Search Results (175)

Beta (β)-type Ti-29Nb-13Ta-4.6Zr (TNTZ) alloys combine low modulus with biocompatibility but require improved surface properties for long-term implantation. This study aimed to enhance the surface mechanical strength and antibacterial performance of TNTZ by applying TiN and TiAlN coatings via PVD. Notably, TiAlN was deposited on TNTZ for the first time, enabling a direct side-by-side comparison with TiN under identical deposition conditions. Dense TiN (~1.06 μm) and TiAlN (~1.73 μm) coatings were deposited onto solution-treated TNTZ and characterized by X-ray diffraction, scanning probe microscopy, Vickers microhardness, Rockwell indentation test (VDI 3198), static water contact angle measurements, and a Kirby–Bauer disk-diffusion antibacterial assay against Escherichia coli (E. coli). Both coatings formed face-centered cubic (FCC) structures with smooth interfaces (Ra ≤ 5.3 nm) while preserving the single-phase β matrix of the substrate. The hardness increased from 192 HV (uncoated) to 1059 HV (TiN) and 1468 HV (TiAlN), and the adhesion quality was rated as HF2 and HF1, respectively. The surface wettability changed from hydrophilic (48°) to moderately hydrophobic (82°) with TiN and highly hydrophobic (103°) with TiAlN. Similarly, the diameter of the no-growth zones increased to 18.02 mm (TiN) and 19.09 mm (TiAlN) compared to 17.65 mm for uncoated TNTZ. The findings indicate that TiAlN, in particular, provided improved hardness, adhesion, and hydrophobicity. Preliminary bacteriostatic screening under diffusion conditions suggested a modest relative antibacterial response, though the effect was not statistically significant between coated and uncoated TNTZ. Statistical analysis confirmed no significant difference between the groups (p > 0.05), indicating that only a preliminary bacteriostatic trend— rather than a definitive antibacterial effect—was observed. Both nitride coatings strengthened TNTZ without compromising its structural integrity, making TiAlN-coated TNTZ a promising candidate for next-generation orthopedic implants. Full article

Klebsiella pneumoniae is the second-most common opportunistic pathogen in clinical practice and has developed resistance to potent antibacterial drugs such as carbapenems. Therefore, developing safe and effective strategies for the prevention and treatment of K. pneumoniae infections remains a critical challenge. In this study, a strain named Tie-10 isolated from Antarctic samples demonstrated potent antibacterial activity against K. pneumoniae, which was subsequently identified as Bacillus nakamurai. The fermentation medium and culture conditions were systematically optimized through single-factor experiments, orthogonal array testing, and response surface methodology. The optimal medium composition was determined to be beef extract, peptone, and KNO₃. The culture conditions included a time of 24 h, temperature of 37 °C, pH of 7.0, and bottling volume of 80 mL. Antagonistic experiments demonstrated that the crude extract of B. nakamurai Tie-10 exhibited significant inhibitory activity against K. pneumoniae. The alkaline protease (AKP) assay demonstrated that the crude extract effectively disrupted the cellular integrity of K. pneumoniae, a finding further corroborated by scanning electron microscopy (SEM) analysis. Furthermore, the crude extract significantly inhibited extracellular protease secretion in K. pneumoniae, downregulated the expression of virulence-associated genes, and effectively disrupted biofilm formation. The study presented innovative strategies for the management and containment of K. pneumoniae infections. Full article

