Bacterial Adhesion Research Articles

Antibacterial evaluation of 2-(6-Chloro-2-p-tolylquinazolin-4-ylthio) acetonitrile against pathogenic bacterial isolates with special reference to biofilm formation inhibition and anti-adherence properties

BackgroundEvaluating the effectiveness of a specific quinazoline molecule with antibacterial activity on microorganisms as a potential antibiotic substitution. MethodsA variety of microorganisms were tested with the designated quinazoline molecule. Differences within two groups were analyzed using the two-tailed Student’s t-test,. ResultsSusceptibility tests revealed that the chemical has stronger antibacterial action against S. saprophyticus than other isolates, with just a slight effect on E. coli and M. smegmatis. The bacterial cells were subjected to varying concentrations of a certain molecule, and the results showed that the inhibition of bacterial adhesion was not consistent. This suggests that the effect of the molecule on bacterial adhesion is dependent on its concentration. After 24 h of treatment with varying chemical doses, all of the periodontal bacterial strains examined showed considerable inhibition of biofilm formation. ConclusionsAccording to the findings, the chemical molecule quinazoline could be utilized as an alternative therapeutic approach for microorganism-caused infections.

Antimicrobial Peptide Screening for Designing Custom Bactericidal Hydrogels.

Staphylococcus aureus (S. aureus) is an opportunistic pathogen that lives on surfaces and skin and can cause serious infections inside the body. Antimicrobial peptides (AMPs) are part of the innate immune system and can eliminate pathogens, including bacteria and viruses, and are a promising alternative to antibiotics. Although studies have reported that AMP-functionalized hydrogels can prevent bacterial adhesion and biofilm formation, AMP dosing and the combined effects of multiple AMPs are not well understood. Here, three AMPs with different antibacterial properties were synthesized and the soluble minimum inhibitory concentrations (MICs) of each AMP against methicillin-susceptible S. aureus (MSSA) and methicillin-resistant S. aureus (MRSA) were determined. Hydrogels with immobilized AMPs at their MIC (DD13-RIP 27.5 µM; indolicidin 43.8 µM; P10 120 µM) were effective in preventing MRSA adhesion and biofilm formation. Checkerboard AMP screens identified synergy between indolicidin (3.1 µM) and P10 (12.5 µM) based on soluble fractional inhibitory concentration indices (FICIs) against MRSA, and hydrogels formed with these AMPs at half of their synergistic concentrations (total peptide concentration, 7.8 µM) were highly efficacious in killing MRSA. Mammalian cells cultured atop these hydrogels were highly viable, demonstrating that these AMP hydrogels are biocompatible and selectively eradicate bacteria, based on soluble checkerboard-screening data.

Controlled Surface Textures of Elastomeric Polyurethane Janus Particles: A Comprehensive Review.

Colloidal particle research has witnessed significant advancements in the past century, resulting in a plethora of studies, novel applications, and beneficial products. This review article presents a cost-effective and low-tech method for producing Janus elastomeric particles of varied geometries, including planar films, spherical particles, and cylindrical fibers, utilizing a single elastomeric material and easily accessible chemicals. Different surface textures are attained through strain application or solvent-induced swelling, featuring well-defined wavelengths ranging from sub-microns to millimeters and offering easy adjustability. Such versatility renders these particles potentially invaluable for medical applications, especially in bacterial adhesion studies. The coexistence of "young" regions (smooth, with a small surface area) and "old" regions (wrinkled, with a large surface area) within the same material opens up avenues for biomimetic materials endowed with additional functionalities; for example, a Janus micromanipulator where micro- or nano-sized objects are grasped and transported by an array of wrinkled particles, facilitating precise release at designated locations through wrinkle pattern adjustments. This article underscores the versatility and potential applications of Janus elastomeric particles while highlighting the intriguing prospects of biomimetic materials with controlled surface textures.

Investigating the Effectiveness of Ceragenins against Acinetobacter baumannii to Develop New Antimicrobial and Anti-Adhesive Strategies.

