BIORESOURCE TECHNOLOGY
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2021
·
IF 9.642
Xiao-Man Fan,Jia-Jia Shen,Yuan-Yuan Xu,Jian Gao,Ye-Wang Zhang
A method for specific immobilization of whole-cell with covalent bonds was developed through a click reaction between alkyne and azide groups. In this approach, magnetic nanoparticle Fe 3 O 4 @SiO 2 -NH 2 -alkyne was synthesized with Fe 3 O 4 core preparation, SiO 2 coating, and alkyne functionalization on the surface. The azides were successfully integrated onto the cell surface of the recombinant E. coli harboring glycerol dehydrogenase, which was employed as the model cell. The highest immobilization yield of 83% and activity recovery of 94% were obtained under the conditions of 0.67 mg mg −1 cell-support ratio, pH 6.0, temperature 45 °C, and 20 mM Cu 2+ concentration. The immobilized cell showed good reusability, which remained over 50% of initial activity after 10 cycles of utilization. Its activity was 9.7-fold higher than that of the free cell at the condition of pH 8.0 and each optimal temperature. Furthermore, the immobilized cell showed significantly higher activity, operational stability, and reusability.
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高影响因子
Food Analytical Methods
·
2020
·Vol. 13
·期 7
·1433-1441
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IF 2.667
Duan Nuo,Yang Wei,Wu Shijia,Zou Ying,Wang Zhouping
In order to monitor and respond rapidly to outbreaks of food-borne pathogens, establishing rapid and sensitive detection methods is becoming increasingly urgent. In this work, through the synthesis of copper-based metal-organic framework nanoparticles (Cu-MOF NPs) and functionalized with aptamers, we developed a colorimetric protocol to detect Escherichia coli . In a typical experimental procedure, aptamer 1 was immobilized onto microplate to act as capture probes. Cu-MOF NPs were synthesized and functionalized with streptavidin and biotinylated aptamer 2 to form the signal probes. In the presence of E. coli , aptamers on both capture and signal probes bind with E. coli and form a sandwich-type complex. The Cu-MOF NPs enable to catalyze the colorless peroxidase substrate to yield a colorimetric output signal. This peroxidase-like mimics-based colorimetric aptasensor showed a rapid and sensitive quantification of E. coli in the concentration range of 16~1.6 × 10 6 cfu/mL with a limit of quantitation (LOQ) of 16 cfu/mL and limit of detection (LOD) of 2 cfu/mL. The application of the developed assay for colorimetric measuring of milk samples was evaluated with satisfactory results. The developed Cu-MOF NPs-assisted visual method can be expected as a powerful alternative and promising tool for foodborne pathogen detection and control.
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JOURNAL OF MATERIALS SCIENCE
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2018
·Vol. 54
·期 2
·1539-1548
·
IF 2.993
Wang Chao,Ping Hang
Biomineralization-associated proteins are responsible for the structure-forming process of biominerals. Aiming to regulate the synthesis of nanostructured TiO 2 anatase, an artificial protein 5R5 derived from silaffins was displayed on Escherichia coli surface through genetic manipulation. The genetically modified bacterial cells serve as the framework for the formation of rod-shaped TiO 2 , assembled by nanoparticles, as well as provide a carbon source in situ during the carbonization process. The particle size and carbon content were controllable by changing the heating temperature and time. The electrode annealed at 800 °C for 1 h shows the highest reversible capacity of 160.2 mA h g −1 after 200 cycles at a current rate of 1C. This unique nanostructured anatase not only shortens the diffusion pathway of lithium ions and electrons, but also improves the electric conductivity and tolerates the volume change during charging/discharging owing to carbon coating. However, the larger particle size and high carbon content were not advantageous to improve lithium storage performance.
