Antibiofilm Efficacy Research Articles

Antibiofilm efficacy of a calcium silicate-based intracanal medicament against Fusobacterium nucleatum strains

This study evaluated the antibiofilm efficacy of a calcium silicate-based intracanal medicament (Bio-C Temp) against Fusobacterium nucleatum (F. nucleatum). Dentin slices (n = 88) were inoculated with F. nucleatum biofilms and divided into experimental groups (n = 24 each) treated with Bio-C Temp, triple antibiotic paste (TAP), or Ca(OH)2 for 1 or 2 weeks. Untreated dentin slices exposed to saline served as a positive control, while sterile dentin slices incubated anaerobically served as a negative control. Bacterial viability was assessed using confocal laser scanning microscopy after staining with LIVE/DEAD®BacLight™ dye. Samples treated with TAP demonstrated the highest percentage of dead bacteria (95%). The antibiofilm effect of TAP and Bio-C Temp significantly increased from Week 1 to Week 2. At Week 2, samples treated with Bio-C Temp showed a significantly higher percentage of dead bacteria (75.25%) than those treated with Ca(OH)2 (58.65%). TAP showed superior efficacy against F. nucleatum biofilms. After an application time of 2 weeks, the antibiofilm efficacy of Bio-C Temp was superior to that of Ca(OH)2.

Antibiofilm and antivirulence efficacy of Pleurotus platypus methanolic extract against Staphylococcus aureus through ROS generation and cell membrane disruption

Multi-drug resistance is recognized as a significant worldwide public health concern in the current century. Biofilm formation further exacerbates bacterial resistance to antibacterial medications, host immunological responses, and phagocytosis, resulting in long-lasting chronic illnesses. Investigating natural resources is a very potent approach for developing alternative anti-infective medications to effectively control multi-drug resistant bacterial infections. In this study, a unique mushroom species namely Pleurotus platypus had been discovered from the Terai-Duars region of West Bengal, India. The myco-chemical profiling and preliminary chemical analysis of Pleurotus platypus methanolic extract determined the significant presence of metabolites belonging to several major chemical classes such as flavonoid, alkaloid, triterpenoid, polyphenol, benzoic acids, coumarin, flavone etc. Most intriguingly, the extract possessed effective antibacterial, antibiofilm and antivirulence properties against Staphylococcus aureus and Methicillin resistant Staphylococcus aureus, one of the most notable drug-resistant opportunistic and nosocomial pathogens. Mechanistically, the mushroom extract enhanced the production of Reactive Oxygen Species (ROS) inside the targeted bacteria, causing alterations in membrane potential, damage to the cellular membrane and further release of intracellular DNA, destined to cell death. Moreover, the methanolic extract reported the eradication of pre-existing biofilms from the urinary catheter surface, hinting towards its future application in the related field. To summarize, Pleurotus platypus methanolic extract could be an excellent alternative antibacterial and antibiofilm therapeutic candidate for the effective management of Staphylococcus infections with improved outcome.

Antibacterial and anti-biofilm efficacy of selenium nanoparticles against Pseudomonas aeruginosa: Characterization and in vitro analysis

Pseudomonas aeruginosa (P. aeruginosa), a Gram-negative opportunistic pathogen, poses significant treatment challenges due to its antibiotic resistance and biofilm formation. This study investigates the anti-bacterial and anti-biofilm activities of chemically synthesized selenium nanoparticles (SeNPs) against P. aeruginosa. SeNPs were synthesized using ascorbic acid as a reducing agent and characterized. Biofilm formation was quantified using a modified microtiter plate method, and the anti-biofilm efficacy of SeNPs was evaluated using confocal microscopy and SEM. The P.aeruginosa isolates exhibited high resistance to piperacillin-tazobactam (60%) and ceftazidime (59%). SeNPs demonstrated a round shape with a diameter of 15-18 nm. UV-Vis spectra showed a peak at 275 nm, and XRD analysis revealed crystalline peaks corresponding to selenium. The FTIR spectra confirmed the presence of various functional groups. SeNPs significantly reduced biofilm formation in a dose-dependent manner, with MIC50 and MIC90 values of 60 μg/mL and 80 μg/mL, respectively. Confocal microscopy and SEM analysis showed a notable decrease in biofilm thickness and bacterial adherence post-SeNPs treatment. These findings suggest that SeNPs could be a promising alternative or adjunctive treatment option for combating antibiotic-resistant P. aeruginosa infections. Further research is warranted to explore the clinical applications of SeNPs in treating biofilm-associated infections.

