15 results about "Gram negative bacterium" patented technology

The present invention belongs to the field of microbiology, and particularly relates to membrane vesicles (MVs) isolated from bacteria, and an isolation and preparation system and method for the membrane vesicles, and applications of the membrane vesicles. The bacteria of the present invention comprise Gram-positive bacteria and Gram-negative bacteria. The invention uses ionizing irradiation to irradiate bacteria, and isolates and purifies the produced membrane vesicles. The membrane vesicles prepared can be used as a vaccine, a vaccine adjuvant and / or a pharmaceutical carrier. In addition, the present invention provides a biological composition comprising the membrane vesicles and inactivated bacteria. In addition, the present invention also provides a preparation system, and isolation and purification system for bacterial membrane vesicles and the corresponding method. The membrane vesicles obtained by using the system and method have high yield, high purity and easy to be industrialized.

The present application relates to a kind of chlorella-nanose complex hydrogel and its preparation method and application, belong to nanose antibacterial technical field.The chlorella-nanose complex hydrogel includes hydrogel matrix, and the chlorella and photo-thermal nanose loaded on the hydrogel matrix.The present application also provides the preparation method of the complex hydrogel, and the application in the preparation of antibacterial drug or dressing and the killing gram-negative bacteria and gram-positive bacteria.The present application combines chlorella and nanose for the first time, and constructs a self-oxygen supply antibacterial platform.The chlorella in the chlorella-nanose complex hydrogel can carry out photosynthesis under illumination, continuously produce oxygen, provide sufficient substrate for nanose oxidase-like reaction, overcome the low activity defect of traditional nanose in anoxic environment.

Endotoxin production inhibition in a water system, or both biofouling inhibition and endotoxin production inhibition can be achieved. In a membrane treatment method or a biofouling inhibition method, a bonded halogen compound is caused to exist in a water system where gram-negative bacteria exist. In an endotoxin production inhibition method in a water system, a bonded halogen compound is caused to exist in the water system.

This invention provides an intelligent computational method for predicting effector proteins in the secretory system of Gram-negative bacteria, comprising: S1: collection and preprocessing of protein sequence datasets; S2: model construction; S3: model training; and S4: model prediction. This invention has advantages such as high prediction accuracy and good anti-interference performance.

The application provides an earthworm antibacterial peptide derived from a popular cavity earthworm and application thereof in broad-spectrum antibacterial aspects. The amino acid sequence of the antibacterial peptide is shown in SEQ ID NO. 1 or SEQ ID NO. 2, and both have 13 amino acid residues and isoelectric points of 10.31 or 10.06. The application adopts a bioinformatics method, finds a new earthworm antibacterial peptide through a machine learning algorithm, optimizes the amino acid sequence according to the prediction result, and finally obtains an antibacterial peptide with better antibacterial effect. The obtained antibacterial peptide has good antibacterial activity on gram-negative bacteria represented by escherichia coli and gram-positive bacteria represented by staphylococcus aureus, and various drug-resistant bacterial variants of the two kinds of bacteria, and can be applied to the preparation of antibacterial products, including antibacterial drugs, additives and preservatives and the like.

The invention relates to the field of biomedicine, and provides an application of a Gram-negative bacterium infection target Kdo in research and development of antibacterial drugs. An authorized antibacterial peptide Ly (PEG)-1 is used as a probe; through computer simulation, affinity determination and gene defect strain identification, the key action target is lipopolysaccharide (LPS) internal core Kdo (3-deoxy-D-mannan-octanone acid), Kdo is used as a key component of bacteria LPS and is a basis for maintaining Gram-negative bacteria cell wall integrity, LPS biosynthesis and biological activity exertion, and the Kdo is used as a key component of bacteria LPS. The deletion or modification can directly cause the loss of LPS function and the reduction of the viability of bacteria. At present, no antibacterial drug aiming at the target spot exists, the problem that in the prior art, no biomolecule capable of targeting Kdo to exert strong antibacterial activity exists is solved, and the biomolecule can be used for developing drugs for diagnosing or treating related diseases.

The application discloses application of BMS-833923 and derivatives thereof and a medicine, and belongs to the technical field of antibiotics. The BMS-833923 and the derivatives thereof can be used as colistin adjuvants to jointly inhibit or eliminate gram-negative bacteria, and can also independently inhibit or eliminate gram-positive bacteria. The gram-negative bacteria can include at least one of Escherichia coli, Klebsiella pneumoniae, Acinetobacter baumannii, Pseudomonas aeruginosa, pan-drug-resistant strains BAA-1800, BAA-1794 and BAA-1792, and the gram-positive bacteria can include at least one of Staphylococcus aureus and Bacillus subtilis. By taking the BMS-833923 and the derivatives thereof as adjuvants of colistin, the therapeutic index of the colistin can be effectively expanded, and lower, non-toxic doses of the colistin can be used in clinical treatment of effective treatment of drug-resistant bacterial infections.

