Bacterial Adhesion Research Articles

Effect of pH and hydroxyapatite-like layer formation on the antibacterial properties of borophosphate bioactive glass incorporated poly(methyl methacrylate) bone cement.

Infection is a leading cause of total joint arthroplasty failure. Current preventative measures incorporate antibiotics into the poly (methyl methacrylate) (PMMA) bone cement that anchors the implant into the natural bone. With bacterial resistance to antibiotics on the rise, the development of alternative antibacterial materials is crucial to mitigate infection. Borate bioactive glass, 13-93-B3, has been studied previously for use in orthopedic applications due to its ability to be incorporated into bone cements and other scaffolds, convert into hydroxyapatite (HA)-like layer, and enhance the osseointegration and antibacterial properties of the material. The purpose of this study is to better understand how glass composition and change in surrounding pH effects the composite's antibacterial characteristics by comparing the incorporation of 30% wt/wt 13-93-B3 glass and pH neutral borophosphate bioactive glass into PMMA bone cement. We also aim to elucidate how HA-like layer formation on the cement's surface may affect bacterial adhesion. These studies showed that 13-93-B3 incorporated cements had significant reduction of bacterial growth surrounding the composite beyond 24h of exposure when compared to a neutral borate bioactive glass incorporated cement (p < 0.01) and cement only (p < 0.0001). Additionally, through soaking cement composites in simulated body fluid and then exposing them to a bioluminescent strand of staphylococcus aureus, we found that the presence of a HA-like layer on the 13-93-B3 or pH neutral glass incorporated cement disks resulted in an increase in bacterial attachment on the composite cement's surface, where p < 0.001, and p < 0.05 respectively. Overall, our studies demonstrated that borate bioactive glass incorporated PMMA bone cement has innate antimicrobial properties that make it a promising material to prevent infection in total joint arthroplasties.

Correlation between gut microbiota dysbiosis and colorectal cancer: review

Introduction and Purpose: The human gut microbiota, comprising a diverse consortium of approximately 100 trillion microorganisms, is integral to maintaining health and modulating disease processes. Its development begins at birth, influenced by maternal microbiota and environmental factors. Dysbiosis, defined as an imbalance in the gut microbial composition, has been implicated in a range of gastrointestinal pathologies, including colorectal cancer (CRC). This review endeavors to elucidate the relationship between gut microbiota and CRC, examining the impact of specific bacterial taxa on the pathogenesis CRC. Description of the State of Knowledge: Gut microbiota encompasses a multitude of microbial species, with their composition differing along the gastrointestinal tract. Healthy gut microbiota perform essential functions such as pathogen protection, metabolic processes, and immune system modulation. Factors like diet and genetics significantly influence microbial composition. Dysbiosis contributes to CRC through inflammation, genotoxin production, and immune modulation. Specific bacteria, such as Fusobacterium nucleatum and Bacteroides fragilis, are associated with CRC. Mechanisms of carcinogenesis include bacterial adherence, invasion of epithelial cells, and activation of pro-inflammatory pathways. Summary:Understanding the gut microbiota's role in CRC highlights the importance of maintaining a balanced microbiome for cancer prevention. Dietary interventions promoting beneficial bacteria and reducing harmful species could mitigate CRC risk. Further research should prioritize the identification of microbial biomarkers for early CRC detection and the development of therapeutic strategies aimed at modulating the gut microbiota. These efforts will enhance CRC prevention and treatment modalities.

Repeat modules and N-linked glycans define structure and antigenicity of a critical enterotoxigenic E. coli adhesin.

