Strong Antibacterial Activity Research Articles

A case report of severe drug-induced immune hemolytic anemia caused by piperacillin

Piperacillin is a beta-lactamase inhibitor frequently used in the treatment of urinary tract infections. It is a broad-spectrum antibiotic with strong antibacterial action against Pseudomonas aeruginosa and Enterobacter, especially extended-spectrum beta-lactamase-producing Enterobacteria and Enterococcus. Side effects of piperacillin include allergic reactions, rashes such as urticaria, leukopenia, interstitial nephritis, asthma attacks, serological reactions, candida infection, and bleeding with more severe reactions resulting in anaphylactic shock. Anemia and hemolytic anemia are rare adverse reactions to piperacillin, with an incidence of 0.01–0.10%. We report herein the case of a severe postoperative immune hemolytic reaction to piperacillin. Fortunately, we quickly recognized and identified the drug reaction caused by piperacillin, immediately stopped the use of piperacillin, and performed a blood transfusion. The patient recovered and was subsequently discharged from the hospital.

Antibacterial and Photocatalytic Applications of Silver Nanoparticles Synthesized from Lacticaseibacillus rhamnosus

The biosynthesis of silver nanoparticles (AgNPs) presents an innovative and sustainable approach in nanotechnology with promising applications in fields such as medicine, food safety, and pharmacology. In this study, AgNPs were successfully synthesized using the probiotic strain Lacticaseibacillus rhamnosus (BCRC16000), addressing challenges related to stability, biocompatibility, and scalability that are common in conventional nanoparticle production methods. The formation of AgNPs was indicated by a color change from yellow to brown, and UV–visible spectrophotometry confirmed their presence with a characteristic absorption peak at 443 nm. Furthermore, Fourier transform infrared (FTIR) spectroscopy revealed the involvement of biomolecules in reducing silver ions, which suggests their role in stabilizing the nanoparticles. In addition, field emission scanning electron microscopy (FE-SEM) showed significant morphological and structural changes. At the same time, dynamic light scattering (DLS) and zeta potential analyses provided valuable insights such as average size (199.7 nm), distribution, and stability, reporting a polydispersity index of 0.239 and a surface charge of −36.3 mV. Notably, the AgNPs demonstrated strong antibacterial activity and photocatalytic efficiency, underscoring their potential for environmental and biomedical applications. Therefore, this study highlights the effectiveness of Lacticaseibacillus rhamnosus in the biosynthesis of AgNPs, offering valuable antibacterial and photocatalytic properties with significant industrial and scientific implications.

Mucus-Penetrable Biomimetic Nanoantibiotics for Pathogen-Induced Pneumonia Treatment.

Bacterial pneumonia has garnered significant attention in the realm of infectious diseases owing to a surge in the incidence of severe infections coupled with the growing scarcity of efficacious therapeutic modalities. Antibiotic treatment is still an irreplaceable method for bacterial pneumonia because of its strong bactericidal activity and good clinical efficacy. However, the mucus layer forming after a bacterial infection in the lungs has been considered as the "Achilles' heels" facing the clinical application of such treatment. Herein, traceable biomimetic nanoantibiotics (BioNanoCFPs) were developed by loading indacenodithieno[3,2-b]thiophene (ITIC) and cefoperazone (CFP) in nanoplatforms coated with natural killer (NK) cell membranes. The BioNanoCFP exhibited excellent demonstrated mucus-penetrating abilities, facilitating their arrival at the infection site. The presence of Toll-like receptors in the NK cell membrane rendered the BioNanoCFP with the capability to recognize pathogen-associated molecular patterns within bacteria, allowing precise targeting of bacterial colonization sites and achieving substantial therapeutic efficacy. Overall, our findings demonstrate the viability and desirability of using NK cell membrane-mediated drug delivery as a promising strategy for precision treatment.

