60 results about "Minimum inhibitory concentration" patented technology

The invention relates to an enzyme response antibacterial carbon dot and a preparation method and application thereof.The carbon dot takes a copper-doped carbon dot as a core and is covalently grafted with a hyaluronic acid shell layer through amidation reaction to form a composite nano material Cu-CDs (at) HA, specifically, soluble copper salt and folic acid are subjected to a hydrothermal reaction to obtain the copper-doped carbon dot, carboxyl is activated through EDC / NHS in a buffer system, and the carbon dot is prepared. And performing grafting reaction with hyaluronic acid to obtain a target product. The hyaluronidase-containing antibacterial composition can be specifically degraded and release antibacterial components under the action of hyaluronidase, shows good bacterial responsive bactericidal performance, has the minimum inhibitory concentrations of 8 g / mL and 16 g / mL for staphylococcus aureus and escherichia coli respectively, and has peroxidase-like activity and free radical scavenging capacity. The antibacterial carbon dots can be used for preparing intelligent wound dressings, antibacterial coatings and other biomedical materials, and have the advantages of responsive drug release, efficient antibacterial property and promotion of wound repair.

The present invention relates to a method for screening compounds for bactericidal activity using thermostable luciferase and based on a real-time bioluminescence measurement. The present invention further relates to a method for determining the sensitivity of a bacterial sample originating from a subject suffering from a bacterial infection to a group of known antibiotics and to a method for assessing the minimum inhibitory concentration (MIC) of a bactericidal compound.

The invention belongs to the technical field of medical chemistry, and discloses a 5-O-carbon mould amine tylosin lactone derivative with a double-target combined antibacterial effect as well as a preparation method and application of the 5-O-carbon mould amine tylosin lactone derivative. The derivative is a compound as shown in a formula I, and pharmaceutically acceptable salt, eutectic, tautomer, polymorphic substance, solvate, prodrug or isotope labeled compound thereof. The compound can act on a bacterial ribosome 50S subunit and DNA topoisomerase IV at the same time, and shows an excellent antibacterial effect in an antibacterial activity test, and the minimum inhibitory concentration (MIC) reaches 0.0625 mu g / mL. The compound has the advantages of being high in antibacterial activity, wide in antibacterial spectrum and capable of achieving rapid sterilization, and a new choice is provided for developing drugs with antibacterial activity.

This invention discloses an antimicrobial peptide cAMP-1 derived from the intestinal microorganisms of wild rodents and its applications, belonging to the field of biotechnology. The amino acid sequence of the antimicrobial peptide cAMP-1 is shown in SEQ ID NO:1. The antimicrobial peptide cAMP-1 exhibits highly efficient, rapid, and safe antimicrobial activity against Streptococcus suis type II. It significantly inhibits bacterial growth even at low concentrations, with a minimum inhibitory concentration (MIC) of 16 µg / mL. Time-kinetic kinetics results show that the antimicrobial peptide can kill all Streptococcus suis type II within 30 min and 15 min at concentrations of 2×MIC and 4×MIC, respectively. Furthermore, within several times the effective concentration range, the peptide exhibits almost no hemolytic activity and low cytotoxicity within a safe dosage range, demonstrating its promising application as a novel anti-infective candidate drug.

The invention discloses an antibacterial peptide sesquidendrin and an application of the antibacterial peptide sesquidendrin. The invention specifically relates to eight sesquistigma polypeptide compounds. The compounds 1-8 show different degrees of antibacterial activity, the compound 2 has broad-spectrum antibacterial activity, the minimum inhibitory concentration of the compound 2 to staphylococcus aureus ATCC 6538 and bacillus cereus CMCC (B) 63301 reaches 20 [mu] g / mL, and the MIC value of the compound 2 to enterococcus faecium 160119481, salmonella typhimurium CMCC (B) 50071 and salmonella typhimurium CMCC (B) 50115 is 40 [mu] g / mL. As staphylococcus, bacillus, enterococcus and salmonella bacteria are common food-borne pathogenic bacteria which seriously threaten food safety, the compounds 1-8 can be used for preparing novel antibacterial peptides which are applied to the field of food safety preservation.