Exploring the potential of naturally occurring antimicrobials for managing orthopedic-device-related infections

Abstract. Orthopedic-device-related infections (ODRIs) are challenging clinical complications that are often exacerbated by antibiotic resistance and biofilm formation. This review explores the efficacy of naturally occurring antimicrobials – including agents sourced from bacteria, fungi, viruses, animals, plants and minerals – against pathogens common in ODRIs. The limitations of traditional antibiotic agents are presented, and innovative naturally occurring antimicrobials, such as bacteriophage therapy and antimicrobial peptides, are evaluated with respect to their interaction with conventional antibiotics and antibiofilm efficacy. The integration of these natural agents into clinical practice could revolutionize ODRI treatment strategies, offering effective alternatives to conventional antibiotics and mitigating resistance development. However, the translation of these compounds from research into the clinic may require the substantial investment of intellectual and financial resources.

Cytocompatibility, Antibacterial, and Anti-Biofilm Efficacy of Grape Seed Extract and Quercetin Hydrogels Against a Mature Endodontic Biofilm Ex Vivo Model

Background/Objectives: To assess the cytocompatibility, antibacterial and anti-biofilm efficacy of grape seed extract (GSE) and quercetin hydrogels versus calcium hydroxide (CH) as intracanal medications (ICMs) against an endodontic ex vivo biofilm model. Methods: Single-rooted teeth (n = 50) were prepared and sterilized before being infected with E. faecalis to develop a mature biofilm. They were divided into five equal groups according to the ICM used: G1: medicated with CH paste, G2: medicated with GSE hydrogel, G3: medicated with quercetin hydrogel, G4: positive control group that was infected and not medicated, and G5: negative control group that was neither infected nor medicated. After 1 week, the ICM was removed, and the root canals were cultured to assess the antibacterial efficacy by counting the colony-forming units and the anti-biofilm efficacy by the crystal violet assay. Dead/live bacterial viability was assessed by CFLSM examination, while the cytocompatibility was assessed using the MTT assay. Results: CH had the best antibacterial efficacy, followed by GSE and quercetin hydrogels (p < 0.001). Regarding the anti-biofilm efficacy, GSE was superior, followed by quercetin and CH (p < 0.001). CFLSM examination showed CH and GSE hydrogel to be highly effective in comparison to the positive control (p < 0.0001), with no statistical difference between them (p > 0.05). CH showed significantly higher cell viability percentages using a 500 μg/mL, while quercetin and GSE started to show cell viability > 70% at concentrations of 125 μg/mL and 62.5 μg/mL. Conclusions: CH fulfilled the ideal requirements of ICM as being both antibacterial and non-cytotoxic compared to the other materials tested.

Synthesis, Antibacterial, Anti-Biofilm Properties, and Docking Study of Indeno[1,2-b]Pyridin-5-One Derivatives

