Search Results (1,623)

Photocatalytic antibacterial coatings have emerged as a promising antibiotic-free strategy for combating healthcare-associated infections, biofilm formation, marine biofouling, and environmental microbial contamination. Unlike conventional antimicrobial approaches, photocatalytic systems continuously generate reactive oxygen species (ROS) under light irradiation, enabling broad-spectrum antimicrobial activity while minimizing the risk of antimicrobial resistance. This review systematically summarizes the fundamental mechanisms underlying photocatalytic antibacterial activity, including photogenerated charge-carrier dynamics, ROS generation pathways, and microbial inactivation processes. We further highlight recent advances in photocatalyst design, spanning conventional semiconductor photocatalysts, heterojunction engineering, cocatalyst modification, and two-dimensional material-assisted strategies for enhanced photocatalytic performance. Crucially, particular emphasis is placed on coating architectures and interfacial regulation, including encompassing fabrication methodologies, coating–substrate adhesion, internal heterointerface design, and coating–microorganism interactions, which dictate long-term durability and antibacterial efficacy. Finally, we explore the diverse applications of these coatings in medical devices, environmental remediation, and marine antifouling, while identifying current bottlenecks and future research trajectories toward developing durable, highly efficient, and clinically translatable antimicrobial surface technologies. Full article

Introduction: One of the fundamental principles of modern medicine, including dentistry, is prevention. However, if treatment is not initiated, tooth loss can occur, necessitating the use of dental prostheses to restore the function and aesthetics of the stomatognathic system. The oral microbiome is a complex ecosystem that is sensitive to external factors, including the biomaterials used to manufacture dental prostheses. Objectives: This narrative literature review aims to identify and compare the effects of various metal alloys used in dentistry, specifically high-precious (gold), precious (silver–palladium) and base (cobalt–chromium and nickel–chromium) alloys, as well as titanium, on the balance of the oral microbiome and biofilm formation. Results: The analysis indicates that gold, silver and palladium alloys demonstrate the most favourable biocompatibility and antibacterial properties, significantly reducing biofilm accumulation. Titanium and titanium-based alloys generally exhibit neutral properties under healthy conditions, although their biocorrosion products can alter the microbial environment in pathological states such as peri-implantitis. In contrast, base metal alloys (cobalt–chromium and nickel–chromium) are highly susceptible to biocorrosion in acidic environments, which can encourage the growth of bacteria that cause tooth decay and inflammation, potentially exacerbating oral dysbiosis. Conclusions: The selection of materials plays a critical role in maintaining oral microbial homeostasis and preventing plaque-related diseases. High-noble alloys and titanium are more biocompatible than base metal alloys. However, further long-term clinical trials and multi-species biofilm models are needed to fully understand these interactions between materials and microbes. Full article

Biomaterial-associated infection remains a persistent challenge for implantable devices, catheters, wound dressings, and tissue-engineering scaffolds. This structured narrative review critically evaluates biomimetic superwetting polysaccharide-based composite hydrogel interfaces based on chitosan, alginate, hyaluronic acid, cellulose/nanocellulose, bacterial cellulose, and dextran. The analysis links polymer network design and cross-linking strategy to pore architecture, swelling, mechanical properties, hydration-layer stabilization, protein adsorption, bacterial adhesion, biofilm development, and cytocompatibility. Stable interfacial hydration can increase the energetic penalty for protein and bacterial approach, but high water uptake alone is insufficient: excessive swelling, low network density, poorly controlled pore interconnectivity, and weak wet-state fixation can compromise durability or provide protected sites for bacterial retention. Study-level comparisons therefore emphasize reported values for network structure, swelling, mechanics, wettability or hydration, and antibacterial/antibiofilm performance, with unreported parameters identified as such. Notably, interactions among biomaterials, bacteria, and host tissues exhibit synergistic and co-evolutionary characteristics, forming a dynamically evolving microecological balance. This eco-synergistic perspective provides a useful conceptual framework for proposing antifouling strategies that aim to regulate rather than eradicate bacterial colonization. Future work should prioritize eco-synergistic design, durable hydration, mechanically stable and porous-yet-cleanable networks, selective interfacial regulation, dynamic characterization, standardized testing, and manufacturable formulations with the minimum necessary active components. Full article

