Antimicrobial Effects Research Articles

Innovative S-Scheme heterojunctions: Boosting methylene blue degradation and antimicrobial efficacy with Ni–CoS@S-g-C3N4

The release of waste, including organic dyes from various industries, directly into water bodies significantly contributes to environmental pollution. Consequently, there is a need for photocatalytic materials that can effectively remove harmful pollutants from water, ensuring its purity and safety. Carbon-based photocatalysts have garnered significant attention in this context because of their exceptional stability, high conductivity, and very small band gap. In the current project, a series of CoS, Ni–CoS, and Ni–CoS/S-g-C3N4 with different concentrations of S-g-C3N4 were synthesized using a simple, efficient, and cost-effective co-precipitation technique, while S-g-C3N4 was constructed through a thermal degradation process using thiourea as a precursor. The produced photocatalysts underwent characterization utilizing sophisticated analytical methods including FTIR, XRD, SEM, and EDX. The photocatalytic degradation behavior of the prepared photocatalysts was assessed using a UV–visible spectrophotometer, and the doping of Ni-metal was found to significantly enhance the degradation rate of methylene blue (MB), a standard pollutant dye in the order of CoS < %8Ni–CoS <8%Ni–CoS@50 % S-g-C3N4.the maximum photocatalytic degradation was shown by the nanocomposites (8%Ni–CoS@50 % S-g-C3N4) i.e. 94 %. The EIS spectra for CoS, 8 % Ni–CoS, and Ni–CoS/50 % SCN were analyzed, and their antimicrobial effectiveness was evaluated.

Identification and Disinfection Treatment Technology of a New Guangdong Choy Sum Disease

Seed-borne diseases cause significant economic losses in modern agriculture. The use of large amounts of chemical pesticides to control seed-borne diseases also results in negative consequences such as environmental pollution and pesticide residue in agricultural products. This has generated great interest among scholars in detecting and controlling seed-borne diseases. This study screened and isolated a new pathogenic fungus, Penicillium decumbens, from three Guangdong choy sum varieties. The virulence test showed that it inhibited seed germination rate by 40% and germination vigor by 50%. The conventional seed disinfectants (Thiram WP) did not completely eliminate the pathogenic bacteria. A comparative study of nine seed disinfectants revealed that 50% Carbendazim WP, 80% Thiram WP, 15% Carbendazim+15% Thiram WP, and 45% Prochloraz EW exhibited significant fungicidal effects against Penicillium decumbents infection in Guangdong choy sum seeds. Based on comprehensive indicators including germination rate, germination vigor, and root length after disinfection treatment, the most effective disinfectant was 45% Prochloraz EW with a sterilization effect of 100%, an increase in germination vigor by 37.5%, and an increase in germination rate by 27.9%.

Synthesis, Characterization, Biological Evaluation, DFT, and Molecular Docking Study of a Co(II) Complex Derived from ON Donor Bidentate Schiff Base Ligand

AbstractThe utilization of biologically active metal complexes in medicine is gaining recognition as an alternative approach to traditional biologically active organic molecules, which often exhibit undesirable side effects. This study focuses on the synthesis and characterization of a Co(II) complex derived from the (E)‐2‐((2‐hydroxybenzylidene)amino)‐5‐methylbenzonitrile ligand system (HL) and cobalt(II) acetate tetrahydrate in a dichloromethane/methanol solution. A comprehensive characterization strategy was employed, involving proton and carbon nuclear magnetic resonance, infrared, electronic spectra, PXRD, SEM‐EDX, and mass spectroscopies, as well as elemental analysis (CHN and Co), TGA, and molar conductance, to confirm the chemical structures of the ligand and its complex. The infrared spectral data revealed the ligand as a bidentate ligand, chelating the Co(II) ion through the oxygen and nitrogen atoms of the phenolate and imine groups. Additionally, PXRD and SEM analyses indicated crystalline and amorphous properties for the ligand and complex, respectively. Assessment of antimicrobial potential using a modified disc diffusion method, with streptomycin as the positive control, demonstrated the complex's enhanced antibacterial activity compared to the ligand against all tested bacteria, showing a concentration‐dependent response. Similarly, antioxidant studies revealed promising results, with the complex exhibiting superior DPPH radical scavenging activity (IC50 values: ligand 64.5 μg.mL−1, complex 43.1 μg.mL−1). Theoretical analysis through DFT calculations and molecular docking provided insights into the electronic properties and binding affinity of the ligand and complex, supporting the experimental findings and affirming the biological activities exhibited by the compounds. Overall, this research showcases the synthesis, characterization, and biological evaluation of a promising Co(II) complex, highlighting its potential as an effective antimicrobial and antioxidant agent.