Wound management is a fundamental skill for veterinarians, requiring a systematic approach to wound care and a deep understanding of the biological principles underlying healing. Sucralfate, widely known as a mucoprotective agent for gastroduodenal ulcers, has recently shown promising topical effects in human skin lesions by binding and protecting growth factors from proteolytic degradation, thereby enhancing their local availability. This action promotes angiogenesis, chemotaxis and cell proliferation, while reducing oxidative stress and exerting bacteriostatic and bactericidal effects against common pathogens. However, the veterinary-specific literature on topical sucralfate is extremely limited, with most available data derived from experimental studies in rodent and porcine models, rather than clinical studies in common veterinary species. Nonetheless, these preliminary studies suggest a potential role for sucralfate in accelerating the healing process through improved collagen synthesis, neovascularization and fibroblast activity. Given the species-specific challenges in veterinary wound healing—especially in horses and cats, prone to delayed healing and exuberant granulation tissue—sucralfate represents a promising, cost-effective and safe candidate for clinical use. This narrative review synthetizes current evidence on sucralfate’s mechanisms and therapeutic benefits across human and veterinary contexts, highlighting the need for controlled, multidisciplinary veterinary studies. Validating sucralfate’s efficacy in clinical settings could enable the growing owner demand for advanced care to be satisfied, shorten recovery times, reduce complications and improve animal welfare. Full article

As the primary biological risk threatening safe dairy production, bovine mastitis control highly relies on environmental disinfection measures. However, the mechanisms by which chemical disinfectants influence host–environment microbial interactions remain unclear. This study systematically investigated the disinfection efficacy and regulatory effects on microbial community composition and diversity of glutaraldehyde-benzalkonium chloride (BAC) and glutaraldehyde-didecyl dimethyl ammonium bromide (DAB) at recommended concentrations (2–5%), using 80 environmental samples from intensive dairy farms in Xinjiang, China. Combining 16S rDNA sequencing with culturomics, the results showed that BAC achieved a disinfection rate of 99.33%, higher than DAB’s 97.87%, and reduced the environment–gut microbiota similarity index by 23.7% via a cationic bacteriostatic film effect. Microbiome analysis revealed that BAC selectively suppressed Fusobacteriota abundance (15.67% reduction) and promoted Bifidobacterium proliferation (7.42% increase), enhancing intestinal mucosal barrier function through butyrate metabolism. In contrast, DAB induced Actinobacteria enrichment in the environment (44.71%), inhibiting pathogen colonization via bioantagonism. BAC’s long-acting bacteriostatic properties significantly reduced disinfection costs and mastitis incidence. This study first elucidated the mechanism by which quaternary ammonium compound (QAC) disinfectants regulate host health through “environment-gut” microbial interactions, providing a critical theoretical basis for developing precision disinfection protocols integrating “cost reduction-efficiency enhancement-risk mitigation.” Full article

The pivotal component in the protection against TB is the tissue macrophages (Mф). These cells have been demonstrated to play a crucial role in the elimination of pathogens and mycobacterial killing. Elucidation of the molecular and phenotypic events that determine the outcome of infection in Mф is fundamental to understanding the key features of these cells that are so important in fighting infection. Mф activation is driven by cytokines and other inflammatory mediators secreted by T lymphocytes. The interaction between Mycobacterium tuberculosis (Mtb) and host Мф has been the subject of extensive in vitro research. This dynamic interplay represents a pivotal step in the progression of mycobacterial infection because pulmonary macrophages constitute the primary line of defense against the pathogen, thereby serving as the initial immune cells to which Mtb must adapt to establish a replicative foothold within the host. Our studies have demonstrated that highly differentiated Th1 effectors with the CD27^low phenotype exhibit superior efficacy in activating both peritoneal (Mф: T cell ratio ranging from 125:1 to 625:1) and pulmonary macrophages (Mф: T cell ratio = 5:1) compared to cells with the CD27^high phenotype. Furthermore, our findings indicate that this activation mechanism is not contingent upon the production of reactive nitrogen species. To effectively activate the bacteriostatic function of macrophages, CD27^high T lymphocytes must differentiate into effectors with the CD27^low phenotype. Full article