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CHEMICAL ENGINEERING JOURNAL
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2024
·
IF 13.3
Lu Han,Xu-Wei Liu,Wei-Xiong Li,Tao Zang,Zhi-Peng Li,Yao Deng,Lu-Lu Tan,Dun-Sheng Liang,Xiao-Jing Zhang,Xiao-Fan Shen,Sheng-Qiu Tang,Xiao-Ping Liao,Hao Ren,Chaoqun Zhang,Gang-Biao Jiang,Jian Sun
Occurrence of inflammatory bowel disease (IBD) is increasing worldwide and has become a global health threat. Nonetheless, the effective prevention and available treatment interventions of IBD are limited. Bacterial outer membrane vesicles (OMVs) derived from probiotic bacteria such as Escherichia coli Nissle 1917 (EcN) exhibit promising anti-inflammatory, anti-oxidant, immunomodulatory, and gut microbiota modulatory functions. However, the application of OMVs in vivo encounters potential challenges due to poor tolerance against gastric juice. A delivery system of probiotic-EcN-derived OMVs was established by aldehyde-coupling to silica microspheres (SAP@OMVs) in this study. These SAP@OMVs microspheres were nontoxic to murine macrophage RAW 264.7 and human intestinal epithelial cell lines Caco-2. In the dextran sulfate sodium (DSS)-induced acute colitis models, the application of SAP@OMVs significantly improved mouse survival and alleviated the harmful effects of DSS by maintaining colon length, reducing colon injury, decreasing expression of inflammatory factors such as TNF-α and IL-1β, and increasing expression of the tight junction proteins gene zonula occludens-1 (ZO-1). The SAP@OMVs restored gut microbiota with increasing abundance of the Lactobacillus . In conclusion, the novel vehicle of OMVs demonstrated anti-inflammatory effects, representing a crucial strategy for clinical translation of OMVs as a potential therapeutic intervention for IBD.
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PHYTOMEDICINE
·
2024
·
IF 6.7
Jiaxing Yang,Laiying Zhang,Xinlian He,Xupeng Gou,Zhiyong Zong,Youfu Luo
Background The increase in antimicrobial resistance leads to complications in treatments, prolonged hospitalization, and increased mortality. Glabridin (GLA) is a hydroxyisoflavan from Glycyrrhiza glabra L. that exhibits multiple pharmacological activities. Colistin (COL), a last-resort antibiotic, is increasingly being used in clinic against Gram-negative bacteria. Previous reports have shown that GLA is able to sensitize first line antibiotics such as norfloxacin and vancomycin on Staphylococcus aureus , implying that the use of GLA as an antibiotic adjuvant is a promising strategy for addressing the issue of drug resistance. However, the adjuvant effect on other antibiotics, especially COL, on Gram-negative bacteria such as Escherichia coli has not been studied. Purpose The objective of our study was to investigate the targets of GLA and the synergistic effect of GLA and COL in E. coli , and to provide further evidence for the use of GLA as an antibiotic adjuvant to alleviate the problem of drug resistance. Methods We first investigated the interaction between GLA and enoyl-acyl carrier protein reductase, also called "FabI", through enzyme inhibition assay, differential scanning fluorimetry, isothermal titration calorimetry and molecular docking assay. We tested the transmembrane capacity of GLA on its own and combined it with several antibiotics. The antimicrobial activities of GLA and COL were evaluated against six different susceptible and resistant E. coli in vitro . Their interactions were analyzed using checkerboard assay, time-kill curve and CompuSyn software. A series of sensitivity tests was conducted in E. coli overexpressing the fabI gene. The development of COL resistance in the presence of GLA was tested. The antimicrobial efficacy of GLA and COL in a mouse model of urinary tract infection was assessed. The anti-biofilm effects of GLA and COL were investigated. Results In this study, enzyme kinetic analysis and thermal analysis provided evidence for the interaction between GLA and FabI in E. coli . GLA enhanced the antimicrobial effect of COL and synergistically suppressed six different susceptible and resistant E. coli with COL. Overexpression experiments showed that targeted inhibition of FabI was a key mechanism by which GLA synergistically enhanced COL activity. The combination of GLA and COL slowed the development of COL resistance in E. coli . Combined GLA and COL treatment significantly reduced bacterial load and mitigated urinary tract injury in a mouse model of E. coli urinary tract infection. Additionally, GLA + COL inhibited the formation and eradication of biofilms and the synthesis of curli. Conclusion Our findings indicate that GLA synergistically enhances antimicrobial activities of COL by targeting inhibition of FabI in E. coli . GLA is expected to continue to be developed as an antibiotic adjuvant to address drug resistance issues.
