subsp. RadD binds Siglec-7 and inhibits NK cell-mediated cancer cell killing.

is an oral commensal bacterium that can colonize extraoral tumor entities, such as colorectal cancer and breast cancer. Recent studies revealed its ability to modulate the immune response in the tumor microenvironment (TME), promoting cancer progression and metastasis. Importantly, subsp.

Antagonistic interaction between two key endodontic pathogens and .

Background: Endodontic infections are known to be caused by pathogenic bacteria. Numerous previous studies found that both and are associated with endodontic infections, with more abundant in primary infection while more abundant in secondary infection. Little is known about the potential interactions between different endodontic pathogens.

Effect of Calcium Ion Supplementation on Oral Microbial Composition and Biofilm Formation In Vitro.

The oral cavity contains a variety of ecological niches with very different environmental conditions that shape biofilm structure and composition. The space between the periodontal tissue and the tooth surface supports a unique anaerobic microenvironment that is bathed in the nutrient-rich gingival crevicular fluid (GCF). During the development of periodontitis, this environment changes and clinical findings reported a sustained level of calcium ion concentration in the GCF collected from the periodontal pockets of periodontitis patients.

Oral microbial extracellular DNA initiates periodontitis through gingival degradation by fibroblast-derived cathepsin K in mice.

Periodontitis is a highly prevalent disease leading to uncontrolled osteoclastic jawbone resorption and ultimately edentulism; however, the disease onset mechanism has not been fully elucidated. Here we propose a mechanism for initial pathology based on results obtained using a recently developed Osteoadsorptive Fluogenic Sentinel (OFS) probe that emits a fluorescent signal triggered by cathepsin K (Ctsk) activity. In a ligature-induced mouse model of periodontitis, a strong OFS signal is observed before the establishment of chronic inflammation and bone resorption.

Correlation between Streptococcus mutans levels in dental plaque and saliva of children.

Purpose: This study was designed to compare the levels of Streptococcus mutans (S. mutans) in saliva with those in occlusal plaque on posterior teeth at different stages of dentition, and to explore the correlation with caries experience to determine the most suitable source of S. mutans for research.

Exploitation of a Bacterium-Encoded Lytic Transglycosylase by a Human Oral Lytic Phage To Facilitate Infection.

Bacteriophages (phages) are an integral part of the human oral microbiome. Their roles in modulating bacterial physiology and shaping microbial communities have been discussed but remain understudied due to limited isolation and characterization of oral phage. Here, we report the isolation of LC001, a lytic phage targeting human oral Schaalia odontolytica (formerly known as Actinomyces odontolyticus) strain XH001.

Tooth-Specific Distribution and Associated Microbiome.

Dental caries is multifactorial and polymicrobial in nature and remains one of the most common oral diseases. While caries research has focused on as the main etiological pathogen, its impact at the tooth level is not fully understood. In this cross-sectional study, the levels and distribution of in the posterior teeth at different dentition stages were investigated along with the corresponding tooth-specific microbiome.

A Denture Use Model Associated with spp. in Immunocompetent Male and Female Rats.

Denture stomatitis (DS) is a common infection in denture wearers, especially women. This study evaluated the induction of DS using acrylic devices attached to the palate of rats combined with inoculation of Candida spp. Immunocompetent male and female rats received a carbohydrate-rich diet.

The Microbiome in Periodontitis and Diabetes.

Objectives: To perform a comprehensive and integrative review of the available literature on the potential changes in the microbiome of healthy and individuals with diabetes under periodontal health and disease.

Materials And Methods: The review was conducted by two independent reviewers. Indexed electronic databases (PubMed/Medline, Cochrane Library, Web of Science and Scopus) were searched, including articles published in English and dated from 5 years ago until December 2021.

Effect of Cigarette and E-Cigarette Smoke Condensates on Biofilm Formation and Gene Expression.

