128 results
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2. Engineering Robust Silver-Decorated calcium peroxide Nano-Antibacterial Platforms for chemodynamic enhanced sterilization.
- Author
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Bai G, Niu C, Liang X, Li L, Feng Y, Wei Z, Chen K, Bohinc K, and Guo X
- Subjects
- Hydrogels chemistry, Hydrogels pharmacology, Hydrogen-Ion Concentration, Hydrogen Peroxide pharmacology, Hydrogen Peroxide chemistry, Particle Size, Silicon Dioxide chemistry, Silicon Dioxide pharmacology, Surface Properties, Sterilization, Silver chemistry, Silver pharmacology, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Escherichia coli drug effects, Staphylococcus aureus drug effects, Peroxides chemistry, Peroxides pharmacology, Metal Nanoparticles chemistry, Microbial Sensitivity Tests
- Abstract
Calcium peroxide (CaO
2 ) is commonly used as a hydrogen peroxide (H2 O2 ) donor to eliminate bacterial infections. However, the rapid dissociation of CaO2 and the explosive release of H2 O2 have limited the development of CaO2 in the antibacterial field. Therefore, a series of silver nanoparticles (AgNPs) functionalized bacteria-triggered smart hydrogels (CSA-H) that integrate sustained release of nanoparticles and localized chemodynamic sterilization were constructed. The pH-responsive hydrogel formed through the Schiff base reaction enables the responsive release of CaO2 nanoparticles while simultaneously regulating the concentration of H2 O2 within the bacterial infection microenvironment. AgNPs are capable of reacting with H2 O2 under mildly acidic conditions to produce hydroxyl radicals with enhanced antimicrobial activity. The antimicrobial results demonstrated that AgNPs functionalized silicon dioxide-coated calcium peroxide (CaO2 @SiO2 /AgNPs) nanoparticles exhibited enhanced bactericidal activity compared to AgNPs or CaO2 alone. Furthermore, CSA-H hydrogels exhibited significant antibacterial activity against S. aureus and E. coli under the dual effect of AgNPs and pH-driven Fenton-like reactions. This chemodynamic antibacterial platform is environmentally responsive and provides a promising strategy for creating multifunctional hydrogels loaded with nano-enzymes, thus advancing the development of AgNPs in chemodynamic-antibacterial related applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)- Published
- 2025
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3. "Mending with silk" enhances aged silk with mechanical and antibacterial properties.
- Author
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Gao D, Yang X, Lyu B, Xue L, Wei Y, Ma J, and Zhou S
- Subjects
- Silk chemistry, Microbial Sensitivity Tests, Transglutaminases metabolism, Transglutaminases chemistry, Surface Properties, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Escherichia coli drug effects, Chitosan chemistry, Chitosan pharmacology, Chitosan analogs & derivatives, Staphylococcus aureus drug effects, Fibroins chemistry, Fibroins pharmacology
- Abstract
The reinforcement and preservation of historical silk are crucial for its continued research, heritage, and display. Herein, silk fibroin (SF) and carboxymethyl chitosan (CMCS) were utilized as raw materials to reinforce aged silk via two reinforcement methods, with transglutaminase (TGase) serving as a catalytic cross-linking agent. The covalent and non-covalent bond network formed by TGase catalytic cross-linking significantly improved the mechanical properties of aging silk, and CMCS as an antibacterial material gave excellent antibacterial properties of the aged silk. Compared with aged silk, the breaking stress and elongation at break of the aged silk after reinforcement are increased by 257.9% and 293.7% respectively. The antibacterial rate of the reinforced aged silk against Escherichia coli (E. coli) and Streptococcus aureus (S. aureus) exceeded 90%. Under accelerated simulated aging conditions, the aging rate of the reinforced silk was significantly reduced, demonstrating notable aging resistance. Notably, the one-step enhanced aged silk outperformed the two-step enhanced aged silk in all performance evaluations, while the appearance of the aged silk was not affected. This work provides a green and efficient process for the reinforcement and protection of silk-based cultural relics and the application of silk cultural relics protection materials., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2025
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- View/download PDF
4. Customized design of host-independent T7 expression system (HITES) for a broad host range.
- Author
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Cui M, Wong O, Shi K, Li Q, and Wang W
- Subjects
- Bacteriophage T7 genetics, Bacteriophage T7 enzymology, Synthetic Biology methods, Metabolic Engineering methods, Host Specificity genetics, Recombinant Proteins genetics, Recombinant Proteins metabolism, Escherichia coli genetics, Escherichia coli metabolism, DNA-Directed RNA Polymerases genetics, DNA-Directed RNA Polymerases metabolism, Viral Proteins genetics, Viral Proteins metabolism
- Abstract
Efficient methods and universal DNA elements are eagerly required for the expression of proteins and the production of target chemicals in synthetic biology and metabolic engineering. This paper develops a customized-design approach by utilizing the host-independent T7 expression system (HITES), which facilitates the rational design and rapid construction of T7 expression systems. Firstly, the E
i L (Upper-limit value of initial enzyme activity) value is discovered to play a pivotal factor in the successful construction of the T7 expression system, different host strains exhibit varying Ei L values, and this study presents a method to measure the Ei L values. Secondly, E. coli DH5α is chosen as the host strain, and it demonstrates that various strategies to modulate T7 RNA polymerase activity can efficiently construct the HITES T7 expression system in E. coli DH5α under the guidance of Ei L. Lastly, the customized-design of HITES enables the efficient expression of sfGFP and D-MIase proteins across 13 host strains, guided by Ei L values. This customized-design method of HITES offers a streamlined pathway for T7 system construction across a broad range of hosts and serves as an enabling tool for synthetic biology, metabolic engineering, and enzyme engineering., Competing Interests: Declaration of Competing Interest The authors declare that we have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier B.V. All rights reserved.)- Published
- 2025
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5. Insights on bacteria inactivation in water by cold plasma: Effect of water matrix and pulsed plasmas waveform on physicochemical water properties, species formation and inactivation efficiency of Escherichia coli.
- Author
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Triantaphyllidou IE and Aggelopoulos CA
- Subjects
- Disinfection methods, Water Microbiology, Water Purification methods, Reactive Oxygen Species metabolism, Hydrogen-Ion Concentration, Escherichia coli drug effects, Plasma Gases pharmacology
- Abstract
This study investigates the inactivation of Escherichia coli (E. coli) using pulsed dielectric barrier discharges (DBDs) powered by high-voltage nanosecond and/or microsecond pulses to establish optimal operational conditions. The effects of pulse voltage waveform and water matrix (distilled vs. tap water) were evaluated in terms of inactivation efficiency and energy consumption, along with the generation of reactive oxygen and nitrogen species (RONS). Complete E. coli inactivation (9-log CFU/ml) in distilled water was achieved within 20 min of nanopulsed-DBD treatment, coinciding with rapid acidification, while in tap water, 90 min was required for complete inactivation. Interestingly, at treatment times with similar pH levels between water types, E. coli inactivation was more effective in tap water. Ozone concentrations showed the most significant difference, being ∼6 times higher in distilled water (10.3 mg/L) than in tap water (1.7 mg/L). Although distilled and tap water had similar concentrations of short- and long-lived plasma species, the differing inactivation efficiencies indicate a synergistic effect between pH reduction and reactive species in impairing E. coli functionality. Micropulsed-DBD led to increased concentration of plasma species, faster acidification and inactivation in tap water (complete inactivation within 8 min), but at significantly higher electrical energy per order (56.9 kWh/m
3 compared to 17.4 kWh/m3 for nanopulsed-DBD). The lowest energy per order was recorded for nanopulsed-DBD in distilled water, at 3.8 kWh/m³, highlighting pulsed-DBD plasma as a safe and energy-efficient method for water disinfection. This study offers valuable insights into using an innovative, sustainable plasma-based approach for bacterial inactivation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)- Published
- 2025
- Full Text
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6. Successful strategies for expression and purification of ABC transporters.
- Author
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Berner B, Daoutsali G, Melén E, Remper N, Weszelovszká E, Rothnie A, and Hedfalk K
- Subjects
- Humans, HEK293 Cells, Recombinant Proteins isolation & purification, Recombinant Proteins metabolism, Recombinant Proteins chemistry, Recombinant Proteins genetics, ATP-Binding Cassette Transporters chemistry, ATP-Binding Cassette Transporters isolation & purification, ATP-Binding Cassette Transporters genetics, ATP-Binding Cassette Transporters metabolism, Escherichia coli genetics, Escherichia coli metabolism
- Abstract
ATP-binding cassette (ABC) transporters are proteins responsible for active transport of various compounds, from small ions to macromolecules, across membranes. Proteins from this superfamily also pump drugs out of the cell resulting in multidrug resistance. Based on the cellular functions of ABC-transporters they are commonly associated with diseases like cancer and cystic fibrosis. To understand the molecular mechanism of this critical family of integral membrane proteins, structural characterization is a powerful tool which in turn requires successful recombinant production of stable and functional protein in good yields. In this review we have used high resolution structures of ABC transporters as a measure of successful protein production and summarized strategies for prokaryotic and eukaryotic proteins, respectively. In general, Escherichia coli is the most frequently used host for production of prokaryotic ABC transporters while human embryonic kidney 293 (HEK293) cells are the preferred host system for eukaryotic proteins. Independent of origin, at least two-steps of purification were required after solubilization in the most used detergent DDM. The purification tag was frequently cleaved off before structural characterization using cryogenic electron microscopy, or crystallization and X-ray analysis for prokaryotic proteins., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2025
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- View/download PDF
7. Multi-scale influences on Escherichia coli concentrations in shellfish: From catchment to estuary.
- Author
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Malham SK, Taft H, Farkas K, Ladd CJT, Seymour M, Robins PE, Jones DL, McDonald JE, Le Vay L, and Jones L
- Subjects
- Animals, Rivers microbiology, Rivers chemistry, Wales, Mytilus edulis microbiology, England, Crassostrea, Water Microbiology, Escherichia coli, Estuaries, Shellfish, Environmental Monitoring
- Abstract
Sustainability of bivalve shellfish farming relies on clean coastal waters, however, high levels of faecal indicator organisms (FIOs, e.g. Escherichia coli) in shellfish results in temporary closure of shellfish harvesting beds to protect human health, but with economic consequences for the shellfish industry. Active Management Systems which can predict FIO contamination may help reduce shellfishery closures. This study evaluated predictors of E. coli concentrations in two shellfish species, the blue mussel (Mytilus edulis) and the Pacific oyster (Crassostrea gigas), at different spatial and temporal scales, within 12 estuaries in England and Wales. We aimed to: (i) identify consistent catchment-scale or within-estuary predictors of elevated E. coli levels in shellfish, (ii) evaluate whether high river flows associated with rainfall events were a significant predictor of shellfish E. coli concentrations, and the time lag between these events and E. coli accumulation, and (iii) whether operation of Combined Sewer Overflows (CSO) is associated with higher E. coli concentrations in shellfish. A cross-catchment analysis gave a good predictive model for contamination management (R
2 = 0.514), with positive relationships between E. coli concentrations and river flow (p = 0.001), turbidity (p = 0.002) and nitrate (p = 0.042). No effect was observed for catchment area, the number of point source discharges, or agricultural land use type. 64% of all shellfish beds showed a significant relationship between E. coli and river flow, with typical lag-times of 1-3 days. Detailed analysis of the Conwy estuary indicated that E. coli counts were consistently higher when the CSO had been active the previous week. In conclusion, we demonstrate that real-time river flow and water quality data may be used to predict potential risk of E. coli contamination in shellfish at the catchment level, however, further refinement (coupling to fine-scale hydrodynamic models) is needed to make accurate predictions for individual shellfish beds within estuaries., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)- Published
- 2025
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8. Engineering an Escherichia coli surface display platform based on an autotransporter from Stenotrophomonas maltophilia: Autodisplay of enzymes with low to high molecular weight.