In this context, we designed and synthesized a series of hydrazonal and their related indeno[1,2-b]pyridin-5-one derivatives to investigate their antibacterial and anti-biofilm properties. Several of the synthesized compounds exhibited significant efficacy against all microorganism species tested. Most of the compounds demonstrated favorable results when tested against Gram-positive bacteria. The derivatives 4a, 4f, 6c, and 6f exhibit the highest antimicrobial efficacy, as indicated by their minimum inhibitory concentration (MIC) values ranging from 4 to 512 μg/mL. We conducted additional investigations on 4a, 6c, and 6f for the purpose of examining their synergy using Checkerboard assay. Compound 6c demonstrated a synergistic impact against methicillin-sensitive Staphylococcus aureus (MSSA) and Pseudomonas aeruginosa, while exhibiting moderate synergistic activity against methicillin-resistant Staphylococcus aureus (MRSA). In addition, the simultaneous use of gentamycin with compounds 4a and 6f demonstrates a synergistic impact in fighting against methicillin-resistant Staphylococcus aureus (MRSA) and Pseudomonas aeruginosa, respectively. Three chosen compounds were evaluated for their antibiofilm efficacy. Application of 4a, 6c, and 6f effectively reduced the production of biofilms in MRSA, MSSA, and Pseudomonas aeruginosa, resulting in a significant decrease compared to the untreated samples. In addition, ADME and pharmacokinetic analyses were conducted for the three most potent derivatives, namely 4a, 6c, and 6f. Compounds 4a and 6c were subjected to docking in the LasR Quorum-Sensing Receptor, whereas compounds 6c and 6f were docked in the sortase enzyme.

Antibiofilm efficacy of plant extracts as root canal irrigants in endodontics: a systematic literature review

Antibiofilm efficacy of plant extracts as root canal irrigants in endodontics: a systematic literature review

Investigation of the Synergistic Effect of Rosehip Vinegar and Propolis Extract on Antibacterial and Antibiofilm Efficacy Against Foodborne Pathogens and Their Protective Effect on Sardine (Sardina pilchardus)

ABSTRACT The antibacterial and antibiofilm effects of rosehip vinegar and propolis extract, separately and as a mixture, were investigated on Staphylococcus aureus and Escherichia coli O157:H7. The organoleptic properties and tissue integrity of sardine fish treated with this mixture were evaluated. The propolis extract was found to have a higher inhibitory effect (>80%) on S. aureus (up to the 5th dilution) than on E. coli O157:H7 (only at the first dilution). A potential synergistic antibacterial and antibiofilm effect of the mixture was observed with an inhibition ratio of ≥50%. This mixture may extend the shelf life of sardines as a natural antibacterial/antibiofilm preservative.

Dual-action defense: A photothermal and controlled nitric oxide-releasing coating for preventing biofilm formation

Biofilms formed by pathogenic bacteria on biomedical devices and implants pose a considerable challenge due to their resistance to conventional treatments and their role in severe infections. Preventing biofilm formation is strategically more advantageous than attempting to eliminate the mature biofilms, particularly in addressing the persistence of such formations. In this context, a dual-action antibiofilm coating is developed, utilizing S-nitrosothiols functionalized candle soot (CS), which capitalizes on CS’s strong light absorption for photothermal therapy and the controlled release of nitric oxide (NO) from S-nitrosothiols to inhibit biofilm formation. This coating exhibits stable and efficient light-to-heat conversion, along with the ability to release NO gradually at physiological temperatures and to rapidly release NO on demand when triggered by a near-infrared (NIR) laser. Under NIR irradition, the coating generates heat swiftly and releases substantial amounts of NO, which synergistically disrupts bacterial membranes, leading to the leakage of intracellular components and the effective eradication of surface-adhered bacteria. In the absence of NIR irradiation, the coating continuously releases low concentrations of NO, which depletes exopolysaccharides and impedes biofilm formation. The antibiofilm efficacy of this coating is assessed against Staphylococcus aureus and Pseudomonas aeruginosa, demonstrating marked reductions in bacterial viability and biofilm formation in vitro. Additionally, the coating exhibits minimal cytotoxicity and can be easily applied to diverse substrates. This study underscores the potential of this coating as a broad-spectrum, non-toxic approach for preventing biofilm-related complications in biomedical applications.

Exploring the Antibacterial and Antibiofilm Efficacy of Psammogeton biternatum Edgew and Identification of a Novel Quinoline Alkaloid using X-ray Crystallography.