The application belongs to the technical field of non-antibiotic compounds as bacteriostatic agents, and discloses an application of a known non-antibiotic compound, cladrabine, in inhibiting the growth of multi-drug resistant Klebsiella pneumoniae. The application finds that cladrabine can inhibit the growth of multi-drug resistant Klebsiella pneumoniae, and the minimum bacteriostatic concentration reaches 64 mg / L. Further exploration of the bacteriostatic mechanism finds that after exposure to cladrabine, the permeability of the bacterial cell membrane is enhanced, and the macromolecular substances (nucleic acids and proteins) in the cell are excreted, causing the integrity of the bacterial cell membrane to be destroyed, and further causing the death of Klebsiella pneumoniae. The application proposes that cladrabine can destroy the cell membrane of bacteria, change the permeability of the cell membrane, has a good inhibitory effect on multi-drug resistant Klebsiella pneumoniae, and can be further applied to the preparation of related drugs.

Heterocyclic compounds with a novel pyrazole thioamide-based NNSN structural motif, having highly effective zinc- or copper-activated toxicity against microbial infections at micromolar or nanomolar minimum inhibitory concentrations (MIC), and methods of making and using the same.

The invention relates to the technical field of biology, in particular to a pagrosomus major antibacterial peptide Pm-NK-lysin as well as a preparation method and application of the pagrosomus major antibacterial peptide Pm-NK-lysin. The amino acid sequence of the antibacterial peptide is as shown in SEQ ID NO: 1. The minimum inhibitory concentration of the antibacterial peptide to vibrio anguillarum is not higher than 8 [mu] g / ml, and / or the minimum inhibitory concentration of the antibacterial peptide to escherichia coli is not higher than 4 [mu] g / ml. The antibacterial peptide is prepared through a pichia pastoris expression system. The antibacterial peptide is applied to preparation of an antibacterial preparation. According to the invention, efficient secretory expression of recombinant Pm-NK-lysin is successfully realized by creatively utilizing a pichia pastoris eukaryotic expression system, and a protein purification process is optimized, so that sufficient sources of high-activity recombinant protein are guaranteed. The Pm-NK-lysin provided by the invention has an excellent killing effect on aquatic pathogenic bacteria. The antibacterial peptide Pm-NK-lysin is used for replacing or reducing the use of antibiotics to control the harm of aquatic bacterial diseases, has wide popularization and application values, and certainly has far-reaching significance for promoting the green and healthy development of the aquaculture industry.

This invention provides modified antimicrobial peptides, belonging to the field of antimicrobial peptide technology. The modified antimicrobial peptides include at least one of a first, second, third, fourth, fifth, and sixth antimicrobial peptide; the amino acid sequences of the first, second, third, fourth, fifth, and sixth antimicrobial peptides are shown sequentially as SEQ ID NO.1 to SEQ ID NO.6. Based on prevotellin-2, the modified antimicrobial peptides were obtained by reducing negatively charged amino acids, increasing positively charged amino acids, introducing hydrophobic amino acids, adjusting or deleting amino acid sequences, and optimizing the peptide structure. In vitro minimum inhibitory concentration (MIC) determination showed that, compared with the initial peptide, the modified antimicrobial peptides exhibited significantly enhanced antimicrobial activity against bacteria and fungi, and also showed significant bactericidal activity against clinically resistant bacteria.

This invention discloses a PKPD-guided method for treating porcine Pasteurella multocida with antibiotics. YDMS injection is used as the antibiotic, administered intramuscularly to pigs infected with Pasteurella multocida. The dosing regimen is adjusted based on in vivo PK / PD target values. The minimum inhibitory concentration (MIC) of YDMS against Pasteurella multocida is 0.06 μg / mL. PK / PD monitoring is performed using a combination of colloidal gold rapid detection and quantitative real-time PCR. This invention clarifies the three-level PK / PD target values ​​of YDMS against Pasteurella multocida and uses AUIC as the core quantitative indicator, avoiding the blindness of traditional empirical dosing. This ensures precise matching of drug concentration and infection severity, effectively reducing the risk of infection aggravation due to insufficient medication or cumulative toxicity caused by overdose, and significantly improving the consistency of treatment efficacy.