- Author
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Gao K, Yu K, Sun J, Mao X, and Dong H
- Subjects
- Bacterial Proteins genetics, Bacterial Proteins metabolism, Bacterial Proteins chemistry, Cell Surface Display Techniques methods, Stenotrophomonas maltophilia enzymology, Stenotrophomonas maltophilia genetics, Stenotrophomonas maltophilia metabolism, Escherichia coli genetics, Escherichia coli metabolism, Molecular Weight
- Abstract
Surface display technology has garnered significant attention for preparing efficient whole cell catalysts, while reported carrier proteins still cannot meet the demand to display various passenger domains, especially for those with high molecular weight. This study demonstrates that the autotransporter of esterase Est7 (E7AT) from Stenotrophomonas maltophilia played a decisive role in its efficient surface display. Guided by the original signal peptide, the surface display ratio of Est7 was determined as 89.67 % with the total enzymatic activity of 16.67 U/mL, which was much higher than 4.60 U/mL and 5.70 U/mL for the signal peptides derived from pectolase B (pelB) and cholera toxin B (ctxB), respectively. Then, the E7AT unit was successfully developed to surface display proteins with varying molecular weight from 19.3 kDa to 117.9 kDa, showing a more effective autodisplay ability than adhesin involved in diffuse adherence (AIDA-I), ice nucleation proteins (InaK and InaP), and outer membrane proteins (lipoprotein/ompA, MltA-interacting protein A, and yiaT) systems. Additionally, a galactosidase (GAL) displayed by E7AT was employed to hydrolyze lactose, achieving a promising hydrolysis rate of 31.63 % in 2 h. The displayed GAL retained 63.24 % and 41.41 % activity in third and sixth batch, respectively, indicating the considerable potential of E7AT in developing efficient whole cell catalysts., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2025
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9. Hollow-structured Zn-doped CeO 2 mesoporous spheres boost enhanced antioxidant activity and synergistic bactericidal effect.
- Author
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Zuo L, Bao Y, Wu K, Li S, Qu Z, Lyu Y, Li X, Meng H, and He Y
- Subjects
- Microscopy, Electron, Transmission, Antioxidants chemical synthesis, Antioxidants pharmacology, Cerium chemistry, Cerium pharmacology, Anti-Bacterial Agents chemical synthesis, Anti-Bacterial Agents pharmacology, Escherichia coli drug effects, Staphylococcus aureus drug effects, Nanospheres, Zinc Compounds chemical synthesis, Zinc Compounds pharmacology
- Abstract
The increasing prevalence of antibiotic-resistant bacteria is regarded as one of the worst threats to the environment and global health, and antimicrobial nanomaterials have been increasingly explored to provide solutions for antimicrobial resistance problems. In this paper, mesostructured Zn-doped CeO
2 hollow spheres (ZDCHS) with various Zn/Ce ratios were successfully prepared by a conventional one-pot hydrothermal synthesis method. The ingenious incorporation of Zn playing a vital role in the fabrication of hollow structure of ZDCHS with high specific surface area, and detailed transmission electron microscopy (TEM) characterization confirmed the homogeneous distribution of Zn element across the ZDCHS. The X-ray photoelectron spectroscopy (XPS) and Raman results indicated that a higher concentration of oxygen vacancies was obtained on the ZDCHS compared to the undoped CeO2 counterparts. In addition, the in vitro antioxidant properties evaluated toward scavenging DPPH radicals, hydroxyl radicals and superoxide radicals further revealed the enhanced antioxidant activity of ZDCHS derived from the doping with Zn ions. Furthermore, the bacteriostatic assay against Gram-negative (E. coli) and Gram-positive (S. aureus) bacteria showed that the ZDCHS possessed synergistically improved bacteriostatic performance and were more susceptible to S. aureus with a maximal antimicrobial ratio of 99.5 %, which is higher than that of the undoped CeO2 samples (80.7 %). These results represent a new paradigm to the design of novel hollow-structured materials, highlighting the doping of Zn ions in the lattice structure of CeO2 provides a feasible means for the preparation of effective antioxidants and antimicrobial agents., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2025
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10. CTX-M, SHV, TEM and VEB β-lactamases, and MCR-1 among multidrug-resistant Escherichia coli and Klebsiella isolates from environment near animal farms in Thailand.
- Author
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Srisrattakarn A, Saiboonjan B, Tippayawat P, Angkititrakul S, Chanawong A, Pornchoo C, Smithkittipol C, and Lulitanond A
- Subjects
- Animals, Thailand epidemiology, Swine, Klebsiella drug effects, Klebsiella genetics, Klebsiella isolation & purification, Klebsiella enzymology, Salmonella drug effects, Salmonella isolation & purification, Salmonella genetics, Salmonella enzymology, Klebsiella pneumoniae drug effects, Klebsiella pneumoniae genetics, Klebsiella pneumoniae isolation & purification, Escherichia coli Proteins genetics, Methicillin-Resistant Staphylococcus aureus drug effects, Methicillin-Resistant Staphylococcus aureus isolation & purification, Methicillin-Resistant Staphylococcus aureus genetics, Environmental Microbiology, beta-Lactamases genetics, Escherichia coli drug effects, Escherichia coli genetics, Escherichia coli isolation & purification, Escherichia coli enzymology, Farms, Drug Resistance, Multiple, Bacterial genetics, Microbial Sensitivity Tests, Anti-Bacterial Agents pharmacology, Chickens microbiology
- Abstract
Background: Currently, antimicrobial agents are widely used in both animals and agriculture, causing the crisis of multidrug-resistant (MDR) bacteria. In this study we surveyed for 4 important antimicrobial-resistant bacteria: extended-spectrum β-lactamase (ESBL)-producing Escherichia coli, Klebsiella pneumoniae and Salmonella spp., and methicillin-resistant Staphylococcus aureus (MRSA) from the environment around chicken and pig farms., Methods: Forty-four soils, 44 water and 15 bootstrap samples were collected from upstream and downstream of the riverside close to 22 animal farms in 2020 (9 farms) and 2023 (13 farms). The samples were cultured in appropriate media and isolated colonies were further identified. Antimicrobial susceptibility and ESBL production were tested by disk diffusion method except for colistin susceptibility determined by broth disk elution test. Common resistance genes were tested by polymerase chain reaction (PCR) methods., Results: A total of 123 E. coli (n = 59) and Klebsiella species (n = 64) were identified and 25 isolates of them were MDR; 21 and 4 isolates from the downstream and upstream areas respectively. In addition, 13 isolates were ESBL producers, of which 12 isolates were from the downstream area. The most common ESBL gene among both organisms was bla
CTX-M , whereas colistin resistance gene, mcr-1, was found in 2 E. coli isolates. Salmonella spp. and MRSA were not isolated from any sample., Conclusions: Antimicrobial-resistant bacteria were found in the environment around the animal farms especially from the downstream area, suggesting the urgent need of judicious use of antimicrobial agents in animal farms., Competing Interests: Declaration of Competing Interest All authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Ltd.. All rights reserved.)- Published
- 2025
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11. Strategies to enhance the hydrolytic activity of Escherichia coli BL21 penicillin G acylase based on heterologous expression and targeted mutagenesis.
- Author
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Ye T, An Z, Song M, Wei X, Liu L, Zhang X, Zhang H, Liu H, and Fang H
- Subjects
- Hydrolysis, Providencia genetics, Providencia enzymology, Providencia metabolism, Catalytic Domain, Mutagenesis, Penicillin Amidase genetics, Penicillin Amidase metabolism, Penicillin Amidase chemistry, Escherichia coli genetics, Escherichia coli metabolism, Mutagenesis, Site-Directed
- Abstract
Penicillin G acylase (PGA) serves as a critical biocatalyst for the hydrolysis of penicillin G, yielding 6-aminopenicillanic acid, a vital precursor for β-lactam semi-synthetic antibiotics. The catalytic efficiency of PGA, however, remains suboptimal in native Escherichia coli strains. To improve this, E. coli BL21 was engineered as a microbial cell factory via heterologous expression and site-directed mutagenesis to enhance PGA activity. The heterologous pga gene from Providencia rettgeri was integrated into E. coli BL21 (DE3) for the biosynthesis of PGA, achieving a PGA activity of 253 ± 2 U/mL after 16 hours of fermentation. The N167 site underwent mutation, producing the sites N167A and N167I. Plasmids carrying these mutations were introduced into E. coli BL21(DE3), and the enzymatic activities were recorded as 293 ± 3 U/mL for the N167A mutant and 238 ± 2 U/mL for the N167I mutant. This study not only introduces a novel approach to enhancing PGA activity but also illustrates the potential for catalytic optimization through targeted modifications of the enzyme's active site., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2025
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12. Examining the impact of hydroxy group position on antibacterial activity of copper complexes derived from vanillin-based Schiff bases: Experimental and computational analysis.
- Author
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Bima DN, Firdaus SN, Darmawan A, and Nugraha MY
- Subjects
- Schiff Bases chemistry, Schiff Bases pharmacology, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Copper chemistry, Copper pharmacology, Escherichia coli drug effects, Coordination Complexes chemistry, Coordination Complexes pharmacology, Microbial Sensitivity Tests, Staphylococcus aureus drug effects, Benzaldehydes chemistry, Benzaldehydes pharmacology
- Abstract
The positioning of the hydroxy group plays a crucial role in the coordination of Schiff bases with copper ions and their antibacterial effectiveness. This potential is an area of interest for future exploration, although no specific studies have been conducted. This study aims to reveal the significance of the positioning of the hydroxy group in the ability of the Schiff base to coordinate with copper ion and its antibacterial efficacy against E. coli and S. aureus. By utilizing ortho-vanillin and para-vanillin as precursors, we successfully synthesized Schiff bases HL1 (ortho) and L2 (para), which were confirmed through Fourier Transform Infrared (FT-IR) and Nuclear Magnetic Resonance (NMR) analyses. HL1 forms the CuL1 complex as a bidentate ligand with N, O donor atoms, while L2 only provides a single N donor atom, forming the CuL2 complex but retaining a free hydroxy group. Crystallographic analysis revealed a tetragonal crystal system for the Schiff base and orthorhombic for the complex. Electronic transition analysis supported by Density Functional Theory (DFT) studies indicated a distorted square plane geometry for the CuL1 and CuL2 complexes. The in vitro antibacterial assessment against E. coli and S. aureus revealed that the CuL1 and CuL2 complexes exhibited significantly better activity than Schiff bases HL1 and L2. Moreover, CuL2 exhibits greater bioactivity against both bacterial strains compared to CuL1. This difference could be attributed to a free hydroxy group, supported by computational analysis. Our findings suggest that the formation of complexes and the presence of free hydroxy groups may enhance the antibacterial activity of the drug., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2025 Elsevier Ltd. All rights reserved.)
- Published
- 2025
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13. Semi-rational engineering of glucosamine-6-phosphate deaminase for catalytic synthesis of glucosamine from D-fructose.
- Author
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Zhang ZH, Liao YX, Deng XT, and Guan ZB
- Subjects
- Protein Engineering, Fructose metabolism, Glucosamine metabolism, Glucosamine chemistry, Escherichia coli genetics, Escherichia coli metabolism, Aldose-Ketose Isomerases genetics, Aldose-Ketose Isomerases metabolism, Aldose-Ketose Isomerases chemistry
- Abstract
Glucosamine (GlcN), as one of the important derivatives of D-glucose, is formed by the substitution of the hydroxyl group at position 2 of glucose with an amino group. As a bioactive amino monosaccharide, GlcN is known for its various biological effects, including immune enhancement, antioxidant, anti-inflammatory, hepatoprotective, joint pain relief, and alleviation of osteoporosis. These properties highlight the broad applications of GlcN and its derivatives in pharmaceuticals, cosmetics, food production, and other fields, underscoring their promising prospects. Thus, the efficient industrial production of GlcN is gaining increasing attention as well. Here, we report a novel biosynthetic method for GlcN, utilizing engineered Escherichia coli expressing glucosamine-6-phosphate deaminase (GlmD) to directly convert D-fructose into GlcN. The best mutant screened using the Morgan-Elson colorimetric method is the triple mutant G42S/G43C/G136T (designated as GlmD-ZH11), which exhibits approximately 21 times higher catalytic activity towards D-fructose compared to the wild type. Using the purified enzyme of GlmD-ZH11 in shaken flask fermentation for six hours, we achieved a conversion rate of 72.11 % from D-fructose to GlcN. To further elucidate the mechanism behind the enhanced activity of the GlmD-ZH11 mutant, we conducted hydrogen bond network analysis to investigate the hydrogen bond interactions between the mutant and fructose. Additionally, we performed molecular dynamics simulations to study the RMSD and RMSF curves of the mutant. The results indicate that the protein structure of the mutant ZH11 is more stable and binds more tightly to the substrate. Calculations of the solvent-accessible surface area and binding free energy suggested that Thr41, Ser42, Asp72, Gly137, and Ala145 may be key amino acid residues in the catalytic process of ZH11. Finally, based on these findings and the catalytic mechanism of the wild type, we hypothesized a potential catalytic reaction mechanism for the ZH11 mutant., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2025
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14. Highly efficient visible-light-driven S-scheme graphene bridged MoS 2 /Co 3 O 4 nanohybrid for the photocatalytic performance of hazardous dye and antibacterial activity.