The Composition, Antioxidant and Antibacterial Activity of Essential Oils from Five Species of the Magnoliaceae Family

The leaves of Magnoliaceae family plants contain abundant essential oils (EOs), and these species can be used in many fields due to their high industrial, medicinal, and ornamental values. This study aims to identify the main compounds of the EOs from the leaves of five common Magnoliaceae species (Michelia maudiae, Michelia hedyosperma, Michelia macclurei, Manglietia lucida, Manglietia conifer) using hydrodistillation, GC–MS analysis, and in vitro tests. Additionally, the antioxidant and antibacterial activities of the EOs were also evaluated. The results show that 151 compounds were identified across five species, with sesquiterpenes being dominant. Some key compounds (such as β-caryophyllene, δ-amorphene, β-guaiene, globulol, and β-acorenol) were common among all the species, highlighting their crucial roles in plant physiology and resilience. Other compounds (like valeranone and nerolidol in M. maudiae and β-elemene in M. macclurei) were specific, indicating different functions. Among the five species, the essential oil of M. macclurei contains β-elemene and nerolidyl acetate, and it has the weakest antioxidant activity (IC50 value: 2918.61~21,341.98 μg/mL) but the strongest antibacterial activity (inhibition zone diameter: 8.55 ± 0.93~22.92 ± 0.46 mm; LC50 value: 0.02~0.78 mg/mL). Meanwhile, the EO of M. maudiae demonstrated the best antioxidant activity (the IC50 value was 1283.58~6258.32 μg/mL) and the second-best antibacterial activity (the inhibition zone diameter ranged from 7.61 ± 0.02 to 26.92 ± 0.46 mm, and the LC50 value was 0.03~2.28 mg/mL). Overall, the EO of M. maudiae had the best comprehensive performance. Therefore, the EOs of M. macclurei and M. maudiae showed different performances in biological activity categories, and they could be developed and used in different fields, with the possibility of discovering new applications. This brings inspiration to the potential commercial and industrial uses of sesquiterpenes in Magnoliaceae.

Development and characterization of antibacterial marine extract-infused cellulose acetate nanofibers as wound dressings for combatting multidrug-resistant wound infections

Wound infections caused by multidrug-resistant bacteria pose a significant challenge globally in healthcare. Traditional wound dressings often lack efficacy against these resilient pathogens, necessitating the exploration of innovative approaches to combat infections and promote wound healing. This study was designed to investigate a novel wound dressing marine extract-infused electrospun cellulose acetate nanofibers (CANF) with particular emphasis on combating multidrug-resistant bacteria. Cellulose acetate solutions were combined with marine extract (Heteroxenia Fuscescens soft coral, H. Fu) before the creation of electrospun nanofibers. The antibacterial activities of H. Fu extract and the prepared nanofiber mats were explored against Pseudomonas aeruginosa, Acinetobacter baumannii, Staphylococcus aureus, and Staphylococcus epidermidis. Furthermore, the antibacterial properties of the crude H. Fu extract were directly assessed, showing potent activity against several pathogens. Results displayed that H. Fu extract has a robust antibacterial action against tested bacteria. Different concentrations of H. Fu (0.05 g, 0.1 g, 0.2 g, and 0.3 g) were added to CA solution, and named as H. Fu-1@CANF, H. Fu-2@CANF, H. Fu-3@CANF and H. Fu-4@CANF, respectively. The obtained results from SEM analysis demonstrated the smooth and uniform fibers. As observed, the addition of H. Fu with specific concentrations (0.05 g, 0.1 g, 0.2 g) has no significant impact on the smooth properties of the formed nanofibers. Increasing the concentration of H. Fu (0.3 g) leads to the formation of nanofibers coated with huge beads. FTIR affirmed the existence of H. Fu that blended with CANF. The hydrophilicity of the formed CANF was significantly enhanced thanks to the presence of H. Fu extract. The contact angle values of CANF, H. Fu-1@CANF, H. Fu-2@CANF, and H. Fu-3@CANF were 33.3°, 57.1°, 60.8° and 62.9°, respectively. The mechanical properties in terms of ultimate force (kg) recoded values were 0.89, 0.95, 1.2, 1.3 for CANF, H. Fu-1@CANF, H. Fu-2@CANF and H. Fu-3@CANF, respectively, those of CNF were markedly enhanced when loaded with H. Fu. This study evaluates the antibacterial efficacy of nanofiber mats loaded with H. Fu extract against common cutaneous bacterial pathogens. Four nanofiber samples were tested for their inhibitory impact on bacterial survival counts using the disc diffusion method. Important results from the study include the observation that H. Fu-3@CANF exhibited the largest zones of inhibition (ZOI) with diameters of 35 ± 0.25 mm for P. aeruginosa, 32 ± 0.65 mm for A. baumannii, 28 ± 0.14 mm for S. aureus, and 27.6 ± 0.48 mm for S. epidermidis. Additionally, the H. Fu-2@CANF sample demonstrated strong antibacterial activity, with ZOI diameters of 32 ± 0.56 mm, 29 ± 0.81 mm, 26 ± 0.27 mm, and 25.4 ± 0.28 mm for the respective bacteria. The Microtox® assay further evaluated the toxicity levels of the nanofiber mats, revealing that while all samples exhibited some toxicity, the H. Fu-3@CANF sample had the lowest toxicity profile. These findings highlight the potential of H. Fu-loaded nanofibers, particularly H. Fu-3@CANF, for broad-spectrum antibacterial applications. The study underscores the importance of incorporating bioactive compounds into nanofiber mats to enhance their antimicrobial properties, making them suitable candidates for medical and environmental applications requiring effective bacterial eradication.