Introduction of Honeycomb (Nidus Vespae) and Some of Its Most Important Pharmacological Benefits

Background:: Nidus Vespae (honeycomb), which is a well-known traditional Chinese medicine, is the honey-comb of Polistes japonicus Saussure, Parapolybia varia Fabricius, or Polistes olivaceus (De Geer), and it is usually harvest in winter and autumn. Methods: Its chemical component is completely complex combining honey, pollen, royal jelly, and propolis and consequently has a significant number of bioactive components such as nitro compounds, flavonoids, and polyphenols. It has shown various pharmacological impacts, such as anti-inflammatory, anti-viral, anti-microbial, and anti-tumor effects. Results: In this review article, all relevant papers from various scholars and researchers were searched in Science Direct, Google Scholar, PubMed, and Scopus. Honeycomb has various activities and numerous pharmacological benefits and health advantages, and it can be considered a valuable source of nutraceuticals, and an effective natural medicine and organic product. Conclusion:: In this mini-review, we have decided to discuss the importance of traditional treatment, and the pharmacological properties of Nidus Vespae

Novel europium(III), terbium(III), and gadolinium(III) Schiff base complexes: Synthesis, structural, photoluminescence, antimicrobial, antioxidant, and molecular docking studies

Three lanthanide (III) complexes, L-Eu, L-Tb, and L-Gd, were synthesized using a Schiff base ligand (H2L) composed of (2,2′-(thiophene-2,5-diylbis(methaneylyl-idene))bis(azaneylyl-idene))diphenol. Complexes with the generic formula LnL(Cl)(H2O)·xH2O, where L is the ligand, was studied using elemental analysis, spectrum analysis (IR, mass- UV–Vis), and molar conductivity. Next, the photoluminescence characteristics of the lanthanide complexes were investigated. An assessment was conducted to ascertain the antioxidant activity of the synthetic compounds compared with that of the stable free radical DPPH. The antibacterial activity of the Schiff base metal complexes was assessed against a strain of yeast as well as against a number of Gram-positive and Gram-negative bacteria. Computational studies were also performed to elucidate the mechanisms of the antimicrobial and antioxidant effects. In molecular docking, 1LL9, 6J2O, 3JPU, 2MBR, and 1HD2 crystal structures were determined as targets and the docking score values of H2L, L-Tb, L-Gd, and L-Eu compounds for these targets were calculated.

Volvariella volvacea (paddy straw mushroom): A mushroom with exceptional medicinal and nutritional properties

Volvariella volvacea, commonly referred to as paddy straw mushroom, is renowned for its remarkable medicinal and nutritional properties. This mushroom, part of the family Pluteaceae, thrives in tropical and subtropical regions and is highly esteemed for its distinctive flavor and substantial health benefits. The fruiting body of V. volvacea is a rich source of bioactive compounds, including antioxidant enzymes, terpenes, polypeptides, sugars, phenolics, and flavonoids. These compounds exhibit an extensive range of therapeutic activities such as anti-tumor, anti-microbial, antioxidant, anti-malarial, anti-cancer, anti-inflammatory, and anti-allergic effects. Nutritionally, V. volvacea is an excellent source of carbohydrates, proteins, fibers, ascorbic acid, and essential minerals. It also boasts a comprehensive profile of amino acids, including valine, arginine, glutamine, serine, aspartic acid, leucine, isoleucine, tyrosine, asparagine, lysine, cystine, proline, glycine, tryptophan, methionine, phenylalanine, threonine, and histidine. This review emphasizes the significant medicinal and nutritional potential of V. volvacea, advocating its inclusion as a functional food to enhance human health and well-being. By highlighting its diverse bioactive compounds and therapeutic benefits, this review aims to foster greater recognition and utilization of paddy straw mushroom in both dietary and medicinal applications.

