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Background: Infected wounds are a major health problem as infection can delay wound healing. Wound dressings play an important part in wound care by maintaining a suitable environment that promotes healing. Silver sulfadiazine dressings have been used to prevent infection in burn wounds. Presently, many commercial silver dressings have obtained FDA clearance. Results: In this study, we report on a novel silver dressing using microporous aluminosilicate zeolites, termed ABF-XenoMEM. Silver and zinc ions are encapsulated in the zeolite supercages. We show that the silver-zinc zeolite (AM30) alone is effective at inhibiting biofilm formation. The encapsulation protects the silver from rapidly precipitating in biological fluids. We exploit the negatively charged zeolite surface to associate positively charged quaternary ammonium ions (quat) with the zeolite. The combination of the AM30 with the quat enhances the antimicrobial activity. The colloidal nature of the zeolite materials makes it possible to make uniform deposits on a commercial extracellular matrix membrane to develop the final dressing (ABF-XenoMEM). The optimum loading of silver, zinc, and quat on the dressing was found to be 30, 3.7, and 221 µg/cm2. Using a colony biofilm model, the activity of ABF-XenoMEM is compared with four well-studied silver-based commercial dressings towards mature biofilms of Pseudomonas aeruginosa PAO1 (ATCC 4708) and methicillin-resistant Staphylococcus aureus (ATCC 33592). Cytotoxicity of the dressings was examined in HepG2 cells using the MTT assay. Conclusion: This study shows that the ABF-XenoMEM is competitive with extensively used commercial wound dressings in a colony biofilm model. Nanozeolite-entrapped silver/zinc antimicrobials in association with quat have the potential for application in biofilm-infected wounds and require animal and clinical studies for definitive proof. [ABSTRACT FROM AUTHOR]

Background/Objectives: Bovine mastitis (BM), a prevalent and economically burdensome bacterial infection affecting dairy cattle, poses a significant challenge to the dairy industry. The traditional approach to combating BM, relying heavily on antibiotics, faces growing concerns due to the increasing antibiotic resistance exhibited by pathogens. The objective of this study was to evaluate and determine the antimicrobial and anti-biofilm potential of chitosan nanoparticles (NQo) on S. aureus strains isolated from milk samples obtained from dairy areas in southern Chile from cows diagnosed with BM. Methods: NQo were synthesized using the ionotropic gelation method and thoroughly characterized by transmission electron microscopy (TEM) and dynamic light scattering (DLS). Results: The NQo exhibit a robust positive charge (Z-potential of +55.4 ± 2.5 mV) and an exceptionally small size (20.3 ± 3.2 nm). This unique combination of properties makes NQo particularly well-suited for targeting and interacting with bacterial pathogens. To assess the effectiveness of NQo against BM, we conducted a series of experiments using a Staphylococcus aureus strain isolated from milk samples of cows diagnosed with BM in southern Chile. NQo demonstrated a remarkable ability to inhibit bacterial proliferation and effectively modulate biofilm formation in the S. aureus strains. Furthermore, the performance of NQo in comparison to established antibiotics like ampicillin and gentamicin strongly suggests that these nanoparticles hold immense potential as an attractive alternative for the control, prevention, and/or treatment of BM. Conclusions: NQo exhibit both antimicrobial and antibiofilm activity against a clinically relevant BM pathogen. Further investigations are necessary to develop a hydrogel formulation optimized for effective delivery to the target diseased tissue. [ABSTRACT FROM AUTHOR]

Lactic acid bacteria (LAB), known for their health benefits, exhibit antimicrobial and antibiofilm properties. This study investigated the cell-free supernatant (CFS) of Lactobacillus spp., particularly L. plantarum KR3, against the common foodborne pathogens S. aureus, E. coli and Salmonella spp. Lactobacillus strains were isolated from cheese, pickles and yoghurt. They were then identified by morphological, physiological and biochemical characteristics and confirmed by 16S rRNA gene sequencing. Culture supernatants from seven lactobacilli isolates showed varying inhibitory activities. Notably, L. plantarum KR3 and L. pentosus had the highest bacteriocin gene counts. L. plantarum KR3 CFS demonstrated significant antibacterial activity, with inhibition zones of 20 ± 0.34 mm for S. aureus, 23 ± 1.64 mm for E. coli, and 17.1 ± 1.70 mm for Salmonella spp. The CFS also exhibited substantial antibiofilm activity, with 59.12 ± 0.03% against S. aureus, 83.50 ± 0.01% against E. coli, and 60. ± 0.04% against Salmonella spp., which were enhanced at the minimum inhibitory concentration (MIC). These results highlighted the potential of L. plantarum KR3 in antimicrobial applications, however, further research is needed to evaluate its viability and functional properties for probiotic use. Additionally, the CFS demonstrated exceptional thermal stability, reinforcing its promise as an antimicrobial agent. [ABSTRACT FROM AUTHOR]

Camellia sinensis renowned for its medicinal properties has been employed for centuries to address various ailments due to its anti-inflammatory, antioxidant, anti-cancer, and anti-diabetic properties. In this research, Camellia sinensis leaf extract was used for the eco-friendly and cost-effective synthesis of silver nanoparticles (CS-AgNPs). UV–Visible spectroscopy confirmed the synthesis of CS-AgNPs with a surface plasmon resonance band near 350 nm. Fourier-transform infrared (FTIR) analysis revealed functional groups such as alcohols, carboxylic acids, and amines, which acted as reducing, capping, and stabilising agents. Field-emission scanning electron microscopy (FESEM) showcased monodisperse, spherical nanoparticles ranging from 10 to 50 nm, while X-ray diffraction (XRD) confirmed their crystalline structure with prominent diffraction peaks at 38.24°, 44.42°, and 77.40°, corresponding to the (111), (200), and (311) planes of silver’s FCC structure. Zeta potential analysis demonstrated nanoparticle stability, revealing a negative surface charge of − 34.6 mV, which reduced agglomeration through electrostatic repulsion. Dynamic light scattering (DLS) analysis showed an average particle size of 148.6 nm, aligning with their suspension behaviour. Antimicrobial studies exhibited significant efficacy, with minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) determined at 25 µg/mL and 50 µg/mL, respectively, in tested V. harveyi, V. parahaemolyticus, and V. alginolyticus. The tolerance level of 2 confirms the best bactericidal potential of CS-AgNPs. CS-AgNPs effectively inhibited the biofilm formation at their respective MIC. Comprehensive biochemical assays, including estimating the leakage of proteins, sugars, malondialdehyde (MDA) quantification, glutathione (GSH) measurement, and evaluation of superoxide dismutase (SOD) and catalase (CAT) activities, offered compelling evidence of CS-AgNPs’ robust antibacterial efficacy. This research underscores the transformative capacity of green tea extract, serving as a catalyst for eco-friendly, cost-effective, and reproducible silver nanoparticle synthesis. CS-AgNPs emerge as a potent and economically viable alternative to conventional antibiotics, poised to redefine therapeutic approaches in biomedical science and in aquafarming industries. [ABSTRACT FROM AUTHOR]

