against P. gingivalis may be associated with the progression of periodontitis.

Biology and pathogenesis of cytomegalovirus in periodontal disease

Human periodontitis is associated with a wide range of bacteria and viruses and with complex innate and adaptive immune responses. Porphyromonas gingivalis, Tannerella forsythia, Aggregatibacter actinomycetemcomitans, Treponema denticola, cytomegalovirus and other herpesviruses are major suspected pathogens of periodontitis, and a combined herpesvirus–bacterial periodontal infection can potentially explain major clinical features of the disease. Cytomegalovirus infects periodontal macrophages and T‐cells and elicits a release of interleukin‐1β and tumor necrosis factor‐α. These proinflammatory cytokines play an important role in the host defense against the virus, but they also have the potential to induce alveolar bone resorption and loss of periodontal ligament. Gingival fibroblasts infected with cytomegalovirus also exhibit diminished collagen production and release of an increased level of matrix metalloproteinases. This article reviews innate and adaptive immunity to cytomegalovirus and suggests that immune responses towards cytomegalovirus can play roles in controlling, as well as in exacerbating, destructive periodontal disease.

Are herpes virus associated to aggressive periodontitis? A review of literature

Periodontal Disease includes a wide variety of infectious entities with various clinical manifestations in the oral cavity and responses to treatment. The determinants of clinical manifestations of periodontal disease include the type of infectious agent, the host immune response and environmental factors. Aggressive periodontitis (AP) is defined as a type of inflammation with specific clinical and laboratory features, which distinguish it from other types of periodontitis, with high incidence rates in a sub-group of individuals. Bacteria have been frequently mentioned as the agent inciting gingival inflammation and tissue destruction that underlies the pathogenesis of periodontitis. However, recent studies, with some controversial results, have suggested that the herpes family of viruses, including CMV and EBV-1 as well as papillomaviruses, HIV, Human T-lymphotropic virus type 1, Torquetenovirus and hepatitis B and C occur with high frequency in active periodontal lesions. There is a lack of information about this disease and the role of herpesviruses in its pathophysiology. This review provides a critical analysis of the scientific evidence linking bacteria and viruses with AP and their potential impact on clinical characteristics, prognosis and therapy.

Prevalence and quantitative analysis of Epstein-Barr virus DNA and Porphyromonas gingivalis associated with Japanese chronic periodontitis patients

Objective

A number of studies have recently suggested Epstein–Barr virus (EBV) involvement in the pathogenesis of periodontitis. In this study, we investigated the association between major periodontopathic bacteria Porphyromonas gingivalis (P. gingivalis) and EBV in Japanese chronic periodontitis (CP) patients.

Materials and methods

A group of 25 patients with CP participated in the study along with 13 individuals without periodontitis. Subgingival samples were obtained with paper points. Quantitative real-time polymerase chain reaction (PCR) was used to detect EBV DNA and P. gingivalis.

Results

In the CP patients, EBV DNA and P. gingivalis were detected in both 80 % of sites with probing pocket depths (PPD) of ≥5 mm and in 40 and 36 % of sites with PPD ≤3 mm, respectively. EBV DNA and P. gingivalis were detected in 50 and 27 % of the sites in periodontally healthy individuals. Coexistence of EBV DNA and P. gingivalis was significantly higher in the deeper PPD sites of CP patients (68 %) than in the PPD sites of the healthy controls (15 %) and shallow PPD sites of CP patients (12 %). PCR-positive deeper PPD sites of CP patients for EBV DNA and P. gingivalis range between 3.74 × 10³∼2.83 × 10⁹ and 2.73 × 10⁵∼6.65 × 10⁹ (copies/ml), respectively.

Conclusion

These results suggest an association between EBV DNA, P. gingivalis, and CP in Japanese individuals. Further studies are required to clarify this association; however, we believe that our enhanced understanding of the pathogenesis of periodontal diseases involving viral infections will lead to new treatments.

Microbial analysis of subgingival plaque samples compared to that of whole saliva in patients with periodontitis

BACKGROUND

The detection of special bacterial species in patients with periodontitis is considered to be useful for clinical diagnosis and treatment. The collection of subgingival plaque samples is the common way for the determination of periodontopathic bacteria. However, recently, salivary analysis has been discussed as an advantageous future diagnostic method for periodontitis because it offers simple quantitative sampling and the possibility to assess various bacteria. The aim of this cross-sectional study is to investigate whether there is a correlation between the results of different bacterial species in saliva and subgingival plaque samples from individuals with aggressive periodontitis (AgP) and chronic periodontitis (CP).

METHODS

Whole saliva and subgingival plaque samples from the deepest pocket of each quadrant were collected from 43 patients with CP and 33 patients with AgP. Twenty different bacterial species from both samplings were determined by the 16S ribosomal RNA-based polymerase chain reaction with microarray technique.

RESULTS

All bacterial species were detected in salivary and subgingival plaque samples. For Aggregatibacter actinomycetemcomitans, Porphyromonas gingivalis, Treponema denticola, and Tannerella forsythia, as well as Actinomyces viscosus, Campylobacter rectus/showae, Prevotella intermedia, Parvimonas micra, Eubacterium nodatum, and Campylobacter gracilis, a significant positive correlation between salivary and subgingival plaque samples was detected in patients with both types of periodontitis. There were no significant differences in bacteria in salivary and subgingival plaque samples between AgP and CP.

CONCLUSION

Salivary analysis might be discussed as a potential alternative to subgingival plaque sampling for microbiologic analysis in both AgP and CP.

Microbial community profiling of human saliva using shotgun metagenomic sequencing

Human saliva is clinically informative of both oral and general health. Since next generation shotgun sequencing (NGS) is now widely used to identify and quantify bacteria, we investigated the bacterial flora of saliva microbiomes of two healthy volunteers and five datasets from the Human Microbiome Project, along with a control dataset containing short NGS reads from bacterial species representative of the bacterial flora of human saliva. GENIUS, a system designed to identify and quantify bacterial species using unassembled short NGS reads was used to identify the bacterial species comprising the microbiomes of the saliva samples and datasets. Results, achieved within minutes and at greater than 90% accuracy, showed more than 175 bacterial species comprised the bacterial flora of human saliva, including bacteria known to be commensal human flora but also Haemophilus influenzae, Neisseria meningitidis, Streptococcus pneumoniae, and Gamma proteobacteria. Basic Local Alignment Search Tool (BLASTn) analysis in parallel, reported ca. five times more species than those actually comprising the in silico sample. Both GENIUSand BLAST analyses of saliva samples identified major genera comprising the bacterial flora of saliva, but GENIUS provided a more precise description of species composition, identifying to strain in most cases and delivered results at least 10,000 times faster. Therefore, GENIUS offers a facile and accurate system for identification and quantification of bacterial species and/or strains in metagenomic samples.