The prevalence of resistance to harmful human pathogens is steadily rising, emphasizing the urgent need to identify novel antimicrobial compounds. For this purpose, plants stand out as a significant source of bioactives worthy of exploration. Among these, alkaloids, a vast and structurally diverse category of plant secondary metabolites, have emerged as a foundation for crucial antibacterial medications such as metronidazole and the quinolones. In the current work, the crude methanol leaf extract of Psammogeton biternatum Edgew collected from District Bannu, Pakistan, was subjected to TLC (indirect) bioautography and X-ray crystallography for the isolation of potential antibacterial agents. From the crude extract, a novel quinoline alkaloid called quinoline dione ((3R,3aS,5aR)-3,5a,9-trimethyl-3a,4,5,5a-tetrahydro-2H-isoxazolo[2,3-a] quinoline-2,8(3H)-dione (C14H17NO3)) was isolated. The crystal information (M = 247.296 g/mol) is as follows: orthorhombic, P212121, a = 7.7339(14) Å, b = 10.7254(19) Å, c = 15.730(2) Å, V = 1304.8(4) Å3, Z = 4, T = 296 K, μ(Mo Kα) = 0.088 mm-1, ρ calc = 1.259 g/cm3, 13928 reflections measured (5.86° ≤ 2Θ ≤ 51.98°), 2478 unique (R int = 0.1613, R σ = 0.1335). The final R 1 was 0.1098 (I ≥ 2u(I)), and wR 2 was 0.2183. The antibacterial activity for both crude extract of leaves and quinoline dione was determined by a well diffusion method. The quinoline dione alkaloid demonstrated excellent inhibition zones against methicillin-resistant Staphylococcus aureus (18 mm), Bacillus subtills (17 mm), Escherichia coli (20 mm), and Pseudomonas aeruginosa (23 mm) compared to the crude extract. The antibiofilm potential was recorded against Pseudomonas aeruginosa by the 96-well microtiter plate method. A dose-dependent biofilm inhibition response was recorded, which increased with the increase in concentration. Moreover, quinoline dione showed a greater antibiofilm effect as compared to the crude extract, which may be linked to the presence of a particular active functional group positioned on the compound isolated in its pure form. Through in silico studies, i.e., molecular docking, quinoline dione shows strong binding energies with the LasR transcriptional regulator (6MVN) at -9.3 and LasR transcriptional activator (3IX4) at -9.2 kcal/mol, as well as moderate affinities with other targets such as AHL synthase LasI (PDB ID 1RO5) and OprM channel (PDB ID 3D5K), indicating its potential as a quorum sensing inhibitor. Thus, the antibacterial and antibiofilm potential of quinoline dione was confirmed.

Colloidal Structure Dictates Antimicrobial Efficacy in LL-37 Self-Assemblies With Glycerol Monooleate.

The antimicrobial peptide LL-37 is a promising alternative to conventional antibiotics to combat bacteria in suspension and biofilms. Its self-assembly with polar lipids is suggested to improve its potential for therapeutic applications with higher stability against degradation and bioavailability. This study investigates the self-assembly of LL-37 with glyceryl monooleate (GMO), establishing the link between colloidal structure and antimicrobial activity. Small-angle X-ray scattering, dynamic light scattering and cryogenic transmission electron microscopy show structural transformation from dispersions of inverse bicontinuous structure (cubosomes) to multilamellar vesicles and direct rod-like mixed-micelles upon increasing the content of LL-37 in GMO. In vitro assays against planktonic and biofilm cells demonstrate that 128 µg mL-1 of GMO cubosomes have no impact on Pseudomonas aeruginosa. Still, the cubosomes reduce the Staphylococcus aureus planktonic population by ≈ 1-log after 24 h. Cylindrical micelles formed at LL-37/GMO 9/1 and 8/2 with 128 µg mL-1 LL-37 decrease the Pseudomonas aeruginosa population by 6-log. This activity is gradually abolished when LL-37 is encapsulated in vesicles or cubosomes. They also demonstrate low antibiofilm efficacy and promote the biomass of Staphylococcus aureus biofilms. These results highlight the importance of colloidal structure for therapeutic outcomes, providing insights for advanced lipid nanocarrier designs.

Active-bromide and surfactant synergy for enhanced microfouling control.