Abstract Nanostructured materials are advantageous within numerous fields of medicine owing to their intriguing qualities, which include their size, reactive surface, bioactivity, potential for modification, and optical characteristics. Cassia javanica flower extract was used as a chelating agent in an environmentally friendly process to create SeNPs FTIR, XRD, and TEM, SAED were utilized to analyze and characterize the synthesized. The findings showed that the MIC of Se NPs against B. subtilis and S. aureus was 500 µg/ml. Conversely, the MIC for P. aeruginosa, E. coli, and C. albicans were 125, 250, and 62.5 µg/ml, respectively. Hence, SeNPs considerably reduced the activity; the inhibition peaked at 77.6% at 250 µg/ml to reach 49.04% at 7.8 µg/ml. Which showed the greatest suppression of MRSA biofilm formation without affecting bacterial growth. SeNPs showed an intriguing antioxidant capacity, achieving an IC50 of 53.34 µg/ml. This study looked how soaking seeds before sowing them with Se NPs at 50, 100, and 200 ppm affected the plants’ development in different parameters, as well as their yield of Vicia faba L. The growth conditions were effectively increased by soaking application of various quantities of Se NPs. The highest values of dry weight/pod (g), number of seeds/plant, weight of 100 seeds (g), and number of pods/plant were caused by high concentrations of Se NPs, by 28.43, 89.60, 18.20, and 94.11%, respectively.

Abstract The continuous growth of biofilm infections and their resilience to conventional cleaning methods and antimicrobial agents pose a worldwide challenge across diverse sectors. This persistent medical, industrial, and environmental issue contributes to treatment challenges and chronic diseases. Lactic acid bacteria have garnered global attention for their substantial antimicrobial effects against pathogens and established beneficial roles. Notably, their biofilms are also predicted to show a promising control strategy against pathogenic biofilm formation. The prevalence of biofilm-related problems underscores the need for extensive research and innovative solutions to tackle this global challenge. This novel study investigates the effect of different extracts (external, internal, and mixed extracts) obtained from Lactobacillus rhamnosus GG biofilm on pathogenic-formed biofilms. Subsequently, external extracts presented an important eradication effectiveness. Furthermore, a 6-fold concentration of these extracts led to eradication percentages of 57%, 67%, and 76% for Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa biofilms, respectively, and around 99.9% bactericidal effect of biofilm cells was observed for the three strains. The results of this research could mark a significant breakthrough in the field of anti-biofilm and antimicrobial strategies. Further studies and molecular research will be necessary to detect the molecules secreted by the biofilm, and their mechanisms of action engaged in new anti-biofilm strategies.

Staphylococcus aureus, prevalent in hospital and community settings, forms biofilms that are highly resistant to antibiotics and immune responses, complicating treatment and contributing to chronic infections. These challenges underscore the need for novel treatments that target biofilm formation and effectively reduce bacterial virulence. This study investigates the antibiofilm and antimicrobial efficacy of novel halogenated pyrimidine derivatives against S. aureus, focusing on three compounds identified as potent biofilm inhibitors: 2,4-dichloro-5-fluoropyrimidine (24DC5FP), 5-bromo-2,4-dichloro-7H-pyrrolo[2,3-d]pyrimidine (24DC5BPP), and 2,4-dichloro-5-iodo-7H-pyrrolo[2,3-d]pyrimidine (24DC5IPP). The three active compounds are bacteriostatic. In particular, 24DC5FP at 5 µg/mL achieved a 95% reduction in hemolysis with a minimum inhibitory concentration (MIC) of 50 µg/mL. Interestingly, 24DC5FP increased cell size and produced wrinkled colonies. qRT-PCR analysis showed that 24DC5FP suppressed the gene expressions of agrA and RNAIII (quorum sensing regulator and effector), hla (α-hemolysin), nuc1 (nucleases nuc1), and saeR (S. aureus virulence regulator). These findings suggest that extensive halogenation enhances the antibiofilm and antivirulence activities of pyrimidine derivatives, offering a promising strategy for combatting S. aureus infections, including those resistant to conventional treatments. [ABSTRACT FROM AUTHOR]

Introduction: Dental caries, caused by oral microbial pathogens, are a global health concern, further exacerbated by the presence of methicillin-resistant Staphylococcus aureus (MRSA). Bioactive proteins and peptides (BAPs) exhibit potent antimicrobial properties, targeting multiple cellular mechanisms within pathogens, reducing the likelihood of resistance development. Given the antimicrobial potential of BAPs, this study aimed to compare the efficacy of BAPs extracted from cultivated (Pleurotus ostreatus , PoC) and wild (Pleurotus ostreatus , PoW) mushrooms against pathogens responsible for dental caries. Methods: BAPs were extracted from both PoC and PoW using a TCA-acetone method. Antimicrobial activities were tested against seven bacteria and one fungus using agar well diffusion and MIC determination. Antibiofilm activity was assessed via modified CV assay, while DPPH and erythrocyte lysis tests evaluated free radical scavenging. Results: PoC showed superior antimicrobial efficacy, with lower MIC and MBC values, and disrupted biofilm integrity at increasing concentrations. PoW exhibited better antioxidant activity with higher DPPH scavenging, though its antimicrobial efficacy was slightly lower than PoC. Discussion: Both PoC and PoW BAPs inhibited dental pathogens, with PoC showing stronger inhibition against MRSA and nystatin-resistant Candida albicans. This suggests BAPs may target additional cellular mechanisms beyond membranes, PBPs, and ergosterols. Despite PoW's stronger antioxidant properties, both BAPs had comparable antibiofilm activity. These findings suggest complementary actions of BAPs from PoC and PoW both, in treating dental caries, offering broad-spectrum antimicrobial and antioxidant benefits. [ABSTRACT FROM AUTHOR]

In this study, antimicrobial, antioxidant and anti-quorum sensing activities of S. oleraceus, T. scaturiginosum, T. bithynicum and L. tuberosus were investigated. T. scaturiginosum and T. bithynicum were effective in terms of antimicrobial activity. The highest antibiofilm inhibition was shown by 33.30% aqueous extract of S. oleraceus on P. aeruginosa ATCC 27853. While S. oleraceus aqueous extract showed 35.32% violacein inhibition, T. bithynicum had a zone diameter of 13 mm for quorum sensing inhibition. L. tuberosus ethanol extract was found remarkable with its 52.5% anti-swarming activity. The most effective plant in terms of antioxidant activity was determined as L. tuberosus. This value is IC50 4.36 mg/mL for DPPH and 67.64% for FTC activity. It has been shown that these edible plants may be suitable candidates for reducing microorganismal resistance and using them in the treatment of diseases. [ABSTRACT FROM AUTHOR]

