Actinomyces europaeus is an emerging Gram-positive bacterium associated with skin and soft tissue infections. It exhibits intrinsic resistance to multiple antibiotics, and its fastidious growth and the polymicrobial nature of infections often delay diagnosis and treatment. This report highlights a rare case of A. europaeus infection following elective surgery. A 78-year-old woman presented with asthenia and purulent umbilical discharge two months after abdominoplasty. A CT scan revealed a large supra-fascial fluid collection. She underwent surgical debridement and lavage. Cultures identified Actinomyces europaeus, alongside Staphylococcus hominis and Staphylococcus haemolyticus. Susceptibility testing for A. europaeus was not performed. Following infectious disease consultation, therapy was switched from piperacillin/tazobactam to intravenous penicillin G, transitioning to oral amoxicillin/clavulanic acid for 12 weeks. The patient recovered fully with no recurrence. A review of the literature, highlights that A. europaeus infections are often polymicrobial, require advanced diagnostics such as MALDI-TOF (matrix-assisted laser desorption/ionization time of flight), and respond favourably to penicillin-based therapy when combined with complete surgical debridement. This case and literature review underscore challenges in managing A. europaeus and emphasize the need for increased awareness and standardized therapeutic guidelines.

Root caries are primarily caused by cariogenic bacteria, posing a significant threat to the oral health of older adults. Due to the lesion's anatomical location and the moist microenvironment, clinical management is challenging and recurrence rates remain high. In order to address this unmet clinical need, we developed an activated chitosan hydrogel loaded with polydopamine-coated regeneration silicon (PDA-Regesi-CS) for early intervention in root caries. In this formulation, chitosan provides potent antibacterial activity, regeneration silicon promotes cementum remineralization, and polydopamine enables durable wet-adhesion properties. In vitro experiments demonstrated that the hydrogel significantly inhibited the growth of Streptococcus mutans, Actinomyces viscosus, Lactobacillus acidophilus, Candida albicans, and a four-species mixed bacterial culture, achieving biofilm inhibition and mature biofilm eradication rates exceeding 92%. Furthermore, it effectively promoted the remineralization of demineralized cementum, with nano-hardness reaching 33.54 kgf/mm[2] after 28 days. In vivo rat model experiments further validated its superior efficacy in early root caries treatment, showing a low Doff score of 0.2 and surface mineral density of 1.31 g/cm[3] on exposed root surfaces. Collectively, these findings demonstrate the promising potential of the PDA-Regesi-CS hydrogel as a targeted therapeutic intervention for the early management of root caries, but further evaluation of its clinical translational feasibility is still needed.

Chlorhexidine is a standard agent for halitosis control but has notable adverse effects; therefore, this study aimed to evaluate the effectiveness of a Clematis chinensis Osbeck (C. chinensis Osbeck) extract mouthwash on halitosis and related oral bacteria in comparison with chlorhexidine and saline.

Gut microbiota is a potential therapeutic target for type 2 diabetes (T2D), but its role remains unclear. Investigating causal associations between them could further our understanding of their biological and clinical significance. A two-sample Mendelian randomization (MR) analysis was conducted to assess the causal relationship between gut microbiota and T2D. Key genes and mechanisms were identified through the integration of Genome-Wide Association Studies (GWAS) and cis-expression quantitative trait loci (cis-eQTL) data. Network pharmacology was applied to identify potential drugs and targets. Additionally, gut microbiota community analysis and machine learning models were used to construct a diagnostic model for T2D. MR analysis identified 17 gut microbiota taxa associated with T2D, with three showing significant associations: Actinomyces (odds ratio [OR] = 1.106; 95% confidence interval [CI]: 1.06-1.15; p < 0.01; adjusted p-value [padj] = 0.0003), Ruminococcaceae (UCG010 group) (OR = 0.897; 95% CI: 0.85-0.95; p < 0.01; padj = 0.018), and Deltaproteobacteria (OR = 1.072; 95% CI: 1.03-1.12; p < 0.01; padj = 0.029). Ten key genes, such as EXOC4 and IGF1R, were linked to T2D risk. Network pharmacology identified INSR and ESR1 as target driver genes, with drugs like Dienestrol showing promise. Gut microbiota analysis revealed reduced α-diversity in T2D patients (p < 0.05), and β-diversity showed microbial community differences (R[2] = 0.012, p = 0.001). Furthermore, molecular docking confirmed the binding affinity of potential therapeutic agents to their targets. Finally, we developed a class-weight optimized Extreme Gradient Boosting (XGBoost) diagnostic model, which achieved an area under the curve (AUC) of 0.84 with balanced sensitivity (95.1%) and specificity (83.8%). Integrating machine learning predictions with MR causal inference highlighted Bacteroides as a key biomarker. Our findings elucidate the gut microbiota-T2D causal axis, identify therapeutic targets, and provide a robust tool for precision diagnosis.