Applications of plant-derived extracellular vesicles in medicine.

Plant-derived extracellular vesicles (EVs) are promising therapeutic agents owing to their natural abundance, accessibility, and unique biological properties. This review provides a comprehensive exploration of the therapeutic potential of plant-derived EVs and emphasizes their anti-inflammatory, antimicrobial, and tumor-inhibitory effects. Here, we discussed the advancements in isolation and purification techniques, such as ultracentrifugation and size-exclusion chromatography, which are critical for maintaining the functional integrity of these nanovesicles. Next, we investigated the diverse administration routes of EVs and carefully weighed their respective advantages and challenges related to bioavailability and patient compliance. Moreover, we elucidated the multifaceted mechanisms of action of plant-derived EVs, including their roles in anti-inflammation, antioxidation, antitumor activity, and modulation of gut microbiota. We also discussed the impact of EVs on specific diseases such as cancer and inflammatory bowel disease, highlighting the importance of addressing current challenges related to production scalability, regulatory compliance, and immunogenicity. Finally, we proposed future research directions for optimizing EV extraction and developing targeted delivery systems. Through these efforts, we envision the seamless integration of plant-derived EVs into mainstream medicine, offering safe and potent therapeutic alternatives across various medical disciplines.

Phytochemical Profiling and Bioactive Properties of Essential Oils from Endemic Palestinian Satureja thymbrifolia.

Despite several studies on the Satureja L. genus, the chemical composition and biological activities of the traditional medicinal plant Satureja thymbrifolia (White Thyme), a Palestinian endemic species, are still unknown. It grows in arid regions and is used by Bedouins as a traditional medicinal herb. This study aimed to investigate S. thymbrifolia essential oils (EOs), mainly from its phytochemical pattern and biological properties. The GC-MS study identified p-cymene (48.53%) and thymol (23.27%) as the leading EOs components. Compared to Trolox, the EOs showed potential anti-DPPH free radical activity and had broad-spectrum antimicrobial potentials, with MIC values ranging from 0.13 ± 0.05 to 25 ± 0.00 µL/mL. They were most effective against Candida albicans species. The S. thymbrifolia EOs most effectively eliminated cancer cells when tested against CaCo-2 and HeLa cell lines (IC50 values of 192.15 ± 2.47 and 194.80 ± 1.87 µg/mL, respectively). The present investigation is the first documented study of S. thymbrifolia EOs' phytochemical composition and bioactivities. The results revealed that S. thymbrifolia EOs have potential antioxidant, antimicrobial, and cytotoxic effects. These outcomes emphasized S. thymbrifolia EO's potential dietary, pharmacological, and cosmetic applications.

Evaluation of antioxidant, antimicrobial, antidiabetic, anti-tyrosinase, and neuroprotective effects of β-ionone: In vitro and in silico analysis