Smoking triggers environmental changes in the oral cavity and increases the risk of mucosal infections caused by such as oral candidiasis. While cigarette smoke has a significant impact on , how e-cigarettes affect this oral pathogen is less clear. Here, we investigated the effect of cigarette and e-cigarette smoke condensates (CSC and ECSC) on growth, biofilm formation, and gene expression.

Oral Microbiome: /Caries Concordant-Discordant Children.

Dental caries remains the most common chronic disease in children, and the respective etiology is not fully understood. Though is an important factor in the initiation and progression of caries, its presence is not always associated with the disease. The existence of caries discordant populations, in which counts do not correlate with caries experience, poses a challenging problem.

The impact of fixed orthodontic appliances and clear aligners on the oral microbiome and the association with clinical parameters: A longitudinal comparative study.

Introduction: Orthodontic treatment interferes with oral hygiene and promotes plaque retention, which leads to gingival inflammation and enamel demineralization. Although removable clear aligners (CAs) are designed to improve oral hygiene compared with fixed appliances (FAs), comprehensive studies comparing their respective effects on the oral microbiome are limited. This longitudinal study investigated the microbial changes during orthodontic treatment with FA and CA in correlation with clinical parameters.

Clinical evaluation of Er,Cr:YSGG laser therapy used as an adjunct to non-surgical treatment of periodontitis: Twelve-month results from a pilot study.

Background: The purpose of this study was to evaluate the results of adjunctive Er,Cr:YSGG laser therapy with scaling and root planing (SRP) as compared with SRP alone in the treatment of moderate to severe periodontitis.

Methods: Fifteen adults (aged 27 to 65 years) with 90 nonadjacent sites probing ≥ 5 mm were treated in split-mouth design with SRP and laser therapy versus SRP alone. Probing pocket depth (PPD), gingival recession (GR), clinical attachment level (CAL), plaque, and bleeding on probing were collected at baseline, 1, 3, 6, 9, and 12 months.

Fusobacterium nucleatum secretes amyloid-like FadA to enhance pathogenicity.

Fusobacterium nucleatum (Fn) is a Gram-negative oral commensal, prevalent in various human diseases. It is unknown how this common commensal converts to a rampant pathogen. We report that Fn secretes an adhesin (FadA) with amyloid properties via a Fap2-like autotransporter to enhance its virulence.

Correction: Shokeen, B., et al. Role of FAD-I in Fusobacterial Interspecies Interaction and Biofilm Formation. 2020, 8, 70.

The authors wish to make the following corrections to this paper [...

Fusobacteriumnucleatum Adheres to Clostridioides difficile via the RadD Adhesin to Enhance Biofilm Formation in Intestinal Mucus.

Background & Aims: Although Clostridioides difficile infection (CDI) is known to involve the disruption of the gut microbiota, little is understood regarding how mucus-associated microbes interact with C difficile. We hypothesized that select mucus-associated bacteria would promote C difficile colonization and biofilm formation.

Methods: To create a model of the human intestinal mucus layer and gut microbiota, we used bioreactors inoculated with healthy human feces, treated with clindamycin and infected with C difficile with the addition of human MUC2-coated coverslips.

Omics and interspecies interaction.

Interspecies interactions are key determinants in biofilm behavior, ecology, and architecture. The cellular responses of microorganisms to each other at transcriptional, proteomic, and metabolomic levels ultimately determine the characteristics of biofilm and the corresponding implications for health and disease. Advances in omics technologies have revolutionized our understanding of microbial community composition and their activities as a whole.

Role of FAD-I in Fusobacterial Interspecies Interaction and Biofilm Formation.

RadD, a major adhesin of oral fusobacteria, is part of a four-gene operon encoding the small lipoprotein FAD-I and two currently uncharacterized small proteins encoded by the and genes. Previously, we described a role for FAD-I in the induction of human B-defensin 2 (hBD2) upon contact with oral epithelial cells. Here, we investigated potential roles for , and in interspecies interaction and biofilm formation.

The subgingival microbiome associated with periodontitis in type 2 diabetes mellitus.

