157 results about "Gram-positive bacterium" patented technology

The invention discloses macromolecular antibacterial artificial leather and a preparation method thereof, and relates to the technical field of artificial leather preparation. The preparation method comprises the following steps: preparing zinc-loaded silicon dioxide with amino grafted on the surface and quaternized polyether polyurethane containing an epoxy group, mixing the zinc-loaded silicon dioxide and the quaternized polyether polyurethane to prepare antibacterial protection slurry, and bonding the zinc-loaded silicon dioxide and the quaternized polyether polyurethane through ring-opening reaction of the amino and the epoxy group during curing to form a cross-linked network, so as to obtain the antibacterial protection layer with antibacterial property, flexibility and wear resistance; zinc ions have an obvious inhibiting effect on bacteria such as gram-positive bacteria and gram-negative bacteria and fungi such as candida albicans, quaternary ammonium salt has an obvious inhibiting effect on influenza viruses, and the zinc ions and the quaternary ammonium salt have a synergistic effect, so that the antibacterial range of the artificial leather is wider, the inhibiting force on germs is stronger, and the antibacterial property of the artificial leather is further improved.

The invention relates to application of a plant-derived extracellular vesicle and a compound thereof in preparation of a pharmaceutical composition for treating or preventing diseases caused by high colonization degree of gram-positive bacteria in skin, in particular to application of a purslane extracellular vesicle and a compound of the purslane extracellular vesicle and hydrogel.

A peptidoglycan hydrolase LysPH1 having a broad-spectrum lytic activity, and a mutant and the use thereof, which belong to the technical field of biological formulations. An antibacterial peptide LysPH1-CP, a peptidoglycan hydrolase LysPH1 containing the antibacterial peptide LysPH1-CP and a peptidoglycan hydrolase mutant LysPH1-K containing the peptidoglycan hydrolase LysPH1 all have good thermal stability, and can broadly lyse both Gram-negative bacteria and Gram-positive bacteria. Moreover, the peptidoglycan hydrolase LysPH1 and the peptidoglycan hydrolase mutant LysPH1-K can be solubly expressed in Escherichia coli, and have high enzymatic activity. Therefore, the antibacterial peptide LysPH1-CP, the peptidoglycan hydrolase LysPH1 and the peptidoglycan hydrolase mutant LysPH1-K have good application prospects in the preparation of an anti-infective drug and the research and development of feed additives.

This disclosure relates to compositions and methods using genetically modified bacteria that express superoxide dismutase (SOD) and catalase enzymes to reduce oxidative stress in the skin, and can be used for various skin conditions. In some embodiments of this disclosure, the genetically modified bacteria are Gram-positive bacteria, for example, of the genus Corynebacterium.

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 application discloses an antibacterial peptide RV15 and application thereof, and belongs to the technical field of biology. The amino acid sequence of the antibacterial peptide RV15 is shown as SEQ ID NO. 1. The antibacterial peptide RV15 provided by the application has broad-spectrum antibacterial activity, has a significant bacteriostatic effect on gram-positive bacteria and gram-negative bacteria, and has a long bactericidal duration. The hemolytic activity is very low, and the biological safety is good. The antibacterial peptide RV15 can be used for treating bacterial infection, and can also be applied to other scenes requiring bactericidal action or bacterial growth inhibition. The antibacterial peptide RV15 provided by the application has a short sequence, a small molecular weight and low chemical synthesis difficulty, and can save the production cost on a large scale.

The application discloses a kind of implant and its preparation method and application, the implant includes material body, metal oxide layer and mixed crystal layer, the mixed crystal layer is located the surface of the metal oxide layer;The metal oxide layer includes metal oxide nanorod array;The metal oxide is selected from zinc oxide, silver oxide or its combination;The mixed crystal layer includes CaP crystal and metal oxide crystal.The implant of the application is sterilized by the bacteriostatic metal ion generated by physical puncture and degradation of metal oxide nanorod, has good antibacterial effect to gram-positive bacteria and gram-negative bacteria, prevents infection;It can also relieve post-implantation inflammatory response, reduce immune response under post-implantation infection, shorten wound healing time.In addition, due to the coating effect of mixed crystal layer on metal oxide layer, the bacteriostatic metal ion is slowly released, the release time is long, and long-lasting antibacterial effect can be achieved, and post-implantation inflammatory response can be reduced.