Nanostructured materials are advantageous within numerous fields of medicine owing to their intriguing qualities, which include their size, reactive surface, bioactivity, potential for modification, and optical characteristics. Cassia javanica flower extract was used as a chelating agent in an environmentally friendly process to create SeNPs FTIR, XRD, and TEM, SAED were utilized to analyze and characterize the synthesized. The findings showed that the MIC of Se NPs against B. subtilis and S. aureus was 500 µg/ml. Conversely, the MIC for P. aeruginosa, E. coli, and C. albicans were 125, 250, and 62.5 µg/ml, respectively. Hence, SeNPs considerably reduced the activity; the inhibition peaked at 77.6% at 250 µg/ml to reach 49.04% at 7.8 µg/ml. Which showed the greatest suppression of MRSA biofilm formation without affecting bacterial growth. SeNPs showed an intriguing antioxidant capacity, achieving an IC50 of 53.34 µg/ml. This study looked how soaking seeds before sowing them with Se NPs at 50, 100, and 200 ppm affected the plants' development in different parameters, as well as their yield of Vicia faba L. The growth conditions were effectively increased by soaking application of various quantities of Se NPs. The highest values of dry weight/pod (g), number of seeds/plant, weight of 100 seeds (g), and number of pods/plant were caused by high concentrations of Se NPs, by 28.43, 89.60, 18.20, and 94.11%, respectively. [ABSTRACT FROM AUTHOR]

Phytochemical composition and antimicrobial, antibiofilm, and antioxidant effects of a newly described Himalayan lichen Placidium deosaiense Usman and Khalid growing in Pakistan were investigated. HPLC–DAD methods were used for identification of secondary metabolites in acetone and methanol extracts. The total phenolics content was measured using a spectrophotometric method. The study investigated the antioxidant (DPPH-scavenging activity assay and reducing-power assay), antibacterial (minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC)), and antibiofilm (inhibition of biofilm formation and reduction in mature biofilm) activities of extracts of the lichen P. deosaiense and isolated parietin. The chemical constituents olivetol, olivetolic acid, haematommic acid, fallacinol, and parietin were identified as major compounds in the tested extracts of the lichen. Parietin was isolated from the acetone extract on a separation column. The methanol extract had higher values of TPC (21.67 mg GAE/g) than the acetone extract. Isolated parietin showed the best antioxidant activity measures, according to the DPPH-scavenging activity assay (IC50 = 51.616 μg/mL) and reducing-power assay. Although the extracts showed the best antibacterial activity (especially against Proteus mirabilis ATCC 12453), parietin demonstrated superior antibiofilm activity (especially against Staphylococcus aureus ATCC 25923). This is the first report on the phytochemical composition of the lichen Placidium deosaiense and the first description of the chemical composition of some of the 45 species of the genus Placidium. This research will pave the way for further exploration of new activities of this lichen and its metabolites, which are important for medicine and pharmacy. [ABSTRACT FROM AUTHOR]

The continuous growth of biofilm infections and their resilience to conventional cleaning methods and antimicrobial agents pose a worldwide challenge across diverse sectors. This persistent medical, industrial, and environmental issue contributes to treatment challenges and chronic diseases. Lactic acid bacteria have garnered global attention for their substantial antimicrobial effects against pathogens and established beneficial roles. Notably, their biofilms are also predicted to show a promising control strategy against pathogenic biofilm formation. The prevalence of biofilm-related problems underscores the need for extensive research and innovative solutions to tackle this global challenge. This novel study investigates the effect of different extracts (external, internal, and mixed extracts) obtained from Lactobacillus rhamnosus GG biofilm on pathogenic-formed biofilms. Subsequently, external extracts presented an important eradication effectiveness. Furthermore, a 6-fold concentration of these extracts led to eradication percentages of 57%, 67%, and 76% for Escherichia coli, Staphylococcus aureus, and Pseudomonas aeruginosa biofilms, respectively, and around 99.9% bactericidal effect of biofilm cells was observed for the three strains. The results of this research could mark a significant breakthrough in the field of anti-biofilm and antimicrobial strategies. Further studies and molecular research will be necessary to detect the molecules secreted by the biofilm, and their mechanisms of action engaged in new anti-biofilm strategies. Key points: • Using L. rhamnosus GG biofilm extracts to eradicate pathogenic biofilms. Antimicrobial effect of L. rhamnosus GG biofilm external extracts against biofilm-associated bacteria. Increasing biofilm eradication by combining with a mixture of antimicrobial agents. [ABSTRACT FROM AUTHOR]

The production of silver nanoparticles (Ag NPs) utilizing biological means with renewable resources is thought to be risk-free, environmentally benign, and safe. In this work, the capacity of Bauhinia variegata to produce Ag NPs was measured. Numerous methods, including UV–Vis spectroscopy, TEM, FTIR spectroscopy, and XRD, were employed for the analysis of the produced Ag NPs. Ag NP antimicrobial capacity has been examined through microtitreplate as well as agar well diffusion techniques. Ag NPs’ ability to scavenge free radicals at varying concentrations was assessed using the DPPH technique. The MICs were 1,000 µg·mL−1 against pathogenic microbes including Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans, while 500 and 250 µg·mL−1 were versus Bacillus subtilis and Escherichia coli, respectively. Silver showed an intriguing antioxidant capacity, achieving IC50 of 46.23 μg·mL−1. Additionally, Ag NPs demonstrated possible anticancer action when applied to the carcinoma cell lines Caco-2, with IC50 of 396.2 μg·mL−1 and cytotoxicity toward normal Vero cell lines with IC50 of 609.45 μg·mL−1. Furthermore, Ag NPs demonstrated a range of antibiofilm activities toward S. aureus (MRSA). In conclusion, Ag NPs biosynthesized via B. variegata show promise for a variety of safe biological applications.

Abstract Background Antimicrobial resistance has emerged as a major global health threat, necessitating the urgent development of new antimicrobials through innovative methods to combat the rising prevalence of resistant microbes. With this view, we developed three novel nanoconjugates using microbial natural pigment for effective application against certain pathogenic microbes. Results A natural red pigment (RP) extracted from the endophyte Monascus ruber and gamma rays were applied to synthesize RP-ZnO, RP-CuO, and RP-MgO nanoconjugates. The synthesized nanoconjugates were characterized by different techniques to study their properties. The antimicrobial potential of these nanoconjugates was evaluated. Moreover, the antibiofilm, protein leakage, growth curve, and UV light irradiation effect of the synthesized nanoconjugates were also studied. Our results confirmed the nano-size, shape, and stability of the prepared conjugates. RP-ZnO, RP-CuO, and RP-MgO nanoconjugates showed broad antimicrobial potential against the tested bacterial and fungal pathogens. Furthermore, the RP-ZnO nanoconjugate possessed the highest activity, followed by the RP-CuO against the tested microbes. The highest % inhibition of biofilm formation by the RP-ZnO nanoconjugate. Membrane leakage of E. coli and S. aureus by RP-ZnO nanoconjugate was more effective than RP-MgO and RP-CuO nanoconjugates. Finally, UV light irradiation intensified the antibiotic action of the three nanoconjugates and RP-ZnO potential was greater than that of the RP-MgO, and RP-CuO nanoconjugates. Conclusion These findings pave the way for exploiting the synthesized nanoconjugates as potential materials in biomedical applications, promoting natural, green, and eco-friendly approaches.