Enterotoxigenic Escherichia coli (ETEC) cause hundreds of millions of cases of infectious diarrhea annually, predominantly in children from low-middle income regions. Notably, in children, as well as volunteers challenged with ETEC, diarrheal severity is significantly increased in blood group A (bgA) individuals. EtpA, is a secreted glycoprotein adhesin that functions as a blood group A lectin to promote critical interactions between ETEC and blood group A glycans on intestinal epithelia for effective bacterial adhesion and toxin delivery. EtpA is highly immunogenic resulting in robust antibody responses following natural infection and experimental challenge of volunteers with ETEC. To understand how EtpA directs ETEC-blood group A interactions and stimulates adaptive immunity, we mutated EtpA, mapped its glycosylation by mass-spectrometry (MS), isolated polyclonal (pAbs) and monoclonal antibodies (mAbs) from vaccinated mice and ETEC-infected volunteers, and determined structures of antibody-EtpA complexes by cryo-electron microscopy. Both bgA and mAbs that inhibited EtpA-bgA interactions and ETEC adhesion, bound to the C-terminal repeat domain highlighting this region as crucial for ETEC pathogen-host interaction. MS analysis uncovered extensive and heterogeneous N-linked glycosylation of EtpA and cryo-EM structures revealed that mAbs directly engage these unique glycan containing epitopes. Finally, electron microscopy-based polyclonal epitope mapping revealed antibodies targeting numerous distinct epitopes on N and C-terminal domains, suggesting that EtpA vaccination generates responses against neutralizing and decoy regions of the molecule. Collectively, we anticipate that these data will inform our general understanding of pathogen-host glycan interactions and adaptive immunity relevant to rational vaccine subunit design.

Evaluation of antibacterial activity on nanoline-array surfaces with different spacing

Extensive research has been conducted on anti-biofouling or antibacterial surfaces, with nanostructured surfaces that mimic cicada and dragonfly wings emerging as promising candidates for mechano-bactericidal applications. These biomimetic nanostructured surfaces are capable of exerting a bactericidal effect by directly damaging the membranes of bacteria attached to nanostructures. Although research on bactericidal effect using various nanostructures have been conducted, no specific studies have yet reported on the antibacterial efficiency of the surface having nanoline array, especially regarding the spacing between nanolines. This study details the fabrication of nanoline array via ultraviolet (UV) molding with polyurethane acrylate (PUA), noted for its UV sensitivity and rapid curing, enabling the fabrication of precise and scalable nanoscale structures. Investigation into the nanoline array’s antibacterial effects against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) reveals that nanoline spacing critically influences bacterial adherence and viability, with specific spacings enhancing antibacterial properties. Scanning electron microscopy (SEM) and confocal microscopy analyses show that surface topography significantly affects bacterial behavior, with specific spacings leading to varied bacterial responses, including membrane damage and altered attachment patterns. The study highlights the potential of nanoline array in fabricating surfaces with tailored antibacterial properties, emphasizing the importance of nanoscale design in influencing bacterial interaction and viability. We also confirm the relative mechanical rigidity of the nanoline array, which exhibits antibacterial effects, through both experimental observations and numerical analysis. This indicates our proposed nanoline-array surface could have potential future applications in mechanical anti-bacterial functions that require such structural robustness.