Biofilms are structured microbial communities encased in a matrix of self-produced extracellular polymeric substance (EPS) and pose significant challenges in various industrial cooling systems. A nuclear power plant uses a biocide active-bromide for control of biological growth in its condenser cooling system. This study is aimed at evaluating the anti-bacterial and anti-biofilm efficacy of active-bromide against planktonic and biofilm-forming bacteria that are commonly encountered in seawater cooling systems. The results demonstrated that active-bromide at the concentration used at the power plant (1 ppm) exhibited minimal killing activity against Pseudomonas aeruginosa planktonic cells. The bacterial cell surface hydrophobicity assay using Staphylococcus aureus and P. aeruginosa indicated that Triton-X 100 significantly decreased the hydrophobicity of planktonic cells, enhancing the susceptibility of the cells to active-bromide. Biofilm inhibition assays revealed limited efficacy of active-bromide at 1 ppm concentration, but significant inhibition at 5 ppm and 10 ppm. However, the addition of a surfactant, Triton-X 100, in combination with 1 ppm active-bromide displayed a synergistic effect, leading to significant biofilm dispersal of pre-formed P. aeruginosa biofilms. This observation was substantiated by epifluorescence microscopy using a live/dead bacterial assay that showed the combination treatment resulted in extensive cell death within the biofilm, as indicated by a marked increase in red fluorescence, compared to treatments with either agent alone. These findings suggest that active bromide alone may be insufficient for microfouling control in the seawater-based condenser cooling system of the power plant. Including a biocompatible surfactant that disrupts established biofilms (microfouling) can significantly improve the efficacy of active bromide treatment.

Segment-Based Peptide Design Reveals the Importance of N-Terminal High Cationicity for Antimicrobial Activity Against Gram-Negative Pathogens.

Host defense antimicrobial peptides (AMPs) are recognized candidates to develop a new generation of peptide antibiotics. While high hydrophobicity can be deployed in peptides for eliminating Gram-positive bacteria, high cationicity is usually observed in AMPs against Gram-negative pathogen. This study investigates how the sequence distribution of basic amino acids affects peptide activity. For this purpose, we utilized human cathelicidin LL-37 as a template and designed four highly selective ultrashort peptides with similar length, net charge, and hydrophobic content. LL-10 + , RK-9 + , KR-8 + , and RIK-10 + showed similar activity against methicillin-resistant Staphylococcus aureus in vitro and comparable antibiofilm efficacy in a murine wound model. However, these peptides showed clear activity differences against Gram-negative pathogens with RIK-10 + (i.e., LL-37mini2) being the strongest and LL-10 + the weakest. To understand this activity difference, we characterized peptide toxicity; the effects of salts, pH, and serum on peptide activity; and the mechanism of action and determined the membrane-bound helical structure for RIK-10 + by two-dimensional NMR spectroscopy. By writing an R program, we generated charge density plots for these peptides and uncovered the importance of the N-terminal high-density basic charges for antimicrobial potency. To validate this finding, we reversed the sequences of two peptides. Interestingly, sequence reversal weakened the activity of RIK-10 + but increased the activity of LL-10 + especially against Escherichia coli, Pseudomonas aeruginosa, and Acinetobacter baumannii. Those more active peptides with high cationicity at the N-terminus are also more hydrophobic based on HPLC retention times. A database search found numerous natural sequences that arrange basic amino acids primarily at the N-terminus. Combined, this study not only obtained novel peptide leads but also discovered one useful strategy for designing novel antimicrobials to control drug-resistant Gram-negative pathogens.

