Anti-adhesive Activity Research Articles

Polycation-Intercalated MXene Membrane with Enhanced Permselective and Anti-Microbial Properties.

Two-dimensional (2D) nanomaterial-based membranes feature attractive properties for molecular separation and transport, which exhibit huge potential in various chemical processes. However, the low permeability and bio-fouling of the MXene membrane in water treatment become huge obstacles to its practical application. Herein, a highly permselective and anti-bacterial 2D nanofiltration membrane is fabricated by intercalating a polycation of polydiallyldimethylammonium chloride (PDDA) into the Ti3C2Tx MXene laminar architecture through a facile and patternable electrostatic assembly strategy. As a result, the as-fabricated Ti3C2Tx/PDDA composite membrane exhibits higher water permeance up to 73.4 L m-2 h-1 with a rejection above 94.6% for MgCl2. The resultant membrane simultaneously possesses good resistance to swelling and long-term stability in water environments, even after 8 h. Additionally, the Ti3C2Tx/PDDA membrane also demonstrates a high flux recovery ratio of nearly 96.1% to bovine serum albumin proteins after being cleaned. More importantly, the current membrane shows excellent anti-adhesive and anti-microbial activity against Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus), with inhibition rates of 90% and 95% against E. coli and S. aureus, respectively. This holds great potential for the application of the polyelectrolyte-intercalated MXene membrane in serving as a promising platform to separate molecules and/or ions in an aquatic environment.

Improved in vitro Hemagglutination Assays Utilizing P-Type and Type 1 Uropathogenic Escherichia coli to Evaluate Bacterial Anti-Adhesion Activity of Cranberry Products

Cranberries have a long history of use in the prevention of urinary tract infections. Cranberry products vary in proanthocyanidin content, a compound implicated in preventing the adhesion of uropathogenic Escherichia coli (E. coli) to uroepithelial cells. Testing is routinely done by cranberry product formulators to evaluate in vitro bacterial anti-adhesion bioactivity, shelf-life, and potential efficacy of cranberry products for consumer use to maintain urinary tract health. Hemagglutination assays evaluate the anti-adhesion bioactivity of cranberry products by determining how effectively the products prevent agglutination of specific red blood cells with E. coli expressing P-type and Type 1 fimbriae. The current study sought to improve upon an established anti-adhesion assay method by expanding the number of E. coli strains used to broaden potential in vivo efficacy implications and presenting results using photomicrographic data to improve accuracy and build databases on products that are routinely tested. Different lots of cranberry powder ingredient and two formulated products were tested independently for anti-adhesion activity using the established method and the improved method. Positive harmonization of results on the same samples using rigorous controls was achieved and provides the substantiation needed for the cranberry industry to utilize the improved, rapid in vitro testing method to standardize cranberry products for sufficient anti-adhesion bioactivity and maintain consumer confidence.

Enhanced in vitro immersion behavior and antibacterial activity of NiTi orthopedic biomaterial by HAp-Nb2O5 composite deposits

NiTi is a class of metallic biomaterials, benefit from superelastic behavior, high biocompatibility, and favorable mechanical properties close to that of bone. However, the Ni ion leaching, poor bioactivity, and antibacterial activity limit its clinical applications. In this study, HAp-Nb2O5 composite layers were PC electrodeposited from aqueous electrolytes containing different concentrations of the Nb2O5 particles, i.e., 0–1 g/L, to evaluate the influence of the applied surface engineering strategy on in vitro immersion behavior, Ni2+ ion leaching level, and antibacterial activity of the bare NiTi. Surface characteristics of the electrodeposited layers were analyzed using SEM, TEM, XPS, and AFM. The immersion behavior of the samples was comprehensively investigated through SBF and long-term PBS soaking. Gram-negative Escherichia coli (E. coli) and Gram-positive Staphylococcus aureus (S. aureus) infective reference bacteria were employed to address the antibacterial activity of the samples. The results illustrated that the included particles led to more compact and smoother layers. Unlike bare NiTi, composite layers stimulated apatite formation upon immersion in both SBF and PBS media. The concentration of the released Ni2+ ion from the composite layer, containing 0.50 g/L Nb2O5 was ≈ 60% less than that of bare NiTi within 30 days of immersion in the corrosive PBS solution. The Nb2O5-reinforced layers exhibited high anti-adhesive activity against both types of pathogenic bacteria. The hybrid metallic-ceramic system comprising HAp-Nb2O5-coated NiTi offers the prospect of a potential solution for clinical challenges facing the orthopedic application of NiTi.