β-Ionone is a bioactive phytochemical that has been extracted from many flowers, vegetables, and fruits. β-Ionone is an intriguing lead molecule from which several derivatives have been generated and exhibiting a variety of biological effects. Here, we investigated the β-Ionones’ antioxidant, anti-cholinesterases (AChE and BChE), anti-α-amylase, anti-α-glucosidase, and anti-tyrosinase activities. The antibacterial and antifungal effects were also studied. Moreover, in silico studies using molecular docking were carried out to understand the obtained results. The antioxidant activity performed by six different assays including phosphomolybdenum, CUPRAC, FRAP, DPPH, ABTS and metal chelating assay showed that β-Ionone exhibits a promising antioxidant activity. Besides, a good inhibition of AChE and BChE, as well as α-glucosidase, α-amylase, and tyrosinase was obtained. Molecular docking evidenced that β-Ionone correctly occupied the active site of the five studied enzymes through various kind of interactions which corroborate the in vitro outcomes. Moreover, in silico ADMET assessment showed that β-Ionone presented a good ADMET profile. Gram positive bacteria, specifically S. aureus (DIZ = 25 ± 1.5 mm; MIC = 6.25 mg/mL; CMB = 6.25 mg/mL) and B. cereus (DIZ = 21.5 ± 1 mm; MIC = 0.78 mg/mL; CMB = 0.78 mg/mL), showed greater susceptibility. Regarding Gram negative ones, P. aeruginosa exhibited also marked sensitivity (DIZ = 20.33 ± 1.5 mm; MIC = 12.5 mg/mL; CMB = 12.5 mg/mL). Additionally, β-Ionone can limit the growth of C. albicans (DIZ = 23 ± 1 mm; MIC = 1.56 mg/mL; CMB = 1.56 mg/mL). A bactericidal and fungicidal efficacy could be suggested as the MBC/MIC towards all the four inhibited pathogens was equal to 1. To sum up, data suggested that β-Ionone could have potential applications as an antioxidant, antimicrobial, and antifungal compound, as well as a potential inhibitor of tyrosinase, α-amylase, α-glucosidase, and cholinesterases. Furthermore, it can serve as a lead chemical in the creation of a new semisynthetic drug intended in order to treat numerous illnesses, including diabetes, Alzheimer’s disease, and pigmentation disorders

Enhancing food safety: Employing ultraviolet-C light emitting diodes for water, leaf, and surface disinfection

This study aimed to explore the use of ultraviolet-C light emitting diodes that emit light at 255 nm and 265 nm, to disinfect bacteria present at occurrence levels and spiked in water matrices, salads and stainless-steel surfaces. The UV-C LEDs effectively inactivated bacteria associated with food outbreaks (Salmonella enterica, Listeria monocytogenes and Escherichia coli) as well as a cocktail of bacteria isolated from packaged salads. Combining the wavelengths did not enhance disinfection. Even low UV fluences of 4 mJ/cm2 achieved a significant 6-log reduction of bacteria spiked in water at high initial concentrations of approximately 108 CFU/mL. Exposure of salad (lettuce and arugula) leaves (110 mJ/cm2) and contaminated stainless-steel surfaces (11 mJ/cm2) to three small LEDs that emitted light at 265 nm reduced the pathogenic bacteria by 3 and 2-logs, respectively. The results obtained show that this disinfection technology could be promising for the food industry to guarantee effective inactivation of bacteria associated with foodborne diseases present in water, food and surfaces. Industrial relevanceThis study demonstrated the potential of ultraviolet-C light emitting diodes, emitting at 255 nm and 265 nm, to provide an effective and sustainable disinfection solution for the food industry, ensuring the inactivation of bacteria associated with foodborne diseases on water, food, and surfaces, thereby enhancing food safety. Additionally, this technology holds potential for extending product shelf-life, further benefiting the food industry. The results highlighted the effectiveness of UV-C LEDs even at low fluences, making them a practical choice for modern disinfection needs.

Natural biocide-assisted ultrasonic disinfection of wastewater effluent following a response surface methodology approach