Naturally derived 3-aminoquinuclidine salts as new promising therapeutic agents

Quaternary ammonium compounds (QACs) are a biologically active group of chemicals with a wide range of different applications. Due to their strong antibacterial properties and broad spectrum of activity, they are commonly used as ingredients in antiseptics and disinfectants. In recent years, the spread of bacterial resistance to QACs, exacerbated by the spread of infectious diseases, has seriously threatened public health and endangered human lives. Recent trends in this field have suggested the development of a new generation of QACs, in parallel with the study of bacterial resistance mechanisms. In this work, we present a new series of quaternary 3-substituted quinuclidine compounds that exhibit potent activity across clinically relevant bacterial strains. Most of the derivatives had minimal inhibitory concentrations (MICs) in the low single-digit micromolar range. Notably, QApCl and QApBr were selected for further investigation due to their strong antibacterial activity and low toxicity to human cells along with their minimal potential to induce bacterial resistance. These compounds were also able to inhibit the formation of bacterial biofilms more effectively than commercial standard, eradicating the bacterial population within just 15 min of treatment. The candidates employ a membranolytic mode of action, which, in combination with the generation of reactive oxygen species (ROS), destabilizes the bacterial membrane. This treatment results in a loss of cell volume and alterations in surface morphology, ultimately leading to bacterial cell death. The prominent antibacterial potential of quaternary 3-aminoquinuclidines, as exemplified by QApCl and QApBr, paves the way for new trends in the development of novel generation of QACs.

Ag enhanced CuS nanoflower catalyst coupling dielectric barrier discharge plasma for disinfection performance and mechanism

In this study, the hydrothermal method was employed to grow submicron CuS on carbon cloth (CC), and the photoreduction method was used to grow Ag nanoparticles on the CuS submicron flowers, thus forming the Ag/CuS/CC catalytic electrode. The application of Ag/CuS/CC electrode-coupled dielectric barrier discharge (DBD) plasma in the disinfection of pathogenic bacteria in water was studied. The Ag/CuS/CC electrode exhibits strong antibacterial activity, and under an external voltage of 30 V, the degradation efficiency of Bacillus subtilis reaches 99.99% within 15 min without regeneration. After five cycles, the inactivation rate of Bacillus subtilis reached 99.99% within 25 min. The practical applicability of the Ag/CuS/CC-coupled DBD system for treating actual wastewater was evaluated, and the changes in biological toxicity were investigated. The results indicate that the prepared Ag/CuS/CC coupled DBD has great potential for safe disinfection of pathogenic bacteria in water through integrated processes.

