106 results about "Vancomycin" patented technology

The invention belongs to the technical field of gram-positive bacterium detection, and particularly relates to a nano-probe for detecting gram-positive bacteria and a preparation method, a detection method and application of the nano-probe for detecting the gram-positive bacteria, and the nano-probe for detecting the gram-positive bacteria comprises concanavalin A modified magnetic nanoparticles and vancomycin modified long afterglow nanoparticles, the magnetic nanoparticles comprise FeCl3, the long afterglow nanoparticles comprise ZnGa2O4: Cr, and the preparation method comprises a preparation method of the concanavalin A modified magnetic nanoparticles and a preparation method of the vancomycin modified long afterglow nanoparticles. The nano-probe provided by the invention has the functions of recognition, separation and enrichment, interference resistance and signal providing in the detection of gram-positive bacteria, and provides a new detection means for the recognition and detection of gram-positive bacteria.

The invention discloses an application of a small molecule compound DK419 in preparation of a drug for resisting staphylococcus infection, and the CAS number of the small molecule compound DK419 is 2102672-22-8; the staphylococcus comprises at least one of staphylococcus aureus, staphylococcus epidermidis, staphylococcus hominis, staphylococcus capitis and staphylococcus haemolyticus. According to the technical scheme, the novel medical application of DK419 is disclosed, DK419 has the effects of inhibiting growth of staphylococcus and killing staphylococcus aureus, the antibacterial effect is better than that of first-line antibiotic vancomycin, and the bactericidal effect is equal to that of vancomycin; the DK419 has the effect of efficiently removing a biofilm; the DK419 can play a role in resisting staphylococcus aureus infection in an in-vivo skin infection model.

The invention belongs to the technical field of biology, and particularly relates to bifidobacterium longum subsp.infantis FMBL B250020GXY for metabolizing breast milk oligosaccharide and application of the bifidobacterium longum subsp.infantis FMBL B250020GXY, the bifidobacterium longum subsp.infantis FMBL B250020GXY is preserved in China Center for Type Culture Collection on September 1, 2025, and the preservation number is CCTCC M 20251931; three kinds of breast milk oligosaccharides, namely 2 '-fucosyllactose (2'-FL), lactose-N-neotetraose (LNnT) and lactose-N-tetraose (LNT), can be metabolized; plant source carbohydrates such as fructo-oligosaccharide and synanthrin can be metabolized; the compound has a relatively strong capability of removing DPPH and ABTS free radicals; a good inhibition effect is achieved on common pathogenic bacteria; good tolerance to acid and cholate is achieved; the strain is sensitive to gentamicin, streptomycin, tetracycline, chloramphenicol and vancomycin; the compound can be used for preparing antioxidant products, medicines for inhibiting pathogenic bacteria, infant foods and fermented foods, and has a wide application prospect.

The invention discloses a Weissella virida 38-3 strain and an application thereof. Relates to the technical field of microorganisms. The invention provides a strain and application thereof. The strain is safe in separation source, high in growth speed and excellent in fermentation performance; the strain has the advantages of good biological safety, no hemolytic activity and no generation of bioamine, is sensitive to antibiotics such as ampicillin, erythromycin, kanamycin, streptomycin, tetracycline, vancomycin, chloramphenicol, gentamicin, clindamycin, ciprofloxacin, cefixime and the like, has good probiotic performance, has good gastric juice and intestinal juice tolerance and strong cell surface adhesion, and can be used for preparing antibiotics. Good pathogenic bacterium inhibiting and cholesterol lowering capabilities are realized. The strain disclosed by the invention can be used as a probiotic to prepare a food leavening agent, multifunctional medicines, functional foods or health-care foods, and has wide market prospects and application values.