The consumption of traditional medicinal herbs has gained popularity as a viable alternative approach for addressing microbial infections or infectious structures. In this study, Verbascum detersile, Verbascum eskisehirensis, and Verbascum gypsicola endemic species belonging to the Scrophulariaceae family, spreading in Eskişehir and its surroundings, were collected from natural habitats and evaluated in terms of antimicrobial and antibiofilm activities. In biological activity studies, different concentrations of three plant extracts showed various antimicrobial and antibiofilm activities on selected standard microorganism cultures (Staphylococcus aureus ATCC 29213, Staphylococcus epidermidis ATCC 14990, Pseudomonas aeruginosa ATCC 27853, Candida albicans ATCC 90028, and Candida krusei ATCC 6258). It was observed that the selected three endemic Verbascum extracts had a minimum inhibitory and minimum biofilm eradication concentration value of 1250 μg/mL.

Plants have been widely used as a pharmaceutical to treat diseases in many cultures for centuries. In vitro biological activities of some plants consumed as food and used in traditional medicine in Southwestern Anatolia have been reported. The present study focused on the antimicrobial, antibiofilm, antioxidant, and quorum sensing (QS) inhibitory activities of aqueous and ethanolic extracts of aerial parts of Scandix pecten-veneris L., Artedia squamata L., Oenanthe pimpinelloides L. The antimicrobial activity was evaluated against fifteen bacteria and one yeast using disc diffusion and microdilution methods. The aqueous and ethanol extracts of A. squamata showed the highest activity against Staphylococcus aureus MU 47 with 20 and 23 mm zone diameters, respectively. The ethanol extract of S. pecten-veneris inhibited Staphylococcus aureus ATCC 25923 at a 5 mg/mL MIC value. The aqueous extract of O. pimpinelloides inhibited biofilm formation of S. aureus MU 40, P. aeruginosa ATCC 27853, and C. albicans ATCC 10239 at MIC value. All extracts displayed violacein inhibition against Chromobacterium violaceum CV12472 in the concentration range of 1.25 mg/mL to 25 mg/mL. The aqueous extract of A. squamata showed valuable anti-quorum sensing (anti-QS) activity with a pigment inhibition zone of 17 mm on Chromobacterium violaceum CV026. The aqueous extract of S. pecten-veneris inhibited the swarming motility of Pseudomonas aeruginosa PA01 by 47.6%. The aqueous and ethanol extracts of A. squamata indicated the best antioxidant activity. It was proved that these edible plant extracts could be used as natural alternative inhibitors to control microbial pathogenesis and diseases.

Introduction: One effective method to combat bacterial infections is by using bacteria itself as a weapon. Lactobacillus is a type of fermenting bacterium that has probiotic properties and has demonstrated antimicrobial benefits against other bacteria. Cyclodipeptides (CDPs), present in the supernatant of Lactobacillus, possess several antimicrobial properties. Methods: In this study, the CDP fraction was isolated from the supernatant of Lactobacillus plantarum (L. plantarum). This fraction was then loaded onto graphene oxide nanosheets (GO NSs). The study assessed the substance’s ability to inhibit bacterial growth by using the minimum inhibitory concentration (MIC) method on A. baumannii and S. aureus strains that were obtained from clinical samples. To determine the substance’s impact on biofilm formation, the microtiter plate method was used. Moreover, the checkerboard technique was employed to explore the potential synergistic effects of these two substances. Results and discussion: According to the study, the minimum inhibitory concentration (MIC) of the desired compound was found to be 1.25  mg/ mL against S. aureus and 2.5  mg/mL against A. baumannii. Furthermore, at a concentration of 10  mg/mL, the compound prevented 81.6% (p  <  0.01) of biofilm production in A. baumannii, while at a concentration of 1.25  mg/mL, it prevented 47.5% (p  <  0.05) of biofilm production in S. aureus. The study also explored the synergistic properties of two compounds using the checkerboard method. Conclusion: In general, we found that GO NSs possess antimicrobial properties and enhance cyclodipeptides’ activity against S. aureus and A. baumannii. [ABSTRACT FROM AUTHOR]

An in‐depth investigation was conducted on a promising composite material (BiVO4/TiO2), focusing on its potential toxicity, photoinduced catalytic properties, as well as its antibiofilm and antimicrobial functionalities. The preparation process involved the synthesis of 2D TiO2 using the lyophilization method, which was subsequently functionalized with sphere‐like BiVO4 through wet impregnation. Finally, we developed BiVO4/TiO2 S‐scheme heterojunctions which can greatly promote the separation of electron‐hole pairs to achieve high photocatalytic performance. The evaluation of concentration‐ and time‐dependent viability inhibition was performed on human lung carcinoma epithelial A549 cells. This assessment included the estimation of glutathione levels and mitochondrial dehydrogenase activity. Significantly, the BiVO4/TiO2 composite demonstrated minimal toxicity towards A549 cells. Impressively, the BiVO4/TiO2 composite exhibited notable photocatalytic performance in the degradation of rhodamine B (k=0.135 min−1) and phenol (k=0.016 min−1). In terms of photoinduced antimicrobial performance, the composite effectively inactivated both gram‐negative E. coli and gram‐positive E. faecalis bacteria upon 60 minutes of UV‐A light exposure, resulting in a significant log 6 (log 10 CFU/mL) reduction in bacterial count. In addition, a 49 % reduction of E. faecalis biofilm was observed. These promising results can be attributed to the unique 2D morphology of TiO2 modified by sphere‐like BiVO4, leading to an increased generation of (intracellular) hydroxyl radicals, which plays a crucial role in the treatments of both organic pollutants and bacteria. This research has significant potential for various applications, particularly in addressing environmental contamination and microbial infections. [ABSTRACT FROM AUTHOR]

The emerging field of green synthesis within nanobiotechnology presents significant environmental and economic advantages compared to conventional methodologies. This study investigates the synthesis and application of chitosan nanoparticles (ChNPs) using Cassia fistula (CF) leaf extract as a sustainable, and bio-based approach. Characterization of CF-ChNPs confirmed effective bioconversion and also demonstrated significant antimicrobial activity. Notably, CF-ChNPs demonstrated a remarkable antimicrobial effect against Pseudomonas aeruginosa, with a zone of inhibition of 17 ± 0.2 mm surpassing the impact on other organisms tested. The CF-ChNPs exhibited an initial burst release of 28 ± 0.28% after 2 h, gradually achieving a controlled release of 76.3 ± 0.43% within 24 h. In addition, CF-ChNPs exhibited an antioxidant activity of 43.1 ± 0.48% and showed excellent antibiofilm activity against Staphylococcus aureus in comparison to other organisms. The cell viability assay results have confirmed that CF-ChNPs do not have any negative impact on the viability of L929 fibroblasts, further highlighting their potential as versatile nanomaterials for treating microbial infections and other therapeutic applications. [ABSTRACT FROM AUTHOR]