433 Use of polyclonal antibodies to improve the efficiency of rumen function

Abstract Technologies such as polyclonal antibody preparations (PAP) have been investigated as a tool to improve rumen function, by targeting specific bacteria or molecules. While PAP can be sourced from the serum of immunized mammals, isolating targeted avian-derived antibodies (immunoglobulin Y; IgY) from egg yolk gained popularity due to its reduced impact on hens and greater IgY concentration in yolks. Advantages of avian-derived PAP utilization include cost-effectiveness and convenient production, high stability, and reduced cross-reactivity compared with other PAPs. Furthermore, IgY does not activate the host immune complement system, as observed with PAP derived from mammalian serum. Several proposed strategies explain how PAP might protect the host. It is suggested that PAP can agglutinate bacteria, inhibit bacterial adhesion, suppress bacterial virulence factors, and neutralize toxins. Avian-derived PAP, mainly administered as a direct-fed product in beef and dairy cattle diets, has been studied for its impact on specific rumen microbial populations, especially during high-grain feeding. Research confirms the effectiveness of PAP-IgY in inhibiting the growth of targeted bacteria. In beef steers, feeding PAP-IgY against Streptococcus bovis and Fusobacterium necrophorum resulted in growth inhibition, while IgY against cellulolytic rumen bacteria also showed efficacy in reducing the growth of the targeted strains in vitro. In other studies, PAP-IgY targeting S. bovis and F. necrophorum increased ruminal pH in beef steers and heifers and dairy cows, while also cattle-fed PAP-IgY against F. necrophorum had reduced severity of liver abscesses. When performance was evaluated, PAP-IgY against S. bovis improved feed efficiency of feedlot beef steers, and milk production increased when dairy cows were supplemented with PAP-IgY against lipopolysaccharides, with no observed impact on cow health status. However, not all studies have consistently demonstrated positive effects of PAP-IgY on nutrient digestibility or on mitigating systemic inflammation during high-grain feeding. A recent study revealed that supplementation with PAP-IgY against Methanobrevibacter ruminantium M1 decreased methane output ex-situ and tended to increase molar proportion of propionate in beef steers. In summary, polyclonal antibody preparations, particularly avian-derived IgY, offer a promising alternative to improve rumen function and animal performance. This is evidenced by increased ruminal pH during high grain feeding, inhibition of targeted bacterial growth, and, most recently, methane reduction. However, not all studies demonstrate consistent effects regarding nutrient digestibility. Further research is needed to refine recommendations, including dosage and antibody combinations, and to explore the broader impacts of PAP-IgY supplementation on ruminal and systemic variables to optimize livestock performance.

Prevention of bacterial adhesion in water conduction systems using vanillin-functionalized grates

Pathogenic microorganisms can adhere to the surfaces of water conducting systems, finally resulting in biofilm structures. Considering the importance of the adhesion capability of cells and the biofilm formation in these surfaces, their inhibition by using naturally occurring antimicrobial compounds can be a potential alternative or complement to water chlorination. This work aimed to study the antiadhesive capability of vanillin-functionalized stainless-steel surfaces against bacteria present in low-pressure water distribution network. Stainless-steel surfaces were pretreated (by sanding or polishing) and activated, allowing the covalent anchoring of vanillin to the stainless-steel. Characterization of functionalized surfaces, by macroscopic, microscopic, and elemental analysis confirmed the efficiency of the vanillin anchoring protocol. Subsequently, in vitro antiadhesive capability assays were performed with Staphylococcus epidermidis as a model microorganism to assess the antiadhesiveness capacity of the functionalized surfaces. This assay allowed the confirmation of the capacity of vanillin-functionalized surfaces to prevent the adhesion of S. epidermidis to the stainless-steel surfaces. Finally, grates were functionalized and placed in low-pressure water conduction pipes in the city of Valencia, Spain. After placement, samples of the biofilm adhered to the grates were taken at certain times and analyzed through metagenomic analysis. The results showed statistically significant differences in both the amount and type of bacterial strains adhered to vanillin-functionalized and non-functionalized grates. These findings demonstrated for the first time the potential application of vanillin-functionalized stainless-steel surfaces in water conduction systems to avoid the adhesive ability of bacteria, preventing their contamination and/or biofilm formation.

Salmonella pathogenesis-based In-silico design and immunoinformatic analysis of multi-epitope vaccine constructs in broiler veterinary medicine

Salmonellosis, a zoonotic gastrointestinal disease, presents a significant global health burden with a high incidence rate. Transmission primarily occurs through the consumption of contaminated poultry products, although water and contact with asymptomatic animals are also vectors. The disease’s pervasiveness has prompted international health organizations to advocate for robust prevention and control strategies. This study focuses on the in-silico design of a multi-epitope vaccine targeting Salmonella enterica serovar Typhimurium’s fimH protein, a fimbriae component crucial for bacterial adhesion and pathogenicity. The vaccine construct was developed by identifying and synthesizing non-allergenic, antigenic, and non-toxic epitopes for both Cytotoxic T Lymphocytes and Helper T Lymphocytes. Adjuvants were incorporated to enhance immunogenicity, and the vaccine’s structure was modeled using advanced bioinformatics tools. The proposed vaccine demonstrated promising antigenicity and immunogenicity profiles, with a favorable physical-chemical property analysis. The vaccine’s structures, designed by computational analysis, suggests high likelihood to native protein configurations. Antigenicity and allergenicity assessments validate the vaccine’s immunogenic potential and hypoallergenic nature. Physicochemical evaluations indicate favorable stability and solubility profiles, essential for vaccine efficacy. This comprehensive approach to vaccine design expressed in Chlorella vulgaris holds promises for effective salmonellosis control. The multi-epitope vaccine, designed through meticulous in-silico methods, emerges as a promising candidate for controlling salmonellosis. Its strategic construction based on the fimH protein epitopes offers a targeted approach to elicit a robust immune response, potentially curbing the spread of this disease in poultry.