In-Vitro Antioxidant Potential of Beta-Sitosterol: A Preface.

Introduction Beta-sitosterol, a plant sterol, has been linked to antibacterial and antinociceptive effects. Plant sterols exhibit valuable medicinal properties, including anti-adhesive activities. The dietary composition of sterols includes carbohydrates, lipids, proteins, and various minerals, along with beneficial reinforcements like essential nutrients. Methodology This study primarily aims to evaluate the antioxidant potential of beta-sitosterol through assessments using diphenylpicrylhydrazyl (DPPH), hydrogen peroxide (H2O2), and total antioxidant assays. Results The investigation into beta-sitosterol's antioxidant properties revealed a positive correlation between its concentration and antioxidant activity. Similar trends were observed in the present study, indicating an increase in antioxidant activity at lower concentrations. Discussion and conclusion Our findings demonstrate that beta-sitosterol exhibits significant antioxidant activity in the tested samples. These results highlight beta-sitosterol's potential as a potent antioxidant and contribute to our understanding of its beneficial effects.

Development by emulsion templating of a novel Tunisian clay-polyvinyl alcohol/extra-virgin olive oil scaffold with antibiofilm properties

A biobased porous scaffold with antibacterial and antioxidant properties was developed using the emulsion templating method. This technique represents a new route for the development of porous materials with controllable pore size. To take into account the environmental and economic aspects, polyvinyl alcohol (PVA) was chosen as the polymer matrix, raw Tunisian clay as the Pickering emulsion stabilizer, and extra virgin olive oil (EVOO) as the oil phase. PVA is often chosen for producing wound dressings that create a moist environment and consequently promote healing. Clay was used as a barrier against bacteria and as emulsifier due to its nanoscale and layered structure. In EVOO, the polyphenolic compounds have antioxidant activity and fatty acids have a plasticizer role. X-ray fluorescence, X-ray diffraction and Fourier transform infrared spectroscopy were used to analyze the raw clay. Then, the obtained films were structurally and chemically characterized, and their performance, antimicrobial activity against Pseudomonas aeruginosa, and antioxidant activity were evaluated. The emulsion characterization showed that clay addition influenced the emulsion type and increased the emulsion stability index to 98%, even after 3 months of storage. This was explained by the irreversible adsorption of clay platelets on the droplet surface that formed a rigid shell to prevent coalescence. The film characterization demonstrated that the oil: water ratio did not influence the surface porosity, although it affected the pore size uniformity and interconnection. Conversely, shortening the curing time improved the surface porosity. The resulting PVA-clay/EVOO scaffold displayed an exceptional performance, including high mechanical strength (∼2.1 MPa), interconnected porous structure with a size ranging from few µm to > 30 µm, and hydrophobic properties (∼90° ± 2). In addition, it showed antiadhesive and antibiofilm activities against P. aeruginosa. Therefore, this scaffold could be used for the early prevention of biofilm formation during wound healing and is a promising candidate for the controlled release of drugs and potentially for various applications in soft tissues.

Biological Activity of Acinetobacter calcoaceticus IMV B-7241 Surfactants Synthesized in the Presence of Competitive Bacteria Bacillus subtilis BT-2