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高影响因子
JOURNAL OF FOOD QUALITY
·
2018
·
IF 0.841
Wenxue Chen,Lan Zou,Weijun Chen,Yueying Hu,Haiming Chen
The chemical composition and antimicrobial mechanism of action of black pepper chloroform extract (BPCE) were investigated, as well as the potential antibacterial activities of BPCE against Escherichia coli and Staphylococcus aureus. The results showed that 1H-Cycloprop[e]azulen-7-ol, decahydro-1,1,7-trimethyl-4-methylene-, [1ar-(1aα,4aα,7β,7a,β,7bα.)]- (8.39%) and 2-methylene-4,8,8-trimethyl-4-vinyl-bicyclo[5.2.0]nonane (6.92%) were identified as the two primary components of BPCE. The release of intracellular transaminases from bacteria after being incubated with BPCE revealed that the bacterial cell walls and membranes were degraded and that protein synthesis was inhibited to some extent. The inhibition of bacterial Na+/K+-ATPase activity upon the addition of BPCE also indicated an enhanced permeability of bacterial cell membranes. Moreover, an analysis of hexokinase and pyruvate kinase activities showed that BPCE affected the metabolic rate of glycolysis and disrupted the normal metabolism of bacteria. This phenomenon was supported by an observed accumulation of lactic acid (LA) in the treated bacterial cells. Overall, our results indicated that BPCE damaged bacterial cell walls and membranes, which was followed by a disruption of bacterial cell respiration.
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JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY
·
2024
·
IF 5.7
Yaqiong Liu,Fang Wu,Ming Zhang,Yutong Jin,Xinlei Yuan,Yanling Hao,Lishui Chen,Bing Fang
Human milk oligosaccharides could prevent pathogenic bacterial infections in neonates; however, direct in vivo anti-infection evidence was still lacking. Here, we systematically evaluated the effects of 2′-fucosyllactose (2′-FL) and 3′-sialyllactose (3′-SL) on the structural development and functional maturation in neonates and their defense against enteroaggregative Escherichia coli infection. It was found that supplementation with 2′-FL and 3′-SL improved the resistance of weaned mice to enteroaggregative E. coli. The mechanism related to the promotion of 2′-FL and 3′-SL in the maturation of intestinal mucosal immunity by promoting stem cell differentiation, mucus layer integrity, and tight junction formation. 2′-FL and 3′-SL significantly increased the ratio of Th1 and Treg cells in the lamina propria, contents of short-chain fatty acids, as well as the serum content of IgA. This study lays a theoretical basis for the application of 2′-FL and 3′-SL in infant formula, as well as the development of intestinal health products.
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高影响因子
MICROCHEMICAL JOURNAL
·
2024
·
IF 4.9
Panxue Wang,Ying Liu,Xiang Li,Cen Li,Guoliang Li
Rapid and reliable determination of pathogenic bacteria is crucial for food safety and public health. Surface-enhanced Raman spectroscopy (SERS) based aptasensors have attracted increasing attention in the determination of pathogenic bacteria due to their high specificity and sensitivity. However, the sensitivity and reliability of the SERS aptasensors for the determination of pathogens were hindered by the uneven distribution of SERS tags. To tackle this limitation, a SERS aptasensor based on a hybridization chain reaction (HCR) mediated signal conversion strategy was fabricated for the determination of E. coli O157:H7. In the presence of E. coli O157:H7, the blocked aptamer specifically binds with it and releases the blocker DNA. Then the blocker DNA hybridizes with the capture DNA on the SERS probe and initiates the HCR reaction, which further leads to the formation of double stranded DNA and the reduction of the SERS signal intensity of 4-mercaptobenzonitrile (4-MBN). Under the optimal conditions, the SERS signal intensity at 1073.9 cm −1 and the logarithmic value of the concentration of E. coli O157:H7 in the range of 8 × 10 2 –8 × 10 7 CFU·mL −1 exhibited a good linear relationship, with a coefficient of determination of 0.92. The limit of detection for E. coli O157:H7 was 409 CFU·mL −1 . Besides, this aptasensor exhibited satisfactory specificity for E. coli O157:H7. In addition, it showed excellent stability in real sample analysis with relative standard deviations (RSDs) below 3.76 % (n = 3). The established SERS aptasensor employed a HCR mediated signal conversion strategy and overcame the drawback of unevenly distribution of SERS tags in classical SERS aptasensors for the determination of pathogenic bacteria. This study offered a new reference for the rapid and reliable detection of pathogens with a portable Raman spectrometer.