Covalent Grafting of Tanfloc on Titania Nanotube Arrays: An Approach to Mitigate Bacterial Adhesion and Improve the Antibacterial Efficacy of Titanium Implants

AbstractImplanted medical devices often face the challenge of infections, which can compromise their successful integration and use. To address this issue, this study demonstrates the covalent grafting of a tannin‐based antimicrobial biopolymer tanfloc (TAN) onto the titania nanotube arrays (TiNTs) surface to enhance antibacterial properties. Due to its polyphenolic and ionic structural configuration, tanfloc possesses unique properties that enable it to interact with and disrupt bacterial cell walls and membranes. Combining the topographical effect of TiNTs with the inherent antibacterial properties of tanfloc, this approach aims to mitigate bacterial threats on medical implants effectively. The successful attachment of tanfloc on TiNTs is confirmed through X‐ray photoelectron spectroscopy (XPS) and Fourier‐transform infrared spectroscopy (FT‐IR). The antibacterial and antibiofilm efficacy of the tanfloc‐functionalized TiNTs is evaluated against Staphylococcus aureus (Gram‐positive) and Pseudomonas aeruginosa (Gram‐negative) bacteria. The findings suggest that the covalent conjugation of tanfloc onto TiNTs is a promising approach to improve the infection resistance of titanium‐based medical implants, with potential applications in orthopedic, dental, and other biomedical device areas.

Biofilm inhibition of Staphylococcus aureus by silver nanoparticles derived from Hellenia speciosa rhizome extract

Staphylococcus aureus is the most common cause of serious health conditions because of the formation of biofilm, which lowers antibiotic efficacy and enhances infection transmission and tenacious behavior. This bacteria is a major threat to the worldwide healthcare system. Silver nanoparticles have strong antibacterial characteristics and emerged as a possible alternative. This work is most relevant since it investigates the parameters influencing the biogenic nanoparticle-assisted control of bacterial biofilms by Staphylococcus aureus.Nanoparticles were fabricated utilizing Hellenia speciosa rhizome extracts, which largely comprised physiologically active components such as spirost-5-en-3-yl acetate, thymol, stigmasterol, and diosgenin, enhanced with the creation of silver nanocomposites. GC-MS, XRD, DLS, SEM, EDX, FTIR and TEM were used to investigate the characteristics of nanoparticles. The microtiter plate experiment showed that nanoparticles destroyed biofilms by up to 92.41 % at doses that ranged from 0 to 25 μg/ml. Fluorescence microscopy and SEM demonstrated the nanoparticles' capacity to prevent bacterial surface adhesion. EDX research revealed that the organic extract efficiently formed silver nanoparticles with considerable oxygen incorporation, which was attributed to phytochemicals that stabilize AgNPs and prevent accumulation. FTIR spectroscopy indicated the existence of hydroxyl, carbonyl, and carboxylate groups, which are essential for nanoparticle stability. TEM revealed that the AgNPs were spheroidal, with diameters ranging from 40 to 60 nm and an average of 46 nm. These results demonstrate the efficacy of H. speciosa extract in creating stable, well-defined AgNPs suited for a variety of applications. This work underlines the potential of green-synthesized AgNPs in biomedical applications, notably in the treatment of S. aureus biofilm-associated illnesses. The thorough characterization gives important information on the stability and efficiency of these biogenic nanoparticles.