The aim of combining agents with different antibacterial mechanisms of action is to achieve a combined effect, which could be either the sum of their individual effects or a synergistic effect greater than the sum of these individual contributions. Mathematically, it seems reasonable to use the simple addition of agent efficacy coefficients to simplify calculations. However, this article examines the validity of this simplification in mathematical models by calculating individual and synergistic bactericidal effects using the “black box” model. All agents were characterized according to current laboratory practice. The relative antibacterial efficacy coefficients of silver nanoparticles in a colloid with chitosan succinate (nAg SCC HTZ) and graphene oxide nanoparticles (GO) were determined. In particular, the activity of silver colloid was found to be 0.29 times the bactericidal activity of erythromycin, while the activity of GO was 0.107 times the bactericidal activity of the same antibiotic against Pseudomonas aeruginosa. At the same time, all the agents demonstrated stable bacteriostatic activity and were well described by linear regression. Testing the combined effects of agents did not reveal any drug synergy. Thus, the effect of silver at a given dose, followed by the addition of GO at a bacteriostatic dose, yielded an unreliable response, different from that of the “silver–GO” system at the same simultaneous inhibition doses (p > 0.1). The data obtained can be used to develop novel combined composite materials with bactericidal properties and to predict their characteristics. Full article

Pichia manshurica is the main spoilage fungus that causes the deterioration of paocai. Our previous study found that the compound essential oils (CEOs) of lemon, lemongrass, and nutmeg had a good inhibitory effect; however, the antimicrobial mechanism was unknown. In order to elucidate the mechanism of action of the CEO in inhibiting P. manshurica, transcriptomics and metabolomics were used for joint analysis. The results showed that the minimum inhibitory concentration (MIC) of P. manshurica was 2 µL/mL, and the combined multi omics analyses indicated that the treatment of the CEO disrupted the ABC transporters, glycophospholipid metabolism, and nucleotide metabolism of P. manshurica, leading to the disruption of the integrity of P. manshurica cell wall and cell membrane, resulting in energy and metabolic dysfunction, and ultimately achieving the effect of inhibiting P. manshurica. The results of this study provided new insights into the mechanism of P. manshurica inhibition by CEOs, and provide a reference basis for the development of food-related bacteriostatic agents by CEOs. Full article

The World Health Organization notes that some bacteria have been demonstrated to possess significant public health risks; they have antibiotic resistance, and there are fewer alternatives for control. The n-hexane extract and cinaguaiacin obtained from Artemisia cina show promising antibacterial activity, including against multidrug-resistant bacteria that affect animal and human health. Objective: The aim of this study was to determine the antibacterial activity of the n-hexane extract of A. cina and cinaguaiacin against multidrug-resistant bacteria. Methods:A. cina was collected in the pre-flowering period, the n-hexane extract was obtained, and chromatographic techniques and structure were used to separate the lignans, which were elucidated with nuclear magnetic resonance techniques. Four ATCC strains were used, and four strains were isolated from clinical cases with different resistance profiles. The antibacterial activity was determined by calculating the Minimum Inhibitory Concentration (MIC), Minimum Bactericidal Concentration (MBC), the time-kill kinetics assay, and the cell membrane integrity and DNA release assay. Molecular docking studies of lignans demonstrated the binding mode involved in the active site of DNA gyrase B. Results: The n-hexane extract inhibited growth against 87.5% of the strains tested (MIC 5.31 to 42.5 mg/mL) and showed bactericidal activity against 25% of the strains tested (MBC 0.62 to 85 mg/mL). Cinaguaiacin inhibited growth against 100% of the strains tested (MIC, 0.56 to 2.25 mg/mL) and exhibited bactericidal activity against 25% of the strains tested (MBC, 0.62 to 85 mg/mL). Conclusions: The mechanism of cinaguaiacin’s action may be associated with damage to the plasma membrane, as the protein and DNA levels were higher than those of the positive control. The n-hexane extract and cinaguaiacin obtained from A. cina showed a bacteriostatic or bactericidal effect, depending on the strain evaluated. Full article