- Author
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Chen L, Chen CW, and Dong CD
- Subjects
- Catalysis, Coloring Agents chemistry, Photolysis, Environmental Restoration and Remediation methods, Graphite chemistry, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents pharmacology, Molybdenum chemistry, Methylene Blue chemistry, Light, Oxides chemistry, Cobalt chemistry, Disulfides chemistry, Escherichia coli drug effects
- Abstract
A novel graphene-bridged MoS
2 /Co3 O4 (MCG) nanohybrid was well fabricated by a hydrothermal route. The purpose of valuable and economical S-scheme systems with vigorous interface interactions is pressing to photocatalytic efficiency and efficient utilization. While mighty progress has been created with respect to charge carrier bridges, the charge transferring ability of the facility charge carrier bridges is far from capable owing to lower electrical conductivity. The photocatalytic antibacterial tests were performed with visible light activity, and the results exhibited that the as-prepared MCG nanohybrid with powerful interfacial coupling presented excellent photodegradation performance in comparison with bare MoS2 and Co3 O4 samples for the removal of methylene blue (MB) and E-coli with visible light irradiation. In addition, a better photocatalytic MB capability and antibacterial activity of 99.5 % and 100 % are approached through MCG-4 nanohybrid, which is 2.76 and 8.32 folds higher than that of the pristine MoS2 sample. The PL measurements and EIS analysis also illustrated that MCG-4 nanohybrid possesses a great separation efficiency of photoinduced charge carriers. This work provides a new objective for high-potential S-scheme photocatalysts and their utilization in the field of environmental remediation., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)- Published
- 2025
- Full Text
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15. Development of an advanced acetaldehyde detection solution based on yeast and bacterial surface display technology.
- Author
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Liu W, Cao J, Wu D, Wu Y, Qin Y, Liu Y, Zhao X, and Song Y
- Subjects
- Bacterial Outer Membrane Proteins genetics, Bacterial Outer Membrane Proteins metabolism, Cell Surface Display Techniques methods, Beverages analysis, Beverages microbiology, Wine analysis, Wine microbiology, Acetaldehyde metabolism, Acetaldehyde analysis, Saccharomyces cerevisiae genetics, Saccharomyces cerevisiae metabolism, Escherichia coli genetics, Escherichia coli metabolism, Biosensing Techniques methods, Aldehyde Oxidoreductases metabolism, Aldehyde Oxidoreductases genetics
- Abstract
Acetaldehyde, a carcinogen widely present in various beverages and the natural environment, necessitates convenient and efficient detection methods. In this work, two different host strains were used to develop a sensitive, convenient, and efficient whole-cell optical biosensor for acetaldehyde detection. Acetaldehyde dehydrogenase (AldH) was displayed on the cell surface of Saccharomyces cerevisiae and E. coli using flocculin protein and the N-terminal ice nucleation protein (INP), respectively. The successful construction of yeast and bacteria surface display platforms was confirmed by laser scanning confocal microscopy. Then, the optimal AldH-display system for yeast and bacteria was confirmed. The optimum reaction conditions were determined by changing testing temperatures and pH values. The differences between the two display systems were compared. The highest whole-cell activities of yeast and bacteria under optimal conditions were 3.68 ± 0.07 U/mL/OD
600 for BY-S6G and 6.95 ± 0.04 U/mL/OD600 for E-32-Ir A. The strains with the best performance were chosen for the detection of acetaldehyde in wine and other beverage samples and showed substrate specificity and accuracy, in which the recovery rate ranged between 94.4 % and 110.1 %. The results demonstrated that the AldH surface display strains could be used as an optical biosensor to detect acetaldehyde in beverages and red wine., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2025
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16. Green-synthesised silver and zinc oxide nanoparticles from stingless bee honey: Morphological characterisation, antimicrobial action, and cytotoxic assessment.
- Author
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Bahari N, Hashim N, Abdan K, Akim AM, Maringgal B, and Al-Shdifat L
- Subjects
- Animals, Bees, Mice, Anti-Infective Agents pharmacology, Anti-Infective Agents chemistry, Anti-Infective Agents toxicity, Zinc Oxide chemistry, Honey analysis, Silver chemistry, Silver toxicity, Metal Nanoparticles chemistry, Metal Nanoparticles toxicity, Staphylococcus aureus drug effects, Escherichia coli drug effects, Green Chemistry Technology, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents toxicity, Microbial Sensitivity Tests
- Abstract
This study investigated the green synthesis of silver nanoparticles (Ag-NPs) and zinc oxide nanoparticles (ZnO-NPs) using an aqueous extract of stingless bee honey (SBH) as a reducing and stabilising agent. The rich compositions of SBH containing flavonoids, phenolics, organic acids, sugars, and enzymes makes the SBH extract an ideal biocompatible precursor for the NPs synthesis. Physicochemical characterisation of the synthesised NPs was performed using UV-Vis spectroscopy, FESEM, TEM, XRD, and FTIR spectroscopy. The results revealed that the Ag-NPs and ZnO-NPs exhibited polydispersity, with size ranges between 25-50 nm and 15-30 nm, respectively. A majority of the NPs possessed a spherical morphology. Furthermore, the study evaluated the antimicrobial activity of the SBH-based NPs against gram-positive (Staphylococcus aureus, ATCC 43300) and gram-negative (Escherichia coli, ATCC 25922) bacteria. The findings demonstrated significantly higher antimicrobial efficacy of the Ag-NPs with a zone of inhibition (ZOI) of 16.91 mm against S. aureus, and 17.43 mm against E. coli compared to the ZnO-NPs which having a ZOI of 13.05 mm and 14.01 mm, respectively. Notably, cytotoxicity assays revealed no adverse effects of the synthesised NPs on normal mouse fibroblast (3T3) and human lung fibroblast (MRC5) cells up to 100 μg/ml of concentration. These findings suggest the potential of SBH-based Ag-NPs and ZnO-NPs as safe and effective antibacterial agents for various applications, including pharmaceuticals, cosmetics, ointments, and lotions., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: NORHASHILA HASHIM reports financial support was provided by Universiti Putra Malaysia. NORHASHILA HASHIM reports a relationship with UNIVERSITI PUTRA MALAYSIA that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Ltd. All rights reserved.)
- Published
- 2025
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17. The ABC transporter Opp imports reduced glutathione, while Gsi imports glutathione disulfide in Escherichia coli.
- Author
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Knoke LR, Muskietorz M, Kühn L, and Leichert LI
- Subjects
- Biological Transport, Escherichia coli Proteins metabolism, Escherichia coli Proteins genetics, Escherichia coli metabolism, Escherichia coli genetics, Glutathione metabolism, ATP-Binding Cassette Transporters metabolism, ATP-Binding Cassette Transporters genetics, Glutathione Disulfide metabolism, Oxidation-Reduction
- Abstract
Glutathione is the major thiol-based antioxidant in a wide variety of biological systems, ranging from bacteria to eukaryotes. As a redox couple, consisting of reduced glutathione (GSH) and its oxidized form, glutathione disulfide (GSSG), it is crucial for the maintenance of the cellular redox balance. Glutathione transport out of and into cellular compartments and the extracellular space is a determinant of the thiol-disulfide redox state of the organelles and bodily fluids in question, but is currently not well understood. Here we use the genetically-encoded, glutathione-measuring redox probe Grx1-roGFP2 to comprehensively elucidate the import of extracellular glutathione into the cytoplasm of the model organism Escherichia coli. The elimination of only two ATP-Binding Cassette (ABC) transporter systems, Gsi and Opp, completely abrogates glutathione import into E. coli's cytoplasm, both in its reduced and oxidized form. The lack of only one of them, Gsi, completely prevents import of GSSG, while the lack of the other, Opp, substantially retards the uptake of reduced glutathione (GSH)., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier B.V. All rights reserved.)
- Published
- 2025
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18. Recent advances in recombinant production of soluble proteins in E. coli.
- Author
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de Marco A
- Subjects
- Glycosylation, Protein Folding, Solubility, Escherichia coli metabolism, Escherichia coli genetics, Recombinant Proteins biosynthesis, Recombinant Proteins genetics
- Abstract
Background: E. coli still remains the most commonly used organism to produce recombinant proteins in research labs. This condition is mirrored by the attention that researchers dedicate to understanding the biology behind protein expression, which is then exploited to improve the effectiveness of the technology. This effort is witnessed by an impressive number of publications, and this review aims to organize the most relevant novelties proposed in recent years., Results: The examined contributions address several of the known bottlenecks related to recombinant expression in E. coli, such as improved glycosylation pathways, more reliable production of proteins whose folding depends on the formation of disulfide bonds, the possibility of controlling and even benefiting from the formation of aggregates or the need to overcome the dependence of bacteria on antibiotics during bacterial culture. Nevertheless, the majority of the published papers aimed at identifying the conditions for optimal control of the translation process to achieve maximal yields of functional exogenous proteins., Conclusions: Despite community commitment, the critical question of what really is the metabolic burden and how it affects both host metabolism and recombinant protein production remains elusive because some experimental results are contradictory. This contribution aims to offer researchers a tool to orient themselves in this complexity. The new capacities offered by artificial intelligence tools could help clarifying this issue, but the training phase will probably require more systematic experimental approaches to collect sufficiently uniform data., Competing Interests: Declarations. Ethics approval and consent to participate: Not applicable. Consent for publication: Not applicable. Competing interests: The authors declare no competing interests., (© 2025. The Author(s).)
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- 2025
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19. Wireless matrix metalloproteinase-9 sensing by smart wound dressing with controlled antibacterial nanoparticles release toward chronic wound management.
- Author
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Deng P, Shi Z, Fang F, Xu Y, Zhou LA, Liu Y, Jin M, Chen T, Wang Y, Cao Y, Su L, Liang H, and Liu Q
- Subjects
- Humans, Hydrogels chemistry, Wireless Technology, Wound Infection drug therapy, Wound Healing drug effects, Metal Nanoparticles chemistry, Metal Nanoparticles therapeutic use, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents therapeutic use, Matrix Metalloproteinase 9 metabolism, Biosensing Techniques methods, Silver chemistry, Bandages, Staphylococcus aureus drug effects, Diabetic Foot drug therapy, Diabetic Foot therapy, Escherichia coli drug effects
- Abstract
Chronic wounds cause serious health and economic burdens on patients and society. Herein, a wireless and flexible smart wound dressing was developed for matrix metalloproteinase-9 (MMP-9) monitoring and antimicrobial treatment toward chronic wound management. The highly sensitive radio frequency MMP-9 sensor was realized based on a bioresponsive hydrogel with the bioactive peptide sequences. Taking advantage of the flexible inductive-capacitive (LC) circuit and bioresponsive hydrogel, the wireless and wearable smart wound dressing offered an efficient strategy for in-situ wound analysis. Besides, the controlled release of silver nanoparticles (AgNPs) from the degradable hydrogel exhibited significant antimicrobial efficacy against typical bacteria in wound infection including Escherichia coli and Staphylococcus aureus. The analysis of MMP-9 in wound exudate from diabetic foot ulcer (DFU) patients demonstrated good accuracy cross-validated with gold-standard fluorescent measurements, providing great potential for personalized wound management., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2025
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20. Chitosan-based hydrogel incorporated with polydopamine and protoporphyrin for photothermal-oxidation sterilization of bacteria-infected wound therapy.
- Author
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Wang X, Zhang X, Zhao W, Zhu L, Hong L, Cui K, Yu N, Chen Z, and Wen M
- Subjects
- Oxidation-Reduction, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Animals, Wound Infection drug therapy, Wound Infection microbiology, Surface Properties, Particle Size, Sterilization, Reactive Oxygen Species metabolism, Microbial Sensitivity Tests, Wound Healing drug effects, Indoles chemistry, Indoles pharmacology, Chitosan chemistry, Chitosan pharmacology, Hydrogels chemistry, Hydrogels pharmacology, Polymers chemistry, Polymers pharmacology, Protoporphyrins chemistry, Protoporphyrins pharmacology, Escherichia coli drug effects, Photosensitizing Agents chemistry, Photosensitizing Agents pharmacology, Staphylococcus aureus drug effects
- Abstract
Phototherapy has emerged as a potential treatment strategy for bacteria-infected wounds, but the inadequate bacteria-capturing ability and excessive damage to normal tissues from single phototherapy are huge limitations. To solve the issues, herein we report the design of chitosan-based hydrogel with bacteria capturing and combined photothermal/photodynamic sterilization functions. Such hydrogel is prepared by mixing chitosan (CS) as matrix, protoporphyrin (PpIX) as photosensitizer and polydopamine (PDA) as photothermal agent and then chemically cross-linking CS with glutaraldehyde. The resulting CS-PpIX-PDA hydrogel possesses a porous architecture (average pore porosity = 60.9 %), excellent swelling capabilities (swelling ratio = 1855 %) and rheological property (G' > G″). The hydrogel can effectively produce reactive oxygen species (ROS) under 660 nm light irradiation due to the photodynamic effect of PpIX. Owing to the presence of PDA, the hydrogel displays a photoabsorption range between 600 and 1500 nm and can generate maximal temperature of 60 °C within 10 min under 808 nm laser illumination (0.6 W/cm
2 ) through photothermal effect. Besides, under synergetic illumination of 808/660 nm laser, CS-PpIX-PDA hydrogel can induce the death of 99.9999 % of E. coli and 99.99999 % of S. aureus. Importantly, when coated on the wound site, the hydrogel exhibits a remarkable bacteria-trapping ability due to its porous structure and the presence of amino groups on chitosan. Under the excitation of 660/808 nm, the combined photothermal and photodynamic effects can effectively eradicate bacteria. Simultaneously, the hydrogel also demonstrates anti-inflammatory properties and upregulates Heat Shock Protein 90 (HSP90) expression, thereby promoting collagen deposition and facilitating wound healing. Therefore, the study may provide some new insights into the development of multifunctional hydrogel for photothermal-oxidation sterilization of bacteria-infected wound therapy., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)- Published
- 2025
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21. Designing a whole-cell biosensor applicable for S-adenosyl-l-methionine-dependent methyltransferases.