Considering the scarcity of medications with a wide range of therapeutic effects for the endodontic treatment, this study aimed to synthesize two morin (Mo) derivatives and test their cytotoxicity and effect on multispecies biofilm, in solution and loaded in nanoemulsions (NE). Minimum inhibitory and bactericidal concentration (MIC/MBC) of Mo, penta-acetylated Mo (Ac-Mo), Mo complexed with strontium (Sr-Mo) and control chlorhexidine digluconate (CHX) were determined against Enteroccocus faecalis, Actinomyces israelii, Streptococcus mutans, Lactobacillus casei, Fusobacterium nucleatum. NE were physiochemically characterized by analysis of droplet size and polydispersity index using dynamic light scattering, by determination of zeta potential, by Nanoparticle Tracking Analysis, and by Fourier Transform Infrared Spectroscopy analysis. NE containing Mo, its derivatives (at 2 mg/mL), and CHX (at 0.5 mg/mL) were evaluated against multispecies biofilms by bacterial counts, scanning electron microscopy, and confocal microscopy. The cytotoxicity of the compounds and NE was also determined in fibroblasts (L929) using resazurin assays. The data were statistically evaluated (p < 0.05). All compounds were considered potentially bactericidal against the bacteria tested. The values of MBC ranged from 0.25 to 1 mg/mL. Metabolic activity of fibroblasts was higher than 70% after treatment with compounds up to 0.25 mg/mL. Data from physiochemical characterization confirmed the successful formation of stable, uniformly dispersed nanoemulsion suitable for drug delivery applications. The highest bacterial reduction in multispecies biofilms was observed in NE + Ac-Mo, followed by NE + Mo, CHX, and NE + Sr-Mo groups. All NE diluted at 12.5% did not affect fibroblast metabolism after 24 h of treatment. Although in different concentrations, morin and its derivatives, either alone or loaded in nanoemulsions, were bactericidal (up to 1 mg/mL) and demonstrated antibiofilm effect (at 2 mg/mL). They also were cytocompatible at lower concentrations (0.25 mg/mL). Nanoemulsion containing penta-acetylated morin could be an alternative intracanal medication for reducing residual bacteria between short-term clinical appointments in endodontic approaches.

Chinese cabbage (Brassica rapa subsp. pekinensis) and cabbage (Brassica oleracea var. alba) are global staples. The diamondback moth (Plutella xylostella), a serious pest that causes billions of dollars in economic loss globally. Climate change has increased its survival and reproductive potential, boosting its range and population density. The development of resistance to commercial insecticides, such as spinetoram and spinosad, make pest management more difficult. Biopesticides are promising alternatives owing to their environmental compatibility and target specificity. This study aimed to identify novel bio-insecticidal agents from microbial sources against diamondback moth (DBM). In total, 500 actinomyces were isolated from soil samples collected in South Korea. Among them, Saccharopolyspora sp. AN150100 showed 80-90 % insecticidal activity against P. xylostella larvae, even when the culture broth was diluted 20-fold. Notably, spinosyn α4, a compound produced by this strain, exhibited 70 % larvicidal activity at a concentration of 0.025 mg/L, which was comparable to the efficacy of spinetoram and spinosad. Spinosyn biosynthesis gene clusters (PKS: spnA,- E and other additional spnF - M) were compared from the genomes of all Saccharopolyspora genus belonging members through antiSMASH. It is the first time to report insecticidal activity of spinosyn α4 against DBM. These findings suggest that spinosyn α4 from Saccharopolyspora sp. AN150100 could serve as an effective and eco-friendly alternative for controlling P. xylostella.