Type 2 diabetes mellitus (T2DM) is a systemic disease, predisposing patients to other inflammatory conditions including periodontitis. The subgingival microbiome, a key player in periodontitis pathogenesis, is not well characterized in T2DM population. To better understand whether the subgingival microbiome is different between T2DM and systemically healthy, nondiabetic (ND) subjects, we performed a longitudinal analysis of the subgingival microbiome in T2DM patients (n = 15) compared with ND subjects (n = 16).

Histone Lys demethylase KDM3C demonstrates anti-inflammatory effects by suppressing NF-κB signaling and osteoclastogenesis.

Histone Lys-specific demethylases (KDMs) play a key role in many biological processes through epigenetic mechanisms. However, the role of KDMs in inflammatory responses to oral bacterial infection is poorly understood. Here, we show a novel regulatory role of KDM3C in inflammatory responses to oral bacterial infection.

and emerge as lone survivors following long-term starvation of oral microbiota.

It is well-understood that many bacteria have evolved to survive catastrophic events using a variety of mechanisms, which include expression of stress-response genes, quiescence, necrotrophy, and metabolic advantages obtained through mutation. However, the dynamics of individuals leveraging these abilities to gain a competitive advantage in an ecologically complex setting remain unstudied. In this study, we observed the saliva microbiome throughout the ecological perturbation of long-term starvation, allowing only the species best equipped to access and use the limited resources to survive.

Ultraviolet Light Treatment of Titanium Suppresses Human Oral Bacterial Attachment and Biofilm Formation: A Short-Term In Vitro Study.

Purpose: Antibacterial dental implants and related prosthetic components could help to reduce infection and prevent peri-implantitis. The purpose of this study was to determine the effect of ultraviolet (UV) light treatment of titanium on biofilm formation of human oral bacteria.

Materials And Methods: Machine-prepared commercially pure titanium disks were treated with UV light for 12 minutes.

The Oral Bacterium Fusobacterium nucleatum Binds Staphylococcus aureus and Alters Expression of the Staphylococcal Accessory Regulator sarA.

Staphylococcus aureus, an opportunistic pathogen member of the nasal and skin microbiota, can also be found in human oral samples and has been linked to infectious diseases of the oral cavity. As the nasal and oral cavities are anatomically connected, it is currently unclear whether S. aureus can colonize the oral cavity and become part of the oral microbiota, or if its presence in the oral cavity is simply transient.

Quorum Sensing Modulates the Epibiotic-Parasitic Relationship Between and Its Saccharibacteria epibiont, a Strain, TM7x.

The ultra-small, obligate parasitic epibiont, TM7x, the first and only current member of the long-elusive Saccharibacteria (formerly the TM7 phylum) phylum to be cultivated, was isolated in co-culture with its bacterial host, subspecies , XH001. Initial phenotypic characterization of the TM7x-associated XH001 co-culture revealed enhanced biofilm formation in the presence of TM7x compared to XH001 as monoculture. Genomic analysis and previously published transcriptomic profiling of XH001 also revealed the presence of a putative AI-2 quorum sensing (QS) operon, which was highly upregulated upon association of TM7x with XH001.

Conceptual Perspectives: Bacterial Antimicrobial Peptide Induction as a Novel Strategy for Symbiosis with the Human Host.

Human beta defensins (hBDs) are small cationic peptides, expressed in mucosal epithelia and important agents of innate immunity, act as antimicrobial and chemotactic agents at mucosal barriers. In this perspective, we present evidence supporting a novel strategy by which the oral bacterium induces hBDs and other antimicrobial peptides (AMPs) in normal human oral epithelial cells (HOECs) and thereby protects them from other microbial pathogens. The findings stress (1) the physiological importance of hBDs, (2) that this strategy may be a mechanism that contributes to homeostasis and health in body sites constantly challenged with bacteria and (3) that novel properties identified in commensal bacteria could, one day, be harnessed as new probiotic strategies to combat colonization of opportunistic pathogens.