The present invention relates to a pyrazine macrolide compound and the use thereof. Specifically disclosed is a compound as represented by formula I or a pharmaceutically acceptable salt thereof. The compound of the present invention exhibits activity against bacteria, mycoplasmas, or chlamydias, and is useful for preventing and / or treating diseases caused by bacteria, mycoplasmas, or chlamydias. Further, the compound of the present application can achieve an antibacterial activity comparable to or better than that of azithromycin or solithromycin at a lower dosage. Furthermore, the compound of the present application achieves a superior antibacterial effect on Gram-positive bacteria. Still furthermore, the compound of the present application exhibits a better inhibitory activity against mycoplasmas and a lower hepatotoxicity.

The invention relates to an antimicrobial peptide consisting of the amino acid sequence: RX1WILX2WLRTWX3X4 wherein X1, X2, X3 and X4 are independently selected from K and R, and wherein each amino acid is independently in the L or D configuration, or a salt or solvate thereof. The use of said antimicrobial peptide in the treatment of an infection caused by Gram negative bacteria, Gram positive bacteria, fungi, and / or yeasts, as well as the use of said peptide as an antimicrobial agent for the prevention of contamination of an article or a living tissue by and / or for the decontamination of an article or a living tissue from Gram negative bacteria, Gram positive bacteria, fungi, and / or yeasts are further aspects of the invention.

The invention discloses a pearl sac antibacterial peptide and application thereof, and belongs to the technical field of biological medicine. The amino acid sequence of the gene is KRLF. According to the present invention, the theoretical molecular weight is 562.76 Da, the isoelectric point is 11.54, and the net charge is + 2 when the pH value is 7.0, and the antibacterial experiment result shows that the polypeptide has broad-spectrum and efficient antibacterial activity, and has significant inhibition effect on the proliferation of Gram-positive bacteria and Gram-negative bacteria. Safety evaluation experiment results show that the antibacterial peptide is beneficial to proliferation of keratinocytes and fibroblasts and is safe and non-toxic.

This invention belongs to the field of antimicrobial peptide technology, and particularly relates to a broad-spectrum antimicrobial peptide with low hemolytic activity and its applications, as well as a broad-spectrum antibacterial drug. The antimicrobial peptide is named AY6, and its amino acid sequence is shown in SEQ ID NO.1. Antimicrobial peptide AY6 exhibits significant antibacterial effects against both Gram-positive and Gram-negative bacteria, with a bactericidal rate far exceeding that of traditional antibiotics, enabling highly effective responses to bacterial infections. AY6 has low hemolytic activity and good biocompatibility, making it suitable for medical anti-infective applications. The antimicrobial peptide provided in this application has a short sequence, is easy to synthesize chemically, can save on large-scale production costs, and has broad application prospects.

The application provides a fluorescent compound, a preparation method and application of the fluorescent compound, and the compound is shown in formula (I). The compound can be used as a fluorescent probe for Gram-positive bacteria targeted imaging, and can directly kill bacteria, so that dual effects of fluorescent identification and bacterial killing on Gram-positive bacteria are realized.

The application provides a composite antibacterial peptide preparation, a preparation method and application. The composite antibacterial peptide preparation comprises a first defensin, a second defensin, a first cecropin and a second cecropin. The amino acid sequence of the first defensin is shown in SEQ ID NO:1, the amino acid sequence of the second defensin is shown in SEQ ID NO:2, the amino acid sequence of the first cecropin is shown in SEQ ID NO:3, and the amino acid sequence of the second cecropin is shown in SEQ ID NO:4. Compared with a single antibacterial peptide, the composite antibacterial peptide preparation has good stability, and shows good inhibitory effect on various gram-positive bacteria, gram-negative bacteria and fungi.

The invention provides bacillus licheniformis for high-yield protein glutaminase as well as a construction method and application of the bacillus licheniformis, a target strain is obtained by knocking out an alkaline protease gene aprE and extracellular protease genes bpr, epr, vpr or wpr and heterologously expressing the protein glutaminase gene, an EPE strain is optimal in expression, PG enzyme activity reaches 0.358 U / mL and is improved by 3.55 times compared with that of a wild type, and the bacillus licheniformis has the advantages that the bacillus licheniformis is high in yield and high in protein glutaminase yield. In addition, the growth condition of each mutant strain is not obviously abnormal, and the growth speed is obviously increased. It is fully proved that the expression level of the heterologous protein PG can be remarkably improved by targeted knockout of the extracellular protease gene of the bacillus licheniformis, and a theoretical basis is laid for construction of an efficient protein expression host. The invention not only provides a new scheme for high-efficiency expression of PG, but also provides important reference for expression optimization of heterologous proteins of other gram-positive bacteria, and shows a wide industrial application prospect.