Omiganan-Based Synthetic Antimicrobial Peptides for the Healthcare of Infectious Endophthalmitis.

Bacterial endophthalmitis is a severe infection of the aqueous or vitreous humor of the eye that can lead to permanent vision loss. Due to the rapid emergence of antibiotic resistance and dose-limiting toxicities, the standard treatment of bacterial endophthalmitis via the intravitreal injection of broad-spectrum antibiotics remains inadequate. Membrane active cationic antimicrobial peptides (AMPs) have emerged as a promising class of effective and broad-spectrum antimicrobial agents with potential to overcome antibiotic resistance. In this work, we investigate, for the first time, the use of omiganan (IK-12), a 12-amino acid indolicidin derivative for the treatment of bacterial endophthalmitis. Additionally, IK-12 was used as a template to perform amino acid rearrangements, without altering the length or type of amino acids, to yield a series of new derivative AMPs with varying extents of secondary structure formation under membrane mimicking conditions. IK-12 and its derivatives demonstrated strong and broad-spectrum antibacterial activities against a panel of clinically isolated Gram-positive and Gram-negative bacteria, including methicillin-resistant Staphylococcus aureus commonly implicated in bacterial endophthalmitis. Interestingly, two of the new IK-12 derivatives, IP-12 and WP-12, showed lower geometric mean minimum inhibitory concentration and higher 50% hemolysis concentration values, which effectively translated into 2- to 3.4-fold higher bacterial selectivity than the parent IK-12. Furthermore, the intravitreal injection of IK-12, IP-12, and WP-12 in a rabbit model of MRSA-induced endophthalmitis led to considerably improved clinical presentation and reduced recruitment of inflammatory cells. In all, these results demonstrate the potential of IK-12 and its derivatives, IP-12 and WP-12, as promising candidates for the treatment of bacterial endophthalmitis.

Correlation analysis between phytochemical composition and biological activities of Artemisiascoparia

As a homologous plant of medicine and food, Artemisia scoparia has rich nutritional value and medicinal components. The main contents are to analyze the phytochemical composition and various biological activities of A. scoparia, and to explore the Pearson correlation between the contents of each phytochemical composition and biological activities. The ethanol extract (EA) and its fractions (n-hexane extract (NHE), ethyl acetate extract (EAC), n-butanol extract (NBA), and water extract (HO)) of A. scoparia were rich in polyphenols, polysaccharides, terpenoids, coumarins, flavonoids and showed potential for antibacterial, antioxidant, hypoglycemic, lipid-lowering, and anti-inflammatory activities. EAC contains the highest amount of coumarins and flavonoids, shows strong antibacterial, antioxidant, hypoglycemic, lipid-lowering and anti-inflammatory (COX-2) activities. In addition, the inhibition rate of NHE on LOX was higher, and Pearson correlation reveled a strong association between phytochemical composition and biological activities: Coumarins had antimicrobial properties, flavonoids had antioxidant and hypoglycemic effects, and flavonoids and terpenoids had anti-inflammatory effects. There was a significant negative correlation between coumarins and MBC of S. aureus (r = 0.84, p < 0.001) and C. albicans (r = 0.84, p < 0.001). Flavonoids (r = 0.86, p < 0.001) showed a significant negative correlation with α-glucosidase scavenging ability. Terpenoids also showed a significantly negative correlation with LOX scavenging ability (r = 0.70, p < 0.001). A comprehensive understanding of both physiological functionalities and potential applications related to the bioactive elements present in extracts from A. scoparia could potentially provide valuable scientific insights to guide its medical or health-related utilization.