The consumption of traditional medicinal herbs has gained popularity as a viable alternative approach for addressing microbial infections or infectious structures. In this study, Verbascum detersile, Verbascum eskisehirensis, and Verbascum gypsicola endemic species belonging to the Scrophulariaceae family, spreading in Eskişehir and its surroundings, were collected from natural habitats and evaluated in terms of antimicrobial and antibiofilm activities. In biological activity studies, different concentrations of three plant extracts showed various antimicrobial and antibiofilm activities on selected standard microorganism cultures (Staphylococcus aureus ATCC 29213, Staphylococcus epidermidis ATCC 14990, Pseudomonas aeruginosa ATCC 27853, Candida albicans ATCC 90028, and Candida krusei ATCC 6258). It was observed that the selected three endemic Verbascum extracts had a minimum inhibitory and minimum biofilm eradication concentration value of 1250 µg/mL. [ABSTRACT FROM AUTHOR]

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Nanoparticles play a crucial role in the field of nanotechnology, offering different properties due to their surface area attributed to their small size. Among them, silver nanoparticles (AgNPs) have attracted significant attention due to their antimicrobial properties, with applications that date back from ancient medicinal practices to contemporary commercial products containing ions or silver nanoparticles. AgNPs possess broad-spectrum biocidal potential against bacteria, fungi, viruses, and Mycobacterium, in addition to exhibiting synergistic effects when combined with certain antibiotics. The mechanisms underlying its antimicrobial action include the generation of oxygen-reactive species, damage to DNA, rupture of bacterial cell membranes and inhibition of protein synthesis. Recent studies have highlighted the effectiveness of AgNPs against various clinically relevant bacterial strains through their potential to combat antibioticresistant pathogens. This review investigates the proteomic mechanisms by which AgNPs exert their antimicrobial effects, with a special focus on their activity against planktonic bacteria and in biofilms. Furthermore, it discusses the biomedical applications of AgNPs and their potential non-preparation of antibiotic formulations, also addressing the issue of resistance to antibiotics. [ABSTRACT FROM AUTHOR]

The emergence of biofilm-induced drug tolerance poses a critical challenge to public healthcare management. Pseudomonas aeruginosa, a gram-negative opportunistic bacterium, is involved in various biofilm-associated infections in human hosts. Towards this direction, in the present study, a combinatorial approach has been explored as it is a demonstrably effective strategy for managing microbial infections. Thus, P. aeruginosa has been treated with cuminaldehyde (a naturally occurring phytochemical) and gentamicin (an aminoglycoside antibiotic) in connection to the effective management of the biofilm challenges. It was also observed that the test molecules could show increased antimicrobial activity against P. aeruginosa. A fractional inhibitory concentration index (FICI) of 0.65 suggested an additive interaction between cuminaldehyde and gentamicin. Besides, a series of experiments such as crystal violet assay, estimation of extracellular polymeric substance (EPS), and microscopic images indicated that an enhanced antibiofilm activity was obtained when the selected compounds were applied together on P. aeruginosa. Furthermore, the combination of the selected compounds was found to reduce the secretion of virulence factors from P. aeruginosa. Taken together, this study suggested that the combinatorial application of cuminaldehyde and gentamicin could be considered an effective approach towards the control of biofilm-linked infections caused by P. aeruginosa. [ABSTRACT FROM AUTHOR]

The wound management field faces significant challenges due to antimicrobial resistance (AMR) and the complexity of chronic wound care. Effective wound treatment requires antimicrobial dressings to prevent bacterial infections. However, the rise of AMR necessitates new antimicrobial agents for wound dressings, particularly for addressing bacterial pathogens like methicillin-resistant Staphylococcus aureus (MRSA). Endophytic fungi, known for producing diverse bioactive compounds, represent a promising source of such new agents. This study tested thirty-two endophytic fungi from thirteen distinct Australian native plants for their antibacterial activity against S. aureus. Ethyl acetate (EtOAc) extracts from fungal culture filtrates exhibited inhibitory effects against both methicillin-sensitive S. aureus ATCC 25923 (MIC = 78.1 µg/mL) and MRSA M180920 (MIC = 78.1 µg/mL). DNA sequence analysis was employed for fungal identification. The most active sample, EL 19 (Chaetomium globosum), was selected for further analysis, revealing that its EtOAc extracts reduced S. aureus ATCC 25923 biofilm formation by 55% and cell viability by 57% to 68% at 1 2 × MIC. Furthermore, cytotoxicity studies using the brine shrimp lethality test demonstrated low cytotoxicity up to 6 × MIC (25% mortality rate) with an LC50 value of 639.1 µg/mL. Finally, the most active sample was incorporated into polycaprolactone (PCL) fiber mats via electrospinning, with resultant inhibition of S. aureus species. This research underscores the potential of endophytic fungi from Australian plants as sources of substances effective against common wound pathogens. Further exploration of the responsible compounds and their mechanisms could facilitate the development of wound dressings effective against MRSA and innovative biofilm-resistant electrospun fibers, contributing to the global efforts to combat AMR. [ABSTRACT FROM AUTHOR]

Public health is facing a worldwide challenge due to the emergence of multiple antibiotic resistance in ESKAPE (Enterococcus faecalis, Staphylococcus aureus, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, and Escherichia coli) infections. The natural antimicrobial nature of bee venoms makes them promising antimicrobial candidates against antibiotic-resistant pathogens. In this study, melittin and apamin bee venoms were investigated to generate novel antimicrobial agents effective against ESKAPE microorganisms. The antimicrobial and antibiofilm activities of melittin and apamin synthesized from endemic Apis mellifera L. bee venom were tested against ESKAPE microorganisms using minimal inhibition, minimal bactericidal inhibition and time-kill curve methods. The in-vitro cytotoxicity effect of melittin and apamin for L929 fibroblast cells was also examined. Synthesized melittin and apamin (0.78-600 μg/mL) were antimicrobial against ESKAPE pathogens. Time-kill curve studies confirmed the growth retardation effect and bactericidal activity of melittin and apamin. Antibiofilm studies also showed that melittin and apamin significantly (melittin 8%-82%, apamin 1.8%-78%) inhibited the biofilm formed by ESKAPE pathogens. Melittin and apamin were not cytotoxic to L929 fibroblast cells. We found that melittin and apamin have high antibacterial properties. These naturally synthesized bee venoms offer a promising powerful solution to fight various pathogens. [ABSTRACT FROM AUTHOR]

A novel lactone derivative, named Streptolactone A (1), was unearthed from Streptomyces sp. A31 isolated from marine sediments. Its structure was elucidated through a comprehensive analysis of 1D, 2D NMR, and HRESIMS data. Assessment of its antibiofilm and antibacterial effects against P. aeruginosa was conducted via the microdilution and crystal violet staining method, revealing Streptolactone A's notable potency in inhibiting biofilm formation. [ABSTRACT FROM AUTHOR]

IntroductionDental caries, caused by oral microbial pathogens, are a global health concern, further exacerbated by the presence of methicillin-resistant Staphylococcus aureus (MRSA). Bioactive proteins and peptides (BAPs) exhibit potent antimicrobial properties, targeting multiple cellular mechanisms within pathogens, reducing the likelihood of resistance development. Given the antimicrobial potential of BAPs, this study aimed to compare the efficacy of BAPs extracted from cultivated (Pleurotus ostreatus, PoC) and wild (Pleurotus ostreatus, PoW) mushrooms against pathogens responsible for dental caries.MethodsBAPs were extracted from both PoC and PoW using a TCA-acetone method. Antimicrobial activities were tested against seven bacteria and one fungus using agar well diffusion and MIC determination. Antibiofilm activity was assessed via modified CV assay, while DPPH and erythrocyte lysis tests evaluated free radical scavenging.ResultsPoC showed superior antimicrobial efficacy, with lower MIC and MBC values, and disrupted biofilm integrity at increasing concentrations. PoW exhibited better antioxidant activity with higher DPPH scavenging, though its antimicrobial efficacy was slightly lower than PoC.DiscussionBoth PoC and PoW BAPs inhibited dental pathogens, with PoC showing stronger inhibition against MRSA and nystatin-resistant Candida albicans. This suggests BAPs may target additional cellular mechanisms beyond membranes, PBPs, and ergosterols. Despite PoW’s stronger antioxidant properties, both BAPs had comparable antibiofilm activity. These findings suggest complementary actions of BAPs from PoC and PoW both, in treating dental caries, offering broad-spectrum antimicrobial and antioxidant benefits.