The invention belongs to the technical field of prevention and control of drug-resistant bacteria, and particularly discloses a composite bactericidal composition and application thereof in preparation of a reagent for killing aeromonas hydrophila oxytetracycline drug-resistant strains. The minimum inhibitory concentration of the epsilon-polylysine to an aeromonas hydrophila oxytetracycline drug-resistant strain is as low as 3.125 g / mL. Meanwhile, the sterilization mechanism of the epsilon-polylysine on aeromonas hydrophila oxytetracycline drug-resistant strains is discussed through metabonomics research. On the basis, the application finds that various exogenous small molecule metabolites such as 2-phenylacetamide and the like are combined with epsilon-polylysine for use, so that the absorption of drug-resistant bacteria on epsilon-polylysine can be promoted, the sterilization effect of the epsilon-polylysine is effectively enhanced, and the problem of drug resistance of bacteria is solved. Therefore, when the epsilon-polylysine and the exogenous small molecule metabolite are jointly applied, compared with the existing single antibiotic therapy, the epsilon-polylysine has higher activity and better safety and operability in preparation of the reagent for resisting the aeromonas hydrophila oxytetracycline drug-resistant strain.

The invention discloses an antibacterial peptide NyAmp-a and application thereof, and relates to the technical field of biological medicines. The amino acid sequence of the antibacterial peptide is as shown in SEQ ID NO. 1. The invention also provides an application of the antibacterial peptide NyAmp-a in preparation of an antibacterial product for inhibiting staphylococcus aureus, bacillus subtilis, escherichia coli and aeromonas hydrophila, and a minimum inhibitory concentration of the antibacterial peptide NyAmp-a to each bacterium. The invention provides a novel efficient antibacterial solution for four common pathogenic bacteria, namely staphylococcus aureus, bacillus subtilis, escherichia coli and aeromonas hydrophila. The antibacterial peptide NyAmp-a has the characteristic that drug resistance is not easy to generate, a related antibacterial composition can be applied to the fields of medicine, agriculture, food and the like, has important practical application value, and effectively solves the problems that traditional antibiotics are easy to generate drug resistance, and existing antibacterial peptides are high in cytotoxicity and lack of selectivity for specific strains.

A catheter cap (100) includes a housing defining at least one cavity (104) and an opening (106) at a distal end of the housing, and an antimicrobial agent (108) within the at least one cavity. The housing is configured to couple to a catheter luer (22) at the distal end. The at least one cavity is configured to contain a catheter lock solution in contact with the catheter luer at the opening. The antimicrobial agent is present in an amount sufficient to maintain a minimum inhibitory concentration (MIC) of the antimicrobial agent in the catheter lock solution for a period of time between successive operations of the catheter luer.

This invention discloses an antimicrobial peptide, its pharmaceutical composition, and its applications. The invention optimizes the structure of the antimicrobial peptide through deuteration modification technology, significantly enhancing its targeted binding ability to β-1,3-D-glucan synthase. The affinity of this antimicrobial peptide for the aforementioned target is 9-27 times that of the control peptide. In vitro assays show that its minimum inhibitory concentration (MIC) against nine standard Candida strains is consistently 0.002 μg / mL, exhibiting significantly superior activity compared to fluconazole, anidoxurine, and the control peptide. It also exhibits extremely low cytotoxicity against L02 human normal hepatocytes. In in vivo experiments, in a neutropenic mouse model of Candida albicans infection, the antimicrobial peptide at all doses showed superior reduction in renal fungal load compared to anidoxurine and the control peptide. The antimicrobial peptide of this invention combines highly efficient anti-Candida activity, low cytotoxicity, and excellent in vivo efficacy, providing a safe and effective candidate drug for the treatment of drug-resistant candidiasis and possessing good clinical translational value.