A growing body of experimental data indicates that ceragenins (CSAs), which mimic the physicochemical properties of the host's cationic antimicrobial peptide, hold promise for the development of a new group of broad-spectrum antimicrobials. Here, using a set of in vivo experiments, we assessed the potential of ceragenins in the eradication of an important etiological agent of nosocomial infections, Acinetobacter baumannii. Assessment of the bactericidal effect of ceragenins CSA-13, CSA-44, and CSA-131 on clinical isolates of A. baumannii (n = 65) and their effectiveness against bacterial cells embedded in the biofilm matrix after biofilm growth on abiotic surfaces showed a strong bactericidal effect of the tested molecules regardless of bacterial growth pattern. AFM assessment of bacterial cell topography, bacterial cell stiffness, and adhesion showed significant membrane breakdown and rheological changes, indicating the ability of ceragenins to target surface structures of A. baumannii cells. In the cell culture of A549 lung epithelial cells, ceragenin CSA-13 had the ability to inhibit bacterial adhesion to host cells, suggesting that it interferes with the mechanism of bacterial cell invasion. These findings highlight the potential of ceragenins as therapeutic agents in the development of antimicrobial strategies against bacterial infections caused by A. baumannii.

A comparative study on the mechanical and antibacterial properties of BPA-free dental resin composites

ObjectiveThe commonly used base monomer utilized in resinous commercial dental restorative products is bis-GMA which is derived from bisphenol-A (BPA) - a well-known compound which may disrupt endocrine functions. To address concerns about its leaching into the oral environment and to optimize the quality of dental composites, a BPA-free alternative base monomer, fluorinated urethane dimethacrylate (FUDMA), was designed by modifying a UDMA monomer system. MethodsNine groups of composites were prepared by mixing the base monomers and TEGDMA in a ratio of 70/30 wt% to which were added silanized glass particles (mean diameter: 0.7 µm) in 3 different volume fractions (40, 45, and 50 vol%). Bis-GMA and UDMA base monomers were used as control groups in the same ratios. Various properties including degree of conversion (DC), flexural strength (FS) and flexural modulus (FM), water sorption (WS), solubility (SL), surface hardness and roughness, and initial adhesion property against S.mutans were investigated. One-way analysis of variance followed by Bonferroni test at α = 0.05 was used to analyze the results. ResultsA significant difference in FS between FUDMA-based composite with 40 vol% filler (120.3 ± 10.4 MPa) and Bis-GMA-based composite with the same filler fraction (105.8 ± 10.0 MPa) was observed but there was no significant difference among other groups. The UDMA based group exhibited the highest WS (1.3 ± 0.3 %). Bis-GMA showed greater initial bacterial adhesion but was not statistically different from the other groups (p = 0.082). SignificanceFUDMA-based resin composites exhibit comparable mechanical and bacterial adhesion properties compared with Bis-GMA and UDMA-based composites. The FUDMA composites show positive outcomes indicating they could be used as substitute composites to Bis-GMA-based composites.

Isolation and complete genome sequence analysis of Vibrio rotiferianus strain TO-01 from Trachinotus ovatus to reveal its pathogenicity and drug resistance

Vibrio rotiferianus is a pathogenic bacterium that is widely distributed in the ocean and can cause diseases in a variety of marine animals, including fish, shrimp and shellfish. In this study, we isolated and identified V. rotiferianus strain TO-01 from diseased Trachinotus ovatus. Infected fish exhibited a range of pathological symptoms, including lethargy in swimming, blackened body coloration, skin ulceration and erratic side swimming. Tissue section examination revealed pronounced damage to the liver, spleen and gills of the infected fish. An analysis of immune factor expression revealed a significant increase in the expression of inflammatory factors, including interleukin (IL)-1, IL-2, IL-6 receptor and IL-21, in the spleen and kidney of fish infected with TO-01 at 6 h post-infection. To gain a more in-depth comprehension of the pathogenicity and drug resistance of V. rotiferianus, we conducted whole genome sequencing. The total genome length of V. rotiferianus was 4734,075 bp, and 74 virulence factors were predicted within the genome. Most of these virulence genes were associated with bacterial adhesion and flagellar motility. A gene associated with group sensing, cqsA, and a gene associated with hemolysin, tlh, were also identified. The prediction of drug resistance genes was in agreement with the results of drug sensitivity assays, both of which indicated that TO-01 has significant resistance to β-lactams. The findings of this study significantly enhance our understanding of the pathogenic mechanism of V. rotiferianus and give crucial insights into disease prevention and control in the management of T. ovatus.