Abstract Scientists know very little about the mechanisms underlying fish skin mucus, despite the fact that it is a component of the immune system. Fish skin mucus is an important component of defence against invasive infections. Recently, Fish skin and its mucus are gaining interest among immunologists. Characterization was done on the obtained silver nanoparticles Ag combined with Clarias gariepinus catfish epidermal mucus proteins (EMP-Ag-NPs) through UV–vis, FTIR, XRD, TEM, and SEM. Ag-NPs ranged in size from 4 to 20 nm, spherical in form and the angles were 38.10°, 44.20°, 64.40°, and 77.20°, Where wavelength change after formation of EMP-Ag-NPs as indicate of dark brown, the broad band recorded at wavelength at 391 nm. Additionally, the antimicrobial, antibiofilm and anticancer activities of EMP-Ag-NPs was assessed. The present results demonstrate high activity against unicellular fungi C. albicans, followed by E. faecalis. Antibiofilm results showed strong activity against both S. aureus and P. aeruginosa pathogens in a dose-dependent manner, without affecting planktonic cell growth. Also, cytotoxicity effect was investigated against normal cells (Vero), breast cancer cells (Mcf7) and hepatic carcinoma (HepG2) cell lines at concentrations (200–6.25 µg/mL) and current results showed highly anticancer effect of Ag-NPs at concentrations 100, 5 and 25 µg/mL exhibited rounding, shrinkage, deformation and granulation of Mcf7 and HepG2 with IC50 19.34 and 31.16 µg/mL respectively while Vero cells appeared rounded at concentration 50 µg/mL and normal shape at concentration 25, 12.5 and 6.25 µg/ml with IC50 35.85 µg/mL. This study evidence the potential efficacy of biologically generated Ag-NPs as a substitute medicinal agent against harmful microorganisms. Furthermore, it highlights their inhibitory effect on cancer cell lines.

Abstract Honey produced by stingless bees (Tribe: Meliponini) is well‐known for their medicinal and antimicrobial properties from their diverse content of bioactive compounds. However, it has not been possible to fully characterize its active principles. The present systematic review is based on 117 full‐text articles. Our review highlights (1) the need to apply complementary methodologies and consolidate protocols to quantify antimicrobial activity (2) to characterize antimicrobial agents in honeys of Heterotrigona itama, Tetragonisca angustula, and Melipona beecheii, and; (3) to search for compounds against multidrug‐resistant and/or biofilm‐forming pathogens. Moreover, we performed a meta‐analysis of 29 articles with quantitative data using diffusion assays and minimum inhibitory concentration (MIC). Staphylococcus aureus and Escherichia coli were the most evaluated pathogens, evidencing 221 and 149 antimicrobial activity assays against honey samples of 36 and 24 stingless bee species, respectively. The highest pooled mean in diffusion assays against S. aureus showed a difference between methicillin‐resistant S. aureus (MRSA) and non‐MRSA strains {14.43 [95% confidence interval (CI): 12.16–16.71] mm vs. 11.55 (95% CI: 10.22–12.87) mm}, whereas E. coli showed pooled means of 9.09 (95% CI: 7.93–10.25) mm. Regarding MIC expressed as volume/volume percentage (%, v/v), the estimated inhibitory concentrations were 7.89 (95% CI: 3.94–11.83) mL/100 mL for MRSA and 5.60 (95% CI: 2.66–8.55) mL/100 mL considering all S. aureus strains. In contrast, the estimated MICs as weight/volume percentage (%, w/v) showed 15.00 [(95% CI: 12.84–17.16) g/100 mL for S. aureus and 16.17 (95% CI: 5.78–26.55) g/100 mL for E. coli. However, honey remains an unexplored source of antimicrobial molecules.

Nanoparticles have drawn significant interest in a range of applications, ranging from biomedical to environmental sciences, due to their distinctive physicochemical characteristics. In this study, it was reported that simple biological production of Ag, Se, and bimetallic Ag2Se nanoparticles (NPs) with Pseudomonas aeruginosa is a promising, low-cost, and environmentally friendly method. For the first time in the scientific literature, Ag2Se nanoparticles have been generated via green bacterial biosynthesis. UV-vis spectroscopy, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), transmission electron microscopy (TEM), scanning electron microscopy (SEM), and EDX were used to characterize the produced NPs. Biosynthesized NPs were examined for antibacterial, antibiofilm, and photocatalytic properties, and it was determined that the effects of NPs were dose dependent. The biosynthesized AgNPs, SeNPs, and Ag2Se NPs showed anti-microbial activity against Escherichia coli and Staphylococcus aureus. Minimal inhibitory concentrations (MICs) of E. coli and S. aureus were between 150 and 250 µg/mL. The NPs showed antibiofilm activity against E. coli and S. aureus at sub-MIC levels and reduced biofilm formation by at least 80% at a concentration of 200 µg/mL of each NPs. To photocatalyze the breakdown of Congo red, Ag, Se, and Ag2Se NPs were utilized, and their photocatalytic activity was tested at various concentrations and intervals. A minor decrease of photocatalytic degradation was detected throughout the NPs reuse operation (five cycles). Based on the encouraging findings, the synthesized NPs demonstrated antibacterial, antibiofilm, and photocatalytic properties, suggesting that they might be used in pharmaceutical, medical, environmental, and other applications. [ABSTRACT FROM AUTHOR]