The increasing prevalence of multidrug-resistant (MDR) bacteria in wastewater poses a significant threat to public health and the environment, necessitating more effective and sustainable disinfection methods. Ozonation and chlorination frequently fall short of eliminating these bacteria and can create toxic byproducts. This study introduces a novel disinfection strategy that combines ultrasonication with tea tree oil to target MDR bacteria in residential wastewater treatment systems, aiming to provide an eco-friendly, efficient, and scalable solution. The method harnesses tea tree oil's natural biocidal properties alongside the physical effects of ultrasonication, particularly acoustic cavitation, to enhance bacterial inactivation. Temperature, biocide dosage, and ultrasonication power were the three main factors that were optimized using response surface methodology. The system achieved a 2.2–2.4 log CFU/mL reduction of total bacteria in secondary effluent within 30 min and complete disinfection of modified effluent inoculated with high-strength MDR bacteria (6-log CFU/mL) in 50 min. Optimal conditions were 698.4 Watt power, 1.234 µl/mL tea tree oil, and 20.64 °C. Nucleic acid release and respiratory chain dehydrogenase inhibition indicated bacterial cell membrane rupture. Regrowth tests showed long-term effectiveness, with no bacterial colonies after three days. Using a natural biocide, the hybrid technique reduces operational costs and time, thus having commercial and environmental benefits. The capacity to remove MDR bacteria makes it an attractive contender for large-scale wastewater treatment.

Periodic phenotypic profile analysis of Acinetobacter baumannii drug resistance characteristics showing the emergence of PDR.

Acinetobacter baumannii, one of the ESKAPE pathogens, is on the World Health Organization (WHO) list of priorities needing urgent new effective antimicrobial agents due to exhibited high resistance by the bacterium to currently available antibiotics. This study examines the periodic changes of clinical A. baumannii isolates and their antimicrobial resistance patterns and types in Southeastern region of Saudi Arabia. One hundred and seventy-seven randomly selected A. baumannii isolates were used for the investigation with bacterial identities (IDs) and antimicrobial assay ascertained with Gram-negative (GN) ID cards and antimicrobial susceptibility test (AST) cards of Vitek 2 Compact Automated System according to manufacturer's guidelines. Descriptive phenotypic types of isolates were compared using comparison proportion and Fisher extraction test, while Morpheus versatile matrix visualization and analysis software was used for the dendrogram of hierarchical clustering. A significantly higher proportion of samples were from males compared to females (p = 0.025), with 33.33% of samples originating from patients aged 51-70 years. Resistance was high for imipenem (93%), meropenem (94%), levofloxacin, ciprofloxacin (99%), and aztreonam (98%). There was less percentage resistance to colistin (18%), tigecycline (23%), and minocycline (23%). Multidrug resistance (MDR)/carbapenem-resistant Acinetobacter baumannii (CRAB) was observed consistently across all years. There was no extensive drug resistance (XDR) among isolates from 2013 to 2014, but it was present in the 2016 to 2018 and 2019 to 2020 periods, while pandrug resistance was seen only in the 2019 to 2020 isolates. The study shows a clear trend of the isolates changing from MDR to XDR and then to pandrug resistance over the study period. Also, it indicates that carbapenems might no longer be a treatment choice in this study region. Although colistin exhibited less resistance, the toxicity of the drug reduces its usefulness. The development of pandrug resistance is a critical concern.

Improving ready-to-eat meat safety: Evaluating the bacterial-inactivation efficacy of microplasma-based far-UVC light treatment of food-contact surfaces and deli turkey breast

The safety of ready-to-eat (RTE) deli meats, especially those sliced in retail establishments, may be improved by light-based surface decontamination. Conventional 254 nm ultraviolet-C (UVC) systems have strong germicidal effects but pose human-health hazards that make them unsuitable for retail use. This study therefore explores the efficacy of microplasma-based 222 nm far-UVC lamps as a safer alternative for decontaminating liquid buffer, two common food-contact surfaces (polyethylene terephthalate and stainless steel), and RTE turkey breast. In all three non-meat cases, the system achieved approximately 5-log reductions of both Listeria monocytogenes and Salmonella Typhimurium. The system also caused a 1.3-log reduction of L. monocytogenes and a 1-log reduction of S. Typhimurium on turkey breast at the highest tested dose of 786.3 mJ/cm2. Color is a key quality indicator for RTE meat consumers, and treatment caused no significant change in L*, a*, or b* color values (p > 0.05) until doses reached 224.7 mJ/cm2. However, higher doses could lead to statistically significant color changes. Given that far-UVC light has been deemed human-safe by other studies, the proposed system has considerable potential to improve RTE food-related safety in retail establishments, even when consumers and workers are present.