The invention discloses a micro-fluidic chip system for detecting staphylococcus aureus and escherichia coli and a detection method. The micro-fluidic chip system comprises a micro-fluidic chip, vancomycin modified iron oxide magnetic nano particles (Fe3O4-Van MNPs), silver (at) aure-4-mercaptobenzoic acid-staphylococcus aureus aptamer nano particles (Ag (at) Au-MBA-Apt NPs) and silver (at) aure-5 '5-dithiobis (2-nitrobenzoic acid)-escherichia coli aptamer nano particles (Ag (at) Au-DTNB-Apt NPs), and the micro-fluidic chip system comprises a micro-fluidic chip, a magnetic nano particle (Fe3O4-Van MNPs), a magnetic nano particle (Ag (at) Au-MBA-Apt NPs) and a magnetic nano particle (Ag (at) Au-MBA-Apt NPs), wherein the micro-fluidic chip integrates a magnetic capture unit, a composite structure construction unit and an SERS in-situ detection unit, and the micro-pipeline is provided with a plurality of necks and cylindrical baffles. When the micro-fluidic chip system is used for detecting the staphylococcus aureus and the escherichia coli in the blood, the sensitivity is high, and the limit of detection (LOD) of the staphylococcus aureus and the escherichia coli is as low as 2.01 FU / mL and 3.28 CFU / mL respectively.

The invention discloses a cytochalasin compound with wide antibacterial activity as well as a preparation method and application thereof. According to the present invention, the cytochalasin polymer is obtained by separation from the fermentation product derived from the Aspergillus izzukae (Aspergillus izzukae), such that the cytochalasin polymer can be obtained, the preservation number of the Aspergillus izzukae PJ03-11 is CGMCC (China General Microbiological Culture Collection Center) No.40601, and the preservation number of the Aspergillus izzukae PJ03-11 is CGMCC No.40601. The compound has a structure of a cytochalasin mother nucleus and an epiccine mother nucleus, and shows good activity in the aspects of inhibiting or killing staphylococcus aureus, methicillin-resistant staphylococcus aureus, multidrug-resistant staphylococcus aureus, streptococcus pneumoniae, staphylococcus epidermidis and vancomycin-resistant enterococcus faecalis; the compound can be used for preparing novel agricultural or medical antibacterial drugs.

The invention discloses preparation and application of a hand mycin derivative with gram-positive bacterium activity resistance, and belongs to the technical field of medicine preparation. According to the present invention, the ctd gene cluster is subjected to heterologous expression in the strain Streptomyces lividans TK64, such that the obtained hand mycin derivatives Carpatamide N and Carpatamide O show excellent biological activity on the gram-positive bacteria; the MIC (minimal inhibitory concentration) values of the Carpamide N and the Carpamide O on streptococcus faecium and enterococcus faecium are 4 mu g / mL and 1 mu g / mL respectively; the MIC (minimal inhibitory concentration) values for staphylococcus aureus and bacillus subtilis are respectively 0.25 mu g / mL and 0.125 mu g / mL, the MIC values for MRSA (Methicillin-Resistant Staphylococcus Aureus) are respectively 1 mu g / mL and 0.5 mu g / mL, and the Gram-positive bacterium resisting activity of the compound is equivalent to or better than that of vancomycin.

The invention belongs to the technical field of biological medicines, and particularly relates to a cyclic ester peptide compound, a producing strain thereof, a preparation method and application of the cyclic ester peptide compound in preparation of antibacterial medicines. The invention provides a cyclic ester peptide compound as shown in a formula I, a stereoisomer, a tautomer and an isotope derivative of the cyclic ester peptide compound, or a pharmaceutically acceptable salt of the cyclic ester peptide compound, a producing strain Streptomyces alboflavus sp.NX-12 of the cyclic ester peptide compound, and fermentation, separation and purification methods of the cyclic ester peptide compound and the stereoisomer, the tautomer and the isotope derivative of the cyclic ester peptide compound. The cyclic ester peptide compound has strong inhibitory activity on a variety of gram-positive bacteria, can be used for preparing antibacterial drugs, shows application potential in treatment of infection and other related diseases, and compared with the existing similar gram-positive bacterium-resistant glycopeptide antibiotic vancomycin, the cyclic ester peptide compound has the advantages that the cyclic ester peptide compound can be used for preparing the antibacterial drugs; the cyclic ester peptide compound disclosed by the invention has an equivalent antibacterial effect. The preparation method of the cyclic ester peptide compound is simple in process, short in time consumption, capable of greatly reducing the medicine cost and suitable for large-scale production. # imgabs0 #