Novel carboxymethylcellulose (CMC) films with liquid products of pyrolysis (LPP) from wood pine were produced. The obtained CMC-LPP films were plasticized with 5% glycerol. CMC-LPP films were a light brown colour with a characteristic smoky scent, and showed a higher oxygen permeability when compared to control film without the addition of the LPP. CMC-LPP exhibited high antioxidant activity (5 and 18 times higher than CMC films). Furthermore, the antibacterial activity of the CMC-LPP films was tested, showing a strong inhibiting growth effect on the seven tested human pathogenic bacteria. The new material had the most substantial bacteriostatic effect on Listeria monocytogenes, Salmonella typhimurium, and Pseudomonas aeruginosa. Introduction of LPP to plasticised CMC produces an eco-friendly material with biocidal effect and favourable mechanical and structural properties, which shows its potential for possible use in many industries. Full article

Development of bio-based active packaging systems for lipid stabilization presents critical importance in preserving lipid integrity and ensuring food safety. Zein/citric acid (Z/CA) composite films containing grape seed ethanol extract (GSEE) (0–8% w/w) were prepared by the solvent casting method. The structural, functional, and environmental properties of the films, including physical and chemical properties, mechanical properties, antioxidant capacity, antibacterial activity, oxidation inhibition effect, and biodegradability, were comprehensively characterized and evaluated. Progressive GSEE enrichment significantly enhanced film thickness (p < 0.05), hydrophobicity, and total phenolic content, while increasing water vapor permeability by 61.29%. Antioxidant capacity demonstrated radical scavenging enhancements of 83.75% (DPPH) and 89.33% (ABTS) at maximal GSEE loading compared to control films. Mechanical parameters exhibited inverse proportionality to GSEE concentration, with tensile strength and elongation at break decreasing by 28.13% and 59.43%, respectively. SEM microstructural analysis revealed concentration-dependent increases in surface asperity and cross-sectional phase heterogeneity. Antimicrobial assays demonstrated selective bacteriostatic effects against Gram-negative pathogens. Notably, the composite film containing 6 wt% GSEE had a remarkable restraining effect on the oxidation of lard. The soil degradation experiment has confirmed that the Z/CA/GSEE composite film can achieve obvious degradation within 28 days. The above results indicate that the Z/CA/GSEE composite material emerges as a promising candidate for sustainable active food packaging applications. Full article

Aphis gossypii Glover (Homoptera: Aphidinae), a major pest of Chinese pepper (Zanthoxylum bungeanum Maxim), causes significant agricultural damage. Ginger (Zingiber officinale Roscoe) has shown potential as a source for developing botanical pesticides due to its strong bacteriostatic and insecticidal properties; however, the underlying mechanisms remain poorly understood. This study evaluated the repellent activity of ginger shoot extract (GSE) across four solvent phases—petroleum ether, trichloromethane, ethyl acetate, and methanol—against A. gossypii. The results demonstrated that GSE exhibited significant repellent effects, with the methanol phase showing the most pronounced activity. Twelve fractions were chromatographically separated from the methanol phase, and electroantennography (EAG) analysis revealed that fraction 4 induced strong EAG responses in both winged and wingless aphids. Further identification of active compounds in fraction 4 by gas chromatography–mass spectrometry (GC–MS) indicated the presence of terpenes, aromatics, alkanes, esters, and phenols as major constituents. Subsequent EAG analysis identified several key compounds—octahydro-pentalene (C1), (Z)-cyclooctene (C2), dimethylstyrene (C3), tetramethyl-heptadecane (C5), tetrahydro-naphthalene (C6), and heptacosane (C9)—as responsible for eliciting EAG responses in both aphid forms. Additionally, results from Y-tube olfactometer assays showed that (Z)-cyclooctene and heptacosane were significantly attractive, while octahydro-pentalene acted as a strong repellent to both winged and wingless aphids. These findings offer valuable insights for the development of synthetic attractants and repellents for A. gossypii and provide a theoretical foundation for utilizing ginger in the creation of botanical pesticides targeting this pest. Full article