Fabrication of highly flexible biopolymeric chitosan/agarose based bioscaffold with Matricaria recutita herbal extract for antimicrobial wound dressing applications

A flexible biopolymer-based antimicrobial wound dressing has the potential to alleviate the burden of bacterial infections in wounds by enhancing antimicrobial effectiveness and promoting faster wound healing. This study focuses on the development of a highly flexible chitosan-agarose (CS-AG) bioscaffold, incorporating Matricaria recutita chamomile flower extract (CH) through a conventional casting method. The flexible CS-AG bioscaffold's physiochemical properties were confirmed by FTIR, indicating secondary interactions, and XRD, showing its crystalline structure. The addition of CH to the optimized CS-AG bioscaffold resulted in significant tensile strength (17.28 ± 0.33 MPa), distinctive structural morphology (SEM), surface roughness (AFM), contact angle, improved thermal properties (DSC), and enhanced thermal stability (TGA). Furthermore, the CH-infused bioscaffold significantly increased swelling capacity (~81.09 ± 1.74 % over 48 h), and degradation profile (~52 % over 180 h). The release studies of CS-AG-CH bioscaffold demonstrate controlled release of CH with in the bioscaffold at different pH conditions. The bioscaffold demonstrated effective antibacterial activity against S. aureus and E. coli strains. Additionally, cytotoxicity assays indicated that the bioscaffold supports better cell viability and proliferation in fibroblast (NIH 3T3) cell lines. Consequently, this antimicrobial bioscaffold shows promise as a drug release system and biocompatible wound dressing suitable for tissue engineering applications.

Antimicrobial effects of a multimodal wound matrix against methicillin-resistant Staphylococcus aureus and Pseudomonas aeruginosa in an in vitro and an in vivo porcine wound model.

Chronic non-healing wounds pose significant challenges due to an elevated inflammatory response caused in part by bacterial contamination (Physiol Rev. 2019;99:665). These wounds lead to billions being spent in the health care system worldwide (N Engl J Med. 2017;376:2367, Int J Pharm. 2014;463:119). We studied the in-vitro and in-vivo antimicrobial effects of a multimodal wound matrix (MWM) against two common wound pathogens, Methicillin-Resistant Staphylococcus aureus (MRSA USA300) and Pseudomonas aeruginosa ATCC 27312 (PA27312) (Int Wound J. 2019;16:634). The in-vitro study conducted was a zone of inhibition test with the two microbes at 104 Log CFU/mL inoculated on Tryptic soy agar with 5% sheep blood (TSAII) plates. Treatments used were MWM, Mupirocin (Positive control for MRSA), Silver Sulfadiazine (Positive Control for PA), Petrolatum and Sterile Saline (both serving as Negative Controls). Treatments were allowed to diffuse into the agar for 3 h and then were incubated for 24 h at 37°C. The in-vivo study utilized a deep dermal porcine wound model (22 × 22 × 3 mm) created on six animals. Three animals were inoculated with MRSA USA300 and the other three with PA27312 with each allowing a 72-h biofilm formation. After 72 h, baseline wounds were assessed for bacterial concentration and all remaining wounds were treated with either MWM alone, Silver Treatment or Untreated Control. Wounds were assessed on days 4, 8 and 12 after treatment application for microbiological analysis. In-vitro, MWM exhibited significant inhibition of MRSA USA300 and PA27312 growth when compared to negative controls (p ≤ 0.05). Likewise, in-vivo, the MWM-treated wounds exhibited a significant (p ≤ 0.05) bacterial reduction compared to all other treatment groups, especially on days 8 and 12 for both pathogens. MWM demonstrated promise in addressing colonized wounds with biofilms. Additional studies on MWM's benefits and comparisons with existing treatments are warranted to optimize wound care strategies (Adv Wound Care. 2021;10:281).