The invention provides amphiphilic resorcinol calixarene based on guanidino carbonyl pyrrole functionalization and a nano particle containing the amphiphilic resorcinol calixarene. Firstly, nanoparticles are constructed on the basis of amphiphilic resorcinol calixarene, then antibiotic norfloxacin is entrapped in the nanoparticles, and binary nanoparticles with a synergistic antibacterial effect are prepared and are used for efficient antibiosis. The nanoparticles show excellent synergistic antibacterial effect and biocompatibility under the condition that the concentration is far lower than the minimum inhibitory concentration of subjects and guests, and the problem of drug resistance of bacteria is avoided to the greatest extent due to the use of low-dose antibiotics.

The present application relates to the technical field of gynecological bacteriostatic gel, and particularly relates to a ulipristal bacteriostatic gel and a preparation method thereof; the ulipristal bacteriostatic gel comprises the following components in parts by weight: chlorhexidine acetate 1-3 parts, meihua grass extract 4-8 parts, carbomer 0.8-1.2 parts, triethanolamine 0.4-0.6 parts, penetration enhancer 0.5-1.5 parts, modified nano-silver 0.04-0.07 parts, glycerol 5-8 parts, hydrogenated polyisobutylene 0.03-0.07 parts, disodium edetate 0.1-0.3 parts and purified water in a remainder amount; the chlorhexidine acetate and the meihua grass ethanol extract are compounded at a ratio of 1:(2.5-4), the flavones and polyphenols in the meihua grass can destroy the cell membrane permeability of microorganisms, promote the chlorhexidine acetate to enter the inside of the microorganism, and significantly reduce the minimum bacteriostatic concentration.

The application provides an application of a grass Wu extract, relates to the field of bacteriostatic technology, and is used for inhibiting growth of escherichia coli; the minimum bacteriostatic concentration of the grass Wu extract is 2.5 mg / mL; the grass Wu extract can directly destroy the cell wall and the cell membrane of bacteria, down-regulate key genes of a flagellum assembly path, interfere with a core metabolic path of bacteria, and down-regulate related genes such as a two-component system and ABC transporter proteins; the MIC of the grass Wu extract on escherichia coli is determined as 2.5 mg / mL for the first time, which provides an accurate dose basis for developing the grass Wu extract into an antibacterial preparation, proves that the grass Wu extract has a definite and quantifiable direct bacteriostatic effect; meanwhile, through a multi-target attack strategy of 'breaking a membrane'-'breaking a leg'-'breaking food'-'causing blindness', the bacteria are difficult to produce drug resistance through a single mutation, and a new idea is provided for solving the problem of antibiotic drug resistance.

We report improved adjuvant compounds that have an aryl 2-aminoimidazole structure for macrolide potentiation against a virulent strain of gram-negative bacteria, AB5075. Compounds were discovered to retain significant adjuvant activity at 10 μM, lowering the minimum inhibitory concentration (MIC) of clarithromycin (CLR) from 8-fold to 128-fold or greater. 2-Aminoimidazole compounds linked to aryl groups via either an amide or urea linker showed significantly improved activity over control compounds.

The application provides a degradable small-molecule double quaternary ammonium salt with high antibacterial activity, a degradation product thereof and a synthesis and degradation method thereof, and relates to the technical field of organic small molecules. The synthesis method specifically comprises the following steps: S1, under the catalysis of an organic base, a silane compound and a halogenated alkyl alcohol compound are combined to obtain a condensation intermediate with silicon-oxygen groups and halogen atoms at both ends; S2, the intermediate obtained in the synthesis is subjected to a nucleophilic substitution reaction with a triamine compound, thereby obtaining a silicon-based small-molecule double quaternary ammonium salt. The double quaternary ammonium salt has high antibacterial capacity, the minimum inhibitory concentration of the double quaternary ammonium salt on Staphylococcus aureus can reach 0.1 mu g / mL, the minimum inhibitory concentration of the double quaternary ammonium salt on Escherichia coli can reach 5 mu g / mL, and the double quaternary ammonium salt has low toxicity on human normal cells. In addition, the double quaternary ammonium salt also has the ability of pH response and temperature response controlled degradation. The degradation product, a single quaternary ammonium salt, has almost no bactericidal effect. Thus, the bactericidal toxicity is changed from yes to no through the degradation reaction.