The Role of Streptococcus mutans Virulence Proteins in the Pathogenesis of Endocarditis: Mechanisms of Action and Impact on Heart Infections, A Review

Background: Streptococcus mutans, known for causing dental caries, can also lead to endocarditis, a severe heart infection involving inflammation of the heart's inner lining and valves. This study focuses on the virulence proteins of Streptococcus mutans and their role in endocarditis pathogenesis. Objective: To investigate the mechanisms of action of Streptococcus mutans virulence proteins and their impact on the development of endocarditis. Methods: A comprehensive literature review focused on the virulence factors of Streptococcus mutans, such as Glucosyltransferases (Gtf), Adhesin P1 (Antigen I/II), Dextranase, and proteolytic enzymes. The role of these proteins in bacterial adhesion, biofilm formation, and tissue invasion was analyzed. Results: Glucosyltransferases facilitate biofilm formation by synthesizing sticky glucans from sucrose, protecting bacteria, and aiding the colonization of heart valves. Adhesin P1 enables bacterial attachment to host tissues, which is crucial for initial colonization. Dextranase modifies biofilm structure, enhancing stability and resistance. Proteolytic enzymes degrade host proteins, aiding bacterial invasion and causing tissue damage. Conclusion: Streptococcus mutans employ multiple virulence proteins to adhere to, colonize, and invade heart tissues, leading to endocarditis. Understanding these mechanisms is essential for developing preventive and therapeutic strategies against this severe infection.

In situ borneol-modified polyester with antibacterial adhesion and long-term fungal-repellent properties

Polyester is widely used in biomedical, textile, and food packaging fields. Therefore, enhancing it with antimicrobial properties would be a significant advancement. In this paper, a series of borneol-triazine polyesters (BTPs) with different structures are synthesized through room temperature polycondensation. The structure and composition of BTPs are systematically characterized by 1H NMR, FTIR and GPC. Antimicrobial results reveal that the ability of BTPs to resist bacterial or fungal adhesion is directly related to the polymer structure. When the polymer chain of BTPs adopts a rigid structure, they exhibit excellent anti-adhesive and inhibitory performances against both Gram-negative bacteria (Escherichia coli) and Gram-positive bacteria (Staphylococcus aureus). Meanwhile, the as-synthesized BTPs poses a fungal-repelling effect on common fungal strains (Aspergillus niger) for up to 30 d. Further studies have shown that a stereochemical structure brought by borneol is key for imparting effective antimicrobial properties to BTPs. In addition, BTPs are non-leaching materials with low cellular cytotoxicity. Taking into consideration, BTP provides a potential strategy for preparing a new class of antimicrobial polyester materials.

Imipenem reduces the efficacy of vancomycin against Elizabethkingia species.