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Frontiers in Nutrition
·
2025
·
IF 5.1
Min Du,Xinran Liu,Xu Ji,Yue Wang,Xiaodan Liu,Chunfang Zhao,Erhui Jin,Youfang Gu,Hongyu Wang,Feng Zhang
Introduction: Enterotoxic Escherichia coli (ETEC) is the main pathogen that causes diarrhea, especially in young children. This disease can lead to substantial morbidity and mortality and is a major global health concern. Managing ETEC infections is challenging owing to the increasing prevalence of antibiotic resistance. Berberine, categorized as a substance with similarities in “medicine and food,” has been used in China for hundreds of years to treat gastrointestinal disorders and bacteria-induced diarrhea. This study investigated the preventive effect of dietary berberine on the intestinal mucosal barrier induced by ETEC and the microbial community within the intestines of weaned piglets.Methods: Twenty-four piglets were randomly divided into four groups. Piglets were administered either a standard diet or a standard diet supplemented with berberine at concentrations of 0.05 and 0.1%. and orally administered ETEC or saline.Results: Dietary supplementation with berberine reduced diamine oxidase, d-lactate, and endotoxin levels in piglets infected with ETEC (P < 0.05). Berberine increased jejunal villus height, villus/crypt ratio, mucosal thickness (P < 0.05), and goblet cell numbers in the villi and crypts (P < 0.05). Furthermore, berberine increased the optical density of mucin 2 and the mucin 2, P-glycoprotein, and CYP3A4 mRNA expression levels (P < 0.05). Berberine increased the expressions of zonula occludins-1 (ZO-1), zonula occludins-2 (ZO-2), Claudin-1, Occludin, and E-cadherin in the ileum (P < 0.05). Moreover, berberine increased the expression of BCL2, reduced intestinal epithelial cell apoptosis (P < 0.05) and decreased the expression of BAX and BAK in the duodenum and jejunum, as well as that of CASP3 and CASP9 in the duodenum and ileum (P < 0.05). Berberine decreased the expression of IL-1β, IL-6, IL-8, TNF-α, and IFN-γ (P < 0.05) and elevated total volatile fatty acids, acetic acid, propionic acid, valeric acid, and isovaleric acid concentrations (P < 0.05). Notably, berberine enhanced the abundance of beneficial bacteria including Enterococcus, Holdemanella, Weissella, Pediococcus, Muribaculum, Colidextribacter, Agathobacter, Roseburia, Clostridium, Fusicatenibacter, and Bifidobacterium. Simultaneously, the relative abundance of harmful and pathogenic bacteria, such as Prevotella, Paraprevotella, Corynebacterium, Catenisphaera, Streptococcus, Enterobacter, and Collinsella, decreased (P < 0.05).Discussion: Berberine alleviated ETEC-induced intestinal mucosal barrier damage in weaned piglets models. This is associated with enhancement of the physical, chemical, and immune barrier functions of piglets by enhancing intestinal microbiota homeostasis.