Photocatalytic and antibacterial activity properties of Ti surface treated by femtosecond laser–a prospective solution to peri-implant disease

Laser texturing seems to be a promising technique for reducing bacterial adhesion on titanium implant surfaces. This work aims to demonstrate the possibility of obtaining a functionally orientated surface of titanium implant elements with a specific architecture with specific bacteriological and photocatalytic properties. Femtosecond laser-generated surface structures, such as laser-induced periodic surface structures (LIPSS, wrinkles), grooves, and spikes on titanium, have been characterised by XRD, Raman spectroscopy, and scanning electron microscopy (SEM). The photocatalytic activity of the titanium surfaces produced was tested based on the degradation effect of methylene blue (MB). The correlation between the photocatalytic activity of TiO2 coatings and their morphology and structure has been analysed. Features related to the size, shape, and distribution of the roughness patterns were found to influence the adhesion of the bacterial strain on different surfaces. On the laser-structurised surface, the adhesion of Escherichia coli bacteria were reduced by 80% compared to an untreated reference surface.

Human transferrin and lactoferrin cooperatively support Neisseria meningitidis colonization in the murine nasopharynx.

Neisseria meningitidis is a human-restricted bacteria that is a normal nasopharyngeal resident, yet it can also disseminate, causing invasive meningococcal disease. Meningococci are highly adapted to life in humans, with human-specific virulence factors contributing to bacterial adhesion, nutrient acquisition and immune evasion. While these factors have been explored in isolation, their relative contribution during infection has not been considered due to their absence in small animal models and their expression by different human cell types not readily combined in either in vitro or ex vivo systems. Herein, we show that transgenic expression of the iron-binding glycoproteins human transferrin and lactoferrin can each facilitate N. meningitidis replication in mouse serum but that transferrin was required to support infection-induced sepsis. While these host proteins are insufficient to allow nasopharyngeal colonization alone, mice co-expressing these and human CEACAM1 support robust colonization. In this case, meningococcal colonization elicits an acute elevation in both transferrin and lactoferrin levels within the upper respiratory mucosa, with transferrin levels remaining elevated while lactoferrin returns to basal levels after establishment of infection. Competitive infection of triple transgenic animals with transferrin- and lactoferrin- binding protein mutants selects for bacteria expressing the transferrin receptor, implicating the critical contribution of transferrin-based iron acquisition to support colonization. These transgenic animals have thus allowed us to disentangle the relative contribution of three virulence factors during colonization and invasive disease, and provides a novel in vivo model that can support extended meningococcal colonization, opening a new avenue to explore the meningococcal lifestyle within its primary niche.

An innovative process chain for the production of antibiofouling polymer parts using ultrafast laser texturing

Polymers are versatile materials widely used in various industries, with significant applications in biomedicine where biofouling on polymer surfaces presents major health and economic challenges. Biofouling, initiated by bacterial adhesion, can be mitigated by modifying surface properties through laser micro- and nano-texturing, an approach that offers advantages over chemical treatments. This study introduces an economical mass production process for textured polymeric components using injection molding to replicate hierarchical textures. Testing revealed that all textured samples significantly reduced bacterial adhesion compared to untextured surfaces across different designs and bacteria types after 24 h of culture. The study examined factors like wettability, nanoscale roughness, and pattern dimensions to explain these outcomes, comparing them with existing studies. Despite all textured samples showing decreased wettability and roughness, these factors alone did not ensure reduced bacterial adhesion. The most effective anti-adhesive performance was observed in surfaces with parallel ridge patterns, which segmented the surface into isolated areas that limited bacterial interaction and hindered micro-colony formation, highlighting the importance of specific surface patterning in combating biofouling.