Bimetallic FeCo metal–organic framework based cascade reaction system: Enhanced peroxidase activity for antibacterial performance

Metal-organic frameworks (MOFs), as a peroxidase (POD), can catalyze the conversion of H2O2 to reactive oxygen species (ROS) for antibacterial application. To achieve strong antibacterial activity, it is necessary to improve the enzyme-like activity of MOFs. In this study, FexCoMOF was synthesized by incorporating Co(II) to improve the electron transfer of Fe(III)/Fe(II), which enhanced its redox capacity as a nanozyme and further promoted the generation of hydroxyl radical (⋅OH), exhibiting higher POD activity. Doping with different amounts of Co(II) altered the particle size, specific surface area, and surface defects of FexCoMOF, thus exhibiting differential enzyme-like activities. Additionally, a glucose-responsive enzyme cascade reaction system based on Fe4CoMOF/glucose oxidase (GOx) was established. In the presence of glucose, the in situ-generated substrate H2O2 was in contact with the catalytic site and the generated gluconic acid enabled Fe4CoMOF to maintain maximum enzyme activity under physiological pH conditions, avoiding damage caused by the use of exogenous high concentrations of H2O2. In the in vitro antibacterial experiment, the minimum inhibitory concentration (MIC) of Fe4CoMOF/GOx was 10 μg mL−1 for Escherichia coli (E. coli) and 5 μg mL−1 for Staphylococcus aureus (S. aureus) (∼108 CFU mL−1). The increase in enzyme activity resulted in a considerable reduction in the dose of the antibacterial agent, which was conducive to improving bio-safety. The in vivo experiment in mice demonstrated that the glucose-responsive Fe4CoMOF-based cascade reaction system had excellent antibacterial properties and remarkably promoted wound healing. The antibacterial agent based on bimetallic MOF developed in this work provides a new idea for cascade catalytic antibacterial therapy and will have remarkable application prospects in biomaterials and nanomedicine.

Therapeutic Potential of Insect Defensin DLP4 Against Staphylococcus hyicus-Infected Piglet Exudative Epidermitis

Background/Objectives: The emergence of resistance to Staphylococcus hyicus (S. hyicus), the major cause of exudative epidermatitis (EE) in piglets, has led to the need for new antimicrobial agents. The study aimed to evaluate the potential efficacy of the insect defensin DLP4 against EE in piglets caused by clinically isolated S. hyicus ACCC 61734. Methods and Results: DLP4 showed strong antibacterial activity against S. hyicus ACCC 61734 (minimum inhibitory concentration, MIC: 0.92 μM, median effect concentration, EC50: 3.158 μM). DLP4 could effectively inhibit the formation of S. hyicus early biofilm with an inhibition rate of 95.10–98.34% and eradicate mature biofilm with a clearance rate of 82.09–86.41%, which was significantly superior to that of ceftriaxone sodium (CRO). Meanwhile, DLP4 could efficiently inhibit bacteria in early and mature biofilm, killing up to 95.3% of bacteria in early biofilm and 87.2–90.3% of bacteria in mature biofilm. The results showed that DLP4 could be effective in alleviating the clinical symptoms of EE by down-regulating the nuclear factor κB (NF-κB) signaling pathway, balancing cytokines, inhibiting bacterial proliferation, and reducing organ tissue damage. Conclusions: This study firstly demonstrated the potential efficacy of DLP4 against EE caused by S. hyicus ACCC 61734 infection in piglets, which may be used as an alternative to antibiotics in treating EE.

Broad-spectrum antimicrobial activities of a food fermentate of Aspergillus oryzae.

The development of NP, a potent broad-spectrum antimicrobial, is a significant breakthrough in the ongoing challenge against microbial foodborne illnesses and the growing threat of antibiotic resistance. This food-grade culture broth of Aspergillus oryzae demonstrates exceptional broad-spectrum efficacy against a variety of harmful bacteria and fungi, including drug-resistant strains such as methicillin-resistant Staphylococcus aureus and prevalent food spoilage molds. NP exhibits strong bactericidal activity against various foodborne and ESKAPE pathogens, and strong antifungal activity against Penicillium species, Aspergillus fumigatus, and Candida albicans. The potent bactericidal and antifungal properties of NP are a result of its ability to disrupt microbial cell membranes leading to increased permeability. Furthermore, the genome-wide impact of NP on fungal gene expression and metabolic pathways underscores its comprehensive antimicrobial action, leading to transcriptomic and metabolic changes associated with cell death in A. fumigatus.