Antibacterial and antibiofilm efficacy of silver nanoparticles mediated by Oplopanax elatus adventitious root extract against mixed bacteria with different species

Antibacterial and antibiofilm efficacy of silver nanoparticles mediated by Oplopanax elatus adventitious root extract against mixed bacteria with different species

Improve anti-biofilm efficacy of ultrasound by modulating the phase transition of exopolysaccharides

This study focused on the adverse sonochemical effect of ultrasound on biofilm extracellular polysaccharide and the adaptive biofilm responses for ultrasound resistance. Results showed ultrasound triggered phase transition of polysaccharides within biofilm from solation to gelation, which induced following biofilm viscoelasticity enhancement, consequential failure of biofilm removal and bacteria killing. Introducing additional cationic polysaccharide, 1.25 % chitosan, inhibited the ultrasound responsive polysaccharides gelation and biofilm viscoelasticity enhancement, exerted synergistic antibacterial (97.40 %) and antibiofilm (96.38 %) effects with 120 W ultrasound combined on S. aureus biofilm, prolonged the preservation time of milk 2.45 times longer compared with ultrasound alone. These findings indicated the possible mechanism and solution to improve ultrasound efficacy on biofilm control and bacteria suppression, exhibit the promising prospect of ultrasound combined strategy in hygiene issues of food and medical industry

Synthesis of cytocompatible gum Arabic–encapsulated silver nitroprusside nanocomposites for inhibition of bacterial pathogens and food safety applications

Silver nitroprusside (AgN) exhibits significant antibacterial activity; however, its inherent toxicity poses a major concern. This study synthesized AgN with enhanced antibacterial properties while minimizing toxicity. Gum Arabic (GA), a natural polysaccharide widely utilized in food and biomedical applications owing to its exceptional cytocompatibility, was selected for encapsulating AgN to mitigate toxicity while preserving or enhancing its biological activity. The resulting composite material, GA–AgN nanocomposites (NCs), was systematically characterized using various analytical techniques. Transmission electron microscopy analysis revealed that GA–AgN NCs exhibited a rectangular morphology, with an average size of 230.13 ± 62.8 nm. The zeta potential of GA–AgN NCs was measured at −29.3 ± 0.70 mV. Furthermore, GA–AgN NCs demonstrated stability over diverse storage durations, incubation periods, and pH conditions by maintaining its size and surface charge. X-ray diffraction results indicated a reduction in the crystallinity of AgN when incorporated into the amorphous GA matrix, while Fourier-transform infrared spectroscopy analysis confirmed that the functional properties of both AgN and GA were preserved in the NCs. The release of Ag and Fe ions from the NCs was observed to be time- and pH-dependent. Importantly, the incorporation of GA did not compromise the antibacterial or antibiofilm efficacy of AgN against bacterial pathogens. Additionally, GA significantly mitigated the cytotoxic effects of AgN on NIH3T3 cells and red blood cells. Furthermore, GA–AgN NCs effectively extended the shelf-life of Salmonella enterica–infected green grapes. Thus, this study illustrates that GA-fabricated AgN NCs exhibit potential as an antibacterial agent in food preservation applications.

Comparative in vitro Study of Antimicrobial, Antibiofilm and Quorum Sensing Inhibitory Activities of Hypericum calycinum L. and Parietaria officinalis L. Extracts

Aim: This study aims to elucidate both the anti-virulence and antimicrobial effects of ethanol extracts from Hypericum calycinum L. and Parietaria officinalis L. Material and Methods: Antimicrobial activity was evaluated using the well diffusion method against five bacteria and two yeast isolates involved in human urinary tract infections (UTIs). The potential of the extracts to inhibit quorum sensing (QS), was assessed using the biosensor strain Chromobacterium violaceum ATCC 12472. Additionally, the antibiofilm activities were investigated using a microplate biofilm assay on Escherichia coli and Pseudomonas aeruginosa. Results: H. calycinum exhibited the highest inhibitory effect at a concentration of 100 mg/mL against Candida albicans with an inhibition zone of 24.5±0.71 mm, while P. officinalis showed its highest effect at the same concentration against E. coli with an inhibition zone of 15.5±0.71 mm. Overall, H. calycinum demonstrated stronger antimicrobial activity compared to P. officinalis. Both plant extracts inhibited QS at similar levels, with inhibition zones ranging between 10-12 mm. The antibiofilm effect varied depending on the bacterial species, but notably, P. officinalis extract exhibited over 80% antibiofilm efficacy against E. coli at all concentrations. Conclusion: This study demonstrates that H. calycinum L. and P. officinalis L. are potent antimicrobial agents against UTI pathogens. While their anti-QS efficacy is not exceptional, the significant inhibition of E. coli biofilm formation underscores their potential as formidable agents. Designed as a fundamental study, it highlights the promising antimicrobial properties of these plant extracts and marks the first investigation into their capabilities as QS and biofilm-preventive agents.