Fermented foods contain diverse microorganisms that may influence oral microbial ecology and contribute to oral health. This narrative review aimed to examine the current evidence regarding microorganisms present in fermented foods and their role in oral health promotion. Twenty relevant clinical, experimental, observational, and review studies published between 2016 and 2026 were identified through a structured literature search and critically synthesized according to major thematic areas, including oral microbiota modulation, dental caries prevention, periodontal health, probiotic delivery systems, and evidence from review articles. The findings appear to indicate that fermented food-derived microorganisms may reduce cariogenic and periodontal pathogens, modulate oral biofilms, improve gingival health, and promote microbial homeostasis. Yogurt, kefir, fermented dairy products, and kimchi-derived microorganisms were the most frequently investigated sources. Emerging evidence further suggests that the benefits of these microorganisms are linked to ecological regulation of the oral microbiome and host–microbe interactions rather than direct antimicrobial activity alone. Microorganisms associated with fermented foods may therefore represent promising functional dietary components for supporting oral health and complementing preventive oral healthcare strategies. Further well-designed clinical studies are needed to establish strain-specific recommendations and explore the potential of postbiotic applications in dentistry. Full article

Streptococcus mutans is the primary etiological agent of dental caries due to its ability to form acidogenic biofilms on tooth surfaces. Natural monoterpenes have attracted considerable interest as potential antibiofilm agents for oral healthcare. The present study investigated the antibiofilm activity and possible mechanism of action of (+)-endo-borneol isolated from the essential oil of Achillea millefolium against S. mutans. The chemical composition of the essential oil was characterized by gas chromatography–mass spectrometry (GC–MS), and (+)-endo-borneol was isolated by chromatographic separation. Antibiofilm activity was evaluated using the crystal violet biofilm assay, while antimicrobial activity was determined by minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) assays. The influence of subinhibitory concentrations of (+)-endo-borneol on the expression of the biofilm-associated genes gtfB and yycF was assessed by quantitative real-time PCR. Molecular docking was performed to investigate ligand–protein interactions, using a ligand geometry pre-optimized by density functional theory (DFT, B3LYP/6-31G**). The essential oil inhibited S. mutans biofilm formation by up to 98%, whereas isolated (+)-endo-borneol reduced biofilm biomass by 97–98% at concentrations of 2–10 mg/mL. The MIC and MBC values of (+)-endo-borneol were 2.5 and 5.0 mg/mL, respectively. Gene expression analysis demonstrated that subinhibitory concentrations of (+)-endo-borneol modulated the transcription of gtfB and yycF, indicating activation of bacterial regulatory responses. Molecular docking revealed favorable binding of (+)-endo-borneol to biofilm-related protein targets. These findings demonstrate that (+)-endo-borneol is a promising natural antibiofilm compound with potential application in the development of novel preventive and therapeutic oral healthcare products targeting S. mutans biofilms. Full article

Background and Objectives: This narrative review aims to evaluate the correlation between dental luting cements, peri-implantitis and the molecular mechanisms governing tissue destruction, with a specific focus on the role of autophagy and nanotechnology. Methods: A comprehensive literature search was conducted across electronic databases, including PubMed, Scopus and Web of Science, to identify relevant studies on cement cytotoxicity, cellular responses and nanomaterial integration. Results: Residual cement in the peri-implant sulcus promotes biofilm accumulation and severe inflammation. At a cellular level, resin-base monomers (e.g., Bis-GMA) impair human gingival fibroblasts via oxidative stress and mitochondrial dysfunction. Autophagy serves as a vital cytoprotective mechanism against cement toxicity and titanium particle accumulation. Experimental studies suggest that incorporating nanomaterials, specifically graphene oxide and silver nanoparticles (≤1 wt.%), has shown promising results in enhancing antimicrobial efficacy without compromising biocompatibility in vitro. Conclusions: To minimize peri-implantitis, clinical protocols should prioritize the meticulous removal of excess cement and the development of nano-reinforced luting agents. Optimizing these molecular pathways offers actionable preventive strategies, guiding clinicians toward safer cementation protocols and enhanced long-term implant success. Full article