Currently, the effectiveness of technologies for microbial surfactants, which are characterized by a complex of practically valuable physicochemical and biological properties is lower than that of synthetic analogues. To reduce the cost of these products of microbial synthesis, industrial waste is used as substrates for their biosynthesis. In previous studies, it has been established that surfactants synthesized by Acinetobacter calcoaceticus IMV B-7241 on crude glycerol have lower antimicrobial activity compared to that obtained on purified glycerol. The main approaches to the regulation of the biological activity of microbial surfactants are their post-fermentation chemical modification, as well as the improvement of producer strains by methods of metabolic and genetic engineering. In recent years, numerous studies have appeared on the co-cultivation of producers of antimicrobial compounds with competitive microorganisms (biological inductors), in response to the presence of which the antimicrobial activity of the final product increases. Aim. To study the effect of live and inactivated cells of Bacillus subtilis BT-2, as well as the corresponding supernatant, on the antimicrobial and anti-adhesive activity and the ability to destroy biofilms of A. calcoaceticus IМV B-7241 surfactants synthesized in a medium with glycerol of different degrees of purification. Methods. The A. calcoaceticus IMV B-7241 strain was grown in a liquid mineral medium with purified and crude glycerol, into which live and inactivated B. subtilis BT-2 cells as well as the supernatant after growing the B. subtilis BT-2 strain (2.5—10%, v/v) were added. Surfactants were extracted from the supernatant of the culture liquid with Folch’s mixture. Anti-adhesive activity and the degree of destruction of biofilms were determined by the spectrophotometric method, and antimicrobial activity — by the indicator of the minimum inhibitory concentration. The activity of enzymes of surface-active aminolipids biosynthesis (NADP+-dependent glutamate dehydrogenase) and glycolipids (phosphoenolpyruvate (PEP)-carboxylase, PEP-synthetase, PEP-carboxykinas, trehalose-phosphate synthase) was analyzed in cell-free extracts obtained after сells sonication. Results. It was established that the introduction of inactivated B. subtilis BT-2 cells and supernatant into the medium with both substrates did not affect the indicators of the surfactant synthesis, while in the presence of live cells of the B. subtilis BT-2 strain in the medium with purified glycerol, a decrease in the concentration of the final product by 1.5 times, and in the culture medium with crude glycerol — an increase by1.4 times were observed compared to the indicators with no inductor. The study of the antimicrobial activity of surfactants showed that the most effective of the used inductors (live, inactivated cells, supernatant) were live cells of B. subtilis BT-2. The introduction of B. subtilis BT-2 strain live cells into the culture medium with both substrates was accompanied by the formation of surfactants, the minimum inhibitory concentrations of which in relation to bacterial (Bacillus subtilis BT-2, Staphylococcus aureus BMS-1, Proteus vulgaris PA-12, Enterobacter cloacae С-8) and yeast (Candida albicans D-6, Candida tropicalis PE-2) test-cultures were 3—23 times lower than established for those synthesized on the medium with no inductor. Anti-adhesive activity of surfactants obtained on purified and crude glycerol in the presence of all types of inductors was higher compared to those synthesized in the culture medium without inductors (cells adhesion of bacterial and yeast test-cultures on polyvinyl chloride was 13—70 and 33—96%, respectively). Introduction of live and inactivated B. subtilis BT-2 cells or the supernatant into A. calcoaceticus IMV B-7241 cultivation medium was accompanied by the synthesis of surfactants, in the presence of which the disruption of bacterial biofilms was on average 10-20% higher compared to using surfactants synthesized without an inductor. In the presence of B. subtilis BT-2 in the medium, in the cells of the A. calcoaceticus IMV B-7241 strain, the activity of NADP+-dependent glutamate dehydrogenase (a key enzyme of aminolipids biosynthesis) increased by 1.5—2 times, while the activity of biosynthesis of glycolipids enzymes remained practically at the same level as without an inductor. Such data indicate that the higher biological activity of surfactants obtained by A. calcoaceticus IMV B-7241 in the presence of biological inductors might be due to an increase in the content of aminolipids in their composition. Conclusions. This research has established the possibility of regulating the antimicrobial and anti-adhesive activity as well as the ability to disrupt biofilms of A. calcoaceticus IМV B-7241 surfactants by introducing competitive bacteria B. subtilis BT-2 into the culture medium. It is important that under such cultivation conditions, the antimicrobial activity of surfactants synthesized on toxic crude glycerol significantly increases.