The present invention relates to the technical field of pharmaceutical compounds and specifically discloses a selenocyanine pregnenol ketamide compound having the following general structural formula: #imgabs0#. The selenocyanine pregnenol ketamide compound of the present invention exhibits strong inhibitory activity against human breast cancer cells, cervical cancer cells, ovarian cancer cells, and human liver cancer cells. Furthermore, the selenocyanine pregnenol ketamide compound of the present invention also exhibits strong inhibitory effects against methicillin-resistant Staphylococcus aureus (MRSA) and vancomycin-resistant Enterococci (VRE). The selenocyanine pregnenol ketamide compound of the present invention has low toxicity to humans and exhibits strong inhibitory effects against cancer cells and various drug-resistant bacteria at low concentrations. It can be used to prepare cancer treatment drugs and as an antibacterial agent against drug-resistant bacteria.

The invention belongs to the field of microbial technology, and specifically relates to a strain of acid fish lactobacillus PKC6 and an application thereof. The acid fish lactobacillus PKC6 is deposited in the General Microbiological Center of the China Microbiological Culture Collection Administration Committee, and the deposit number is CGMCC NO. 27201. The new strain of acid fish lactobacillus PKC6 screened by the invention is resistant to gentamicin, polymyxin B, vancomycin, kanamycin and norfloxacin, sensitive to ampicillin, penicillin, cephalexin and doxycycline, and has a good inhibitory effect on Escherichia coli and Staphylococcus aureus; the strain screened by the invention, after being compounded with a composite enzyme and co-fermented with palm meal, can greatly increase the content of nutrients in the fermentation product, and has a more obvious promoting effect on the intestinal development of raised animals, thereby achieving the purpose of improving the palatability of feed and promoting intestinal development.

The invention discloses a preparation method of a 2-sulfydryl-1, 3, 4-thiadiazole-gold nanocluster comparable with vancomycin and an application of the 2-sulfydryl-1, 3, 4-thiadiazole-gold nanocluster in infection, and the 2-sulfydryl-1, 3, 4-thiadiazole-gold nanocluster is used for treating methicillin-resistant staphylococcus aureus. The result shows that the 2-sulfydryl-1, 3, 4-thiadiazole-gold nanocluster can be adsorbed on the surface of bacteria, down-regulate a Na < + > / H < + > transporter on a cell membrane, influence the potential of the cell membrane, reduce the activity of bacterial ATPase synthetase and the generation of ATP, and finally show the effect of killing the bacteria. The 2-sulfydryl-1, 3, 4-thiadiazole-gold nanocluster is good in antibacterial stability, low in cytotoxicity and good in blood compatibility, and in a rat wound infection model experiment, the gold nanocluster has a relatively remarkable curative effect of promoting wound healing, is mainly characterized by reduction of local inflammation, increase of generation of blood vessels and collagenous fibers, down-regulation of inflammatory factors and the like, and can be used for preparing a drug for treating wound healing. And no obvious side effect is observed during the treatment period. The 2-sulfydryl-1, 3, 4-thiadiazole-gold nanocluster can be used as a material comparable to vancomycin and used for treating infection caused by methicillin-resistant staphylococcus aureus.

The invention provides a composition for inhibiting formation of a staphylococcus aureus biofilm, and relates to the technical field of biological medicines, and the composition comprises an inhibitor and vancomycin with sub-inhibitory concentration. In order to solve the clinical problem that vancomycin with sub-inhibitory concentration promotes formation of a staphylococcus aureus biofilm, the invention provides an inhibition method with very high feasibility. Through joint use of the vancomycin with the sub-inhibitory concentration and the arginine, formation of a staphylococcus aureus biofilm can be effectively inhibited, the treatment effect of the vancomycin with the sub-inhibitory concentration is improved, the treatment dosage of the vancomycin is expected to be reduced, and drug resistance generated by bacteria is avoided.