A bifunctional lactoferrin-derived amyloid coating prevents bacterial adhesion and occludes dentinal tubules via deep remineralization

Dentin hypersensitivity (DH) manifests as sharp and uncomfortable pain due to the exposure of dentinal tubules (DTs) following the erosion of tooth enamel. Desensitizing agents commonly used in clinical practice have limitations such as limited depth of penetration, slow remineralization and no antimicrobial properties. To alleviate these challenges, our study designed a lactoferrin-derived amyloid nanofilm (PTLF nanofilm) inspired by the saliva-acquired membrane (SAP). The nanofilm utilises Tris(2-carboxyethyl)phosphine (TCEP) to disrupt the disulfide bonds of lactoferrin (LF) under physiological conditions. The PTLF nanofilm modifies surfaces across various substrates and effectively prevents the early and stable adhesion of cariogenic bacteria, such as Streptococcus mutans and Lactobacillus acidophilus. Simultaneously, it adheres rapidly and securely to demineralized dentin surfaces, facilitating in-situ remineralization of HAP through a simple immersion process. This leads to the formation of a remineralized layer resembling natural dentin, with an occlusion depth of dentinal tubules exceeding 80 µm after three days. The in vivo and vitro results confirm that the PTLF nanofilm possesses good biocompatibility and its ability to exert simultaneous antimicrobial effects and dentin remineralization. Accordingly, this innovative bifunctional PTLF amyloid coating offers promising prospects for the management of DH-related conditions. Statement of significance1.We design a simple, fast, inexpensive, and easy-to-process PTLF nanofilm for nearly any material surface or shape.2.The PTLF nanofilm modifies surfaces across various substrates and effectively prevents the adhesion of cariogenic bacteria, such as Streptococcus mutans and Lactobacillus acidophilus.3.The abundant functional groups on the surface of PTLF nanofilm facilitate bioactive hydroxyapatite (HAP) formation and maintain stability at the HAP remineralization interface.

Facile Surface Modification with Croconaine-Functionalized Polymer on Polypropylene for Antifouling and NIR-Light-Mediated Photothermal Sterilization.

Biomedical-device-associated infection (BAI) is undoubtedly a major concern and a serious challenge in modern medicine. Therefore, the development of biomedical materials that are capable of resisting or killing bacteria is of great importance. In this work, a croconaine-functionalized polymer with antifouling and near-infrared (NIR) photothermal bactericidal properties was prepared and facilely modified on polypropylene (PP) to combat medical device infections. Croconaine dye is elaborately modified as a "living" initiator, termed CR-4EBiB, for preparing amphiphilic block polymers by atom transfer radical polymerization (ATRP). In the formed polymer coating, the hydrophobic block can strongly adhere to the surface of the PP substrate, whereas the hydrophilic block is located on the outer layer by solvent-induced resistance to bacterial adhesion. Under the irradiation of an NIR laser (808 nm), the croconaine dye in the coating achieved maximum conversion of light to heat to effectively kill E. coli, S. aureus, and methicillin-resistant Staphylococcus aureus (MRSA). This work provides a facile and promising strategy for the development of implantable antibacterial biomedical materials.

Quantitative study of early-stage transient bacterial adhesion to bioactive glass and glass ceramics: atomic force microscopic observations

Antimicrobial potential of bioactive glass (BAG) makes it promising for implant applications, specifically overcoming the toxicity concerns associated with traditional antibacterial nanoparticles. The 58S composition of BAG (with high Ca and absence of Na) has been known to exhibit excellent bioactivity and antibacterial behaviour, but the mechanisms behind have not been investigated in detail. In this pioneering study, we are using Atomic Force Microscopy (AFM) to gain insights into 58S BAG’s adhesive interactions with planktonic cells of both gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria; along with the impact of crystallinity on antibacterial properties. We have recorded greater bacterial inhibition by amorphous BAG compared to semi-crystalline glass–ceramics and stronger effect against gram-negative bacteria via conventional long-term antibacterial tests. AFM force distance curves has illustrated substantial bonding between bacteria and BAG within the initial one second (observed at a gap of 250 ms) of contact, with multiple binding events. Further, stronger adhesion of BAG with E.coli (~ 6 nN) compared to S. aureus (~ 3 nN) has been found which can be attributed to more adhesive nano-domains (size effect) distributed uniformly on E.coli surface. This study has revealed direct evidence of impact of contact time and 58S BAG’s crystalline phase on bacterial adhesion and antimicrobial behaviour. Current study has successfully demonstrated the mode and mechanisms of initial bacterial adhesion with 58S BAG. The outcome can pave the way towards improving the designing of implant surfaces for a range of biomedical applications.