Elizabethkingia spp. are emerging as nosocomial pathogens causing various infections. These pathogens express resistance to a broad range of antibiotics, thus requiring antimicrobial combinations for coverage. However, possible antagonistic interactions between antibiotics have not been thoroughly explored. This study aimed to evaluate the effectiveness of antimicrobial combinations against Elizabethkingia infections, focusing on their impact on pathogenicity, including biofilm production and cell adhesion. Double-disc diffusion, time-kill, and chequerboard assays were used for evaluating the combination effects of antibiotics against Elizabethkingia spp. We further examined the antagonistic effects of antibiotic combinations on biofilm formation and adherence to A549 human respiratory epithelial cells. Further validation of the antibiotic interactions and their implications was performed using ex vivo hamster precision-cut lung sections (PCLSs) to mimic in vivo conditions. Antagonistic effects were observed between cefoxitin, imipenem and amoxicillin/clavulanic acid in combination with vancomycin. The antagonism of imipenem toward vancomycin was specific to its effects on the genus Elizabethkingia. Imipenem further hampered the bactericidal effect of vancomycin and impaired its inhibition of biofilm formation and the adhesion of Elizabethkingia meningoseptica ATCC 13253 to human cells. In the ex vivo PCLS model, vancomycin exhibited dose-dependent bactericidal effects; however, the addition of imipenem also reduced the effect of vancomycin. Imipenem reduced the bactericidal efficacy of vancomycin against Elizabethkingia spp. and compromised its capacity to inhibit biofilm formation, thereby enhancing bacterial adhesion. Clinicians should be aware of the potential issues with the use of these antibiotic combinations when treating Elizabethkingia infections.

The serine-rich repeat glycoprotein Srr2 mediates Streptococcus agalactiae interaction with host fibronectin

BackgroundGroup B Streptococcus (GBS) is a commensal of healthy adults and an important pathogen in newborns, the elderly and immunocompromised individuals. GBS displays several virulence factors that promote colonisation and host infection, including the ST-17 strain-specific adhesin Srr2, previously characterised for its binding to fibrinogen. Another common target for bacterial adhesins and for host colonization is fibronectin, a multi-domain glycoprotein found ubiquitously in body fluids, in the extracellular matrix and on the surface of cells.ResultsIn this study, fibronectin was identified as a novel ligand for the Srr2 adhesin of GBS. A derivative of the ST-17 strain BM110 overexpressing the srr2 gene showed an increased ability to bind fibrinogen and fibronectin, compared to the isogenic wild-type strain. Conversely, the deletion of srr2 impaired bacterial adhesion to both ligands. ELISA assays and surface plasmon resonance studies using the recombinant binding region (BR) form of Srr2 confirmed a direct interaction with fibronectin with an estimated Kd of 92 nM. Srr2-BR variants defective in fibrinogen binding also exhibited no interaction with fibronectin, suggesting that Srr2 binds this ligand through the dock-lock-latch mechanism, previously described for fibrinogen binding. The fibronectin site responsible for recombinant Srr2-BR binding was identified and localised in the central cell-binding domain of the protein. Finally, in the presence of fibronectin, the ability of a Δsrr2 mutant to adhere to human cervico-vaginal epithelial cells was significantly lower than that of the wild-type strain.ConclusionBy combining genetic and biochemical approaches, we demonstrate a new role for Srr2, namely interacting with fibronectin. We characterised the molecular mechanism of this interaction and demonstrated that it plays a role in promoting the adhesion of GBS to human cervico-vaginal epithelial cells, further substantiating the role of Srr2 as a factor responsible for the hypervirulence of GBS ST-17 strains. The discovery of the previously undescribed interaction between Srr2 and fibronectin establishes this adhesin as a key factor for GBS colonisation of host tissues.

Multifunctional curcumin-based polymer coating: A promising platform against bacteria, inflammation and coagulation