The application discloses a material for preventing tissue adhesion and hemostasis and a preparation method thereof, and relates to the technical field of medical biomaterials.The carboxymethyl cellulose, chitosan and vancomycin / ceftazidime are synergistically matched, so that the three functions of hemostasis, adhesion prevention and antibiosis are integrated;meanwhile, the water absorption and gelation of the carboxymethyl cellulose and the blood coagulation activation of the chitosan can jointly strengthen the hemostasis effect; the tissue barrier function of the chitosan and the gel isolation of the carboxymethyl cellulose can jointly improve the adhesion prevention performance; the broad-spectrum antibiosis of the vancomycin and the ceftazidime can respond to the infection risk in different surgical scenes; the material preparation process is simple, the dosage form can be adjusted according to different surgical scenes, the material has good biocompatibility and can be completely degraded, the problem that the existing medical materials have single function and are difficult to meet the needs of complex surgical wounds is solved, and the material has significant clinical application value.

The invention provides a macrolide compound and a preparation method and application of an intermediate compound of the macrolide compound, and belongs to the field of organic synthesis. The macrolide compound provided by the invention has the following chemical structure. The macrolide compound prepared by the invention is a compound with a 19-membered lactone ring structure, has a [5, 6]-tetrahydroindene ring structural unit and a (Z, E, Z) conjugated triene unit, and has a chemical structure completely different from that of MRSA drug-resistant bacterium antibiotics clinically used at present, such as polypeptide drugs (vancomycin and the like) and quinolone drugs (ofloxacin and the like), and the MRSA drug-resistant bacterium antibiotics can be used in clinical application. The macrolide is proved to have new drug-resistant bacterium resisting action targets and mechanisms. The macrolide compound provided by the invention has strong anti-MRSA activity, the minimum inhibitory concentration (MIC) is 1-2mg / mL and is equivalent to the anti-MRSA activity of vancomycin, and based on the strong anti-drug-resistant bacterium activity, the macrolide provided by the invention can be developed into a novel anti-drug-resistant bacterium drug. # imgabs0 #

The invention relates to the technical field of materials for preventing and treating local infection, in particular to drug-loaded composite nanoparticles as well as a preparation method and application thereof. The drug-loaded composite nanoparticles provided by the invention comprise hollow polydopamine grafted with vancomycin and lipoic acid-quaternary ammonium salt ionic liquid loaded into a cavity of the hollow polydopamine. In the invention, the HPDA nanoparticles have a hollow structure, and the structure provides sufficient space for loading of drug molecules. The lipoic acid-quaternary ammonium salt ionic liquid can generate heat energy under the microwave heat effect, and bacteria are effectively killed. Besides, under microwave stimulation, the lipoic acid-quaternary ammonium salt ionic liquid not only can enhance the sterilization effect, but also can reduce inflammatory response caused by bacterial infection through the synergistic effect of microwave heat effect and chemical sterilization.

The invention discloses antibiotic-loaded in-situ modified platelet-rich fibrin gel as well as a preparation method and application thereof. The antibiotic-loaded in-situ modified platelet-rich fibrin gel is prepared from the following components in percentage by mass: 88 to 92 percent of PRF (platelet-rich fibrin) matrix, 5 to 8 percent of antibiotic and 3 to 4 percent of modifier, the PRF matrix comprises platelets, leukocytes and fibrin, the antibiotic is vancomycin or gentamicin, and the modifier is a zinc ion-containing compound or quaternized chitosan. The gel can be applied to preparation of chronic infection wound dressing, the antibiotic loading rate of the gel is increased, the gel has the slow release characteristic, the accumulative release within 7 days is 82.3 + / -5.6%, the burst release within 24 hours is less than 15%, the wound healing speed is increased by 40%, and the biological membrane clearance rate is 100%.