- Author
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Zhen Z, Xiang, Li S, Li H, Lei Y, Chen W, Jin JM, Liang C, and Tang SY
- Subjects
- Coumaric Acids chemistry, Caffeic Acids chemistry, Caffeic Acids analysis, Escherichia coli Proteins metabolism, Escherichia coli Proteins chemistry, Escherichia coli Proteins genetics, Homocysteine analysis, Homocysteine metabolism, Arabidopsis Proteins metabolism, Arabidopsis Proteins genetics, Arabidopsis Proteins chemistry, Directed Molecular Evolution, Biosensing Techniques methods, Methyltransferases metabolism, Methyltransferases chemistry, Escherichia coli genetics, Arabidopsis enzymology, Arabidopsis genetics, S-Adenosylmethionine metabolism, S-Adenosylmethionine chemistry
- Abstract
This study was undertaken to develop a high-throughput screening strategy using a whole-cell biosensor to enhance methyl-group transfer, a rate-limiting step influenced by intracellular methyl donor availability and methyltransferase efficiency. An l-homocysteine biosensor was designed based on regulatory protein MetR from Escherichia coli, which rapidly reported intracellular l-homocysteine accumulation resulted from S-adenosyl-l-homocysteine (SAH) formation after methyl-group transfer. Using S-adenosyl-l-methionine (SAM) as a methyl donor, this biosensor was applied to caffeic acid 3-O-methyltransferase derived from Arabidopsis thaliana (AtComT). After several rounds of directed evolution, the modified enzyme achieved a 13.8-fold improvement when converting caffeic acid to ferulic acid. The best mutant exhibited a 5.4-fold improvement in catalytic efficiency. Characterization of beneficial mutants showed that improved O-methyltransferase dimerization greatly contributed to enzyme activity. This finding was verified when we switched and compared the N-termini involved in dimerization across different sources. Finally, with tyrosine as a substrate, the evolved AtComT mutant greatly improved ferulic acid biosynthesis, yielding 3448 mg L
-1 with a conversion rate of 88.8%. These results have important implications for high-efficiency O-methyltransferase design, which will greatly benefit the biosynthesis of a wide range of natural products. In addition, the l-homocysteine biosensor has the potential for widespread applications in evaluating the efficiency of SAM-based methyl transfer., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2025
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22. Liquid crystal nanoparticles for oral combination antibiotic therapies: A strategy towards protecting commensal gut bacteria during treatment.
- Author
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He X, Karlsson PA, Xiong R, Moodie LWK, Wang H, Bergström CAS, and Hubert M
- Subjects
- Administration, Oral, Enterococcus faecalis drug effects, Microbial Sensitivity Tests, Clarithromycin pharmacology, Clarithromycin administration & dosage, Clarithromycin chemistry, Humans, Particle Size, Drug Carriers chemistry, Surface Properties, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents administration & dosage, Nanoparticles chemistry, Liquid Crystals chemistry, Gastrointestinal Microbiome drug effects, Escherichia coli drug effects, Vancomycin pharmacology, Vancomycin chemistry, Vancomycin administration & dosage
- Abstract
Antibiotics are essential for treating infections and reducing risks during medical interventions. However, many commonly used antibiotics lack the physiochemical properties for an efficient oral administration when treating systemic infection. Instead, we are reliant on intravenous delivery, which presents complications outside of clinical settings. Developing novel formulations for oral administration is a potential solution to this problem. We engineered hexosome and cubosome liquid crystal nanoparticles (LCNPs) characterized by small-angle X-ray scattering and cryogenic transmission electron microscopy, and could encapsulate the antibiotics vancomycin (VAN) and clarithromycin (CLA) with high loading efficiencies. By rationally choosing stable lipid building blocks, the loaded LCNPs demonstrated excellent resilience against enzymatic degradation in an in vitro gut model LCNP stability is crucial as premature antibiotic leakage can negatively impact the gut microbiota. In screens against the representative gut bacteria Enterococcus faecalis and Escherichia coli, our LCNPs provided a protective effect. Furthermore, we explored co-administration and dual loading strategies of VAN and CLA, and demonstrated effective loading, stability and protection for E. faecalis and E. coli. This work represents a proof of concept for the early-stage development of antibiotic-loaded LCNPs to treat systemic infection via oral administration, opening opportunities for combination antibiotic therapies., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2025
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23. Enhancing osmotic stress tolerance of cell mimetics by modulating lipid bilayer.
- Author
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Dai S, Wang T, Cui J, Xiang J, Shao Q, Han Y, and Wang Y
- Subjects
- Surface-Active Agents chemistry, Surface-Active Agents pharmacology, Glucosides chemistry, Glucosides pharmacology, Particle Size, Osmotic Pressure drug effects, Lipid Bilayers chemistry, Lipid Bilayers metabolism, Escherichia coli drug effects, Polyethylene Glycols chemistry, Polyethylene Glycols pharmacology, Unilamellar Liposomes chemistry, Unilamellar Liposomes metabolism
- Abstract
Seeking effective ways to maintain cellular homeostasis is crucial to the survival of organisms when they encounter osmotic stress. Glycine betaine (GB) is a widely generated natural osmolyte, but its endogenous production and action are limited. Herein, a kind of nonionic surfactant dodecyl-β-d-glucopyranoside (DG) and a common polymer polyethylene glycol (PEG) are proven to have the ability to enhance the osmotic stress (induced by sugar concentration changes) tolerance of cell and organism models, those are giant unilamellar vesicles (GUVs) and gram-negative Escherichia coli. DG or PEG only induces small size decrease and certain shape change of GUVs. Importantly, DG or PEG at the concentration 100 times lower than that of GB effectively increases the survival rate of bacteria under both hypoosmotic and hyperosmotic conditions. This intriguing result is attributed to the insertion of DG or adsorption of PEG in the lipid bilayer membrane, leading to enhanced membrane permeability. These exogenous substances can replace GB to facilely and highly efficiently augment adaptation of organisms to osmotic stress., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Yuchun Han, Yilin Wang reports financial support was provided by National Natural Science Foundation of China. Yilin Wang reports financial support was provided by Ministry of Science and Technology of the People’s Republic of China. Qing Shao reports a relationship with National Natural Science Foundation of China that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)
- Published
- 2025
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24. Impact of a random TN5 mutation on endoglucanase secretion in ruminal cellulolytic Escherichia coli.
- Author
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Pang J, Zhang L, Qi Q, and Liu Z
- Subjects
- Mutation, Protease La genetics, Protease La metabolism, Genome, Bacterial, Escherichia coli genetics, Escherichia coli metabolism, Cellulase genetics, Cellulase metabolism, DNA Transposable Elements genetics, Escherichia coli Proteins genetics, Escherichia coli Proteins metabolism
- Abstract
Objective: Most protein secretion systems are found in gram-negative bacteria, but the mechanism of endoglucanase (BcsZ) secretion in Escherichia coli (E. coli) remains unclear., Methods: In this study, we used JBZ-DH5α (which overexpresses BcsZ on the E. coli DH5α genome) as the initial strain. A mutant library was created by randomly inserting the TN5 transposon into the genome, and mutants with reduced transparent circles were identified on Congo red plates. The insertion sites of transposons in the genome were determined through whole-genome sequencing., Results: The results revealed that the genes rnc, lon, and suhB, which encode RNC-ribonuclease III (RNC), LON-protease (LON), and SuhB-inositol phosphatase (SuhB), respectively, were disrupted. BcsZ secretion decreased in E. coli DH5α when the lon, rnc, or suhB genes were deleted, but the overexpression of these genes restored their secretion levels., Conclusion: These findings suggest that the lon, rnc, and suhB genes play a role in BcsZ secretion in E. coli, potentially enhancing our knowledge of BcsZ secretion and offering a strategy to increase protein secretion in E. coli as a cell factory., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2025
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25. Photonic sensor based on surface imprinted polymers for enhanced point-of-care diagnosis of bacterial urinary tract infections.
- Author
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Myndrul V, Arreguin-Campos R, Iatsunskyi I, Di Scala F, Eersels K, and van Grinsven B
- Subjects
- Humans, Limit of Detection, Point-of-Care Systems, Silicon chemistry, Escherichia coli Infections diagnosis, Escherichia coli Infections urine, Escherichia coli Infections microbiology, Molecularly Imprinted Polymers chemistry, Luminescent Measurements, Biosensing Techniques methods, Urinary Tract Infections diagnosis, Urinary Tract Infections microbiology, Urinary Tract Infections urine, Escherichia coli isolation & purification, Polymers chemistry
- Abstract
Effective bacterial detection is crucial for health diagnostics, particularly for the detection of pathogenic species like Escherichia coli (E. coli), which is responsible for up to 90% of urinary tract infections (UTIs), is especially crucial. Current detection methods are time-consuming, often delaying diagnosis and treatment. This study introduces an innovative approach for rapid E. coli detection using porous silicon (PSi) substrates combined with Surface Imprinted Polymers (SIPs) for photoluminescence-based (PL-based) E. coli detection. The PSi/SIP substrates offer high sensitivity, selectivity, and a low limit of detection (LOD) without the need for natural recognition elements. These substrates, fabricated via metal-assisted chemical etching (MACE) and PDMS-based E. coli imprinting, demonstrate reliable repeatability and a fast detection. Real-time detection experiments in phosphate-buffered saline (PBS) and urine showed consistent stair-like quenching of the PL signal with increasing E. coli concentrations, achieving theoretical LODs of approximately 13 ± 2 CFU/mL in PBS and 17 ± 3 CFU/mL in urine. The substrates exhibited excellent selectivity, differentiating E. coli from other species such as Cronobacter sakazakii (C. sakazakii) and Listeria monocytogenes. The high sensitivity and reproducibility of PSi/SIP substrates, along with the ease of use and rapid detection capabilities of the resulting sensor, highlight the potential of this novel platform for point-of-care (PoC) applications in clinical diagnostics., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2025
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26. 2D/2D Co 3 O 4 /BiOCl nanocomposite with enhanced antibacterial activity under full spectrum: Synergism of mesoporous structure, photothermal effect and photocatalytic reactive oxygen species.
- Author
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Wang X, Shao Y, Yao C, Huang L, Song W, Yang X, and Zhang Z
- Subjects
- Porosity, Catalysis, Bismuth chemistry, Bismuth pharmacology, Photochemical Processes, Surface Properties, Particle Size, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Nanocomposites chemistry, Reactive Oxygen Species metabolism, Escherichia coli drug effects, Oxides chemistry, Oxides pharmacology, Cobalt chemistry, Cobalt pharmacology, Microbial Sensitivity Tests
- Abstract
The overuse of antibiotics has caused the emergence of drug-resistant bacteria and even superbugs, which makes it imperative to develop promising antibiotic-free alternatives. Herein, a multimodal antibacterial nanoplatform of two dimensional/two dimensional (2D/2D) mesoporous Co
3 O4 /BiOCl nanocomposite is constructed, which possesses the effect of "kill three birds with one stone": (1) the use of mesoporous Co3 O4 can enlarge the surface area of the nanocomposite and promote the adsorption of bacteria; (2) Co3 O4 displays remarkable full-spectrum absorption and photo-induced self-heating effect, which can raise the temperature of Co3 O4 /BiOCl and help to kill bacteria; (3) the p-type Co3 O4 and n-type BiOCl form a p-n heterojunction, which promotes the separation of photoelectrons and holes, thus producing more reactive oxygen species (ROS) for killing bacteria. The synergism of mesoporous structure, photothermal effect and photocatalytic ROS makes the developed Co3 O4 /BiOCl a promising antibacterial material, which shows outstanding antibacterial activity with an inhibition rate of nearly 100 % against Escherichia coli (E. coli) within 8 min. This work provides inspiration for designing multimodal synergistic nanoplatform for antibacterial applications., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)- Published
- 2025
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27. Uncovering the effects of non-lethal oxidative stress on replication initiation in Escherichia coli.