Multifunctional nanomaterials composed entirely of active pharmaceutical ingredients for synergistically enhanced antitumor and antibacterial effects.

Multifunctional nanomaterials are emerging as promising tools for treating both cancer and bacterial infections. However, integrating dual therapeutic capabilities into a single system remains challenging. This study presents multifunctional nanoparticles (ECI-NPs) based on Epigallocatechin gallate (EGCG) oligomers, Curcumin (CUR), and Indocyanine Green (ICG) for combined cancer and bacterial treatment. ECI-NPs were synthesized via oxidative coupling of EGCG, CUR, and ICG. The nanoparticles were characterized for stability, size, drug loading, and release profiles. Cellular uptake, phototoxicity in melanoma cells, and antibacterial activity against Escherichia coli and Staphylococcus aureus were also evaluated. ECI-NPs demonstrated optimal stability, high drug loading, and controlled release. Cellular studies showed increased uptake and greater phototoxicity in melanoma cells compared to free drugs. ECI-NPs also exhibited enhanced anticancer effects and strong antibacterial activity, outperforming the individual components. The polyphenol-based ECI-NPs offer synergistic therapeutic effects, overcoming the limitations of free drugs in terms of solubility and efficacy. This dual-function platform shows potential for broader biomedical applications, addressing challenges in cancer and bacterial infections. Further research will focus on in vivo studies and clinical translation.

Penicitrisochromans A-C, new isochromans from the marine-derived fungus Penicillium citrinum PSU-MF100.

Three new isochroman derivatives, penicitrisochromans A-C (1-3), together with 25 known polyketides were isolated from the marine-derived fungus Penicillium citrinum PSU-MF100. Their structures were elucidated by extensive spectroscopic analysis. The absolute configurations of 1 and 2 were established by comparison of specific rotations and electronic circular dichroism (ECD) data with those of the known co-metabolite whereas those of 3 were assigned based on the ECD calculation and biosynthetic consideration. Among the isolated polyketides, three known anthraquinone derivatives, ω-hydroxyemodin, penicillanthranin A and emodin, displayed moderate to strong antibacterial activity against methicillin-resistant Staphylococcus aureus with MIC values of 32, 16 and 4 µg/mL, respectively. For antifungal activity, two known benzopyranones, coniochaetones A and C, exhibited moderate antifungal activity against Candida albicans NCPF3153 and Cryptococcus neoformans ATCC90112 with the respective MIC values of 16 and 64 µg/mL.

Investigation on taxonomy, secondary metabolites and antibacterial activity of Streptomyces sediminicola sp. nov., a novel marine sediment-derived Actinobacteria.

Marine actinomycetes, especially Streptomyces, are recognized as excellent producers of diverse and bioactive secondary metabolites on account of the multiplicity of marine habitations and unique ecological conditions, which are yet to be explored in terms of taxonomy, ecology, and functional activity. Isolation, culture and genome analysis of novel species of Streptomyces to explore their potential for discovering bioactive compounds is an important approach in natural product research. A marine actinobacteria, designated strain SCSIO 75703T, was isolated, and the potential for bioactive natural product discovery was evaluated based on genome mining, compound detection, and antimicrobial activity assays. The phylogenetic, phenotypic and chemotaxonomic analyses indicate that strain SCSIO 75703T represents a novel species in genus Streptomyces, for which the name Streptomyces sediminicola sp. nov. is proposed. Genome analysis revealed the presence of 25 secondary metabolite biosynthetic gene clusters. The screening for antibacterial activity reveals the potential to produce bioactive metabolites, highlighting its value for in-depth exploration of chemical constituents. Seven compounds (1-7) were separated from the fractions guided by antibacterial activities, including three indole alkaloids (1-3), three polyketide derivatives (4-6), and 4-(dimethylamino)benzoic acid (7). These primarily antibacterial components were identified as anthracimycin (4), 2-epi-anthracimycin (5) and β-rubromycin (6), presenting strong antibacterial activities against Gram-positive bacteria with the MIC value ranged from 0.125 to 16μg/mL. Additionally,, monaprenylindole A (1) and 3-cyanomethyl-6-prenylindole (2) displayed moderate inhibitory activities against α-glucosidase with the IC50 values of 83.27 and 86.21μg/mL, respectively. Strain SCSIO 75703T was isolated from marine sediment and identified as a novel species within the genus Streptomyces. Based on genomic analysis, compounds isolation and bioactivity studies, seven compounds were identified, with anthracimycin and β-rubromycin showing significant biological activity and promising potential for further applications.