Scientists know very little about the mechanisms underlying fish skin mucus, despite the fact that it is a component of the immune system. Fish skin mucus is an important component of defence against invasive infections. Recently, Fish skin and its mucus are gaining interest among immunologists. Characterization was done on the obtained silver nanoparticles Ag combined with Clarias gariepinus catfish epidermal mucus proteins (EMP-Ag-NPs) through UV–vis, FTIR, XRD, TEM, and SEM. Ag-NPs ranged in size from 4 to 20 nm, spherical in form and the angles were 38.10°, 44.20°, 64.40°, and 77.20°, Where wavelength change after formation of EMP-Ag-NPs as indicate of dark brown, the broad band recorded at wavelength at 391 nm. Additionally, the antimicrobial, antibiofilm and anticancer activities of EMP-Ag-NPs was assessed. The present results demonstrate high activity against unicellular fungi C. albicans, followed by E. faecalis. Antibiofilm results showed strong activity against both S. aureus and P. aeruginosa pathogens in a dose-dependent manner, without affecting planktonic cell growth. Also, cytotoxicity effect was investigated against normal cells (Vero), breast cancer cells (Mcf7) and hepatic carcinoma (HepG2) cell lines at concentrations (200–6.25 µg/mL) and current results showed highly anticancer effect of Ag-NPs at concentrations 100, 5 and 25 µg/mL exhibited rounding, shrinkage, deformation and granulation of Mcf7 and HepG2 with IC50 19.34 and 31.16 µg/mL respectively while Vero cells appeared rounded at concentration 50 µg/mL and normal shape at concentration 25, 12.5 and 6.25 µg/ml with IC50 35.85 µg/mL. This study evidence the potential efficacy of biologically generated Ag-NPs as a substitute medicinal agent against harmful microorganisms. Furthermore, it highlights their inhibitory effect on cancer cell lines. [ABSTRACT FROM AUTHOR]

Growing resistance to antimicrobials, combined with pathogens that form biofilms, presents significant challenges in healthcare. Modifying current antimicrobial agents is an economical approach to developing novel molecules that could exhibit biological activity. Thus, five sulfanilamide Schiff bases were synthesized under microwave irradiation and characterized spectroscopically and in silico. They were evaluated for their antimicrobial and antibiofilm activities against both Gram-positive and Gram-negative bacterial strains. Their cytotoxic potential against two cancer cell lines was also determined. Gram-positive bacteria were susceptible to the action of these compounds. Derivatives 1b and 1d inhibited S. aureus's growth (MIC from 0.014 mg/mL) and biofilm (IC from 0.029 mg/mL), while compound 1e was active against E. faecalis's planktonic and sessile forms. Two compounds significantly reduced cell viability at 5 μg/mL after 24 h of exposure (1d—HT-29 colorectal adenocarcinoma cells, 1c—LN229 glioblastoma cells). A docking study revealed the increased binding affinities of these derivatives compared to sulfanilamide. Hence, these Schiff bases exhibited higher activity compared to their parent drug, with halogen groups playing a crucial role in both their antimicrobial and cytotoxic effects. [ABSTRACT FROM AUTHOR]

In this study, a graphene oxide material was fabricated using the Hummers process. RGO, ZnO, ZnO:B and RGO/ZnO:B nanoparticles were synthesized by the hydrothermal method in an autoclave at a temperature of 160 °C. The structural and morphological changes in the synthesized ZnO nanomaterials were investigated by preparing composite materials with a boron additive and RGO. The prepared nanoparticles were characterized by X-ray diffraction (XRD) and scanning electron microscopy (SEM). Antimicrobial and antibiofilm assays were performed to evaluate the biological activities of the synthesized nanoparticles. The antimicrobial activity of these NPs was investigated against Escherichia coli, Pseudomonas aeruginosa, Staphylococcus aureus, Bacillus cereus, Enterococcus faecalis and Staphylococcus epidermidis pathogenic bacteria. Among the nanoparticles tested, ZnO and ZnO:B NPs showed strong antimicrobial activity against clinically important E. coli, P. aeruginosa and B. cereus strains. The antibiofilm activity of the synthesized nanoparticles was determined using E. coli and P. aeruginosa strains. The biofilm inhibition of both strains by the ZnO:B nanocomposites was greater than that by the other nanocomposites. At a concentration of 20 mg/mL, the ZnO:B nanocomposite showed 42.13% biofilm inhibition of E. coli and 36.21% biofilm inhibition of P. aeruginosa. The RGO/ZnO:B nanocomposite had a specific inhibitory effect on E. coli (34.25%) and P. aeruginosa (30.16%). The antibiofilm effect of the nanocompounds used in the study was greater on E. coli than on P. aeruginosa. As a result, the synthesized boron-reinforced ZnO nanocomposites exhibited strong biological effects. These results will provide valuable information for the development of new treatment regimens for the inactivation of pathogenic bacteria. [ABSTRACT FROM AUTHOR]

IntroductionOne effective method to combat bacterial infections is by using bacteria itself as a weapon. Lactobacillus is a type of fermenting bacterium that has probiotic properties and has demonstrated antimicrobial benefits against other bacteria. Cyclodipeptides (CDPs), present in the supernatant of Lactobacillus, possess several antimicrobial properties.MethodsIn this study, the CDP fraction was isolated from the supernatant of Lactobacillus plantarum (L. plantarum). This fraction was then loaded onto graphene oxide nanosheets (GO NSs). The study assessed the substance’s ability to inhibit bacterial growth by using the minimum inhibitory concentration (MIC) method on A. baumannii and S. aureus strains that were obtained from clinical samples. To determine the substance’s impact on biofilm formation, the microtiter plate method was used. Moreover, the checkerboard technique was employed to explore the potential synergistic effects of these two substances.Results and discussionAccording to the study, the minimum inhibitory concentration (MIC) of the desired compound was found to be 1.25 mg/mL against S. aureus and 2.5 mg/mL against A. baumannii. Furthermore, at a concentration of 10 mg/mL, the compound prevented 81.6% (p

Nanoparticles play a crucial role in the field of nanotechnology, offering different properties due to their surface area attributed to their small size. Among them, silver nanoparticles (AgNPs) have attracted significant attention due to their antimicrobial properties, with applications that date back from ancient medicinal practices to contemporary commercial products containing ions or silver nanoparticles. AgNPs possess broad-spectrum biocidal potential against bacteria, fungi, viruses, and Mycobacterium, in addition to exhibiting synergistic effects when combined with certain antibiotics. The mechanisms underlying its antimicrobial action include the generation of oxygen-reactive species, damage to DNA, rupture of bacterial cell membranes and inhibition of protein synthesis. Recent studies have highlighted the effectiveness of AgNPs against various clinically relevant bacterial strains through their potential to combat antibiotic-resistant pathogens. This review investigates the proteomic mechanisms by which AgNPs exert their antimicrobial effects, with a special focus on their activity against planktonic bacteria and in biofilms. Furthermore, it discusses the biomedical applications of AgNPs and their potential non-preparation of antibiotic formulations, also addressing the issue of resistance to antibiotics.