Preparation and characterization of porous membranes of glucomannan and silver decorated cellulose nanocrystals for application as biomaterial

Bacterial infection usually represents a threat in medical wound care, due to the increase in treatment complexity and the risk of antibiotic resistance. For presenting interesting characteristics for the use as biomaterial, natural polymers have been explored for this application. Among them, a promising candidate is the konjac glucomannan (KGM) with outstanding biocompatibility and biodegradability but lack of antibacterial activity. In this study, KGM was combined with silver decorated cellulose nanocrystals (CNC-Ag) to prepare membranes by using a recent reported casting-freezing method. The results highlight the potential anti-adhesive activity of the new materials against Staphylococcus aureus upon contact, without the burst release of silver nanoparticles. Furthermore, the incorporation of CNC enhanced the thermal stability of these membranes while preserving the favorable mechanical properties of the KGM-based material. These findings highlight a straightforward approach to enhance the antibacterial properties of natural polymers, which can be effectively useful in medical devices like wound dressings that typically lack such properties.

Preparation of Corn Peptides with Anti-Adhesive Activity and Its Functionality to Alleviate Gastric Injury Induced by Helicobacter pylori Infection In Vivo.

More than 50% of the world population is infected with Helicobacter pylori (H. pylori), which is classified as group I carcinogen by the WHO. H. pylori surface adhesins specifically recognize gastric mucosal epithelial cells' (GES-1 cells) receptor to complete the adhesion. Blocking the adhesion with an anti-adhesion compound is an effective way to prevent H. pylori infection. The present study found that corn protein hydrolysate, hydrolyzed by Neutral, effectively alleviated gastric injury induced by H. pylori infection through anti-adhesive and anti-inflammatory effects in vitro and in vivo. The hydrolysate inhibited H. pylori adhesion to GES-1 cells significantly, and its anti-adhesive activity was 50.44 ± 0.27% at 4 mg/mL, which indicated that the hydrolysate possessed a similar structure to the GES-1 cells' receptor, and exhibited anti-adhesive activity in binding to H. pylori. In vivo, compared with the H. pylori infection model group, the medium and high dose of the hydrolysate (400-600 mg/kg·bw) significantly decreased (p < 0.05) the amount of H. pylori colonization, pro-inflammatory cytokines (IL-6, IL-1β, TNF-α and MPO), chemokines (KC and MCP-1) as well as key metabolites of NF-κB signaling pathway levels (TLR4, MyD88 and NF-κB), and it increased antioxidant enzyme contents (SOD and GSH-Px) and the mitigation of H. pylori-induced pathological changes in the gastric mucosa. Taken together, these results indicated that the hydrolysate intervention can prevent H. pylori-induced gastric injury by anti-adhesive activity and inhibiting the NF-κB signaling pathway's induction of inflammation. Hence, the corn protein hydrolysate might act as a potential anti-adhesive agent to prevent H. pylori infection.

Potential anti-adhesion activity of novel carbosilane zwitterionic dendrimers against eukaryotic and prokaryotic pathogenic microorganisms

The development of biofilms on different surfaces continues to be a major public health problem. The antimicrobial resistance and the difficulty of finding drugs capable of combating these established biofilms generates the urgent need to find compounds that prevent cells from settling and establishing of these complex communities of microorganisms. Zwitterionic modification of nanomaterials allows the formation of a hydration layer, and this highly hydrophilic surface provides antifouling properties as well as a good biocompatibility by preventing non-specific interactions. Thus, they are appropriate candidates to prevent microbial adhesion to different surfaces and, in consequence, avoid biofilm formation. For this reason, we have incorporated zwitterionic moieties in multivalent systems, as are carbosilane dendrimers. Characterization of these systems was performed using nuclear magnetic resonance and mass spectrometry. It has been analysed if the new molecules have capacity to inhibit the biofilm formation in Candida albicans, Staphylococcus aureus and Pseudomonas aeruginosa. The results showed that they were more effective against S. aureus, observing a biofilm reduction of 81.5% treating with 32 mg/L of G2SiZWsf dendrimer and by 72.5% using 32 mg/L of the G3SiZWsf dendrimer. Finally, the absence of cytotoxicity was verified by haemolysis and cytotoxicity studies in human cells lines.