Polyphenolic extracts from Diospyros kaki and Vitis vinifera by-products stimulate cytoprotective effects in bacteria-cell host interactions by mediation of transcription factor Nrf2

BackgroundThe intestinal and skin epithelium play a strong role against bacterial stimuli which leads to inflammation and oxidative stress when overwhelmed. Polyphenols from fruit-rich diets and by-products show promise against bacterial deleterious effects; however, their antibacterial and health-promoting effects remain understudied. PurposeThis study aimed to assess the impact of polyphenolic extracts of grape (GrPE), persimmon (PePE) and pomegranate (PoPE) by-products on bacterial pathogen-host interactions, focusing beyond growth inhibition to explore their effects on bacterial adhesion, invasion, and modulation of host responses. MethodsThe microdilution method, as well as the tetrazolium based MTT cell proliferation and cytotoxicity assay with crystal violet staining were used to identify extracts sub-inhibitory concentrations that interfere with bacterial adhesion, invasion or lipopolysaccharides (LPS) effect on cell hosts without compromising host viability. The cytoprotective effects of extracts were assessed in a knock-down model of nuclear factor erythroid 2-related factor 2 (Nrf2). ResultsAll extracts demonstrated significant reductions in pathogen adhesion to Caco-2 and HaCaT cells while preserving cellular integrity. Notably, PePE exhibited specific efficacy against Salmonella enterica adhesion, attributed mostly to its gallic acid content, whereas PoPE reduced S. enterica invasion in Caco-2 cells. The extracts supported the prevalence of non-pathogenic and commensal strains of intestinal and skin surfaces, selectively reducing pathogenic adhesion. The extracts mitigated the oxidative stress, enhanced the barrier function, and modulated the pro-inflammatory cytokines in LPS-challenged cells. GrPE, rich in anthocyanins, and PePE were found to mediate their protective effects through Nrf2 activation, while PoPE exerted multifaceted actions independent of Nrf2. ConclusionOur results highlight the therapeutic potential of GrPE, PePE, and PoPE in shaping bacterial-host interactions, endorsing their utility as novel nutraceuticals for both oral and topical applications to prevent potential bacterial infections through innovative mechanisms.

The Biological Impact of Residual Aluminum Particles on Sand-Blasted Dental Implant Surfaces: A Systematic Review of Animal Studies

(1) Background: The use of alumina particles for surface treatment of dental implants is a common practice aimed at enhancing osseointegration. However, the biological effects of residual alumina particles on implant surfaces remain a subject of debate. This systematic review evaluates the impact of residual alumina particles on the osseointegration, biocompatibility, and bacterial adhesion of dental implants based on available in vivo experimental animal studies. (2) Methods: A comprehensive literature search was conducted across PubMed, Web of Science, and Scopus to identify relevant studies. The inclusion criteria focused on experimental animal studies that assessed the biological effects of alumina-blasted dental implants. Data extraction was carried out, and quality assessments were performed using the SYRCLE risk-of-bias tool. (3) Results: Ten studies met the inclusion criteria, involving various animal models, such as rabbits, pigs, dogs, and sheep. The findings demonstrated that residual alumina particles did not negatively impact osseointegration. Some studies reported accelerated bone growth and improved osseointegration with residual alumina. Additionally, residual alumina showed potential bactericidal properties, reducing bacterial adhesion. (4) Conclusions: The available evidence from animal studies suggests that residual alumina particles do not adversely affect the osseointegration and biocompatibility of dental implants. These particles may even enhance bone growth and reduce bacterial adhesion. However, due to the scarcity of human studies and the impracticality of histological assessments in humans, further research, including long-term clinical trials, is necessary to confirm these findings.