The extensive use of polymers in the medical field has facilitated the development of various devices and implants, contributing to the restoration of organ function. However, despite their advantages such as biocompatibility and robustness, these materials often face challenges like bacterial contamination and subsequent inflammation, leading to implant-associated infections (IAI). Integrating implants effectively is crucial to prevent bacterial colonization and reduce inflammatory responses. To overcome these major issues, surface chemical modifications have been extensively explored. Indeed, click chemistry, and particularly, copper (I)-catalyzed azide-alkyne cycloaddition (CuAAC) reaction has emerged as a promising approach for surface functionalization without affecting material bulk properties. Curcumin, known for its diverse biological activities, suffers from low solubility and stability. To enhance its bioavailability, bioconjugation strategy has garnered attention in recent years. This study represents pioneering work in immobilizing curcumin derivative onto polyethylene terephthalate (PET) surfaces, aiming to combat bacterial adhesion, inflammation and coagulation. Before curcumin derivative bioconjugation, a fluorophore, dansyl derivative, was employed in order to monitor and determine the efficiency of the proposed methodology. Previous surface chemical modifications were required for the immobilization of both dansyl and curcumin derivatives. Ultraviolet-Visible (UV-Vis) demonstrated the amidation functionalization of PET surface. Other surface characterization techniques including X-ray Photoelectron Spectroscopy (XPS), Attenuated Total Reflectance Fourier Transformed Infrared (ATR-FTIR), Scanning Electron Microscopy (SEM) and contact angle, among others, confirmed also the conjugation of both dansyl and curcumin derivatives. On the other hand, different biological assays corroborated that curcumin derivative immobilized PET surfaces do not exhibit cytotoxicity effect. Additionally, corresponding inflammation test were performed, indicating that these polymeric surfaces do not produce inflammation and, when curcumin derivative is immobilized, they decrease the inflammation marker level (IL-6). Moreover, the bacterial growth of both Gram positive and Gram negative bacteria were measured, demonstrating that the immobilization of curcumin derivative on PET provided antibacterial properties to the material. Finally, hemolysis rate analysis and whole blood clotting assay demonstrated the antithrombogenic effect of PET-Cur surfaces as well as no hemolysis concern in the fabricated functional surfaces.

Enhanced applications in dentistry through autoclave-assisted sonochemical synthesis of Pb/Ag/Cu trimetallic nanocomposites

In recent years, researchers have increasingly focused on the development of multiphase trimetallic nanocomposites (TMNC) incorporating ternary metals or metal oxides, which hold significant potential as alternatives for combatting biofilms and bacterial infections. Enhanced oral health is ensured by the innovative techniques used to effectively prevent bacterial adherence and formation of biofilm on dental sutures. In this investigation, TMNC, which consists of Pb, Ag, and Cu, was synthesized using an autoclave-assisted sonochemical technique. Following synthesis, TMNC were characterized using FTIR, XRD, BET, XPS, TGA, and Raman spectroscopy to analyze their shape and microstructure. Subsequent evaluations, including MTT assay, antibacterial activity testing, and biofilm formation analysis, were conducted to assess the efficiency of the synthesized TMNC. Cytotoxicity and anti-human oral squamous cell carcinoma activities of TMNC were evaluated using the Human Oral Cancer cell line (KB) cell line through MTT assay, demonstrating a dose-dependent increase in anti-human oral squamous cell carcinoma activity against the KB cell line compared to the normal cell line, resulting in notably high cell viability. Furthermore, an ultrasonic probe was employed to incorporate TMNC onto dental suturing threads, with different concentrations of TMNC, ultrasonic power levels, and durations considered to determine optimal embedding conditions that result in the highest antibacterial activity. The inhibitory effects of TMNC, both in well diffusion assays and when incorporated into dental suturing threads, against gram-positive (Staphylococcus aureus) and gram-negative (Escherichia coli) bacteria on Mueller-Hinton agar (MHA) were assessed using various concentrations of TMNC. The results of the study indicated that the efficacy of TMNC in inhibiting bacterial growth on dental suturing threads remained impressive, even at low concentrations. Moreover, an evaluation of their potential to destabilize biofilms formed by S. aureus and E. coli, the two pathogens in humans, indicated that TMNC would be a promising anti-biofilm agent.