The present invention belongs to the technical field of biomedicine, and relates to use of linoleic acid in the preparation of a drug for improving the sensitivity of Gram-positive bacteria to an antibiotic. It has been discovered for the first time that the combined use of linoleic acid and an antibiotic can significantly improve the sensitivity of Gram-positive bacteria to the antibiotic. In vivo study data have shown that the combination of linoleic acid and the antibiotic can not only improve the survival rate of mice infected with Gram-positive bacteria, but also enhance the ability of the mice to clear Gram-positive bacteria. Furthermore, formulating linoleic acid and the antibiotic into an anti-infection composition can, in one aspect, achieve a significant clinical anti-infection effect, and in another aspect, prolong the post-antibiotic effect. Moreover, linoleic acid is an essential fatty acid in human and animal nutrition, with high nutritional value, and it has been widely used in food and pharmaceutical products, demonstrating high safety.

The invention discloses a self-assembled nano-capture antibacterial peptide KIL4 and a preparation method and application thereof, and belongs to the technical field of biology, and the amino acid sequence is shown as SEQ ID No.1. The preparation method comprises the following steps: adopting an alpha-spiral heptapeptide repetitive sequence (abcdefg) 4 template, and selecting lysine to provide positive charges at positions b and c; isoleucine and leucine are respectively filled to a position a and a position d to provide intermolecular hydrophobic force, and lysine and glutamic acid are selected to be respectively filled to a position e and a position g to provide intermolecular electrostatic force; the position f of the center of the hydrophilic surface of the polypeptide is filled with tryptophan to optimize the hydrophobicity of the polypeptide, on the basis, the sequence is repeated for four times, and the invention further discloses application of the polypeptide in preparation of drugs for treating gram-positive bacteria or / and gram-negative bacteria infectious diseases. The antibacterial peptide disclosed by the invention has dual effects of resisting bacteria and capturing bacteria, has excellent biocompatibility, and provides an effective technical support for developing novel antibacterial drugs.

The application discloses a complex preparation containing bovine lactoferrin and lyticase and application thereof, and belongs to the technical field of biology. The preparation is composed of bovine lactoferrin and streptococcal lyticase, and both are prepared through a baculovirus-insect cell eukaryotic expression system. Researches show that the complex preparation has a significant synergistic antibacterial effect. The complex preparation not only can effectively inhibit a plurality of gram-positive bacteria, but also can overcome the limitation that single streptococcal lyticase has weak activity on gram-negative bacteria, and significantly enhances the inhibiting effect on escherichia coli and salmonella. Especially, the complex preparation still has clear in-vitro antibacterial activity on multi-drug resistant escherichia coli such as ciprofloxacin and doxycycline, thereby providing a new way for developing a new type of drug for resisting drug-resistant bacteria.

The invention discloses a gram-positive bacterium extracellular electron transport chain construction method and a synthetic microbial agent. It is found that after a lipophilic material is added into an iron reduction system, the iron reduction speed and the iron reduction amount of gram-positive bacteria with weak electron transfer capacity are remarkably increased, and the iron reduction amount of the gram-positive bacteria can be consistent with the iron reduction magnitude of gram-negative strong iron reduction bacteria. The lipophilic degree and the iron reduction rate are subjected to correlation analysis and show significant positive correlation, which reveals that the lipophilic degree and the permeable membrane capacity of the material are key parameters for determining the iron reduction capacity of gram-positive bacteria. The lipophilic material not only can smoothly penetrate through the cell wall of gram-positive bacteria, but also can be enriched on a cell membrane in quantity, and gradually permeates into a cytoplasm matrix to generate electron exchange with NADH (Nicotinamide Adenine Dinucleotide Hormone) so as to construct a gram-positive bacteria extracellular electron transport chain. The invention provides a brand-new strategy for preparing the biological geological catalytic synthetic microbial inoculum for soil iron reduction.