An antifouling electrochemical sensor based on a U-shaped four-in-one peptide and poly(3,4-ethylenedioxythiophene) for vancomycin detection in fresh goat milk

Nonspecific adsorption of biomolecules (notably, proteins) and bacteria from unsterilized food may occur on sensor surfaces, which is still a challenge for food safety sensing. To achieve sensitive detection of unsterilized raw-food materials, in this study, a U-shaped four-in-one peptide with the sequence Ac-FLKLLKKLL-DOPA3-PPPPEEKDQDKEKaa that exhibited anchoring, antifouling, antibacterial, and recognition properties was designed. The peptide-modified sensor surface effectively prevented bacterial adhesion and proliferation while resisting biomolecule adsorption (signal inhibition rate as low as 0.51 % in single-protein solutions). A highly conductive polymer layer of poly(3,4-ethylenedioxythiophene) was introduced to improve the electrochemical performance before U-shaped four-in-one peptide anchoring. The proposed sensor could accurately detect vancomycin, with a wide linear range and limit of detection of 0.05–10 μg mL−1 and 2.06 ng mL−1 (S/N = 3), respectively. Satisfactory recovery rates (101.3–105.3 %) were achieved using diluted fresh goat milk.

The lysogenic filamentous Pseudomonas bacteriophage phage Pf slows mucociliary transport.

Pseudomonas aeruginosa is a major pulmonary pathogen causing chronic pulmonary infections in people with cystic fibrosis (CF). The P. aeruginosa filamentous and lysogenic bacteriophage, Pf phage, is abundant in the airways of many people with CF and has been associated with poor outcomes in a cross-sectional cohort study. Previous studies have identified roles for Pf phage in biofilm formation, specifically forming higher-order birefringent, liquid crystals when in contact with other biopolymers in biofilms. Liquid crystalline biofilms are more adherent and viscous than those without liquid crystals. A key feature of biofilms is to enhance bacterial adherence and resist physical clearance. The effect of Pf phage on mucociliary transport is unknown. We found that primary CF and non-CF nasal epithelial cells cultured at air-liquid interface treated with Pf phage exhibit liquid crystalline structures in the overlying mucus. On these cell cultures, Pf phage entangles cilia but does not affect ciliary beat frequency. In both these in vitro cell cultures and in an ex vivo porcine trachea model, introduction of Pf phage decreases mucociliary transport velocity. Pf phage also blocks the rescue of mucociliary transport by CF transmembrane conductance regulator modulators in CF cultures. Thus, Pf phage may contribute to the pathogenesis of P. aeruginosa-associated CF lung disease via induction of liquid crystalline characteristics to airway secretions, leading to impaired mucociliary transport. Targeting Pf phage may be useful in treatment CF as well as other settings of chronic P. aeruginosa infections.

Microbial adhesion on different types of orthodontic brackets and wires: An in vitro study

ObjectiveThe objective of this study was to compare the microbial adhesion of different oral pathogens on different wires used in orthodontic treatment and to evaluate the potential of these pathogens to form biofilms on different types of orthodontic wires and brackets. MethodsIn this in vitro investigation, we calculated that the sample size for each group (i.e., those with brackets [metal braces, ceramic braces, and self-ligating braces] and wires [nickel titanium, titanium molybdenum, and stainless steel]) should be 15 individuals. Five types of microbes (Streptococcus mutans, Escherichia coli, Enterococcus faecalis, Staphylococcus aureus, and Candida albicans) were used. Three types of brackets and three types of wires were used with five types of bacteria, and the process was repeated three times to collect the average. ResultsNo significant differences were observed in the mean concentrations of bacteria in the different brackets (p > 0.05) or in the mean concentrations in the different orthodontic materials used in these brackets. In contrast, there were considerable differences between the concentrations of bacteria in the wires and those in the brackets (p < 0.05). ConclusionDifferent wires and brackets have different associations with bacterial adhesion and concentration. The wires exhibited more substantial biofilm absorbance and concentrations than the brackets. The adhesion of biofilm may be a decisive factor when choosing a type of orthodontic wire, particularly for individuals at high risk of developing bacterial oral diseases, such as periodontal diseases and dental caries.