Background: Dental caries is a highly prevalent, biofilm-mediated disease characterized by microbial dysbiosis, excessive acid production, and progressive enamel demineralization. Although traditionally managed through restorative treatment, increasing attention has shifted toward preventive strategies focused on modulation of the oral microbiota and maintenance of ecological balance within the oral cavity. Methods: This narrative review summarizes current evidence regarding the ecological and mechanistic basis of dental caries and microbiota-centered prevention strategies. Literature published between January 2000 and March 2026 was retrieved from PubMed/MEDLINE, Scopus, Web of Science, and Google Scholar using keywords related to dental caries, oral microbiota, cariogenic bacteria, biofilms, probiotics, prebiotics, salivary diagnostics, metabolomics, quorum sensing, and artificial intelligence. Results: Current evidence demonstrates that dental caries is driven by ecological shifts favoring acidogenic and aciduric microorganisms within cariogenic biofilms. Emerging preventive approaches include dietary modification, oral hygiene optimization, probiotics, prebiotics, synbiotics, and functional dietary agents aimed at restoring microbial homeostasis and inhibiting cariogenic biofilm maturation. In addition, advances in salivary microbiome profiling, metabolomics, artificial intelligence-assisted predictive modeling, and smart responsive materials have shown promising potential for improving early diagnosis, risk assessment, and personalized prevention strategies. Conclusions: Microbiota-based approaches represent a promising paradigm shift in dental caries prevention by emphasizing ecological modulation rather than pathogen eradication alone. Continued interdisciplinary research integrating microbial ecology, diagnostics, biomaterials, and digital technologies may facilitate the development of personalized and preventive oral healthcare strategies. Full article

Species of the genus Streptococcus constitute important pathogens in human and veterinary medicine, being responsible for a wide spectrum of infections ranging from mild illnesses to severe invasive pathologies. Although β-lactams continue to be effective against most species, the global increase in resistance to macrolides, lincosamides, tetracyclines, and, in some cases, reduced susceptibility to penicillin represents a growing challenge for antimicrobial therapy. This review synthesizes the clinical and epidemiological landscape of antimicrobial resistance in the main Streptococcus species, including Streptococcus pyogenes, Streptococcus agalactiae, Streptococcus pneumoniae, Streptococcus dysgalactiae, and other species of clinical and veterinary relevance, addressing their epidemiological profiles, molecular mechanisms of resistance, and virulence factors. The main genetic determinants involved in resistance are discussed, namely the erm, mef, and tet genes, as well as the impact of alterations in penicillin-binding proteins, horizontal gene transfer, and biofilm formation on the persistence of infections and decreased therapeutic efficacy. Simultaneously, the main virulence factors are analyzed, including polysaccharide capsules, adhesins, toxins, extracellular enzymes, and immune response evasion mechanisms that contribute to the colonization, dissemination, and severity of infections. The importance of epidemiological and genomic surveillance, particularly through whole-genome sequencing, in monitoring the spread of resistant clones and identifying determinants of resistance and virulence is also highlighted. Taken together, the data highlight the need to strengthen programs for the rational use of antimicrobials, to promote integrated surveillance strategies from a One Health perspective, and to deepen knowledge about the interaction between antimicrobial resistance and virulence, in order to improve strategies for the prevention, diagnosis, and treatment of infections caused by Streptococcus spp. Full article

Background: Prosthetic joint infection (PJI) following total shoulder arthroplasty (TSA) is a rare but clinically relevant complication, largely attributable to the distinctive shoulder skin microbiome, predominantly composed of Cutibacterium acnes and coagulase-negative staphylococci (CoNS), which are considered low-virulence pathogens. Standard skin disinfection protocols do not completely prevent bacterial infiltration into the surgical field; therefore, the World Health Organization (WHO) recommends the use of intraoperative irrigation to reduce the risk of shoulder PJIs. Recently, the use of povidone–iodine (PVI) irrigation has been shown to significantly reduce both bacterial load and diversity after TSA; however, its activity against C. acnes remains suboptimal. Therefore, the aim of this study was to evaluate improved in vitro disinfection protocols by combining PVI and hydrogen peroxide for use as intraoperative irrigation in shoulder arthroplasty, which is characterized by a distinctive microbiome. Methods: In vitro broth dilution assays and time-kill experiments were performed to test PVI and H₂O₂, alone or in combination, against CoNS, Staphylococcus aureus, and Escherichia coli as representative aerobic bacteria, and against C. acnes as an anaerobic pathogen. Results: The results revealed that, when used alone, PVI exerted a more pronounced bactericidal effect against staphylococci, whereas H₂O₂ was more effective against C. acnes, even at a high bacterial inoculum, although at cytotoxic concentrations, particularly for PVI. Notably, when the disinfectants were used in combination, bacterial killing was achieved against all the tested pathogens, starting from short exposure times, mainly 3 min, and at low concentrations. Moreover, the antiseptics significantly reduced mature biofilm, although complete eradication was not achieved. Conclusions: A targeted irrigation protocol to prevent shoulder PJI can be achieved by combining PVI and H₂O₂ at non-toxic concentrations and for short exposure times that do not interfere with operating room costs or increase the risk of infection. Full article