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高影响因子
INTERNATIONAL MICROBIOLOGY
·
2022
·Vol. 26
·期 1
·59-68
·
IF 3.097
Yang Hua,Zhao Dengqi,Wang Shuping,Yang Lijun,Huang Jianying,Zhang Zibin,Li Shijun
An increasing number of infections caused by multidrug-resistant (MDR) Staphylococcus aureus （ S. aureus ） and Escherichia coli （ E. coli ） have severely affected human society. Thus, it is essential to develop an alternative type of antibacterial agents that has a different bacterial resistance mechanism from that of traditional antibiotics. After the synthesis and structural characterization of a cationic pillar[5]arene with pyridinium groups (PP5), the antibacterial and antibiofilm activities as well as its microbial resistance were systematically investigated. In-depth evaluation of biological studies revealed that PP5 was an active antibacterial agent, with surprising antibiofilm formation ability against E. coli and S. aureus. From the results of differential scanning calorimetry and transmission electron microscopy, it was concluded that the microbicidal activity of PP5 was due to the physical disruption of the pathogen’s membrane and the subsequent leakage of cytoplasmic components, which could greatly reduce the rapid generation of resistance. It was presented that the easily available PP5 has high activity to inhibit Gram-positive and Gram-negative bacteria and/or their biofilms with low cytotoxicity. This pillar[5]arene derivative can be used as a good candidate for controlling drug-resistant pathogenic bacterial infections and treating MDR bacteria.
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CHEMOSPHERE
·
2019
·
IF 5.108
Nannan He,Shihai Cao,Lihao Zhang,Zhidan Tian,Huan Chen,Fang Jiang
The porous graphitic carbon nitride nanosheets (PCNSs) with high yields were synthesized by using one–step chemical exfoliation method. PCNSs accelerated separation efficiency of photo-generated electron−hole pairs in comparison to bulk graphitic carbon nitride. The PCNS5 (exfoliation for 5 h) exhibited optimal photocatalytic disinfection capability towards Escherichia coli K-12 under simulated solar light irradiation with complete disinfection of 6.5 log 10 cfu/mL of E. coil K-12 within 2 h. The enhanced photocatalytic activity of PCNS5 originated from mesoporous nanosheet structure. The possible mechanism of photocatalytic disinfection has proposed that intracellular reactive oxygen species levels and the activities of antioxidant enzymes (e.g., catalase and superoxide dismutase) were enhanced. Transmission electron microscope images observed during photocatalytic disinfection process suggested that the cell membrane was regarded as the first target for oxidation, resulting in a faster leakage of cytoplasmic content and finally degradation of DNA leading to bacterial death. Furthermore, the trapping experiment showed that superoxide radical (•O 2 − ) and holes (h + ) were responsible for E. coli K-12 disinfection by PCNS5.
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Journal of Global Antimicrobial Resistance
·
2023
·
IF 4.6
Jingchun Kong,Yue Wang,Yijia Han,Huijing Zhou,Zhenyun Huang,Xiaodong Zhang,Cui Zhou,Tieli Zhou,Jianming Cao
Objectives The emergence of carbapenem-resistant Escherichia coli (CREC) is a global concern as its prevalence restricts treatment options and poses a considerable threat to public health. In this study, in vitro and in vivo activity of the antimicrobial peptide Octominin against CREC were evaluated, and investigated its possible mechanism of action was investigated. Furthermore, its safety and factors influencing its antibacterial effect were assessed. Additionally, the anti-inflammatory effects of Octominin were examined. Methods The antimicrobial activity of Octominin against 11 strains of CREC was determined using the broth microdilution method, growth curve, and time-kill assay. Its possible mechanism of action was unraveled using the propidium iodide and N-phenyl-1-naphthylamine fluorochrome and lipopolysaccharide-binding assays. To understand the safety and stability of Octominin, its cytotoxicity, hemolysis, and antibacterial activity under various conditions, such as temperature and ions, were estimated. Additionally, a Galleria mellonella infection model was utilized to evaluate the efficacy of Octominin in vivo , and qRT-PCR was performed to assess its impact on the expression of proinflammatory cytokines. Results Octominin displayed a significant antibacterial effect, with MICs of 4 to 8 μg/mL and MBCs of 8 to 16 μg/mL. Octominin exerted its antibacterial effect by disrupting bacterial membranes. Cytotoxicity and hemolysis tests demonstrated the potential application of Octominin in vivo . The G. mellonella infection model asserted the in vivo efficacy of Octominin. Furthermore, Octominin inhibited the expression of proinflammatory cytokines. Although the temperature had little effect on its the activity, serum and ions reduced activity. Conclusions Octominin is a promising alternative agent with remarkable antibacterial and anti-inflammatory effects for treating infections caused by CREC .
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