This invention discloses a strain of *Bacillus parabrachium* ABX1 and its applications, belonging to the field of beneficial microbial technology. The *Bacillus parabrachium* ABX1 provided by this invention is a Gram-positive bacterium isolated from the intestinal fluid of *Bombyx mori*. On CMC-Na solid medium, the ratio of the diameter of the hydrolysis zone to the colony diameter can reach 11. Enzyme activity identification results show that the filter paper enzyme activity of *Bacillus parabrachium* ABX1 is as high as 109.79 U·mL. ‑1 The exo-β-glucanase activity was 107.59 U·mL. ‑1 The cellulase activity reached 107.37 U·mL ‑1 It exhibits excellent cellulose and / or crystalline cellulose degradation capabilities; it is easy to use and has a wide range of enzyme production conditions, showing excellent enzyme activity at pH 5–10 and 25–50℃; the enzyme production time is short, with high enzyme yield achieved in just 12 hours, and there is no significant adverse effect on enzyme yield with prolonged reaction time; it is highly safe to use and has great application prospects in areas such as oak garden waste branch treatment, improvement of oak silkworm digestibility, industrial degradation of cellulose, and improvement of soil fertility.

The invention relates to the technical field of molecular biology and immunity, in particular to urechis unicinctus C-type lectin and a preparation method and application thereof. The amino acid sequence of the urechis unicinctus C-type lectin is as shown in SEQ ID No. 1. The C-type lectin is a recombinant protein obtained by expression in escherichia coli. The recombinant protein can be widely combined and agglutinated with various gram-positive bacteria and gram-negative bacteria, and can promote the removal of pathogenic bacteria in urechis unicinctus. The recombinant C-type lectin can be used for preparing a bacterial agglutination preparation, an anti-bacterial infection preparation and the like, and is especially suitable for prevention and control of aquaculture pathogenic bacteria.

The invention belongs to the technical field of biology, and particularly relates to endolysin derived from staphylococcus warneri mild bacteriophage and application of the endolysin. The endolysin has a nucleotide sequence as shown in SEQ ID NO: 1 or a nucleotide sequence obtained after further optimization of the endolysin. The endolysin gene sequence is completely and successfully obtained on the basis of the staphylococcus warneri mild bacteriophage vBG3001, the endolysin protein (endolysin 65) is successfully expressed and purified, and the endolysin protein has an inhibition effect on the growth of a gram-positive bacterium bacillus velezensis and a gram-negative bacterium burkholderia. The staphylococcus warneri mild bacteriophage perforin gene and endolysin gene are co-expressed in escherichia coli, so that the staphylococcus warneri mild bacteriophage has relatively strong bactericidal activity on host escherichia coli. The effects provide a theoretical basis for prevention and treatment of gram-negative pathogenic bacteria.

The invention provides application of aeromonas hydrophila bacteriophage lyase Lys56 in preparation of a bacteriostatic agent, and belongs to the technical field of biology. The aeromonas hydrophila bacteriophage lyase Lys56 disclosed by the invention has an inhibiting effect on certain gram-negative bacteria and gram-positive bacteria, and has no splitting effect on certain probiotics. The Lys56 is not resistant to high temperature and has high acid-base tolerance, the inhibition effect of the Lys56 can be enhanced by low-concentration divalent metal ions, the inhibition effect of the Lys56 can be enhanced by combined use of 1-10 mM of ethylenediamine tetraacetic acid (EDTA) and the Lys56, and the Lys56 can effectively inhibit and remove biofilms of host bacteria. In an artificial pollution model of the fish blocks, the antibacterial effect of the Lys56 is in direct proportion to the concentration of the Lys56. Lys56 has a good sterilization effect and has a good application prospect.

In some embodiments, the present disclosure provides methods of using π-conjugated compounds having a charge as part of the π-conjugated structure to treat microbial infections. These methods can be used, in particular, to treat Gram-positive bacterial infections in patients. In another embodiment, the present disclosure provides methods of using π-conjugated compounds having a charge as part of the π-conjugated structure to treat cancer.

The invention belongs to the technical field of peptide antibiotics, and discloses an antibacterial peptide humAMP43 and polynucleotide, an expression vector, a host cell, a preparation method and application thereof, the antibacterial peptide humAMP43 is a polypeptide composed of 12 amino acids, and the amino acid sequence of the antibacterial peptide humAMP43 is shown as SEQ ID NO.1. The invention further discloses a preparation method of the antibacterial peptide humAMP43. The polypeptide is obtained through deep learning model screening and experimental verification, and meanwhile, the invention provides a coding gene, a recombinant expression system and an adaptive solid-phase synthesis method of the polypeptide. The antibacterial peptide has a broad-spectrum efficient inhibition effect on gram-positive bacteria and gram-negative bacteria, and the antibacterial rate can reach 98.6%. The invention further provides application of the antibacterial peptide in preparation of antibacterial agents, antibacterial infection drugs, food preservatives and feed additives, and a new candidate molecule is provided for development and application of the antibacterial peptide in medicine, agriculture and food industries.