Background: Antimicrobial resistance mediated by ESBL-producing Klebsiella pneumoniae is an emerging concern in both human and veterinary medicine, with companion animals increasingly considered relevant within the One Health framework. This study aimed to investigate the fecal carriage of ESBL-producing K. pneumoniae complex in cats from Italy and to characterize the strains by the phenotypic and genetic profile of ESBL production, virulent pathotypes, antibiotic resistance profile and biofilm production. Methods: Fecal samples collected from cats admitted to the Veterinary Teaching Hospital of Milan (Italy) in 2020–2026 were bacteriologically and genetically analyzed. Results: All the Klebsiella pneumoniae strains isolated [4/200 (2%, 95% CI: 0.06–3.94%)] were ESBL-producing K. pneumoniae complex isolates harboring bla_CTX-M-15, bla_SHV, and bla_TEM genes. The isolates were detected with higher presence in cats with diarrhea and were found only in cats treated with antibiotics and hospitalized. All four ESBL-producing isolates were classified as the classical K. pneumoniae pathotype based on the negative string test results, the absence of reliable virulence genes used for pathotype identification (peg-344, iucA, rmpA and rmpA2), and the lack of K1 and K2 serotypes, despite the detection of terB and irp2 virulence genes in one and two isolates, respectively. All four ESBL-producing K. pneumoniae complexes were classified as multidrug-resistant, with resistance mainly observed to β-lactams, fluoroquinolones, quinolones and folate antagonists. All four ESBL-producing K. pneumoniae complexes demonstrated biofilm-forming abilities, with two isolates showing weak adhesion, one moderate adhesion, and one strong adhesion. Conclusions: The detection of ESBL genes together with the MDR pattern, biofilm-forming capacity and selected virulence determinants suggests the potential epidemiological relevance of cats in the dissemination of antimicrobial-resistant K. pneumoniae complexes, underscoring the need for strengthened surveillance and prevention strategies in veterinary settings to provide information to pet cat owners and children who may interact with stray cats, in full implementation of the One Health approach. Full article

Peri-implantitis, a biofilm-driven inflammatory disease that causes progressive loss of the bone supporting dental implants, is common and difficult to treat: mechanical debridement cannot fully decontaminate the implant surface, and antibiotic adjuncts act non-selectively while promoting resistance. Antimicrobial peptides (AMPs) have emerged as a promising preventive strategy. As cationic, membrane-disrupting molecules they kill a broad spectrum of organisms with a low propensity to select for resistance, and as host-defense peptides they additionally modulate inflammation and promote epithelial and connective-tissue repair. This review examines AMP-functionalized titanium as a prospective strategy against peri-implantitis through a dermatological lens, drawing on the established roles of the cathelicidin LL-37 and the β-defensins in cutaneous and oral wound healing. We argue that the peri-implant transmucosal interface behaves as a healing epithelial barrier, so that a single class of host-defense peptides can address two goals usually pursued separately—suppressing the peri-implant biofilm and reinforcing the soft-tissue seal. Because peri-implant disease initiates at the transmucosal region, we give particular attention to the abutment or transmucosal collar as the primary sealing target, and we consider how the concept extends to zirconia and hybrid components. The evidence assembled here, however, is predominantly preclinical, derived from in vitro and animal studies, and does not yet demonstrate clinical prevention of peri-implantitis in patients. After surveying peri-implant epidemiology, microbiology, AMP biology, surface-engineering strategies, and the in vivo evidence, we appraise the translational barriers—stability, cytotoxicity, cost, regulation, and the absence of human trials—that remain. We conclude that biologically intelligent, multifunctional peptide coatings represent a rational direction for next-generation implant surfaces. Full article

Prosthetic joint infections (PJIs) remain a major challenge in orthopedic surgery due to the increasing prevalence of antimicrobial-resistant pathogens and their ability to form biofilms on implant surfaces. Local delivery of non-traditional antimicrobials through implant-associated biomaterials represents a promising strategy for preventing bacterial colonization while minimizing systemic antibiotic exposure. This study evaluated the antimicrobial activity and cytocompatibility of two bacteriophages (Phage K and Phage F1) and two antimicrobial peptide dendrimers (AMPDs; TNS18 and G3KL) against clinical isolates of Staphylococcus aureus and Staphylococcus epidermidis recovered from PJIs. Antimicrobial efficacy was assessed using solid and liquid culture assays, while cytocompatibility was evaluated using human osteoblast progenitor cells. Biofilm formation was also investigated under various in vitro conditions. Phages K and F1 demonstrated strong antibacterial activity against S. aureus isolates, whereas TNS18 showed pronounced inhibitory effects against S. epidermidis. All agents exhibited appropriate osteoblast compatibility, except Phage F1, at the highest multiplicity of infection tested. Biofilm formation was observed under several culture conditions, although substantial variability in biofilm stability limited the quantitative assessment of antimicrobial activity. These findings demonstrate complementary antimicrobial activity profiles between bacteriophages and AMPDs and support their further investigation as candidates for implant-associated antimicrobial delivery systems and orthopedic implant coatings. Full article