As an important body fluid of the human body, saliva harbors a diverse microbial community, yet the dynamic succession of its microbiota following environmental exposure remains incompletely understood. Most current studies focus solely on relative abundance and community structure derived from sequencing, which may lead to misinterpretation of microbial dynamics. Moreover, existing research has almost exclusively centered on bacterial communities, largely overlooking the role of fungi. In this study, we conducted a 90-day exposure experiment in two environments (an incubator and an indoor setting) and used 16S rRNA gene and ITS absolute quantification sequencing to characterize the structure and abundance of bacterial and fungal communities. Despite prolonged environmental exposure, core bacterial genera in saliva, such as Streptococcus, Actinomyces, Rothia, Neisseria, Veillonella, and Prevotella, persisted in the samples. An interaction between salivary and environmental bacterial communities was observed, which strengthened over time. Relative and absolute abundance analyses revealed different patterns: relative abundance suggested a moderately stable community structure with individual specificity, whereas absolute quantification demonstrated a significant decrease in total bacterial load over time. Fungal communities were nearly undetectable in fresh saliva but became detectable after 25 days of exposure in the incubator and subsequently increased in abundance, dominated by Aspergillus. In contrast to the significant decline in bacterial absolute abundance over time, fungi exhibited a continuous increase, with a negative correlation between the two. Relative abundance was more effective for individual identification, while absolute abundance performed better in time since deposition (TsD) estimation. Further incorporation of fungal data enhanced the accuracy of the TsD prediction model, as indicated by a mean absolute error (MAE) of 7.485 days and an R[2] of 0.905, highlighting the advantage of multi-kingdom microbial analysis.

Osteoarthritis (OA) is the most prevalent joint disease among the middle-aged and elderly individuals, primarily characterized by synovitis and cartilage damage. Although non-steroidal anti-inflammatory drugs (NSAIDs) are widely used to manage OA, they fail to fundamentally prevent or alleviate cartilage damage and can cause severe gastrointestinal or cardiovascular side effects. Therefore, developing OA drugs that address both symptoms and underlying causes is of significant importance. Our study found that tigloside (TIG), a main metabolite derived from symbiotic actinomyces, could repolarize macrophages from pro-inflammatory M1 type to anti-inflammatory M2 type, suppress the release of multiple inflammatory factors and facilitate the secretion of the anti-inflammatory cytokine IL-10, thereby creating a favorable microenvironment for chondrocyte regeneration and extracellular matrix (ECM), and alleviating pain, synovitis and OA cartilage damage. Mechanistically, TIG competes with the signaling adaptor molecule Traf1 to bind at the middle region (aa 104-414) of Trafd1, disrupting the interaction between Trafd1 and Traf1. This disruption promotes the degradation of Trafd1 and Traf1 via proteasome-ubiquitination pathway, leading to a reduction in their protein levels. Consequently, the downregulation of Trafd1 further inhibits NF-κB signaling and M1 polarization while promoting STAT6 pathway and M2 polarization, resulting in the repolarization of macrophages from M1 to M2 type and the amelioration of OA. Importantly, these findings were further validated in human macrophages derived from OA patients. In summary, this study highlights the potential of TIG as a disease-modifying drug for OA, and identifies Trafd1 as a novel therapeutic target for OA treatment.

Anaerobic bacteria cause a wide range of infections, varying from mild to severe, whether localized, implant-associated, or invasive, often leading to high morbidity and mortality. These infections are challenging to manage due to antimicrobial resistance against common antibiotics such as carbapenems and nitroimidazoles. The empirical use of antibiotics has contributed to the emergence of resistant organisms, making the identification and development of new antibiotics increasingly difficult. This highlights the need for adjuvant treatments. Antimicrobial peptides (AMPs) have garnered attention as promising agents in combating resistant bacteria. Researchers are interested in AMPs due to their broad-spectrum activity, multiple mechanisms of action, and reduced likelihood of inducing resistance. Moreover, AMPs can enhance the effectiveness of conventional antibiotics through synergistic effects. Researchers suggest that AMPs could play a valuable role in the development of new drugs targeting anaerobic pathogens. Exploring the properties and functions of these peptides represents a significant step toward alternative therapies. This paper reviews natural and synthetic AMPs derived from various sources that target different cellular components and functions of anaerobic bacteria, including Actinomyces, Fusobacterium, Bacteroides, Porphyromonas, Prevotella, Clostridium, Clostridioides, Lactobacillus, Peptostreptococcus, Propionibacterium, Bifidobacterium, Veillonella, and Tannerella. The described AMPs act on the cell membrane, peptidoglycan, lipopolysaccharide (LPS), biofilms, ion channels, toxins, DNA, transcription, and translation. The data indicate that these peptides demonstrate significant potential against anaerobes, presenting a promising strategy for combating antibiotic resistance.