- Author
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Qiao J, Du D, Wang Y, Xi L, Zhu W, and Morigen
- Subjects
- Superoxide Dismutase metabolism, Superoxide Dismutase genetics, Protease La metabolism, Protease La genetics, Bacterial Proteins genetics, Bacterial Proteins metabolism, DNA Glycosylases genetics, DNA Glycosylases metabolism, Endopeptidase Clp genetics, Endopeptidase Clp metabolism, Acetylcysteine pharmacology, Catalase, Oxidative Stress drug effects, Escherichia coli genetics, Escherichia coli metabolism, Escherichia coli drug effects, Escherichia coli Proteins genetics, Escherichia coli Proteins metabolism, DNA Replication drug effects, Hydrogen Peroxide pharmacology
- Abstract
Cell cycle adaptability assists bacteria in response to adverse stress. The effect of oxidative stress on replication initiation in Escherichia coli remains unclear. This work examined the impact of exogenous oxidant and genetic mutation-mediated oxidative stress on replication initiation. We found that 0-0.5 mM H
2 O2 suppresses E. coli replication initiation in a concentration-dependent manner but does not lead to cell death. Deletion of antioxidant enzymes SodA-SodB, KatE, or AhpC results in delayed replication initiation. The antioxidant N-acetylcysteine (NAC) promotes replication initiation in ΔkatE and ΔsodAΔsodB mutants. We then explored the factors that mediate the inhibition of replication initiation by oxidative stress. MutY, a base excision repair DNA glycosylase, resists inhibition of replication initiation by H2 O2 . Lon protease deficiency eliminates inhibition of replication initiation mediated by exogenous H2 O2 exposure but not by katE or sodA-sodB deletion. The absence of clpP and hslV further delays replication initiation in the ΔktaE mutant, whereas hflK deletion promotes replication initiation in the ΔkatE and ΔsodAΔsodB mutants. In conclusion, non-lethal oxidative stress inhibits replication initiation, and AAA+ proteases are involved and show flexible regulation in E. coli., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2025
- Full Text
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28. Aggregation-prone antimicrobial peptides target gram-negative bacterial nucleic acids and protein synthesis.
- Author
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Chen P, Zhang T, Li C, Praveen P, Parisi K, Beh C, Ding S, Wade JD, Hong Y, Li S, Nkoh JN, Hung A, Li W, and Shang C
- Subjects
- Animals, DNA, Bacterial genetics, DNA, Bacterial metabolism, Protein Biosynthesis drug effects, Staphylococcus aureus drug effects, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Microbial Sensitivity Tests, Protein Aggregates drug effects, Antimicrobial Peptides pharmacology, Antimicrobial Peptides chemistry, Escherichia coli drug effects
- Abstract
Aggregation of antimicrobial peptides (AMPs) enhances their efficacy by destabilising the bacterial cell wall, membrane, and cytosolic proteins. Developing aggregation-prone AMPs offers a promising strategy to combat antibiotic resistance, though predicting such AMPs and understanding bacterial responses remain challenging. Octopus bimaculoides, a cephalopod species, lacks known AMP gene families, yet its protein fragments were used to predict AMPs via artificial intelligence tools. Four peptides (Oct-P1, Oct-P2, Oct-P3, and Oct-P4) were identified based on their aggregation propensity. Among them, Oct-P2 reduced the viability of Escherichia coli and Staphylococcus aureus by up to 90 %, confirmed by confocal laser scanning microscopy and scanning electron microscopy. It further aggregated plasmid DNA in vitro, and the presence of extracellular DNA reduced their antibacterial activity. With knockout mutants, it revealed that Oct-P2 was internalized into bacterial cells, possibly through membrane transport proteins, enhancing its antibacterial effect. Aggregation-induced emission assays and molecular dynamics simulations revealed that Oct-P2 aggregates with transcription promoter DNA, inhibiting transcription and translation in vitro. This dual-target mechanism not only highlights the potential of Oct-P2 as a lead template for new antimicrobial drug development, but also opens a new window for discovering AMPs from protein fragments against the upcoming challenge of bacterial infections. STATEMENT OF SIGNIFICANCE: A popular strategy for identifying antimicrobial peptides (AMPs) in specific genomes uses the conserved regions of AMP families, but this strategy has limitations in organisms lacking classical AMP gene families, such as Octopus. Fragments from non-antimicrobial proteins serve as a rich source for the identification of new AMPs. In this study, we used artificial intelligence tools to search for potential candidate AMP sequences from non-antimicrobial proteins in Octopus bimaculoides. The successful identification of aggregation-prone AMPs was shown to decrease bacterial viability, increase permeability, and reduce biomass. One candidate, Oct-P2, kills the gram-negative bacteria E. coli by aggregating with DNA and inhibiting transcription and translation, suggesting a new intracellular mechanism of AMP activity., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2025
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29. Survival of Generic Escherichia coli on In-Field Mature and Immature Gala and Golden Delicious Apples With or Without Overhead Evaporative Cooling Treatment.
- Author
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Murphy CM, Jeong KH, Walter L, Mendoza M, Green T, Liao A, Killinger K, Hanrahan I, and Zhu MJ
- Subjects
- Fruit microbiology, Food Microbiology, Food Contamination analysis, Humans, Malus microbiology, Escherichia coli, Colony Count, Microbial
- Abstract
The application of overhead evaporative cooling (EC) with untreated surface water is common in Washington State to decrease sunburn on apples. While this practice reduces crop and economic losses, applying untreated surface water to produce introduces potential risks of foodborne pathogen contamination. This study examined EC and the survival of inoculated generic Escherichia coli for two apple varieties over three growing seasons. Factors examined included EC treatment (conventional, untreated), canopy location (high, low), and apple variety (Gala, Golden Delicious). Fruit maturity (mature, immature) was also examined for one year. A rifampicin-resistant generic E. coli cocktail was applied to apples at 7.3 ± 0.4 log CFU/apple, and apples were enumerated for E. coli levels at 0, 2, 10, 18, 34, 42, 58, 82, 106, and 154 h postinoculation. Log-linear, Weibull, and Biphasic models were utilized to characterize the die-off pattern of E. coli. For most treatments, inoculated E. coli decreased by almost or over 6 log CFU/apple over the study duration; however, E. coli remained detectable at low levels on apples at 154 h postinoculation. EC treatment and canopy location did not significantly impact daily linear E. coli die-off rates. Apple variety and maturity demonstrated small but statistically significant impacts on daily linear die-off rates. Nonlinear models (i.e., biphasic and Weibull) best captured E. coli die-off on apples, showing a rapid initial decrease followed by a slower decline over time. Overall, results demonstrate that EC, a useful fruit quality practice, did not impact the survival of inoculated generic E. coli on apple surfaces. The study provides valuable insights for the apple industry regarding E. coli die-off rates on in-field apples, guiding practical decisions to mitigate risk., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2025
- Full Text
- View/download PDF
30. Detection of Viable but Nonculturable E. coli Induced by Low-Level Antimicrobials Using AI-Enabled Hyperspectral Microscopy.
- Author
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Papa M, Wasit A, Pecora J, Bergholz TM, and Yi J
- Subjects
- Anti-Infective Agents pharmacology, Anti-Bacterial Agents pharmacology, Artificial Intelligence, Food Microbiology, Microbial Viability, Microscopy, Escherichia coli
- Abstract
Rapid detection of bacterial pathogens is essential for food safety and public health, yet bacteria can evade detection by entering a viable but nonculturable (VBNC) state under sublethal stress, such as antimicrobial residues. These bacteria remain active but undetectable by standard culture-based methods without extensive enrichment, necessitating advanced detection methods. This study developed an AI-enabled hyperspectral microscope imaging (HMI) framework for rapid VBNC detection under low-level antimicrobials. The objectives were to (i) induce the VBNC state in Escherichia coli K-12 by exposure to selected antimicrobial stressors, (ii) obtain HMI data capturing physiological changes in VBNC cells, and (iii) automate the classification of normal and VBNC cells using deep learning image classification. The VBNC state was induced by low-level oxidative (0.01% hydrogen peroxide) and acidic (0.001% peracetic acid) stressors for 3 days, confirmed by live-dead staining and plate counting. HMI provided spatial and spectral data, extracted into pseudo-RGB images using three characteristic spectral wavelengths. An EfficientNetV2-based convolutional neural network architecture was trained on these pseudo-RGB images, achieving 97.1% accuracy of VBNC classification (n = 200), outperforming the model trained on RGB images at 83.3%. The results highlight the potential for rapid, automated VBNC detection using AI-enabled hyperspectral microscopy, contributing to timely intervention to prevent foodborne illnesses and outbreaks., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Author(s). Published by Elsevier Inc. All rights reserved.)
- Published
- 2025
- Full Text
- View/download PDF
31. The Effect of Heat-treated Poultry Pellets and Composted Poultry Litter on E. coli Survival in Southeastern US Soils: Florida and Georgia.
- Author
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Kharel K, Bardsley CA, Appolon CB, Dunn LL, Kumar GD, Prabha K, Sharma M, Danyluk MD, and Schneider KR
- Subjects
- Animals, Georgia, Florida, Hot Temperature, Colony Count, Microbial, Composting, Soil Microbiology, Escherichia coli, Poultry, Soil
- Abstract
Biological soil amendments of animal origin (BSAAO) are a source of foodborne pathogens that can contaminate fresh produce. This study evaluated the survival of E. coli over 140 d in agricultural soils amended with composted poultry litter (PL), heat-treated poultry pellets (HTPP), or unamended (UN) in Florida (FL) and Georgia (GA). Raised-bed plots (1 × 3 m
2 ; n = 3) were either left unamended (UN) or amended with PL or HTPP (680 g/plot). Each plot was spray-inoculated with 1 L of rifampicin-resistant E. coli (7-8 log CFU/mL) and hand-tilled into the soil (∼5.9 and 4.5 log CFU/g for FL and GA, respectively). Soil samples were enumerated using a spread plate or most probable number technique at 0, 1, 3, 7, 14, 28, 56, 84, 112, and 140 d. Weather-related parameters were collected to assess their impact on E. coli survival. A mixed-model analysis was used to evaluate factors influencing E. coli survival, a biphasic model was used for the E. coli die-off rate, and Spearman correlations were used to understand the associations between environmental factors and survival. Time, amendment type, and location * treatment * time influenced (P < 0.05) the survival of E. coli in soil. In FL, HTPP-amended soils supported higher levels of E. coli compared to PL-amended soils; in Georgia, similar survival was observed between PL- and HTPP-amended soils, both of which were higher (P < 0.05) than in UN soils. In both locations, E. coli levels fell to the limit of detection (-0.24 log MPN/g) by 112 d in UN plots; however, they persisted at levels between 0.30 and 1.57 log CFU/g in HTTP- and PL-amended soils until 140 d. Weak to moderate correlations were observed for rainfall and soil moisture and their effect on E. coli survival; no other weather factors were impactful. The use of BSAAO in soils can prolong the survival of E. coli (>140 d) irrespective of the factors intrinsic to the locations and have implications regarding the safe use of BSAAOs during fruit and vegetable production., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Inc. All rights reserved.)- Published
- 2025
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32. Co, Cu, Ni, and Zn complexes of N-[(3-phenoxy phenyl)methylidene]-l-valine as α-glycosidase and α-amylase inhibitors: Synthesis, molecular docking & antimicrobial evaluation.
- Author
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Sankar R and Sharmila TM
- Subjects
- Structure-Activity Relationship, Molecular Structure, Candida albicans drug effects, Valine chemistry, Valine pharmacology, Nickel chemistry, Cobalt chemistry, Coordination Complexes chemistry, Coordination Complexes pharmacology, Coordination Complexes chemical synthesis, Glycoside Hydrolase Inhibitors chemical synthesis, Glycoside Hydrolase Inhibitors pharmacology, Glycoside Hydrolase Inhibitors chemistry, alpha-Glucosidases metabolism, Dose-Response Relationship, Drug, Humans, Antifungal Agents pharmacology, Antifungal Agents chemical synthesis, Antifungal Agents chemistry, Enzyme Inhibitors pharmacology, Enzyme Inhibitors chemical synthesis, Enzyme Inhibitors chemistry, Molecular Docking Simulation, Copper chemistry, Microbial Sensitivity Tests, Escherichia coli drug effects, Escherichia coli enzymology, alpha-Amylases antagonists & inhibitors, alpha-Amylases metabolism, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemical synthesis, Anti-Bacterial Agents chemistry, Zinc chemistry
- Abstract
The ligand N-[(3-phenoxyphenyl)methylidene]-l-valine (HL) and its Co, Ni, Cu, and Zn derivatives (1-4) were synthesized and characterized. These compounds were tested for α-glucosidase and α-amylase inhibition activity, showing IC
50 values of 10.51-51.36 µg/mL and 15.38-46.74 µg/mL, respectively, compared to Ascarbose. In silico molecular docking studies revealed strong binding affinities for α-glucosidase (-207.78 to -222.04 kcal/mol) and α-amylase (-159.5 to -161.82 kcal/mol), and potential anticancer activity against CDK2 (-119.6 to -126.53 kcal/mol). Antimicrobial assays against E. coli and C. albicans demonstrated significant activity, with inhibition zones of 12.5-16.8 mm and 13.5-20.05 mm, respectively. The results reveal a fascinating array of pharmacological properties of these compounds and suggest their potential for future drug development., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)- Published
- 2025
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33. Utilizing a high-throughput visualization screening technology to develop a genetically encoded biosensor for monitoring 5-aminolevulinic acid production in engineered Escherichia coli.