Continuous Material Deposition on Filaments in Fused Deposition Modeling.

A novel approach, i.e., Continuous Material Deposition on Filaments (CMDF), for the incorporation of active materials within 3D-printed structures is presented. It is based on passing a filament through a solution in which the active material is dissolved together with the polymer from which the filament is made. This enables the fabrication of a variety of functional 3D-printed objects by fused deposition modeling (FDM) using commercial filaments without post-treatment processes. This generic approach has been demonstrated in objects using three different types of materials, Rhodamine B, ZnO nanoparticles (NPs), and Ciprofloxacin (Cip). The functionality of these objects is demonstrated through strong antibacterial activity in ZnO NPs and the controlled release of the antibiotic Cip. CMDF does not alter the mechanical properties of FDM-printed structures, can be applied with any type of FDM printer, and is, therefore, expected to have applications in a wide variety of fields.

Interactive effect of biogenic nanoparticles and UV-B exposure on physio-biochemical behavior and secondary metabolism of Artemisia annua L

Biosynthesized silver nanoparticles (AgNPs) are key nanomaterials with unique physio-chemical characteristics and diverse applications. Their strong absorption potential and antibacterial activity make them useful for agriculture, medicine and other industries. AgNPs boost plant growth and metabolism, especially under stress. However, the combined effects of AgNPs and UV-B exposure on plants are unknown. To elucidate the interactive effects of biosynthesized silver nanoparticles (AgNPs) and exposure of ultraviolet B (UV-B) on plant growth and metabolic processes, this study assessed the response of Artemisia annua under controlled in vitro conditions. In total, eight sets of plants were used with the alone/combined treatment of AgNPs and UV-B. For this purpose, spherical and averaged ∼ 31.8 nm in size AaAgNPs were synthesized. The photosynthetic pigments were calculated maximum with the alone treatment of 0.5 mg L−1 AaAgNPs and combined treatment of 0.5 mg L−1 AaAgNPs with 3 h UV-B, respectively. The results evidenced that the co-exposure of AaAgNPs and UV-B led to a significant balance in ROS production of A. annua; as well as improved antioxidative enzyme activity. Fluorescence and scanning electron microscopic (SEM) analysis indicated the enhancement of glandular trichomes (GT) area and density with the combined treatment of AaAgNPs and 3 h UV-B. In accordance with correlation between microscopic GT results, high concentration of artemisinin and up-regulation of related transcripts were found in A. annua plants treated with low concentrations of AaAgNPs and UV-B. Thus, it may be inferred that two distinct plant growth modulators, namely low-concentration biosynthesized AgNPs and short-term UV-B exposure, can enhance the physio-biochemical characteristics and production of secondary metabolites (specially artemisinin) in A. annua synergistically.

Sustainable synthesis of silver nanoparticles from Azadirachta indica: antimicrobial, antioxidant and in silico analysis for periodontal treatment.