Advances of Sulfonated Hyaluronic Acid in Biomaterials and Coatings—A Review

Hyaluronic acid (HA) is a non-sulfated glycosaminoglycan (GAG) that is a versatile material whose biological, chemical, and physical characteristics can be deeply tuned to modifications. However, HA is easy to decompose by hyaluronidase in vivo, and this process will reduce its structure and function stability during application. The sulfonation of HA can improve its stability under the action of hyaluronidase. Sulfated hyaluronic acid (S-HA) can be synthesized by many methods, and it shows significantly slower degradation by hyaluronidase compared with HA. In addition, negatively charged S-HA has other advantages such as anti-adhesive activity, anti-inflammatory, macromolecules by electrostatic interactions, stable site absorption of positively charged molecules, and enhancement of growth factor binding ability. It has numerous applications in medical (anti-aging, inflammation, tissue regeneration, cancer therapy, wound healing, and drug delivery) and cosmetics as biomaterials and coatings. In this article, the advances of S-HA for potential application of biomaterials and biomedical coatings will be reviewed and comprehensively discussed.

Development of κ-carrageenan-PEG/lecithin bioactive hydrogel membranes for antibacterial adhesion and painless detachment

The issue of wound dressing adherence poses a substantial challenge in the field of wound care, with implications both clinically and economically. Overcoming this challenge requires the development of a hydrogel dressing that enables painless removal without causing any secondary damage. However, addressing this issue still remains a significant challenge that requires attention and further exploration. The present study is focused on the synthesis of hydrogel membranes based on κ-carrageenan (CG), polyethylene glycol (PEG), and soy lecithin (LC), which can provide superior antioxidant and antibacterial attachment properties with a tissue anti adhesion activity for allowing an easy removability without causing secondary damage. The (CG-PEG)/LC mass ratio was varied to fabricate hydrogel membranes via a facile approach of physical blending and solution casting. The physicochemical properties of (CG-PEG)/LC hydrogel membranes were studied by scanning electron microscopy (SEM), Fourier transforms infrared spectroscopy (FTIR), X-ray diffraction (XRD), differential scanning calorimetry (DSC), and mechanical analyses. The membranes showed significantly enhanced mechanical properties with excellent flexibility and had high swelling capacity (˃1000 %), which would provide a moist condition for wound healing. The membranes also exhibited excellent free radical scavenging ability (>60 %). In addition, the (CG-PEG)/LC hydrogel membranes showed reduced peel strength 26.5 N/m as a result of weakening the hydrogel-gelatin interface during an in vitro gelatin peeling test. Moreover, the membrane showed superior antibacterial adhesion activity (>90 %) against both S. aureus and E. coli due to the presence of both PEG and LC. The results also suggested that the hydrogel membranes exhibit NIH3T3 cell antiadhesion property, making them promising material for easy detachment from the healed tissue without causing secondary damage. Thus, this novel combination of (CG-PEG)/LC hydrogel membranes have immense application potential as a biomaterial in the healthcare sector.

Biofilm Inhibition, Antibacterial and Antiadhesive Properties of a Novel Biosurfactant from Lactobacillus paracasei N2 against Multi-Antibiotics-Resistant Pathogens Isolated from Braised Fish

This study aimed to assess the antibiotic susceptibility and biofilm formation ability of pathogens isolated from braised fish as well as characterize and evaluate the antibacterial, antiadhesive, and antibiofilm activities of the biosurfactant from Lactobacillus paracasei subsp. tolerans N2 against these pathogens. The susceptibility of six pathogens isolated from braised fish (Escherichia coli EM2, Staphylococcus aureus SA1, Salmonella enteritidis PE1, Pseudomonas aeruginosa CT3, Yersinia enterolitica MH5, Proteus mirabilis MR2, and Klebsiella pneumoniae AG5) to 16 antibiotics revealed multiple resistances with an MAR index greater than 0.3. These pathogens were able to form biofilms with S. aureus SA1, which showed the highest ability. Using biochemical and elemental analyses, FTIR, GC-MS, 1H NMR and high-resolution mass spectrometry, the biosurfactant was characterized as a novel glycolipoprotein made of two congeners of mass 482.28 and 507.27 m/z, respectively. They showed bactericidal and antiadhesive activities against all pathogens. The biosurfactant inhibited biofilm formation by these pathogens and eradicated mature biofilms.