Antibacterial coatings on magnesium formed via plasma electrolytic oxidation in CuO suspension

Biodegradable materials, especially Magnesium (Mg) and its alloys, are preferred for bone implants due to their compatibility with host tissue and biomechanical support. However, their rapid corrosion and vulnerability to structural failure, compounded by infections from antibiotic-resistant bacteria, pose significant challenges. Addressing these issues, we developed silicate-based composite coatings with varying CuO concentrations (1, 5, and 7 wt%) on Mg using plasma electrolytic oxidation (PEO). This study evaluated the coatings' surface characteristics, degradation behavior, and optimum composition. Our analyses, including XPS and EDX, confirmed the presence and influence of CuO on the coatings. We observed enhanced hydroxyapatite crystallization in CuO-doped coatings, which is critical for implant biocompatibility. These coatings also showed improved corrosion resistance and controlled ion release, likely due to silicate composition and CuO's sealing effects. Antimicrobial assays revealed that CuO concentration influenced bacterial and fungal adhesion, varying with microorganism type. Our findings demonstrate that incorporating inert copper particles into PEO coatings alters their chemical and elemental properties, enhancing bioactivity, corrosion resistance, and antimicrobial efficacy. These multifaceted improvements position our CuO-doped silicate coatings as a pioneering solution in bone implant technology, potentially setting new standards for safety, efficacy, and longevity in orthopedic and dental implants.

The Complete Assessment of Small Molecule and Peptidomimetic Inhibitors of Sortase A Towards Antivirulence Treatment.

This review covers the most recent advances in the development of inhibitors for the bacterial enzyme sortase A (SrtA). Sortase A (SrtA) is a critical virulence factor, present ubiquitously in Gram-positive bacteria of which many are pathogenic. Sortases are key enzymes regulating bacterial adherence to host cells, by anchoring extracellular matrix-binding proteins to the bacterial outer cell wall. By targeting virulence factors, effective treatment can be achieved, without inducing antibiotic resistance to the treatment. This is a potentially more sustainable, long-term approach to treating bacterial infections, including ones that display multiple resistance to current therapeutics. There are many promising approaches available for SrtA inhibition, some of which have the potential to advance into further clinical development, with peptidomimetic and in vivo active small molecules being among the most promising. There are currently no approved drugs on the market targeting SrtA, despite its promise, adding to the relevance of this review article, as it extends to the pharmaceutical industry additionally to academic researchers.

Ecological and Biological Aspects of Effect of Nanoparticles and Toxic Forms of Metals on Marine and Opportunistic Bacteria

We studied effects of new materials such as, in particular, earlier obtained biogenic selenium and tellurium nanoparticles on the properties that determine pathogenic potential of type bacterial cultures and aggressiveness of marine-derived strains. We compared the effect of nanoparticles on bacteria to that of known toxicants in several experiments aimed to determine the growth characteristics and activity of enzymes on nutrient media, and also the adhesion to human red blood cells. The following concentrations of toxicants were used: sodium selenite and potassium tellurite, 100 μg/mL; copper sulfate, 10 μg/mL; selenium and tellurium nanoparticles, 100 μg/mL. We found that nanoparticles mainly inhibited the proteolytic, lipolytic, amylase, DNase, and hemolytic activities, whereas copper ions stimulated them. Selenium nanoparticles inhibited the pigment synthesis in Pseudomonas aeruginosa and Staphylococcus aureus. Nanoparticles and soluble forms of selenium and tellurium suppressed the bacterial adhesion to human red blood cells, while copper ions stimulated it. We also carried out an assessment of possible environmental risks of emergence/use of the toxicants under study in the marine environment using an Artemia salina model. Based on the analysis of selenium and tellurium nanoparticles, we could classify them as nontoxic compounds and sodium selenite, potassium tellurite, and copper sulfate as toxic ones.