Innovative synthesis and molecular modeling of actinomycetes-derived silver nanoparticles for biomedical applications

The rising demand for innovative antimicrobial solutions has shifted focus towards silver nanoparticles (AgNPs), especially those produced through eco-friendly methods. This study introduces a novel approach utilizing actinomycetes strains—Streptomyces albus, Micromonospora maris, and Arthrobacter crystallopoietes—to biosynthesize AgNPs with remarkable antibacterial properties. Through molecular characterization, we identified unique features of these nanoparticles, and computational modeling suggested significant ion-ligand interactions with proteins 6REV and 3K07. Our research highlights the promise of these biogenically synthesized nanoparticles in advancing biomedical applications. Actinomycetes were sourced and screened for their ability to produce metallic nanoparticles, revealing that among 35 samples, only six showed this capability. Notably, Streptomyces albus strain smmdk14 (OR685674), Micromonospora maris strain smmdk13 (OR685672), and Arthrobacter crystallopoietes strain smmdk12 (OR685674) were identified as effective silver nanoparticle producers. The synthesized nanoparticles demonstrated potent antibacterial activity against common pathogens including E. coli, Pseudomonas aeruginosa, Klebsiella spp., Enterococcus faecalis, Staphylococcus aureus, and Acinetobacter spp. The data obtained from color change observation, UV–visible spectrophotometry, Zeta potential, FTIR spectroscopy, and transmission electron microscopy (TEM) characterized AgNPs potentiality. The nanoparticles were spherical, with sizes ranging from 6.46 nm to 24.7 nm. Optimization of production conditions, comparison of antimicrobial effects with antibiotics, evaluation of potential toxicity, and assessment of wound-healing capabilities were also conducted. The biosynthesized AgNPs exhibited superior antibacterial properties compared to traditional antibiotics and significantly accelerated wound healing by approximately 66.4 % in fibroblast cell cultures. Additionally, computational analysis predicted interactions between various metal ions and specific amino acid residues in proteins 6REV and 3K07. Overall, this study demonstrates the successful creation of AgNPs with notable antibacterial and wound-healing properties, underscoring their potential for medical applications.

Quantitative analysis of antibacterial efficacy of herbal irrigants against endodontic microflora – A clinical study

Abstract Aims: The study aimed to assess the antimicrobial effectiveness of green tea and neem extract compared to sodium hypochlorite (NaOCl) against various root canal microorganisms. Materials and Methods: Thirty patients with pulpal necrosis were selected, providing 60 samples before and after irrigation. Groups were assigned as follows: Group A: 3% NaOCl (control), Group B: green tea, and Group C: neem extract. Samples were collected before and after irrigation in two phases. Samples were collected maintaining a strict sterile condition and stored in buffer solution at −80°C for bacterial-load measurement through real-time Polymerase chain reaction (PCR). Statistical analysis included within-group comparisons using Wilcoxon’s test and the paired t-test and inter-group comparisons using the Kruskal–Wallis test with post hoc Dunn’s test and one-way analysis of variance with post hoc Tukey’s honestly significant difference test (P ≤ 0.05). Results: While no irrigant achieved complete bacterial eradication, all solutions exhibited significant antimicrobial activity postirrigation. NaOCl yielded the most effective results, with green tea nearly comparable, and neem extract demonstrating the lowest efficacy. Conclusions: Herbal irrigants, particularly green tea, can serve as effective alternatives to chemical solutions. However, neem extract proved less effective than both green tea and NaOCl, indicating its inferiority in root canal disinfection.

Co-delivery of antimicrobial peptide and Prussian blue nanoparticles by chitosan/polyvinyl alcohol hydrogels