The rising antifungal resistance in Nakaseomyces glabratus, especially to azole drugs like fluconazole, itraconazole, and voriconazole, presents a significant clinical challenge. Plant-derived compounds with synergistic antifungal effects offer a promising solution. Fruitless wolfberry bud tea, rich in flavonoids from a Lycium barbarum L. hybrid, shows potential but is underexplored in antifungal therapies. This study assessed FWE’s antifungal efficacy alone and with azoles against resistant N. glabratus isolates, exploring mechanisms like efflux pump inhibition and gene expression changes. A total of 52 clinical isolates were tested. Fruitless wolfberry bud tea was methanol-extracted (FWE) and lyophilized. Antifungal susceptibility was evaluated using broth microdilution, and synergistic effects were analyzed with checkerboard assays. Growth inhibition, rhodamine 6G efflux, and qRT-PCR for resistance-related genes were conducted. FWE demonstrated inhibitory activity with MICs ranging from 16 to 32 μg/mL. When combined with ITR or VRC, synergistic or additive effects were observed, reducing MICs by 2–8-fold. FWE + VRC exhibited synergy (FICI ≤ 0.5) in 50% of isolates, while FWE + ITR showed synergy in 37.5%. Efflux pump activity, measured by rhodamine 6G, significantly decreased in combination groups (11.4–14.6%) compared to monotherapy (17.3–17.5%). qRT-PCR indicated downregulation of CgCDR1, CgERG11, and CgPDR1 in FWE-treated Cg 1 isolate, with greater suppression in combination groups. FWE might boost the bacteriostatic impact of azole antifungal drugs by blocking efflux pumps and altering the expression of resistance genes. This study identifies FWE as a potent adjuvant to overcome cross-resistance, supporting its inclusion in antifungal strategies. Further research to identify bioactive compounds in FWE and in vivo validation is necessary for clinical application. Full article

Fusarium stalk rot (FSR), a devastating soil-borne disease caused by Fusarium species, severely threatens global maize production through yield losses and mycotoxin contamination. Bacillus subtilis, a plant growth-promoting rhizobacterium (PGPR), has shown potential as a biocontrol agent against soil-borne pathogens, but its efficacy and mechanisms against maize FSR remain poorly understood. In this study, an identified strain of B. subtilis A3 was introduced to study its biological control potential against corn stalk rot. The bacteriostatic stability of the biocontrol strain was assessed, revealing that its inhibitory activity against F. graminearum remained consistent over five consecutive generations, indicating robust bacteriostatic stability. The strain also exhibited inhibitory effects on F. verticilliodes, F. proliferalum, and other pathogenic fungi, demonstrating it has broad-spectrum antibacterial activity. Indoor experiments showed that treatment with the biocontrol strain significantly increased plant height, stem diameter, and fresh weight, indicating a positive impact on corn growth. Additionally, the biocontrol strain A3 markedly reduced the lesion length of corn stalk rot, confirming its efficacy in controlling the disease. Field trials demonstrated that the growth of the A3-coated corn seeds was better than the control seeds, the control effect of FSR disease was 45.75%, and the yield increase was 3.6%. Microscopic observations revealed that the biocontrol strain A3 caused the hyphal tips of F. graminearum to swell and exhibit a beaded morphology, inhibiting normal growth. The volatile substances produced by A3 also showed significant antibacterial activity, with the antibacterial spectrum aligning with that of the biocontrol strain. Using headspace solid-phase microextraction and GC-MS, various antibacterial compounds were identified in the volatile substances. Analysis of root-associated microorganisms indicated that A3 significantly changed the microbial community composition. Co-occurrence network analysis revealed that A3-treated plants had fewer edges and lower negative correlations among bacterial communities. This study establishes the strong biocontrol potential of B. subtilis A3 against Fusarium stalk rot in corn, demonstrating its robust bacteriostatic stability, broad-spectrum antibacterial activity, positive impact on plant growth, and significant disease control efficacy, while also revealing its ability to alter root-associated microbial communities. These findings provide a foundation for further research into the mechanism of B. subtilis and its application in field biological control. Full article