The influence of low nitrogen doping on bacterial adhesion of sputtered a-C:H coatings

Heavily dependent on both surface and bacteria characteristics, multiple and complex parameters control bacterial adhesion to any biomaterial surface. That's why there are so many contradictory results regarding the antibacterial and adhesion inhibition properties of Diamond-Like Carbon (DLC) protective coatings, despite the well-established biocompatibility of this very broad group of materials. Aiming at Orthodontics, this study reports the modification of hydrogenated amorphous carbon coatings (a-C:H), by nitrogen incorporation upon reactive magnetron sputtering. The effect of low N content up to 10 at.% on the microstructure and bacterial adhesion was studied. Despite the progressive graphitization upon doping, the surface roughness was not significantly influenced and the water contact angles remained above 70°. The adhesion of three bacterial strains of Staphylococcus aureus, Bacillus subtilis and Pseudomonas aeruginosa was evaluated. The median colony forming units was lower on the a-C:H and a-C:H:N coatings in comparison to the bare AISI 316L medical grade stainless steel surface, regardless the bacterial strain. The best bacterial adhesion inhibition capacity was achieved for N doping of 6 at.%, without using any antibacterial agents.

Inhibitory Potential of Bifidobacterium longum FB1-1 Cell-Free Supernatant against Carbapenem-Resistant Klebsiella pneumoniae Drug Resistance Spread.

The widespread dissemination of carbapenem-resistant Klebsiella pneumoniae (CRKP) and its drug resistance transfer poses a global public health threat. While previous studies outlined CRKP's drug resistance mechanism, there is limited research on strategies inhibiting CRKP drug resistance spread. This study investigates the potential of Bifidobacterium longum (B. longum) FB1-1, a probiotic, in curbing the spread of drug resistance among CRKP by evaluating its cell-free supernatant (CFS) for antibacterial activity. Evaluating the inhibitory effect of FB1-1 CFS on CRKP drug resistance spread involved analyzing its impact on drug resistance and virulence gene expression; drug resistance plasmid transfer FB1-1 CFS exhibited an MIC range of 125 μL/mL against CRKP. After eight hours of co-culture, CFS achieved a 96% and 100% sterilization rate at two and four times the MIC, respectively. At sub-inhibitory concentrations (1/2× MIC), FB1-1 CFS reduced the expression of the bla_KPC gene, which is pivotal for carbapenem resistance, by up to 62.13% across different CRKP strains. Additionally, it markedly suppressed the expression of the uge gene, a key virulence factor, by up to 91%, and the fim_H gene, essential for bacterial adhesion, by up to 53.4%. Our study primarily focuses on determining the inhibitory effect of FB1-1 CFS on CRKP strains harboring the bla_KPC gene, which is a critical resistance determinant in CRKP. Furthermore, FB1-1 CFS demonstrated the ability to inhibit the transfer of drug resistance plasmids among CRKP strains, thus limiting the horizontal spread of resistance genes. This study highlights FB1-1 CFS's inhibitory effect on CRKP drug resistance spread, particularly in strains carrying the bla_KPC gene, thus offering a novel idea and theoretical foundation for developing antibacterial drugs targeting CRKP resistance.

Template bacteria-free fabrication of surface imprinted polymer-based biosensor for E. coli detection using photolithographic mimics: Hacking bacterial adhesion

As one class of molecular imprinted polymers (MIPs), surface imprinted polymer (SIP)-based biosensors show great potential in direct whole-bacteria detection. Micro-contact imprinting, that involves stamping the template bacteria immobilized on a substrate into a pre-polymerized polymer matrix, is the most straightforward and prominent method to obtain SIP-based biosensors. However, the major drawbacks of the method arise from the requirement for fresh template bacteria and often non-reproducible bacteria distribution on the stamp substrate. Herein, we developed a positive master stamp containing photolithographic mimics of the template bacteria (E. coli) enabling reproducible fabrication of biomimetic SIP-based biosensors without the need for the “real” bacteria cells. By using atomic force and scanning electron microscopy imaging techniques, respectively, the E. coli-capturing ability of the SIP samples was tested, and compared with non-imprinted polymer (NIP)-based samples and control SIP samples, in which the cavity geometry does not match with E. coli cells. It was revealed that the presence of the biomimetic E. coli imprints with a specifically designed geometry increases the sensor E. coli-capturing ability by an “imprinting factor” of about 3. These findings show the importance of geometry-guided physical recognition in bacterial detection using SIP-based biosensors. In addition, this imprinting strategy was employed to interdigitated electrodes and QCM (quartz crystal microbalance) chips. E. coli detection performance of the sensors was demonstrated with electrochemical impedance spectroscopy (EIS) and QCM measurements with dissipation monitoring technique (QCM-D).