- Author
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Su H, Chen S, Chen X, Guo M, Liu H, and Sun B
- Subjects
- High-Throughput Screening Assays methods, Escherichia coli Proteins genetics, Escherichia coli Proteins metabolism, Promoter Regions, Genetic, Biosensing Techniques methods, Aminolevulinic Acid, Escherichia coli genetics, Escherichia coli isolation & purification, Metabolic Engineering
- Abstract
5-Aminolevulinic acid (5-ALA) is a non-protein amino acid widely used in agriculture, animal husbandry and medicine. Currently, microbial cell factories are a promising production pathway, but the lack of high-throughput fermentation strain screening tools often hinders the exploration of engineering strategies to increase cell factory yields. Here, mutant AC
103 - 3 H was screened from libraries of saturating mutants after response-specific engineering of the transcription factor AsnC of L-asparagine (Asn). Based on mutant AC103 - 3 H, a whole-cell biosensor EAC103 - 3 H with a specific response to 5-ALA was constructed, which has a linear dynamic detection range of 1-12 mM and a detection limit of 0.094 mM, and can be used for in situ screening of potential high-producing 5-ALA strains. With its support, overexpression of the C5 pathway genes using promoter engineering assistance resulted in a 4.78-fold enhancement of 5-ALA production in the engineered E. coli. This study provides an efficient strain screening tool for exploring approaches to improve the 5-ALA productivity of engineered strains., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2025
- Full Text
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34. Magnetical scafford with ROS-scavenging for bone regeneration under static magnetic field.
- Author
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Chen S, Zhou X, Wang X, Li H, An R, and Qian Y
- Subjects
- Mice, Animals, Tissue Scaffolds chemistry, Staphylococcus aureus drug effects, Staphylococcus aureus physiology, Oligopeptides chemistry, Oligopeptides pharmacology, Polymers chemistry, Polymers pharmacology, Osteogenesis drug effects, Indoles chemistry, Indoles pharmacology, Polylactic Acid-Polyglycolic Acid Copolymer chemistry, Cell Proliferation drug effects, Polyesters chemistry, Cell Differentiation drug effects, Free Radical Scavengers pharmacology, Free Radical Scavengers chemistry, Bone Regeneration drug effects, Reactive Oxygen Species metabolism, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Magnetic Fields, Escherichia coli drug effects
- Abstract
Excessive reactive oxygen species (ROS) and bacterial infection significantly disrupt the microenvironment of tissue regeneration. Magnetic nanoparticles in combination with magnetic fields are emerging strategies to regulate tissue regeneration. In this work, ZnFe
2 O4 (ZFO) nanoparticles were prepared and subsequently decorated with polydopamine (PDA) and RGD peptide. The modified ZFO nanoparticles were loaded into polylactic-glycolic acid/polycaprolactone (PLGA/PCL) scaffolds as PP-ZFO/PDA-RGD magnetic scaffolds. Physicochemical, anti-ROS, antibacterial and osteogenic properties were evaluated in vitro. Under 30 mT static magnetic field, the PP-ZFO/PDA-RGD scaffold significantly enhanced the expression of ALP, RUNX2, BMP2 and mineralized nodules. It indicated that the magnetic system could promote the attachment, proliferation, differentiation and mineralization of MC3T3-E1 cells. The scaffold showed excellent ROS scavenging ability via the additive effect of ZFO, PDA and RGD. The remarkable antibacterial properties of Zn²⁺ and Fe³⁺ endowed the scaffolds with excellent antibacterial activity against E. coli and S. aureus. These results demonstrate that the PP-ZFO/PDA-RGD based magnetic system is a promising approach for bone regeneration under complex microenvironment., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2025
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35. S-Alkylated sulfonium betulin derivatives: Synthesis, antibacterial activities, and wound healing applications.
- Author
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Deng Y, Wang R, Ma Z, Zuo W, and Zhu M
- Subjects
- Structure-Activity Relationship, Molecular Structure, Methicillin-Resistant Staphylococcus aureus drug effects, Sulfonium Compounds chemistry, Sulfonium Compounds pharmacology, Staphylococcus aureus drug effects, Animals, Dose-Response Relationship, Drug, Alkylation, Mice, Humans, Betulinic Acid, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemical synthesis, Anti-Bacterial Agents chemistry, Triterpenes chemistry, Triterpenes pharmacology, Triterpenes chemical synthesis, Wound Healing drug effects, Microbial Sensitivity Tests, Escherichia coli drug effects
- Abstract
Betulin, a bioactive triterpenoid derived from Betulaceae bark with antimicrobial and anti-inflammatory properties, holds great potential as a therapeutic agent. In this work, cationic sulfonium-modified betulin derivatives were synthesized to enhance their antibacterial efficacy for wound healing application. Mono- and dual S-alkylated sulfonium derivatives significantly outperformed betulin in antibacterial activity against pathogens such as S. aureus, Methicillin-resistant S. aureus (MRSA), and E. coli. S-nonylated sulfonium betulin reduced the minimum inhibitory concentration of betulin against MRSA from 24 to 0.015 mM. The sulfonium modification enhanced cationic interactions, leading to bacterial membrane disruption. The derivatives expedited the process of wound healing by mitigating inflammation and exhibited satisfactory biosafety, proposing a viable approach to the development of antibacterial agents., Competing Interests: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Ruili Wang reports financial support was provided by National Key Research and Development Program of China. Zhiyuan MA reports financial support was provided by National Natural Science Foundation of China. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)
- Published
- 2025
- Full Text
- View/download PDF
36. Synergistic photocatalysis for bacteria inactivation and organic pollutant removal by S-scheme heterojunction InVO 4 /Bi 5 O 7 I: Performance evaluation and mechanism investigation.
- Author
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Li Y, Li Y, Huang L, Liu S, Zhu M, Qiu L, Huang J, Fu Y, and Huang L
- Subjects
- Catalysis, Photochemical Processes, Water Pollutants, Chemical chemistry, Water Pollutants, Chemical isolation & purification, Phenols chemistry, Benzhydryl Compounds chemistry, Benzhydryl Compounds isolation & purification, Surface Properties, Particle Size, Photolysis, Anti-Bacterial Agents chemistry, Escherichia coli, Staphylococcus aureus, Bismuth chemistry
- Abstract
The low efficiency of charge carrier separation is a major limitation hindering the application of photocatalytic technology. Constructing S-scheme heterojunction photocatalysts not only effectively promotes the separation of charge carriers, but also maximizes the oxidative and reductive capabilities of the two monomers. In this study S-scheme heterogeneous InVO
4 /Bi5 O7 I photocatalyst was synthesized by hydrothermal method combined with calcination. The optimal sample 20 % InVO4 /Bi5 O7 I can completely deactivate Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli) in 30 min, remove 20 mg/L TC 76.0 % in 60 min and 20 mg/L BPA 93.0 % in 90 min. Intermediate products of TC and BPA degradation were detected using LC-MS, and possible degradation pathways were proposed. The photocurrent and electrochemical impedance spectroscopy (EIS) tests confirm that InVO4 /Bi5 O7 I exhibits excellent photocurrent intensity and photocarrier migration ability, which are crucial reasons for the enhancement of the photocatalytic performance of the InVO4 /Bi5 O7 I composite. Capture experiments indicate that OH, O2 - , h+ and e- are reactive species. EPR further confirms the generation of OH and O2 - . Combined with Kelvin probe force microscopy (KPFM) and band structure analysis, it is proposed that InVO4 /Bi5 O7 I has an S-scheme charge transfer mechanism., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)- Published
- 2025
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37. Copper tannate nanosheets-embedded multifunctional coating for antifouling and photothermal bactericidal applications.
- Author
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Xiang L, Li W, Liu Y, Sathishkumar G, He X, Wu H, Ran R, Zhang K, Rao X, Kang ET, and Xu L
- Subjects
- Animals, Titanium chemistry, Titanium pharmacology, Microbial Sensitivity Tests, Biofilms drug effects, Nanostructures chemistry, Biofouling prevention & control, Mice, Particle Size, Photothermal Therapy, Bacterial Adhesion drug effects, Tannins chemistry, Tannins pharmacology, Copper chemistry, Copper pharmacology, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Escherichia coli drug effects, Staphylococcus aureus drug effects, Coated Materials, Biocompatible pharmacology, Coated Materials, Biocompatible chemistry, Surface Properties
- Abstract
Implant-associated infections (IAIs), triggered by pathogenic bacteria, are a leading cause of implant failure. The design of functionalized coatings on biomedical materials is crucial to address IAIs. Herein, a multifunctional coating with good antifouling effect and antibacterial photothermal therapy (aPTT) performance was developed. The copper tannate nanosheets (CuTA NSs) were formed via coordination bonding of Cu
2+ ions and tannic acid (TA). The CuTA NSs were then integrated into the TA and poly(ethylene glycol) (PEG) network to form the TCP coating for deposition on the titanium (Ti) substrates via surface adhesion of TA and gravitational effect. The resulting Ti-TCP substrate exhibited good antifouling property, reactive oxygen species (ROS) scavenging capability and cytocompatibility. The TCP coating exhibited antifouling efficacy in conjunction with aPTT, curtailing the surface adhesion and biofilm formation of pathogens, such as Staphylococcus aureus and Escherichia coli. Notably, the Ti-TCP substrate also exhibited the ability to prevent bacterial infection in vivo in a subcutaneous implantation model. The present work demonstrated a promising approach in designing high-performance antifouling and photothermal bactericidal coatings to combat IAIs., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2025
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38. Enhanced antifouling and anti-swarming properties poly (sulfobetaine methacrylate-co-2-hydroxy-3-phenoxypropyl acrylate) hydrogel coatings for urinary catheters.
- Author
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Yao C, Teng X, Sun D, McCoy CP, and Zhang S
- Subjects
- Biofilms drug effects, Biofouling prevention & control, Animals, Coated Materials, Biocompatible pharmacology, Coated Materials, Biocompatible chemistry, Mice, Bacterial Adhesion drug effects, Acrylates chemistry, Acrylates pharmacology, Fibrinogen chemistry, Fibrinogen metabolism, Humans, Surface Properties, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Anti-Bacterial Agents chemical synthesis, Betaine chemistry, Betaine pharmacology, Betaine analogs & derivatives, Urinary Catheters microbiology, Escherichia coli drug effects, Methacrylates chemistry, Methacrylates pharmacology, Hydrogels chemistry, Hydrogels pharmacology, Proteus mirabilis drug effects
- Abstract
Catheter-associated urinary tract infection (CAUTI) remains an unsolved challenge to date, particularly with the emergence and rapid spread of antimicrobial-resistant bacterial pathogens. Despite extensive research, a catheter coating that can offer intrinsic resistance to host protein deposition, bacterial biofilm formation, and swarming is still urgently required. Zwitterionic hydrogel coatings due to their superior lubricity and antifouling properties represent a promising candidate, but their weak mechanical stability in water and poor resistance to bacterial swarming migration limit their application in urinary catheters for infection control. In this research, we describe the fabrication of a multifunctional catheter coating by copolymerizing zwitterionic sulfobetaine methacrylate (SBMA) polymers and a swarming inhibitor material, 2-hydroxy-3-phenoxypropyl acrylate (HPA). The introduction of polyHPA (PHPA) effectively impeded the uncontrolled swelling behavior of the zwitterionic PSBMA hydrogel, resulting in enhanced mechanical stability. Moreover, the copolymer coating retains the antifouling and anti-swarming properties of the homopolymers when challenged with fibrinogen, Escherichia coli, and Proteus mirabilis. The HPA content significantly correlated with its anti-adhesion activity against fibrinogen and biofilm, and the coating with an SBMA: HPA monomer feed molar ratio of 4:1 showed the best antifouling activity, reducing fibrinogen deposition by about 40 % and biofilm coverage by around fourfold compared to the uncoated polydimethylsiloxane (PDMS) surface. Furthermore, the copolymer coating also exhibited no cytotoxicity, suggesting it as a promising catheter coating for preventing CAUTI., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2025
- Full Text
- View/download PDF
39. Oral-Delivery Lactococcus lactis expressing cherry fusion lactoferrin peptides against infection of avian pathogenic Escherichia coli in chickens.