P06-033-23 Women Have Different UTI Susceptibility and Responses to Cranberry Juice Intake Based on Urinary Anti-Adhesion Activities Against E. coli

P06-033-23 Women Have Different UTI Susceptibility and Responses to Cranberry Juice Intake Based on Urinary Anti-Adhesion Activities Against E. coli

Use of marine microorganisms in designing anti-infective strategies for sustainable aquaculture production.

Aquaculture, a noteworthy food production sector, is confronted with disease occurrences. Treatment of aquaculture pathogens with antibiotics is often rendered ineffective due to biofilm formation and the development of resistant strains. Marine ecosystems encompass unusual microorganisms that produce novel bioactive compounds, including agents that could be used as alternatives to antibiotics. Moreover, biomass and/or biomolecules associated with these microorganisms could act as feed supplements to enhance overall health of aquaculture species' and improve water quality parameters. The present review summarizes contents of studies on such marine microorganisms with the potential to be developed as agents for tackling bacterial diseases in the aquaculture segment. Bioactive compounds produced by marine bacteria are known to inhibit biofilm associated infections mediated by their bactericidal properties (produced by Bacillus, Vibrio, Photobacterium and Pseudoalteromonas species), surfactant activity (obtained from different species of Bacillus and Staphylococcus lentus), anti-adhesive activity (derived from Bacillus sp. and Brevibacterium sp.) and quorum sensing inhibition. Several marine fungal isolates capable of producing antibacterial agents have also been effective in inhibiting aquaculture associated pathogens. Another strategy followed by investigators to reduce severity of infections is the use of bacterial, yeast and microalgae biomass as feed supplements, probiotics and immunostimulants. In some cases, marine microalgae have been employed as sustainable alternatives to fish oil and fish meal without compromising on nutritional quality. Their inclusion in aquaculture feed have enhanced growth, favoured better survival of cultured species and improved water quality parameters. Marine microorganisms (by providing effective bioactive compounds and being used as feed supplements) could enable aquaculture practices to be more sustainable in the future.

Cell-free supernatant of probiotic bacteria exerted antibiofilm and antibacterial activities against Pseudomonas aeruginosa: A novel biotic therapy.

Aim: This study aims to verify the antibacterial and antibiofilm action of cell-free spent medium (CFSM) from four lactic acid bacteria with potential probiotic characteristics (Lactiplantibacillus plantarum, Lactobacillus acidophilus, Lactobacillus johnsonii, and Lactobacillus delbrueckii) against two Pseudomonas aeruginosa strains. Main methods: The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of the CFSM, antibacterial activity by analysing the formation of inhibition zones, and inhibition of planktonic cultures were determined. Whether an increase in the concentration of CFSM influenced the growth of pathogenic strains and the anti-adhesive activity of the CFSM in biofilm formation (crystal violet and MTT assays) were determined, which were all corroborated by using scanning electron microscopy. Key findings: The relationship between the MIC and MBC values showed a bactericidal or bacteriostatic effect for all the cell-free spent media (CFSMs) tested for P. aeruginosa 9027™ and 27853™ strains. The CFSM supplemental doses of 18 or 22%, 20 or 22%, 46 or 48%, and 50 or 54% of L. acidophilus, L. delbrueckii, L. plantarum, and L. johnsonii, respectively, could completely inhibit the growth of both pathogen strains. The antibiofilm activity of the CFSM in three biofilm conditions (pre-coated, co-incubated, and preformed) demonstrated values ranging between 40% and 80% for biofilm inhibition, and similar results were observed for cell viability. Significance: This work provides strong evidence that the postbiotic derived from different Lactobacilli could be practical as an adjuvant therapy for reducing the use of antibiotics, being a good candidate to overcome the growing challenge of hospital infections due to this pathogen.