The application discloses a food-borne pathogenic bacteria detection method based on composite nanomaterials and belongs to the technical field of food safety detection. The method is characterized by the following steps: synthesizing cerium-based nanomaterial DPA-Ce-GMP with enzyme-like activity based on Ce(CH3COO)3, guanosine-5'-monophosphate disodium (GMP) and 2,6-pyridine dicarboxylic acid (DPA); taking Prussian blue as a carrier; using vancomycin to identify gram-positive bacteria; and constructing a composite nanomaterial PB@DPA-Ce-GMP@Van with targeting and oxidase characteristics, namely PCV. The PCV can be precisely adsorbed on the surface of gram-positive bacteria to form a PCV / gram-positive bacteria composite. The residual PCV in the supernatant after centrifugation can quench the fluorescence of scopolamine (SC) and increase the fluorescence intensity of fluorescent red dye (AR) at the same time. The fluorescence intensity ratio (SC / AR) is used as a detection signal output. The application realizes a composite nanometer platform for rapid detection of bacteria, has high sensitivity and strong anti-interference ability, and has a detection range of 10 1 ~ 10 7 CFU / mL and a detection limit of 5 CFU / mL.

The invention relates to the technical field of biology, in particular to a broad-spectrum bacteriophage lyase mutant, an extraction and purification reagent and a kit. The invention provides a broad-spectrum bacteriophage lyase mutant, an extraction and purification reagent and a kit. A broad-spectrum bacteriophage lyase mutant nucleic acid release liquid containing protein with an amino acid sequence as shown in SEQ ID NO: 1 is adopted; the compound can efficiently act on two important clinical drug-resistant bacteria, namely methicillin-resistant staphylococcus aureus MRSA and vancomycin-resistant enterococcus VRE, at the same time. Through unique molecular design and preparation process optimization, the lyase shows excellent synchronous wall breaking capacity, cell wall destruction can be completed in an extremely short time, and the nucleic acid release efficiency is remarkably superior to that of a traditional method.

The application discloses a kind of smelly danchang dots and preparation method and application, belong to medical technical field.The preparation method of smelly danchang dot includes: smelly danchang fine powder is dispersed in distilled water, and is stirred pyrolysis on heating table;Pyrolysis product is diluted with distilled water, and supernatant is obtained by centrifugation, filter membrane filtration, dialysis, freeze-drying, to obtain carbon dot.The average particle size of obtained carbon dot is 4.51±1.04nm.The smelly danchang dot prepared in the application shows strong inhibitory activity to a variety of gram-positive bacteria (such as listeria, methicillin-resistant staphylococcus aureus MRSA) and fungi (such as Candida albicans), especially to clinically tricky drug-resistant strains, such as vancomycin-resistant enterococci (VRE) and MRSA effective, can be applied to the preparation of antibacterial drugs, antibacterial dressing, disinfectant or preservative, with the advantages of wide raw material source, simple preparation method, low cost, environment-friendly and the like.

This invention discloses the application of the bacterial fission protein FtsZ inhibitor DB1 in the preparation of drugs against drug-resistant bacteria, belonging to the field of drug development technology. The inhibitor provided by this invention is compound DB1, named 3-(2,8-dibromo-10,11-dihydro-5H-dibenzo[b,f]azapheno-5-yl)-N,N-dimethylpropylamine hydrochloride, with the molecular formula C2. 19 H 24 Br2ClN2. This compound, DB1, exhibits significant inhibitory effects against various drug-resistant bacteria, particularly vancomycin-resistant enterococci and methicillin-resistant Staphylococcus aureus (MRSA), and can significantly improve the susceptibility of methicillin to MRSA. The discovery of compound DB1 provides new ideas and technical support for the preparation of drugs against drug-resistant bacteria.

The invention belongs to the technical field of detection of pests in food, and particularly relates to a rapid staphylococcus aureus detection method based on a nano double-fluorescent probe. The method comprises the following steps: synthesizing carbon dots, preparing silicon nanoparticles, carrying out surface functional modification (introducing vancomycin and an antibody), and constructing a ratio-type fluorescent biosensor. The prepared sensor has double emission fluorescence peaks (492 nm and 529 nm), is good in repeatability and high in sensitivity, and quantitatively analyzes the content of staphylococcus aureus by measuring the ratio (F492 / F529) of the two fluorescence peaks. The detection linear range is wide, and the correlation regression coefficient can reach 0.98. The standard recovery rate in actual sample detection is 94-102.9%, and the relative standard deviation is less than 5%. The method is high in specificity and excellent in anti-interference capability, can be widely applied to rapid, accurate and quantitative detection of staphylococcus aureus in complex matrixes such as dairy products and the like, and has a wide application prospect.