- Author
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Li Z, Wang X, Zheng D, Han F, Li Y, Zhou H, Li J, Cui W, Jiang Y, Wang X, Xie W, and Tang L
- Subjects
- Animals, Gastrointestinal Microbiome drug effects, Administration, Oral, Animal Feed analysis, Lactoferrin administration & dosage, Lactoferrin pharmacology, Lactococcus lactis, Chickens, Escherichia coli Infections veterinary, Escherichia coli Infections prevention & control, Escherichia coli, Poultry Diseases prevention & control, Poultry Diseases microbiology
- Abstract
Avian pathogenic Escherichia coli (APEC) infections result in significant economic losses and reduced animal welfare. Historically, antibiotics and vaccinations currently control APEC infections in poultry, however, antibiotic-resistant strains and heterologous serotypes limit their effectiveness. Meanwhile, antibiotic-resistant strains can be transmitted to humans via contact with animals, food or their environment. Probiotics and antimicrobial peptides (AMPs) are potential alternatives to antibiotics and represent promising strategies to combat APEC. Bovine lactoferricin and lactoferrampin possess anti-bacterial, anti-inflammatory, and anti-oxidant properties. Lactococcus lactis (L. lactis) is an excellent vector for delivering recombinant proteins. In this research, we generated a recombinant L. lactis strain MG1363 expressing lactoferrin peptides, which was labeled with a fluorescent marker mCherry and lacked an antibiotic resistance gene (LL-EFLmC). Our investigation focused on the impact of LL-EFLmC strain on the gut microbiota composition and avian pathogenic E. coli O78 challenge. Our findings indicate that LL-EFLmC exhibits inhibitory effects against APEC-O78 and Staphylococcus aureus CVCC26003 (S. aureus CVCC26003) in vitro. Furthermore, the inclusion of LL-EFLmC in chicken feed significantly improved the average daily intake and gain to feed ratio. Additionally, LL-EFLmC treatment resulted in a significant increase in serum IgG and intestinal mucus SIgA levels. Administration of LL-EFLmC was found to effectively suppress APEC-O78 infection and mitigate the expression of pro-inflammatory cytokines, including IL-1β, IL-12, IFN-γ, and TNF-α. Additionally, 16S rDNA sequencing data revealed that LL-EFLmC was able to restore the intestinal flora that had been disrupted by APEC-O78. These findings suggest that LL-EFLmC may serve as a promising feed additive and antibiotic alternative in chicken production, due to its potential to enhance immune regulation, promote growth, and confer resistance against APEC-O78 infection., Competing Interests: Disclosures The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier Inc.)
- Published
- 2025
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40. A novel multifunctional PEEK internal fixation plate regulated by Gentamicin/chitosan coating.
- Author
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Sun J, Li J, Shan A, Wang L, Ye J, Li S, and Zhou W
- Subjects
- Animals, Surface Properties, Microbial Sensitivity Tests, Bone Plates, Osteogenesis drug effects, Mesenchymal Stem Cells drug effects, Mesenchymal Stem Cells cytology, Chitosan chemistry, Chitosan pharmacology, Benzophenones, Staphylococcus aureus drug effects, Polymers chemistry, Polymers pharmacology, Escherichia coli drug effects, Polyethylene Glycols chemistry, Polyethylene Glycols pharmacology, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Ketones chemistry, Ketones pharmacology, Gentamicins pharmacology, Gentamicins chemistry, Coated Materials, Biocompatible chemistry, Coated Materials, Biocompatible pharmacology
- Abstract
Polyetheretherketone (PEEK) has been broadly used in orthopedic implant devices. Nevertheless, the bioinert tended to cause implant loosening and bacterial infection in orthopedic and trauma surgery. In this study, a drug-laden chitosan coating (CS) was constructed and deposited on the porous surface of PEEK (CG-SPEEK) internal fixation plate for multi-functionalization. The physical characterizations of CG-SPEEK were further investigated in the morphology, hydrophilicity, surface energy, roughness, drug release and mechanical properties. CG-SPEEK exhibited excellent antibacterial capabilities in both Staphylococcus aureus and Escherichia coli compared to other groups. Besides, BMSCs cells showed better biocompatibility and certain osteogenic activity on composite coating in vitro. Furthermore, CG-SPEEK promoted bone regeneration to some extent and express certain effect against infections in vivo study. Overall, combining personalized design and modification is an innovative strategy to realized functionalization, which may have a strong potential in clinical application., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationship that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2025
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41. Enhancing leachate management with antibacterial nanocomposites incorporating plant-based carbon dots and Satureja Khuzestanica essential oils.
- Author
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Rezaei A, Monfared-Hajishirkiaee R, Hosseinzadeh-Moghaddam S, Behzadi M, and Shahangian SS
- Subjects
- Quantum Dots chemistry, Oils, Volatile chemistry, Oils, Volatile pharmacology, Nanocomposites chemistry, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Carbon chemistry, Satureja chemistry, Escherichia coli drug effects, Staphylococcus aureus drug effects, Water Pollutants, Chemical chemistry, Microbial Sensitivity Tests
- Abstract
Landfill leachate, a complex mixture of pollutants, poses a significant environmental hazard. This study reports the synthesis and characterization of superabsorbent nanocomposites (SANs) designed for enhanced performance in waste management applications. SANs were prepared using carboxymethyl cellulose (CMC) and sodium polyacrylate (SPA) as the main components, carbon dots (CDs) to improve absorption, and Satureja Khuzestanica essential oil (SEO) for antibacterial performance. The results demonstrated that the addition of CDs significantly increased the absorption capacity and liquid retention of the samples, with a water absorption capacity reaching up to 8621 %. Furthermore, the samples exhibited high mechanical strength, with tensile strength improving by over 100 % in the presence of CDs. The inclusion of SEO provided strong antibacterial activity against Escherichia coli and Staphylococcus aureus, with inhibition zones measuring up to 26 mm. These SANs, with their high absorption capacity, mechanical robustness, and antibacterial properties, show great potential for improving waste management practices, particularly in leachate absorption strategies., Competing Interests: Declaration of Competing Interest The authors state that they do not have any competing financial interests or personal relationships that could potentially sway the integrity of the research detailed in this paper., (Copyright © 2024. Published by Elsevier B.V.)
- Published
- 2025
- Full Text
- View/download PDF
42. Indole phytochemical camalexin as a promising scaffold for AcrB efflux pump inhibitors against Escherichia coli.
- Author
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Irianti MI, Malloci G, Ruggerone P, Lodinsky EV, Vincken JP, Pos KM, and Araya-Cloutier C
- Subjects
- Phytochemicals pharmacology, Multidrug Resistance-Associated Proteins metabolism, Multidrug Resistance-Associated Proteins antagonists & inhibitors, Phytoalexins, Indoles pharmacology, Indoles chemistry, Escherichia coli drug effects, Escherichia coli metabolism, Escherichia coli Proteins metabolism, Escherichia coli Proteins antagonists & inhibitors, Anti-Bacterial Agents pharmacology, Thiazoles pharmacology, Thiazoles chemistry, Microbial Sensitivity Tests, Molecular Docking Simulation
- Abstract
Escherichia coli is amongst the most frequent causative agent of nosocomial infections and the overexpression of the efflux pump gene acrB plays a major role in its resistance to various antibiotics. In this study, we evaluated two indole phytochemicals, camalexin and brassinin, as potential AcrB efflux pump inhibitors. Among these two phytochemicals, camalexin increased the accumulation of ethidium in acrB proficient E.coli with no membrane permeabilization effect observed, indicating a direct interaction of camalexin with the pump. Camalexin also showed up to 64-fold MIC reduction for drugs in the acrB proficient strain. Brassinin was less effective, showing up to 4-fold MIC reduction for the same drugs. Camalexin did not potentiate drugs in the AcrB inactive strain D407N. Plate dilution assays in E. coli acrB variants further corroborated the effect of camalexin in diminishing pump activity. Blind docking results suggested that camalexin and brassinin may enter mainly via CH3, one of the channels present in AcrB, and camalexin showed a more stable binding mode than brassinin in the distal binding pocket of AcrB. Camalexin, therefore, holds potential as a scaffold for further development as a potent AcrB inhibitor to tackle antimicrobial resistance in the gram-negative bacterium E. coli., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests. Carla Araya-Cloutier reports financial support was provided by Dutch Research Council. Giuliano Malloci and Paolo Ruggerone report financial support was provided by The Italian Ministry of University and Research (MUR). If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier Masson SAS.. All rights reserved.)
- Published
- 2025
- Full Text
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43. A three-dimensional printable conductive composite dressing for accelerating wound healing under electrical stimulation.
- Author
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Chai X, Lou Y, Nie L, Shavandi A, Yunusov KE, Sun Y, and Jiang G
- Subjects
- Animals, Electric Stimulation, Mice, Polyvinyl Alcohol chemistry, Zinc Oxide chemistry, Zinc Oxide pharmacology, Carrageenan chemistry, Microbial Sensitivity Tests, Male, Interleukin-6 metabolism, Wound Healing drug effects, Escherichia coli drug effects, Staphylococcus aureus drug effects, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Bandages, Printing, Three-Dimensional, Electric Conductivity
- Abstract
In this study, a bioink based on poly(vinyl alcohol) (PVA) and κ-carrageenan network was prepared using conductive polymer (PEDOT:PSS) as conducting medium, and (+)-Catechin-loaded mesoporous ZnO (CmZnO) as antibacterial and anti-inflammatory active medium. 3D conductive composite dressing was further fabricated by an extrusion 3D printing technology. Our results showed that the as-obtained composite dressing had suitable conductivity, efficient blood clotting capacity, and good adhesiveness. It also showed that the as-fabricated conductive composite had 92.9 % and 95.6 % antibacterial activity against Staphylococcus aureus (S. aureus) and Escherichia coli (E. coli), respectively. Furthermore, the conductive dressing with an optimal electrical stimulation (ES) parameter showed in vivo blood clotting capacity, and it enhanced in vivo wound healing process in a full-thickness skin defect model than commercial dressings by upregulating the gene expression of growth factors including CD-31 and downregulating inflammatory factor expression of IL-6., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2025
- Full Text
- View/download PDF
44. Tangerine peel-derived nitrogen-doped carbon dots incorporated chitosan/pullulan-based active packaging film for bread packaging.
- Author
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Sul Y, Khan A, Kim JT, and Rhim JW
- Subjects
- Antioxidants chemistry, Antioxidants pharmacology, Listeria monocytogenes drug effects, Quantum Dots chemistry, Tensile Strength, Chitosan chemistry, Food Packaging, Nitrogen chemistry, Carbon chemistry, Escherichia coli drug effects, Bread analysis, Bread microbiology, Glucans chemistry, Citrus chemistry
- Abstract
Citrus peel waste carbon dots based on nitrogen-doped (N-TanCD) were developed by a hydrothermal strategy to deliver active packaging fillers and characterized by transmission electron microscopy, photoluminescence, and Fourier transform infrared analyses. The addition of N-TanCD into chitosan-pululan (CS/Pul@N-TanCD) polymer blend amplified the tensile strength of the composite film by 22.8 %, whereas the antioxidant activities against DPPH and ABTS reached 62.7 % and 91.6 %, respectively. The proposed film showed blocked 98.8 % of UV-A and 100 % of UV-B without affecting the film's transparency. The CS/Pul@N-TanCD film lowered the contamination of L. monocytogenes and E. coli by more than 4 and 5 log CFU/mL, respectively. Sliced bread was packaged using CS/Pul-based films and stored for 12 days at 50 % relative humidity and 25 °C to investigate changes in the quality of the bread. It was found that bread packaged with CS/Pul film integrated with N-TanCD maintained excellent bread quality relating to appearance, moisture content, hardness, weight loss, and total viable bacterial count., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2025
- Full Text
- View/download PDF
45. Antimicrobial and antibiofilm potential of α-MSH derived cationic and hydrophobic peptides against Escherichia coli: Mechanistic insight through peptide-lipopolysaccharide interactions.