The pygidial gland secretion of Laemostenus punctatus (Coleoptera, Carabidae): a source of natural agents with antimicrobial, anti-adhesive, and anti-invasive activities

In the present study, we investigated in vitro the antimicrobial activity of the pygidial gland secretion of the guanophilic ground beetle Laemostenus (Pristonychus) punctatus (Dejean, 1828) and some of its chemicals against resistant and non-resistant bacteria and Candida species, the synergistic and additive potential of combinations of selected chemicals and antimicrobial drugs against resistant bacterial and fungal strains, anti-adhesive and anti-invasive potential of the secretion and formic acid alone and in selected combinations with antimicrobial drugs against methicillin-resistant Staphylococcus aureus (MRSA) toward spontaneously immortalized human keratinocyte cell line (HaCaT cells). In addition, we examined the antiproliferative activity of the secretion and formic acid in vitro. The tested secretion and the standards of formic and oleic acids possessed a significant level of antimicrobial potential against all tested strains (P &amp;lt; 0.05). The isolate from guano Pseudomonas monteilii showed the highest resistance to the secretion and formic acid, while MRSA achieved a significantly high level of susceptibility to all agents tested, particularly to the combinations of formic acid and antibiotics, but at the same time showed a certain level of resistance to the antibiotics tested individually. Candida albicans and C. tropicalis were found to be the most sensitive fungal strains to the secretion. Formic acid (MIC 0.0005 mg/mL) and gentamicin (MIC 0.0010 mg/mL) in the mixture achieved synergistic antibacterial activity against MRSA (FICI = 0.5, P &amp;lt; 0.05). The combination of formic acid, gentamicin and ampicillin accomplished an additive effect against this resistant bacterial strain (FICI = 1.5, P &amp;lt; 0.05). The secretion achieved a better inhibitory effect on the adhesion ability of MRSA toward HaCaT cells compared to formic acid alone, while formic acid showed better results regarding the invasion (P &amp;lt; 0.001). The combinations of gentamicin and ampicillin, as well as of formic acid and gentamicin and ampicillin achieved similar anti-adhesive and anti-invasive effects, with a slight advantage of formic acid and antibiotics in combination (P &amp;lt; 0.001). The secretion and formic acid were found to be non-toxic to HaCaT cells in vitro (IC50 ≥ 401 μg/mL).

In vitro Antimicrobial Properties of Pluronic F-127 Injectable Thermoresponsive Hydrogel

Pluronic F-127 (PF-127) hydrogel is a versatile biomaterial with promising applications in drug delivery, tissue engineering, and regenerative medicine. PF-127 has antiadhesive activity that prevents bacterial adhesion by creating a hydrated layer on the bacterial surface. This property makes PF-127 suitable for preventing implant-associated infections. In this study, we aimed to evaluate the antibacterial properties of PF-127 using field isolates of Staphylococcus aureus (Gram-positive bacteria) and Escherichia coli (Gram-negative bacteria) and compare them with different antibiotic standards. The antimicrobial potential was assessed using disk diffusion assays with four standard concentrations (20%, 25%, 30%, and 40%). The test microorganisms were inoculated on agar plates, and sterile filter paper disks infused with PF-127 hydrogels were placed alongside standard antibiotic disks. After incubation, the inhibition zones were measured to determine antimicrobial activity. Our results showed that PF-127 lacked intrinsic antimicrobial activity against S. aureus and E. coli at the tested concentrations. In conclusion, PF-127 hydrogel is a promising neutral carrier hydrogel system for loading antibiotics and antimicrobial compounds. Its unique properties, such as biocompatibility and thermo-responsive behaviour, combined with its antiadhesive activity, make it an ideal candidate for various biomedical applications.