This invention discloses a cell membrane-modified inflammatory-responsive release nanoparticle, its preparation method, and its applications. The nanoparticles use a polylactic-co-glycolic acid (PLA) core, and their surface is modified with an immune cell membrane. The PLA is loaded with an antibacterial drug and modified with a positively charged material and a responsive switch. The immune cell membrane is obtained by isolating immune cells pre-stimulated by pathogens. The nanoparticles prepared by this invention possess the function of rapidly releasing drugs targeting homologous bacteria and sites of inflammation. During systemic circulation, they tend to target sites of inflammation caused by bacterial infection, rapidly releasing the drug under the action of the highly expressed MMP-3 enzyme at the site of inflammation, achieving efficient delivery of antibacterial drugs. This invention has shown good therapeutic effects in a mouse model of bacterial infection, providing not only an effective means for the in vivo delivery of cationic antimicrobial peptides but also a promising therapeutic strategy against Gram-negative bacterial infections.

The present invention aims to provide an antimicrobial product, particularly an antimicrobial composition comprising antimicrobial active agents and solvent and preservative activity, which has antimicrobial efficacy against bacteria, fungi and yeasts at low concentrations, exhibiting broad spectrum effectiveness for gram-positive and gram-negative bacteria and high compatibility with different types of surfactants in formulations of personal hygiene, cleaning and household care products.

This invention discloses a polypeptide derived from human lactoferrin and its applications. This invention relates to the field of biotechnology, providing the application of the polypeptide or related biomaterials in the preparation of products with anti-inflammatory and soothing functions; the amino acid sequence of the polypeptide is shown in SEQ ID NO:1. The lactoferrin peptide of this invention can reduce the expression of the inflammatory factor IL-6 in cells, exhibiting anti-inflammatory and soothing effects. Simultaneously, this lactoferrin peptide has an inhibitory effect on the growth of Gram-negative and Gram-positive bacteria, represented by *Escherichia coli* and *Staphylococcus aureus*. This lactoferrin peptide shows promising application prospects in the preparation of drugs and cosmetics for the prevention and / or treatment of bacterial infectious diseases.

This invention discloses a highly efficient and safe antimicrobial peptide variant and its applications. Based on the natural antimicrobial peptide Upperin 3.6 sequence (as shown in SEQ NO:1), it involves replacing the disordered N-terminal region with the basic amino acid arginine; repeating two amyloid C-terminal sequences and adding three arginine residues to each end; and inserting a four-amino acid sequence DPDG (which has the greatest tendency to form a β-turn structure) between the two repeated amyloid C-terminal sequences and adding three arginine residues to each end. The antimicrobial peptide of this invention enhances the activity and safety of antimicrobial peptides, exhibiting good antimicrobial properties against both Gram-negative and Gram-positive bacteria. This antimicrobial peptide has broad application prospects as a novel antimicrobial agent.

This invention relates to the field of detection and provides a bioaerosol sampling solution. The bioaerosol sampling solution comprises the following components in the following proportions: a chelating agent, a buffer, a surfactant, a protein denaturant, a humectant, and a solubilizer. The sampling solution with specific components of this invention can directly achieve a lysis effect, thereby integrating the nucleic acid extraction step into the collection step, reducing existing sampling operations, reducing system losses, and achieving highly efficient collection results. Simultaneously, the sampling solution with specific components of this invention has excellent bactericidal effects on Gram-negative and Gram-positive bacterial solutions of different concentrations, effectively preventing microbial toxicity and personnel infection during the sampling process. Furthermore, when using the sampling solution of this invention for sampling, there is no need for repeated removal / replacement, further ensuring the potential biosafety of operators.

This invention provides a synergistic antibacterial composition based on small-leaf bitter tea and its preparation method. The composition comprises the following components: 40-60 parts of small-leaf bitter tea extract, 20-30 parts of rosmarinic acid extract, 10-20 parts of baicalin, 5-10 parts of tea polyphenols, and 1-4 parts of pharmaceutical excipients. The preparation method includes the following steps: taking small-leaf bitter tea extract, rosmarinic acid extract, baicalin, tea polyphenols, and pharmaceutical excipients; placing them in a mixer and stirring at 180-240 rpm for 25-35 minutes; passing through an 80-100 mesh sieve to obtain a homogenized composition powder, which is the finished synergistic antibacterial composition based on small-leaf bitter tea. This invention, through the scientific compounding of small-leaf bitter tea extract, rosmarinic acid extract, and baicalin, produces a significant synergistic effect, solving the three major technical problems of traditional small-leaf bitter tea extract: narrow antibacterial spectrum, poor effect against Gram-negative bacteria, insufficient stability, and easy development of drug resistance.

The application discloses a preparation method of a hectorite-based nanometer composite antibacterial material, which comprises the following steps: firstly, uniformly mixing hectorite, zinc nitrate and copper nitrate by stirring; secondly, further uniformly mixing the mixture by spraying a certain amount of water; thirdly, sequentially performing sealing aging, three-roller rolling and calcination; fourthly, dispersing the material in a plant extract solution for modification treatment; and finally, obtaining the nanometer composite antibacterial material through pressure filtration, drying and grinding. The nanometer composite antibacterial material has high charge separation efficiency and strong antibacterial activity to gram-negative bacteria and gram-positive bacteria, and more importantly, has strong antibacterial capacity to drug-resistant bacteria; as a broad-spectrum antibacterial agent, the nanometer composite antibacterial material can be applied to the fields of rubber, plastic, paint and daily-use chemical industry.