Altered skin integrity increases the chance of infection, and bacterial infections often lead to a persistent inflammatory response that prolongs healing time. Functional artificial hydrogels are receiving increasing attention as suitable wound dressing barrier. However, the antimicrobial effect of the new dressing still needs to be explored in depth. In this work, the antimicrobial peptide MSI-1 was covalently attached to chitosan-modified poly (vinyl alcohol) hydrogels mixed with Prussian blue nanoparticles (PBNPs) via a primary amine group coupled to a carboxyl group. The synthesized hydrogel has a long-lasting antimicrobial surface and is able to maintain its bactericidal effect on Staphylococcus aureus and Escherichia coli for 24 h. Due to the presence of PBNPs, the hydrogel was able to rise to 48.3 °C within 10 min under near infrared (NIR) light irradiation at a wavelength of 808 nm and maintain this mild temperature to avoid bacterial biofilms. The hydrogel showed >90 % survival in co-culture with cells for 3 d and did not damage major organs in animal experiments. Thus, the photothermal dual-mode antimicrobial hydrogel synthesized in this study increases the selectivity as a safe and efficient wound dressing for the treatment of infected skin defects.

Exploring the Antimicrobial Activity of Hydrothermally Synthesized Copper Pyrophosphate Nanoflakes

In recent years, infections and the escalating resistance to antimicrobial drugs have emerged as significant health concerns. Due to their remarkable effectiveness and minimal potential for bacteria to develop resistance, copper-based nanomaterials are being considered as prospective alternatives to conventional antibiotics. In this study, copper pyrophosphate nanoflakes were synthesized using a simple hydrothermal technique with an inorganic phosphate source. These nanoflakes, characterized by a high aspect ratio, exert a substantial impact on bacterial cell walls, effectively eliminating microbial pathogens. X-ray diffraction (XRD) analysis confirmed the monoclinic phase of the copper pyrophosphate nanomaterial, while the band gap energy of 2.7 eV was estimated from the tauc plot. Additionally, the antimicrobial efficacy of Cu2P2O7 was evaluated against various gram-negative, gram-positive, and fungal pathogens at different concentrations. Notably, all tested bacterial strains exhibited moderate antimicrobial effects at concentrations of 5 mg/mL. For instance, S. aureus and E. coli displayed a 13 mm zone of inhibition, demonstrating excellent activity and lower cytotoxicity. These findings underscore the potential of Cu2P2O7 as a promising candidate for the development of novel drugs targeting pathogenic bacteria affecting human health.

IDENTIFICATION OF ANTIBACTERIAL AGENTS AGAINST KLEBSIELLA PNEUMONIAE TARGETING THE CTX-M-15 PROTEIN USING INTEGRATED STRUCTURE MODEL-BASED VIRTUAL SCREENING METHODS

The spread of carbapenem-resistant Gram-negative bacteria, particularly those having the bla CTX-M-15 gene, has stimulated a global challenge for β-lactam antimicrobial effectiveness. This study aims to identify commercially available compounds that demonstrate strong antibacterial properties with high efficacy and low toxicity to combat the increasing problem of antibiotic resistance. Virtual screening and molecular docking techniques were employed to generate a pharmacophore model based on the molecular structure. Eleven potential compounds were selected based on their IC50 values. Subsequently, a molecular docking approach was employed to select the best three small molecules for further comprehensive investigation. Moreover, absorption, distribution, metabolism, and excretion (ADME) and toxicity analysis ensured that it can be used as a drug without the effect of health. Finally, molecular dynamic (MD) simulations and generalized Born model and solvent accessibility (MMGB/SA) were carried out to evaluate the stability of these compounds against the receptor. Three selected compounds, specifically ZINCCID (ZINC94211493, ZINC20528448, and ZINC04331046), have exhibited strong binding affinities of -8.4, -8.1, and -7.7 kcal/mol, respectively. This has been predicted as a potential competitive inhibitor targeting CTX-M-15. However, further assessment through experimental lab studies is required to evaluate the efficacy of these compounds. Initially, a structure-based model was constructed, and subsequently, molecular docking, MD simulation, ADMET analysis, and MMGB/SA were performed. Through the A-to-Z virtual screening process, the top three natural compounds were identified as potential lead molecules in the development of novel drugs targeting CTX-M-15 for combating Klebsiella infections. Keywords: Klebsiella; Structure-based; Molecular docking; Pharmacophore modeling; CTX-M-15 protein; ADMET; MMGB/SA, MD simulation.