Introduction: , renowned for its exceptional multidrug resistance and its role as a prevalent nosocomial pathogen, poses a formidable challenge to conventional antibiotic therapies. The primary objective of this investigation was to evaluate the efficacy of Secapin, an antimicrobial peptide, against multidrug-resistant (MDR) . Furthermore, the mechanisms underlying Secapin’s antibacterial and antibiofilm activities were elucidated.Methods: The antimicrobial and antibiofilm effectiveness of Secapin against MDR was assessed through a series of experiments. The minimum inhibitory concentration (MIC) and minimum bactericidal concentration (MBC) of Secapin were determined using established protocols. Time-kill kinetic analysis was performed to assess the concentration-dependent bactericidal effect of Secapin. Additionally, the capacity of Secapin to impede biofilm formation and eradicate biofilms was investigated. Hemolytic potential was evaluated using human red blood cells, while mammalian cell viability was examined at varying Secapin concentrations.Results: Secapin exhibited robust bactericidal activity at minimal concentrations, with an MIC of 5 µg/mL and an MBC of 10 µg/mL against MDR . The time-kill kinetic analysis confirmed the concentration-dependent efficacy of Secapin in diminishing bacterial viability. Moreover, Secapin demonstrated the ability to prevent biofilm formation and eliminate established biofilms. Notably, Secapin exhibited no hemolytic activity and preserved mammalian cell viability up to a concentration of 100 µg/mL.Conclusion: These findings underscore the substantial potential of apin as a potent agent against multidrug-resistant , showcasing its efficacy in both antibacterial and antibiofilm capacities. The favorable attributes of Secapin, characterized by its minimal hemolytic effects and high mammalian cell viability, position it as a promising contender in the fight against antibiotic resistance.

Abstract Background Natural products are one of the best candidates for controlling drug-resistant pathogens, the advantages of which include low production costs and low side effects. In this study, as potential antimicrobials, the anti-bacterial and antibiofilm activities of several Iranian native medicinal plants were screened. Methods The antibacterial/antifungal and anti-biofilm activities of 18 medicinal plants including Reseda lutea L., Nepeta sintenisii Bunge., Stachys turcomanica Trautv., Stachys lavandulifolia Vahl, Diarthron antoninae (Pobed.) Kit Tan., Ziziphora clinopodioides Lam., Euphorbia kopetdaghi Prokh, Euphorbia serpens Kunth., Hymenocrater calycinus Benth., Scutellaria pinnatifida A.Ham., Viola tricolor L., Hypericum helianthemoides (Spach) Boiss., Hypericum scabrum L., Convolvulus lineatus L., Scabiosa rotata M.Bieb Greuter & Burdet, Delphinium semibarbatum Bien. Ex Boiss., Glycyrrhiza triphylla Fisch. & C.A.Mey., and Ziziphus jujuba Mill., against two Gram-positive bacteria, Staphylococcus aureus, Bacillus cereus, as well as two Gram-negative bacteria, Pseudomonas aeruginosa, Escherichia coli; and Candida albicans as a fungal strain, were evaluated. The minimum inhibitory concentration (MIC) and minimum bactericidal/fungicidal concentration (MBC/MFC) values of the extracts against tested microorganisms were reported and we investigated their effect on the biofilm inhibition of Pseudomonas aeruginosa PAO1, Staphylococcus epidermis, Staphylococcus aureus and Streptococcus mutans. In addition, the effect of the extracts on the eradication of the biofilms of these bacteria was evaluated. Results In this study, H. scabrum was found to exhibit potentially significant activity against Gram-positive bacteria with the MIC range of 6.25–25 µg/mL. This extract also showed a significant effect on inhibiting the biofilm of S. aureus, S. mutans, and S. epidermidis and eradicating the biofilm of S. epidermidis DSMZ 3270. In addition, Hymenocrater calycinus root extract had moderate antibacterial activity against B. cereus with the MIC and MBC 62.5 µg/mL, respectively. Conclusions The results of this study showed that the root extracts of two plants, Hypericum scabrum and Hymenocrater calycinus, had antimicrobial and anti-biofilm effects. Based on the observed anti-biofilm effects, these two plants may be considered in future studies to find responsible antimicrobial compounds.

The N,N',N''-trisubstituted hexahydro-1,3,5-triazine derivatives (3a–g) had been created and identified through infrared, nuclear magnetic resonance, and mass spectrometry according to their symmetric basic structure. Three molecules of diverse aromatic amines and three molecules of formaldehyde were assembled in a "1+1+1+1+1+1" condensation reaction to produce hexahydrotriazines. Two Gram-positive (Staphylococcus aureus, Staphylococcus epidermidis) and two Gram-negative (Klebsiella pneumonia, Pseudomonas aeruginosa) bacteria were used to evaluate the antimicrobial activity of the produced compounds. The anti-biofilm activity of 3g against S. aureus was also examined. In this investigation, glucosamine-6-phosphate synthase was employed to investigate the binding affinity of 3g within the enzyme's binding site. The results demonstrated that most of the synthesized hexahydro-1,3,5-triazine compounds have mild antimicrobial effects in comparison with the commonly used drug ampicillin, whereas the compounds 3g are potentially anti-biofilm agents. Molecular docking with the Autodock 4.2 tool was applied to study the binding affinity. It was found to hit (3g) in the active center of glucosamine-6-phosphate synthase as the target enzyme for antimicrobial agents. In silico studies reveal that the discovered hit is a promising glucosamine-6-phosphate inhibitor, as well as that the docking data matched up to the in vitro assay.

Abstract The growing spread of infectious diseases has become a potential global health threat to human beings. According to WHO reports, in this study, we investigated the impact of co-cultivating the isolated endophytic fungus Aspergillus sp. CO2 and Bacillus sp. COBZ21 as a method to stimulate the production of natural bioactive substances. (GC/MS)-based metabolomics profiling of two sponge-associated microbes, Aspergillus sp. CO2 and Bacillus sp. COBZ21, revealed that the co-culture of these two isolates induced the accumulation of metabolites that were not traced in their axenic cultures. By detection of different activities of extracts of Bacillus sp. COBZ21 and Aspergillus sp. CO2 and coculture between Bacillus sp. COBZ21 and Aspergillus sp. CO2. It was noted that the coculture strategy was the reason for a notable increase in some different activities, such as the antimicrobial activity, which showed potent activity against Escherichia coli ATCC 25,922, Staphylococcus aureus NRRLB-767, and Candida albicans ATCC 10,231. The antibiofilm activity showed significant biofilm inhibitory activity toward Bacillus subtilis ATCC 6633, Pseudomonas aeruginosa ATCC 10,145, and Staph aureus NRRLB-767, with activity up to 53.66, 71.17, and 47.89%, while it showed low activity against E. coli ATCC 25,922, while the antioxidant activity based on the DPPH assay showed maximum activity (75.25%). GC-MS investigations revealed the presence of variable chemical constituents belonging to different chemical categories, which reflected their chemical diversity. The main components are (+-) cis-Deethylburnamine (2.66%), Bis(3,6,9,12-tetraoxapentaethylene) crowno-N,N,N’,N’-tetra methylpphanediamine (2.48%), and 11-phenyl-2,4,6,8-tetra(2-thienyl)-11-aza-5,13-dithiaeteracyclo[7.3.0.1(2,8)0.0(3,7)] trideca-3,6-diene-10,12,13-trione (3.13%), respectively, for Bacillus sp. axenic culture, Aspergillus sp. CO2, Aspergillus sp. CO2, and Bacillus sp. COBZ21 coculture. By studying the ADME-related physicochemical properties of coculture extract, the compound showed log P o/w values above 5 (8.82). The solubility of the substance was moderate. In order to provide a comprehensive definition of medicinal chemistry and leadlikness, it is important to note that the latter did not meet the criteria outlined in the rule of three (RO3). The toxicity prediction of the coculture extract was performed using the ProTox II web server, which showed that the selected compound has no pronounced toxicity.