The combined effect of essential oils on wood physico-chemical properties and their antiadhesive activity against mold fungi: application of mixture design methodology

In the heritage field, the microbial adhesion on wood, and consequently the formation of biofilm led to inestimable losses of historical and cultural monuments. Thereby, this study aimed to examine the combined effect of Thymus vulgaris, Myrtus communis, and Mentha pulegium essential oils on wood surface physico-chemical properties, and to elaborate the optimal mixture using the mixture design approach coupled to the contact angle method. It was found that both wood hydrophobicity and electron donor character increased significantly after treatment using an optimal mixture containing 57% and 43% of M. pulegium and M. communis essential oils, respectively. The theoretical and experimental fungal adhesion on untreated and treated wood were also investigated. The results showed that the adhesion was favorable on untreated wood and reduced using the optimal mixture. Moreover, the experimental data demonstrated that the same mixture exhibited an antiadhesive efficacy effect with a reduction of 36–75% in adhesion.

ASSESSMENT OF ANTIBACTERIAL AND ANTIADHESIVE PROPERTIES OF ANTISEPTICS AGAINST CLINICAL ISOLATES OF KOCURIA SPP

According to the literature, microorganisms of the genus Kocuria are becoming widespread, but not as avirulent representatives of the normal microbiota of the human body, but as pathogens.&#x0D; Recently, after the identification of the causative agents of infectious and inflammatory processes, various types of Kocuria have been included in the list of etiological agents isolated from patients with cholecystitis, endocarditis, peritonitis, and meningitis as well as from carious tooth cavities and post-extraction tooth sockets. Bacteria of the genus Kocuria possess pathogenicity that enables them to play an important role in the occurrence of infectious and inflammatory processes in various organs and systems of the human body. Given that antibiotics are the most commonly used drugs of choice in medical and dental practice for the treatment of infections and inflammations, antibiotic resistance is considered as a global health and development threat.&#x0D; In order to overcome the challenge of antibiotic resistance, antiseptics, a group of medicines with a pronounced antimicrobial effect, are being increasingly used for the treatment of infectious and inflammatory processes. The purpose of this study is to investigate the antibacterial and antiadhesive activity of dekasan, and drugs of comparison, chlorhexidine and iodoform, against clinical isolates of Kocuria spp. isolated from the oral cavity of patients with infectious inflammatory post-extraction complications. Materials and methods: five clinical isolates of Kocuria spp. were studied as microorganisms isolated from patients, who received the treatment for infectious and inflammatory post-extraction complications at the medical and surgical departments of Poltava Regional Center of Stomatology – Dental Polyclinic. We determined the minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBcC) of antiseptics against clinical isolates of Kocuria spp. taking into account ISO recommendations. The adhesive properties of clinical isolates of Kocuria spp. were assessed by exposing them to subbacteriostatic concentrations of antiseptics, namely dekasan, chlorhexidine, and iodoform. The evaluation was conducted using erythrocytes of blood group 1(0) Rh+ and considering the index of microorganism adhesion (IAM) following the method developed by V. I. Brillis. The results obtained have demonstrated variations in the antimicrobial and anti-adhesive activities among the tested antiseptics, dekasan, chlorhexidine, and iodoform.

Anti-adhesive activity of some secondary metabolites against Staphylococcus aureus on 3D printing medical materials

Recent improvements in 3D printing technology have increased the usage of 3D printed materials in several areas. An exciting and emerging area of applying these next-generation manufacturing strategies is the development of devices for biomedical applications. The main aim of this work was to investigate the effect of tannic acid, gallic acid, and epicatechin gallate on the physicochemical characteristics of acrylonitrile butadiene–styrene (ABS) and Nylon 3D printing materials using the contact angle method. The adhesion of Staphylococcus aureus on untreated and treated materials was evaluated by scanning electron microscopy (SEM) analysis and the images were treated by MATLAB software. The results of the contact angle measurements showed a significant change in the physicochemical properties of both surfaces, indicated an increase in the electron donor character of 3D printing materials following treatment. Thus, the ABS surfaces treated with tannic acid, gallic acid, and epicatechin gallate have become more electron donating. Furthermore, our results proved the ability of S. aureus to adhere on all materials with a percentage of 77.86% for ABS and 91.62% for nylon. The SEM has shown that all actives molecules were sufficient to obtain better inhibition of bacterial adhesion, which tannic acid has shown a total inhibition of S. aureus on ABS. From these results, our treatment presents a high potential for utilization as an active coating to prevent bacterial attachment and the eventual biofilm development in medical field.