The invention relates to a double-probe detection kit for detecting staphylococcus aureus in meat products and a preparation method of the double-probe detection kit, and belongs to the technical field of food safety. The double-probe detection kit is composed of a magnetic capture probe reagent and a double-signal nano-enzyme probe reagent which are independently packaged and have the same volume; the magnetic capture probe reagent is a vancomycin modified reticular magnetic bead and is used for specifically binding staphylococcus aureus in a meat product detection sample and carrying out separation and enrichment treatment; the double-signal nano-enzyme probe reagent is a blue fluorescent carbon dot modified by a nucleic acid aptamer and is used for specifically combining the staphylococcus aureus subjected to separation and enrichment treatment and generating a staphylococcus aureus concentration dependent colorimetric signal and a fluorescent signal. According to the invention, mutual verification is carried out between dual-mode signals, so that the accuracy of a detection result is improved; according to the method, the detection time is within 1.5 h, the detection time is short, the detection sensitivity is high, and the method has good specificity for common type strains.

The present invention discloses a ratio fluorescent probe for detecting Listeria monocytogenes and a preparation method thereof, and belongs to the field of food safety technology. It is prepared by uniformly mixing a first fluorescent probe as an energy donor and a second fluorescent probe as an energy acceptor; the first fluorescent probe is carbon quantum dots modified with vancomycin; the second fluorescent probe is silicon nanoparticles modified with an aptamer; and the aptamer is used to specifically identify Listeria monocytogenes. It has been verified that the linear fitting coefficient of the ratio fluorescent probe of the present invention for detecting Listeria monocytogenes is 0.99332, and the detection limit is 2.06 CFU / mL. Compared with traditional methods, it also has a lower detection time and better specificity; in addition, under the interference of milk samples, the established linear regression equation still shows excellent applicability.

The present invention belongs to the field of microorganisms, and specifically relates to a strain of Pediococcus pentosaceus PKC10 and its application. The Pediococcus pentosaceus PKC10 is deposited in the General Microbiological Center of the China Microbiological Culture Collection Administration Committee, and the deposit number is CGMCC NO.27203. The new strain Pediococcus pentosaceus PKC10 screened by the present invention is resistant to gentamicin, polymyxin B, vancomycin, kanamycin and norfloxacin, sensitive to ampicillin, penicillin, cephalexin and doxycycline, and has a good inhibitory effect on Escherichia coli and Staphylococcus aureus; the screening method provided by the present invention is simple and efficient; the screened strain has good application prospects in preparing fermentation agents, further preparing feeds, etc., turning agricultural and sideline products into treasures, broadening the source of feeds, reducing breeding costs, alleviating the contradiction of insufficient feed supply, and being conducive to the development of animal husbandry.

The invention belongs to the technical field of high-performance polypropylene, and discloses an antibacterial polypropylene composite material, a preparation method thereof and a medicine bottle. The antibacterial polypropylene composite material is prepared from polypropylene, composite antibacterial particles, a lubricant and the like. Wherein the polypropylene accounts for 78-87.3%, the composite antibacterial particles account for 10-18%, the lubricant accounts for 1-2%, the antioxidant accounts for 0.5-2%, the flexibilizer accounts for 1-3%, and the nucleating agent accounts for 0.2-0.3%. The antibacterial polypropylene composite material disclosed by the invention has very high antibacterial property and mechanical property. The antibacterial polypropylene composite material not only has an antibacterial effect on common bacteria such as escherichia coli and staphylococcus aureus, but also has remarkable antibacterial activity on drug-resistant bacteria such as vancomycin-resistant enterococcus faecalis (VRE) and methicillin-resistant staphylococcus aureus (MRSA), and the outstanding antibacterial characteristic of the antibacterial polypropylene composite material is shown.