Combined antibacterial and antifouling properties of polyethersulfone mixed matrix membranes with zwitterionic graphene oxide nanostructures

AbstractThe impact of zwitterionic graphene oxide (GO‐Arg) nanostructures into polyethersulfone (PES) membranes was studied, aiming to perform mixed matrix membranes (MMMs) with combined antibacterial and antifouling properties. For this purpose, 0.25, 0.50, and 1.0 wt% of GO‐Arg were incorporated through the phase inversion method. The chemical composition reveals that the electrostatic interactions of PES, polyvinylpyrrolidone, and GO‐Arg occur by enhancing the CH/NH vibrations associated with the intrinsic MMMs and their combined antibacterial and antifouling performance. Well‐defined finger‐like morphology was observed, performing the pore distribution and the finger‐cavity inclination induced by the electrostatic charge of GO‐Arg. As a result, GO‐Arg MMM's hydrophobic properties decreased from 77.8° to 52.3°, inducing a partially hydrophilic surface and improved water flux. The isoelectric point of nanostructured membranes slightly changes by the charge modulation produced by zwitterionic GO‐Arg. The antibacterial activity against Gram (−) Escherichia coli was improved, closing the complete bacterial inhibition after 24 h. As a result, antifouling performance was improved, avoiding bacterial adhesion into the membrane surface and the possibility of promoting biofilm formation. Our results demonstrate that zwitterionic nanomaterials in MMMs perform the multifunctional capacity of materials, emerging as an effective alternative with potential application in wastewater treatment.Highlights The incorporation of zwitterionic GO‐Arg improves the mechanical properties of MMMs. GO‐Arg‐enhanced well‐defined porous finger‐like morphology in MMMs. GO‐Arg improves the antibacterial/antifouling performance of PES‐based MMMs.

Exploring the Antibacterial Potential of Lamiaceae Plant Extracts: Inhibition of Bacterial Growth, Adhesion, Invasion, and Biofilm Formation and Degradation in Pseudomonas aeruginosa PAO1.

In response to the global rise in antibiotic resistance and the prevalence of bacterial biofilm-related infections, the antibacterial efficacy of methanolic, ethanolic, and aqueous extracts of 18 Lamiaceae plants from Serbia was evaluated. The total coumarins and triterpenes were detected spectrophotometrically, while a microdilution assay measured their effects on bacterial growth. Additionally, the impact of these extracts was assessed on Pseudomonas aeruginosa PAO1 adhesion and invasion in human fibroblasts and biofilm formation and degradation. The alcoholic extracts had the highest phytochemical content, with Teucrium montanum and Lavandula angustifolia being the richest in coumarins and triterpenes, respectively. Gram-positive bacteria, particularly Bacillus subtilis, were more susceptible to the extracts. Hyssopus officinalis ethanolic and Sideritis scardica methanolic extracts inhibited bacterial growth the most efficiently. Although the extracts did not inhibit bacterial adhesion, most ethanolic extracts significantly reduced bacterial invasion. Origanum vulgare and H. officinalis ethanolic extracts significantly inhibited biofilm formation, while Teucrium chamaedrys extract was the most active in biofilm degradation. This study significantly contributes to the literature by examining the antibacterial activity of Lamiaceae extracts, addressing major literature gaps, and underscoring their antibacterial potential, particularly Satureja montana and O. vulgare ethanolic extracts, linking their efficacy to coumarins and triterpenes.