The study examined the sustained release of neem from the polymeric carrier system chitosan by varying the drug content, ionic strength of the release medium, and pH. Six different kinetic models, i.e., Korsmeyer–Peppas (KP), Peppas–Sahlin (PS), Higuchi, Hixson–Crowell, Zero order, and First order were used to investigate the drug release kinetics. Based on the R² values, the KP and PS models were chosen from the examined models to study the drug release mechanism from the chitosan biopolymer. The values found for model parameters n and m in the KP and PS models differ noticeably, suggesting that Fickian diffusion and Case II relaxation are important components of the neem release mechanism from chitosan. At lower ionic strengths and lower pH values, neem is released from the composite mostly by Fickian diffusion. The diphenyl-2-picrylhydrazyl assay served to assess the composite’s antioxidant properties. The composite’s antioxidant properties ranged from 3.56 ± 1.89% at 10 μg/mL to 51.28 ± 1.14% at 70 μg/mL. The ability of the composite to inhibit the denaturation of egg albumin was also tested and it ranged from 59.68 ± 0.93% at 25 μg/mL to 187.63 ± 3.53% at 1600 μg/mL. The drug composite has exhibited antibacterial activity against Klebsiella pneumoniae, Pseudomonas aeruginosa, Escherichia coli, and Staphylococcus aureus, and proved to be highly effective against P. aeruginosa at lower concentrations and against S. aureus at higher concentrations. The resulting inhibition zones for P. aeruginosa at 5 and 10 mg/mL concentrations were 16.5 ± 2.25 mm, and 14.83 ± 0.6 mm, respectively, whereas for S. aureus, it was 16.67 ± 0.33 mm at 20 mg/mL. The neem–chitosan composite’s minimum inhibitory concentration/minimum bactericidal concentration ratio for K. pneumoniae, P. aeruginosa, and S. aureus was greater than 4, suggesting that they trigger bacteriostatic outcomes, whereas for E. coli, it was 4, which means that bactericidal effects were evident. Full article

The destructive bacterial wilt disease caused by Ralstonia solanacearum leads to substantial losses in pepper production worldwide. Plant-derived pesticides exhibit advantages of high efficiency and broad spectrum when compared to traditional chemical pesticides. Artemisia annua and ‘Tai Jiao’ No. 1 were used as the experimental materials, and treated with 0.75 g·mL⁻¹, 1.5 g·mL⁻¹, and 3 g·mL⁻¹ of A. annua extract and inoculated with R. solanacearum at a concentration of OD600 = 0.1 for 14 days. The inhibitory activity of A. annua extracts against R. solanacearum, as well as the disease index, defense enzyme activities, and defense-related substances contents of pepper seedlings were determined. The results showed that the Minimum Inhibitory Concentration (MIC) of the A. annua extract was 3 g·mL⁻¹. As the concentration of A. annua extract increased, the extent of R. solanacearum cell crumpling intensified, accompanied by a gradual decline in its biofilm-forming ability. On the 14th day after treatment, the disease severity index and incidence rate were significantly reduced when the A. annua extract was applied at concentrations of 0.75 g·mL⁻¹ and 3 g·mL⁻¹. At both the 7th and 14th days after treatment, the application of A. annua extract at concentrations of 0.75 g·mL⁻¹ and 3 g·mL⁻¹ led to enhanced activities of superoxide dismutase (SOD), peroxidase (POD), and catalase (CAT) in peppers at different stages. Simultaneously, it reduced the levels of malondialdehyde (MDA) and hydrogen peroxide (H₂O₂), effectively scavenging reactive oxygen species and alleviating cellular lipid peroxidation. Furthermore, the extract increased the activities of polyphenol oxidase (PPO) and phenylalanine ammonia-lyase (PAL), as well as elevated the contents of soluble protein, flavonoids, and total phenols, ultimately enhancing the disease resistance of peppers. Considering the development costs, the application of A. annua extract at a concentration of 0.75 g·mL⁻¹ demonstrates great potential for green control measures against bacterial wilt in peppers. Full article