Hybrids of 3-Hydroxypyridin-4(1H)-ones and Long-Chain 4-Aminoquinolines as Potent Biofilm Inhibitors of Pseudomonas aeruginosa Potentiate Tobramycin and Polymyxin B Activity.

The biofilm formation of Pseudomonas aeruginosa involves multiple complex regulatory pathways; thus, blocking a single pathway is unlikely to achieve the desired antibiofilm efficacy. Herein, a series of hybrids of 3-hydroxypyridin-4(1H)-ones and long-chain 4-aminoquinolines were synthesized as biofilm inhibitors against P. aeruginosa based on a multipathway antibiofilm strategy. Comprehensive structure-activity relationship studies identified compound 30b as the most valuable antagonist, which significantly inhibited P. aeruginosa biofilm formation (IC50 = 5.8 μM) and various virulence phenotypes. Mechanistic studies revealed that 30b not only targets the three quorum sensing systems but also strongly induces iron deficiency signals in P. aeruginosa. Furthermore, 30b demonstrated a favorable in vitro and in vivo safety profile. Moreover, 30b specifically enhanced the antibacterial activity of tobramycin and polymyxin B in in vitro and in vivo combination therapy. Overall, these results highlight the potential of 30b as a novel anti-infective candidate for treating P. aeruginosa infections.

Screening of Lithium Substituted Ag-TiO2 Nanoparticle Coating for Antibiofilm Application.

Bacterial infections and biofilm growth are common mishaps associated with medical devices, and they contribute significantly to ill health and mortality. Removal of bacterial deposition from these devices is a major challenge, resulting in an immediate necessity for developing antibacterial coatings on the surfaces of medical implants. In this context, we developed an innovative coating strategy that can operate at low temperatures (80 °C) and preserve the devices' integrity and functionality. An innovative Ag-TiO2 based coating was developed by ion exchange between silver nitrate (AgNO3) and lithium titanate (Li4Ti5O12) on glass substrates for different periods, ranging from 10 to 60 min. The differently coated samples were tested for their antibacterial and antibiofilm efficacy.

Novel quinazolin-6-yl Isoindolinone: Altering polysaccharide chemstructure for antibacterial efficacy against Staphylococcus aureus

The ongoing development of novel strategies to combat Staphylococcus aureus and eliminate its biofilm formation has gained significant attention for human health. Antibiotic-resistant S. aureus necessitates the development of novel antibacterial agents with new mechanism of action. This study introduced a promising recently synthesized quinazolin-6-yl isoindolinone (IQE-X1), which exhibited potent antibacterial and antibiofilm efficacy with average median inhibitory concentration (IC50) of 3.37 μg mL−1 and minimal inhibitory concentration (MIC) of 12.5 μg mL−1, coupled with its ability to reduce cell surface hydrophobicity. IQE-X1 dose-dependently decreased extracellular polysaccharides (EPS) and its component monosaccharides, including rhamnose, arabinose, glucosamine, galactose, glucose, xylose, mannose, and ribose, accompanied by an increase in capsular polysaccharides (CP) and its individual monosaccharides, especially glucosamine. IQE-X1 demonstrated specificity in modulating the structural profiles of EPS and CP by altering the compositional ratios of their component monosaccharides. The potential mechanism of polysaccharide modulation was preliminarily elucidated through the response of β-N-acetylaminoglucosidase to IQE-X1 and their direct binding interaction. These findings provide new insights into the potential manipulation of the chemstructure of these biologically important macromolecules, EPS and CP, and highlight the antibacterial potential of IQE-X1 as a polysaccharide modulator for the development of more effective polysaccharide-targeted strategies against S. aureus.