Provided herein are compositions to treat Clostridioides difficile (C. difficile), Mycobacterium tuberculosis (M. tuberculosis) and Enterococcus faecalis (E. faecalis). These compositions are related to the known compounds (+)-Puupehenone and (+)-ent-Chromazonarol, which are both naturally occurring products. The new compositions were shown to potently inhibit both growth and toxin production of C. difficile as well as inhibit the growth and survival of both replicating and dormant M. tuberculosis. In the United States the C. difficile burden is approximately 453,000 hospital cases and 29,000 deaths annually. Globally, about 10 million people fall ill from tuberculosis and 1.4 million died from the disease. In addition, the known compound (+)-ent-Chromazonarol (10) was found for the first time to strongly inhibit the growth of E. faecalis. E. faecalis has grown drug resistant to vancomycin. In 2017, Vancomycin-Resistant Enterococci (VRE) caused an estimated 54,500 infections among hospitalized patients and 5,400 estimated deaths in the United States.

The invention discloses an aromatic polyketone compound as well as a preparation method and application thereof. The compound GaB (3) has an effect of treating infection of multiple drug-resistant bacteria. The compound is obtained by being separated from a secondary metabolite of the symbiotic Streptomyces sp.QHH-9511 of licheniformis, and the compound 2, the compound 3, the compound 4 and the compound 5 are new compounds. According to the present invention, the research results show that the GaB can effectively sterilize a variety of drug-resistant bacteria (methicillin-resistant staphylococcus aureus, vancomycin-resistant enterococcus, carbapenem-resistant acinetobacter baumannii, multi-drug-resistant pseudomonas aeruginosa, multi-drug-resistant salmonella, and the like); in addition, the compound has the characteristics of broad-spectrum sterilization, biofilm formation inhibition and low-frequency drug resistance, and can be combined with other antibiotics to cope with super bacteria. Mechanism research shows that GaB is combined with glucosamine-6-phosphate synthetase (GlmS) to prevent synthesis of cell walls so as to play an antibacterial role, and a plurality of constructed living body models show that the compound can effectively reduce the content of bacteria in a body and promote wound repair and has in-vivo medication safety. The research result shows that the GaB can be used as a safe and effective novel pilot natural active small molecule for resisting infection of multiple drug-resistant bacteria.

The present invention relates to the field of antimicrobial agents, and in particular to quaternized norharman dimers, pharmaceutical compositions thereof, and antimicrobial uses. The present invention provides a quaternized norharman dimer, the MIC value of which against MRSA is 0.015 to 0.5 μg / mL, which is stronger than the clinical first-line drug vancomycin, and can be used to treat infectious diseases caused by MRSA, such as bacteremia, pneumonia, myocarditis, wound infection, bone and joint infection, etc. The quaternized norharman dimer is active against Gram-negative bacteria Escherichia coli, Klebsiella pneumoniae, and Acinetobacter baumannii at the same time, and has a broad-spectrum antibacterial characteristic.

Compositions and methods are provided for the synthesis and use of biguanide-conjugated antibiotics, which provide a generalizable strategy for rapidly synthesizing potent antibiotics derived from clinically relevant agents.

The invention discloses a screening culture medium and a preparation method and application thereof, the screening culture medium comprises a basic culture medium and additives, and the additives comprise amphotericin B, vancomycin, ox bile salt, sodium deoxycholate and No.3 bile salt. According to the screening culture medium provided by the invention, a special infectious microbe inhibitor is added on the basis of a trisaccharide iron culture medium, so that most gram-negative enterobacter, staphylococcus aureus and part of fungi except salmonella enteritis subspecies and shigella cannot grow; the interference of the infectious microbes on the detection of the salmonella enteritis subspecies and the shigella is avoided, so that the fluorescent probe can be applied to the detection of the salmonella enteritis subspecies and the shigella in a clinical anus swab, and the sensitivity of color development is improved.