The application belongs to the technical field of biological medicine, and relates to an antibacterial polypeptide, a composition and application thereof. The amino acid sequence of the antibacterial polypeptide is shown in SEQ ID NO. 1: KWKIKWPVKWFKM-NH2. Experiments show that the antibacterial polypeptide has broad-spectrum antibacterial activity on gram-positive bacteria and / or gram-negative bacteria, and simultaneously has low cytotoxicity and low hemolyticity. The antibacterial polypeptide provided in the application is composed of 14 amino acids, the polypeptide chain is short, the molecular weight is small, and the antibacterial polypeptide is easy to be artificially synthesized, is a small-molecule polypeptide with high application value, and can be used for preparing a novel antibacterial agent, and has wide application prospects.

The invention discloses an inflammation regulation sequence of dairy cow mastitis and application thereof, and belongs to the technical field of biology, the inflammation regulation sequence is a regulation sequence responding to a gram-negative bacterium inflammation signal, the regulation sequence is a promoter sequence of a CXCL2 gene and is shown as SEQ ID NO: 1, and the regulation sequence is a promoter sequence of a CXCL2 gene and is shown as SEQ ID NO: 2. A regulatory sequence responding to a gram-positive bacterium inflammation signal, which is a promoter partial sequence of the NLRP3 gene and is as shown in SEQ ID NO: 2; the regulatory sequence responding to a gram-positive bacterium inflammation signal is a promoter reverse complementary sequence of the TLR2 gene and is shown as SEQ ID NO: 3; the endogenous inflammation regulation sequence provided by the invention is composed of genome elements of the dairy cow, and no exogenous coding gene is introduced, so that potential risks caused by exogenous proteins are avoided.

The invention relates to recombinant human lysozyme with broad-spectrum tumor cell killing activity and application of the recombinant human lysozyme. Specifically, the invention discloses a novel application of recombinant human lysozyme (ghLZ), and the recombinant human lysozyme is completely consistent with natural human lysozyme and does not have any variant. The ghLZ not only retains the broad bactericidal activity of gram-positive bacteria of natural human lysozyme, but also has unique broad-spectrum in-vitro tumor cell killing activity.

The application discloses a benzimidazole substituted cyclopentenone compound and a preparation method and application thereof, and the compound comprises a structural formula shown in formula I or a medicinal salt, an isomer, a medicinal derivative thereof; wherein R1 is a hydrogen atom, a chlorine atom or a fluorine atom; R2 is a hydrogen atom, a chlorine atom, a fluorine atom, a methyl group or a methoxy group; R3 is a hydrogen atom, a chlorine atom, a fluorine atom, a methyl group or a methoxy group; R4 is a hydrogen atom, a chlorine atom or a fluorine atom; R5 is a methyl group, an ethyl group or a propyl group; and R6 is a methyl group, an ethyl group or a propyl group. The compound has good antibacterial activity, and has strong antibacterial activity on various pathogenic microorganisms including gram-positive bacteria and fungi. The application has the advantages of rich raw materials, simple operation, mild conditions, simple post-treatment, good thermal stability and good application prospect.

The invention belongs to the technical field of gene engineering, and relates to a plasmid of bacillus, an artificial recombinant vector as well as a construction method and application thereof, the plasmid is called pBso for short, and the nucleotide sequence of the plasmid is shown as SEQ ID NO.1. In a plasmid sequence, a protein coded by an open reading frame is a replication element Rep protein of a gram-positive bacterium rolling circle replication type plasmid, and the nucleotide sequence of the protein is shown as SEQ ID NO.2. The artificial recombinant vector is constructed by carrying out gene recombination on plasmids of the bacillus. The construction method of the artificial recombinant vector comprises the following steps: cloning a replication element Rep protein by using a molecular cloning means to construct the artificial recombinant vector with neomycin resistance. The replication element Rep protein of the plasmid pBso of the bacillus can be used for constructing an artificial recombinant vector, stably exists in the bacillus subtilis and the bacillus amyloliquefaciens and is subjected to replication and passage, and the steps of obtaining the engineering bacillus are simplified.