This study explores potential application of silver nanoparticles (AgNPs) to treat periodontal infection using Azadirachta indica leaf extract. The eco-friendly green synthesis process uses Azadirachta indica as a natural stabilizer and reducer, allowing AgNPs to be formed. Experimental AgNPs were characterized through transmission electron microscopy (TEM), Fourier-transform infrared spectroscopy (FTIR), Zeta potential, ultraviolet-visible spectroscopy (UV-Vis) etc. The antimicrobial, antioxidant potential of AgNPs was tested to identify its efficacy against periodontal infections. AgNPs were found spherical, nanosized (86nm), with negative surface charge (-26.9mV). TEM study depicted clear formation of discrete nanosize particles with smooth surface texture. Results showed strong antibacterial and anti-oxidant action of experimental AgNPs, preventing biofilm growth and bacterial viability. A higher binding affinity was observed between Quercetin and the selected protein, which is implicated in bacterial growth and biofilm formation on teeth. The study suggests that Azadirachta indica derived AgNPs could be a safe, efficacious, and eco-friendly alternative in place of conventional therapies to treat periodontal infection. Future in vivo studies are however warranted.

Green synthesis of silver, starch, and zinc oxide mediated nanoparticles with probiotics and plant extracts, their characterization and anti-bacterial activity

Nanotechnology has various applications in all branches of science, including engineering, medicine, pharmacy, and other related fields. Conventional techniques, such as the chemical reduction approach, which produces nanoparticles (NPs) using various hazardous chemicals, offer several health risks due to their toxicity and raise serious environmental concerns. In contrast, other techniques are expensive and need a lot of energy. More than 70 % of pathogenic bacterial strains have developed resistance to at least one class of antibiotics, leading to an increase in life-threatening bacterial infections that pose a significant health risk. However, the creation of NPs by biogenic synthesis is risk-free for the environment and clean enough for biological use. This study was aimed at synthesis of novel Moringa oleifera mediated starch capped silver-zinc NPs and green synthesis of ZnO nanoparticles from Aloe vera, papaya, and Lactobacillus plantarum. Antimicrobial activity of both NPs was tested against Gram-negative antibiotic-resistant bacteria Pseudomonas aeruginosa, Gram-positive bacteria Staphylococcus aureus (ATCC 6538), and two foodborne pathogens Listeria monocytogenes and Campylobacter jejuni. Ultraviolet–visible spectroscopy, Fourier Transform Infrared Spectroscopy, and Scanning Electron Microscopy were used for characterization. Majority of the research studies stress the flexibility, repeatability, and desirable features of the metals, polymers, and plant components employed in the production of biomedical nanoparticles. Such an intuitive approach provides several advantages, particularly a reasonable total expense, compliance with healthcare and pharmaceutical implementations, and the ability to produce massive volumes for industrial use. The novelty of the presented work lies in the unusual combination of silver, starch, and zinc oxide nanoparticles using Moringa oleifera, which is an eco-friendly alternative to chemical-based methods. This research exhibits the formation of well-defined nanoparticles with strong antibacterial activity against a wide range of pathogens, giving us insights into their potential applications in various biomedical fields.

Two novel antimicrobial peptides P33-57 and mP168-187 from zebrafish showing potent antibacterial activities

It is known that overuse or abuse of antibiotics has undoubtedly accelerated the global antibiotic resistance crisis, and long-time use of antibiotics may have adverse effects on the health of animal, human, and ecosystem. Therefore, it is necessary to find antibiotic alternatives that can be used in aquaculture and are non-toxic to the human. Here we clearly demonstrated that both the PH and FYVE domain of Plekhf2 in zebrafish have antibacterial properties and can interact with PGN in this study. Therefore, we screened four candidate peptides from the two domains. It was demonstrated that P152-172 and P168-187 had no obvious antibacterial activities, while P33-57 and mP168-187 had strong antibacterial activities, which may be used as antimicrobial peptides. Additionally, transmission electron microscopy experiment revealed that P33-57 and mP168-187 can destroy the cell wall of bacteria, thereby directly killing bacteria. Importantly, it was found that P33-57 and mP168-187 had no hemolysis to red blood cells and lacked cytotoxicity. In summary, P33-57 and mP168-187could be seen as antibacterial activity centers of PLEKHF2 and may be promising antimicrobial peptides to combat bacterial infections facing an antibiotic-resistance crisis.