Staphylococcus aureus (S. aureus), a leading cause of nosocomial infections, contributes significantly to increased morbidity and mortality, especially when it forms biofilms on medical devices. This pathogen, specifically methicillin-resistant S. aureus (MRSA), remains a challenge to treat due to its ability to form biofilms and rapidly develop resistance against antibiotics. Biofilm formation allows bacteria to adhere to biotic and abiotic surfaces, creating a protective matrix that shields them from immune responses and antibiotic therapies. The widespread prevalence of multidrug-resistant S. aureus biofilms poses a significant therapeutic challenge in clinical settings. Several novel therapeutic strategies have been developed to combat S. aureus biofilm-associated infections. Accumulating evidence suggests that natural plants and their derivatives possess antimicrobial and chemo preventive properties that can disrupt established biofilms. Several plant-derived compounds with anti-biofilm activities have been reported to target the regulatory proteins involved in the Agr quorum sensing (Agr-QS) system, underscoring their potential as therapeutic candidates for the prevention and treatment of biofilm-associated infections. However, despite these encouraging findings, clinical validation of these plant-based agents is essential to ensure their efficacy, safety, and optimal application in treating S. aureus biofilm infections. The continued exploration of natural biofilm inhibitors anticipates the urgent need for new treatments to combat biofilm-associated infections and multidrug-resistant pathogens like MRSA. This review provides a detailed overview of preventive and therapeutic interventions to eradicate biofilm-forming S. aureus infections. Full article

The increasing prevalence of antimicrobial resistance has stimulated the development of alternative antimicrobial materials capable of preventing microbial growth and biofilm formation. Chitosan, a natural polysaccharide derived from chitin through deacetylation, possesses intrinsic antimicrobial properties, biodegradability, biocompatibility, and low toxicity, making it an attractive matrix for nanocomposite materials. However, the antimicrobial efficacy of pure chitosan is often limited by different factors, such as pH sensitivity, mechanical weakness, and poor solubility at neutral pH. To overcome these limitations, researchers have developed chitosan composites containing nanoparticles to enhance antimicrobial and antibacterial efficacy. This review provides an update on the status of the action mechanisms, synthesis methods, antimicrobial and antibacterial performances, and potential biomedical applications of chitosan-based composites containing silver nanoparticles (AgNPs) or zinc oxide nanoparticles (ZnONPs). Full article

Methicillin-resistant Staphylococcus aureus (MRSA) poses a serious threat to public health and can form biofilms to enhance its drug resistance. Caffeic acid phenethyl ester (CAPE), which is primarily extracted from propolis, possesses diverse biological activities. However, its effect on anti-MRSA biofilms and the relevant mechanisms have not been fully clarified. Therefore, this study explored the ability of CAPE to combat MRSA biofilms. The results showed that CAPE has significant antibiofilm activities against MRSA. The minimum inhibitory concentration (MIC) values of CAPE were 256 µg/mL for the MRSA strains ATCC 33591, CI2, and CI3. Crystal violet (CV) assay and XTT assays demonstrated that CAPE could inhibit the formation and consolidation of MRSA CI2 biofilms. Experiments on scanning electron microscopy (SEM), bacterial adhesion assays, and the levels of extracellular polysaccharides confirmed that CAPE can inhibit bacterial adhesion, as well as the synthesis of extracellular polysaccharides in MRSA CI2. Real-time quantitative PCR (RT-qPCR) experiments confirmed that CAPE can affect the expression of MRSA icaADBC, sarA, fnbAB, and clfAB genes. Therefore, the proposed antibiofilm mechanism of CAPE involves the downregulation of aforementioned genes, leading to reduced production of extracellular polysaccharides and adhesion-related proteins, thereby weakening MRSA adhesion and ultimately exerting an antibiofilm effect. In conclusion, these findings suggest CAPE is a promising candidate drug as an antimicrobial agent for managing and preventing biofilm-associated infections caused by MRSA. Full article