- Author
-
Patel P, Abdullah SJ, Tiwari K, Bhattacharjya S, and Mukhopadhyay K
- Subjects
- Microbial Sensitivity Tests, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Humans, Biofilms drug effects, Escherichia coli drug effects, Lipopolysaccharides pharmacology, Lipopolysaccharides chemistry, Hydrophobic and Hydrophilic Interactions, alpha-MSH pharmacology, alpha-MSH chemistry, Antimicrobial Cationic Peptides pharmacology, Antimicrobial Cationic Peptides chemistry
- Abstract
The prevalence of infections caused by various Gram-negative pathogens specifically Escherichia coli continuously poses a significant challenge in health care as well as community settings owing to their ability to form biofilm and escalating tolerance towards available antibiotics. While most treatment regimes are targeted at eliminating the E. coli cells, the pathogenicity factors called endotoxin (lipopolysaccharides), associated with the sepsis initiation and the leading cause of death in intensive care units globally, are often ignored. In this study, the potency of alpha-melanocyte stimulating hormone based-peptides, particularly Ana-9 and Ana-10 against E. coli was investigated through microbiological, biophysical, and microscopic assays. Both Ana-9 and Ana-10 demonstrated enhanced activity against planktonic E. coli cells, and retained their activity against biofilm, which was supported by confocal microscopy. From the mechanistic perspective, spectroscopic studies indicated that the binding of peptides with LPS led to structural alteration of peptides due to their insertion into the hydrophobic environment of LPS. The electrostatic interaction of the peptide with LPS leads to outer membrane disorganization, allowing the peptide to access the inner membrane, depolarize it and ultimately inhibit the bacterial cells within the biofilm. These observations were further confirmed by atomic force and scanning electron microscopy. Thus, this study deepens our understanding of the structural characteristics of peptides attached to LPS, which could lead to the gradual improvement in developing more potent, broad-spectrum endotoxin neutralizers., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024. Published by Elsevier B.V.)
- Published
- 2025
- Full Text
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46. Comparative analysis of substrate- and regio-selectivity of HpaB monooxygenases and their application to hydroxydaidzein synthesis.
- Author
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Watanabe S, Kato H, Yoshinaga K, Kohara A, Ukawa Y, Matsuyama A, and Furuya T
- Subjects
- Substrate Specificity, Isoflavones metabolism, Isoflavones chemistry, Rhodococcus enzymology, Pseudomonas aeruginosa enzymology, Pseudomonas aeruginosa genetics, Bacterial Proteins metabolism, Bacterial Proteins genetics, Bacterial Proteins chemistry, Hydroxylation, Mixed Function Oxygenases metabolism, Mixed Function Oxygenases genetics, Escherichia coli genetics, Escherichia coli metabolism, Escherichia coli enzymology
- Abstract
4-Hydroxyphenylacetate 3-hydroxylase (HpaB) has high potential for use in polyphenol synthesis via ortho-hydroxylation. Although the HpaB enzymes from Pseudomonas aeruginosa (PaHpaB) and Escherichia coli (EcHpaB) have been well studied, few studies have compared their activity and substrate selectivity. Thus, which HpaB is optimal for use in the biotechnological production of polyphenols is unclear. In this study, we performed a comparative analysis of the substrate- and regio-selectivity of PaHpaB, EcHpaB, and the recently discovered enzyme from Rhodococcus opacus (RoHpaB). The activity of these enzymes was first compared toward representative aromatic substrates. PaHpaB and EcHpaB exhibited very similar catalytic activity toward p-coumaric acid and tyrosol with one benzene ring, whereas PaHpaB exhibited greater activity than EcHpaB toward resveratrol and naringenin with two benzene rings. These results suggest that PaHpaB is superior to EcHpaB in converting bulky compounds. Furthermore, PaHpaB also exhibited catalytic activity toward a flavonoid, daidzein (7,4'-dihydroxyisoflavone), whereas EcHpaB did not. RoHpaB also exhibited strong activity toward daidzein in addition to other aromatic substrates. Interestingly, PaHpaB hydroxylated the 6-position of daidzein, whereas RoHpaB hydroxylated the 3'-position. PaHpaB and RoHpaB enabled the facile synthesis of not only 6-hydroxydaidzein and 3'-hydroxydaidzein but also 6,3'-dihydroxydaidzein via the cascade reaction. This study is the first to demonstrate synthesis of hydroxydaidzeins using HpaB enzymes., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 The Authors. Published by Elsevier B.V. All rights reserved.)
- Published
- 2025
- Full Text
- View/download PDF
47. Poly-tannic acid coated PLGA nanoparticle decorated with antimicrobial peptide for synergistic bacteria treatment and infectious wound healing promotion.
- Author
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Guo M, Ruan M, Wu J, Ye J, Wang C, Guo Z, Chen W, Wang L, Wu K, Du S, Han N, and Lu Y
- Subjects
- Animals, Mice, Surface Properties, Particle Size, Polyphenols, Polylactic Acid-Polyglycolic Acid Copolymer chemistry, Polylactic Acid-Polyglycolic Acid Copolymer pharmacology, Wound Healing drug effects, Nanoparticles chemistry, Escherichia coli drug effects, Staphylococcus aureus drug effects, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Antimicrobial Peptides pharmacology, Antimicrobial Peptides chemistry, Microbial Sensitivity Tests
- Abstract
Bacterial infections pose a great threat to human health. Therefore, the development of new antibacterial agents or methods is in urgent need. In this study, we prepared polytannic acid (pTA)-coated PLGA nanoparticles decorated with Dermaseptin-PP (Der), an antimicrobial peptide (AMP), on the surface to obtain PLGA-pTA-Der. This nanoplatform could combine AMPs with photothermal treatment (PTT) mediated by pTA to achieve synergistic bacterial killing. The results of in vitro experiments showed that the PLGA-pTA-Der nanoparticles could eliminate nearly 99 % of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) upon near-infrared (NIR) laser irradiation (2.0 W·cm
-2 , 5 min), demonstrating excellent antibacterial properties. In addition, the results of atomic force microscopy (AFM) revealed that PLGA-pTA-Der with laser irradiation can greatly destroy the mechanical integrity of the bacterial outer membrane. And the presence of Der could exacerbate the heat damage caused by the PLGA-pTA NPs to the bacteria, which is helpful to reduce the critical temperature required for bacteria killing by PTT. In vivo experiments showed that PLGA-pTA-Der nanoparticles with laser irradiation significantly accelerated the wound healing process and inhibited the growth of bacterial. Moreover, it can achieve a strong photothermal antibacterial effect at a mild temperature (<45℃) and does not cause any obvious thermal damage to the surrounding normal skin tissues. Results of immunofluorescence staining showed that the expression of CD31 (a marker of new blood vessel formation) was significantly higher in the PLGA-pTA-Der + laser group than other groups, while the pro-inflammatory molecule TNF-α was significantly lower, indicating that PLGA-pTA-Der nanoparticles accelerated wound healing by enhancing angiogenesis and reducing the inflammatory response. In conclusion, PLGA-pTA-Der nanoparticles was a promising antimicrobial nanoplatform for treating bacterial infections and promoting wound healing., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)- Published
- 2025
- Full Text
- View/download PDF
48. Reusable and non-invasive TiO 2 -based photodynamic transdermal patch (RPT) for treating MDR-negative bacteria strain and promote wound healing through a synergistic approach of ROS-induced RNS.
- Author
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K T, Machina A, Parveen S, and Ramana LN
- Subjects
- Animals, Biofilms drug effects, Transdermal Patch, Drug Resistance, Multiple, Bacterial drug effects, Humans, Titanium chemistry, Titanium pharmacology, Wound Healing drug effects, Reactive Oxygen Species metabolism, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Pseudomonas aeruginosa drug effects, Pseudomonas aeruginosa physiology, Photochemotherapy, Reactive Nitrogen Species metabolism, Microbial Sensitivity Tests, Escherichia coli drug effects
- Abstract
Wound healing is delayed due to the infection and biofilm formation of antibiotic-resistant species of gram-negative bacteria especially Pseudomonas aeruginosa and Escherichia coli. Antibacterial photodynamic therapy provides an efficient therapeutic strategy for overcoming drug resistance by producing reactive oxygen species (ROS) and reactive nitrogen species (RNS). Here, we have designed a low-cost light emitting diode (LED) based reusable and non-invasive titanium dioxide nanoparticles patch which is sandwiched between the thin polymer layers. The light-induced pore formation in the polymeric film due to the free radical, in turn, passes through the system and kills the bacteria rather than nanoparticles entering the system resulting in the reusability nature of the patch. The patch's in vitro antibacterial and antibiofilm activity and their mechanism (synergic ROS-induced RNS) were studied. In addition, the reusable antibacterial properties, biocompatibility and wound-healing properties of the patch were also successfully elucidated., Competing Interests: Declaration of Competing Interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2025
- Full Text
- View/download PDF
49. Evaluation of antibacterial activity on nanoline-array surfaces with different spacing.
- Author
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Ganbaatar SE, Kim YM, Kim HK, Cho YS, and Park HH
- Subjects
- Microbial Sensitivity Tests, Bacterial Adhesion drug effects, Polyurethanes chemistry, Polyurethanes pharmacology, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Escherichia coli drug effects, Surface Properties, Staphylococcus aureus drug effects, Nanostructures chemistry
- Abstract
Extensive research has been conducted on anti-biofouling or antibacterial surfaces, with nanostructured surfaces that mimic cicada and dragonfly wings emerging as promising candidates for mechano-bactericidal applications. These biomimetic nanostructured surfaces are capable of exerting a bactericidal effect by directly damaging the membranes of bacteria attached to nanostructures. Although research on bactericidal effect using various nanostructures have been conducted, no specific studies have yet reported on the antibacterial efficiency of the surface having nanoline array, especially regarding the spacing between nanolines. This study details the fabrication of nanoline array via ultraviolet (UV) molding with polyurethane acrylate (PUA), noted for its UV sensitivity and rapid curing, enabling the fabrication of precise and scalable nanoscale structures. Investigation into the nanoline array's antibacterial effects against Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus) reveals that nanoline spacing critically influences bacterial adherence and viability, with specific spacings enhancing antibacterial properties. Scanning electron microscopy (SEM) and confocal microscopy analyses show that surface topography significantly affects bacterial behavior, with specific spacings leading to varied bacterial responses, including membrane damage and altered attachment patterns. The study highlights the potential of nanoline array in fabricating surfaces with tailored antibacterial properties, emphasizing the importance of nanoscale design in influencing bacterial interaction and viability. We also confirm the relative mechanical rigidity of the nanoline array, which exhibits antibacterial effects, through both experimental observations and numerical analysis. This indicates our proposed nanoline-array surface could have potential future applications in mechanical anti-bacterial functions that require such structural robustness., Competing Interests: Declaration of Competing Interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Hyun-Ha Park reports financial support was provided by National Research Foundation of Korea. Young-Sam Cho reports financial support was provided by National Research Foundation of Korea. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier B.V. All rights reserved.)
- Published
- 2025
- Full Text
- View/download PDF
50. A novel Ag/Bi/Bi 2 O 2 CO 3 photocatalyst effectively removes antibiotic-resistant bacteria and tetracycline from water under visible light irradiation.
- Author
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Wang S, Li C, Yin H, Gao B, Yu Z, Zhou Y, Wang J, Xu H, Wu J, and Sun Y
- Subjects
- Catalysis, Silver chemistry, Silver pharmacology, Anti-Bacterial Agents pharmacology, Anti-Bacterial Agents chemistry, Water Pollutants, Chemical chemistry, Drug Resistance, Bacterial, Photolysis, Tetracycline pharmacology, Tetracycline chemistry, Bismuth chemistry, Bismuth pharmacology, Light, Escherichia coli drug effects, Escherichia coli radiation effects
- Abstract
Currently, achieving dual applications of Bi
2 O2 CO3 -based photocatalysts in photocatalytic degradation and sterilization under visible-light conditions is challenging. In this study, a novel Ag/Bi/Bi2 O2 CO3 visible-light photocatalyst with bimetallic doping and rich oxygen vacancies was successfully synthesized using a one-pot hydrothermal crystallization method. The existence of oxygen vacancies was verified by X-ray photoelectron spectroscopy (XPS) and Electron spin resonance (ESR) analysis. The experimental results showed that Ag/Bi/Bi2 O2 CO3 killed ∼100% (log 7) of antibiotic-resistant Escherichia coli (AR-E. coli) within 60 min and degraded 83.81% of tetracycline (TC) within 180 min under visible light irradiation. Moreover, Ag/Bi/Bi2 O2 CO3 can still remove 61.07% of TC in water after 5 cycles, showing excellent photocatalytic cycle stability and reusability. The possible degradation pathway of TC was determined by liquid chromatography-mass spectrometry. It was found that the main active substances in the photocatalytic disinfection of AR-E. coli were1 O2 , h+ , and ·OH, while1 O2 was the dominant active species in the photocatalytic degradation of TC. This study presents a promising Bi2 O2 CO3 -based visible light photocatalyst for treating both antibiotics (TC) and antibiotic-resistant bacteria (AR-E. coli) in water., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2024 Elsevier Inc. All rights reserved.)- Published
- 2025
- Full Text
- View/download PDF
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