The application belongs to the field of pharmaceutical chemistry and medicine, and relates to a cephalosporin compound and its use in preparing antibacterial drugs. Specifically disclosed are the use of a cephalosporin compound, or a pharmaceutically acceptable salt thereof, or a medicine composition taking the cephalosporin compound as an effective active ingredient in preparing a medicine for preventing and treating gram-negative drug-resistant bacterial infections. The compound can irreversibly covalently bind to metal beta-lactamase, inhibit the hydrolysis of beta-lactam antibiotics, effectively reduce the minimum inhibitory concentration (MIC) value and the blood bacterial load of gram-negative drug-resistant bacteria in a mouse with abdominal infection, and can be combined with beta-lactam antibiotics such as meropenem to prepare a compound preparation for treating diseases such as infections caused by gram-negative drug-resistant bacteria.

The invention discloses an antibacterial peptide derived from an animal metagenome as well as a preparation method and application of the antibacterial peptide. Specifically, the amino acid sequence of the antibacterial polypeptide is as shown in any one of SEQ ID NO.1-55. The antibacterial polypeptide provided by the invention has a novel amino acid sequence, and in-vitro experiments prove that the antibacterial polypeptide has inhibitory activity on common pathogenic bacteria such as escherichia coli, salmonella, staphylococcus aureus or streptococcus. According to the invention, evaluation on multiple aspects such as minimum inhibitory concentration, biological safety (namely cytotoxicity and hemolysis effect on mammalian cells) and the like is carried out, and a mouse acute abdominal cavity infection model is established to verify the antibacterial activity of the antibacterial polypeptide in vivo. Results show that the antibacterial polypeptide shows high antibacterial activity in vitro and still keeps certain antibacterial activity in in-vivo experiments, and the survival rate of mice with acute abdominal infection can be increased.

This invention discloses the application of cinnamaldehyde as a potentiator for β-lactam antibiotics in inhibiting carbapenem-resistant Escherichia coli (CREC). The study confirms that cinnamaldehyde not only inhibits the growth of drug-resistant E. coli but also enhances the antibacterial activity of β-lactam antibiotics, effectively reducing the minimum inhibitory concentration (MIC) of meropenem and cefqinome against drug-resistant E. coli. Further research shows that high concentrations of cinnamaldehyde inhibit New Delhi metallo-β-lactamase-5 (NDM-5) enzyme. This discovery provides a new strategy for addressing the resistance of CREC to β-lactam antibiotics.

This invention relates to the field of automated microbial antimicrobial susceptibility testing technology, specifically to an automatic device for measuring the diameter of inhibition zones. The device includes an image acquisition module, an antimicrobial susceptibility test strip center positioning module, a radial transmittance profile construction module, a diffusion-MIC inversion module, and a diameter output module. This invention reconstructs the traditional inhibition zone measurement paradigm based on image edge detection and geometric circle fitting into a radial profile inversion paradigm based on a physical model of antimicrobial substance diffusion in agar. It constructs a radial transmittance profile and a family of azimuth profiles with the center of the antimicrobial susceptibility test strip as the polar coordinate origin, inversely infers the local diffusion coefficient field, and uses Fick's second law to nonlinearly invert the minimum inhibitory concentration (MIC) radius. Simultaneously, it separates dual-zone resistant subgroups through residual multi-peak detection and achieves dynamic prediction through temporal differential constraints. This invention achieves a measurement standard deviation better than 0.1 mm, supports dual-zone identification and culture endpoint prediction, and is significantly superior to existing automatic measurement schemes based on edge detection.

The invention discloses an application of 5-indanol in amomum tsao-ko in an antibacterial aspect. The natural component 5-indanol is separated and purified from amomum tsao-ko kernels by adopting an ethyl acetate extraction mode, experiments show that the natural component 5-indanol is good in antibacterial activity and can effectively inhibit growth and proliferation of bacteria, and the minimum inhibitory concentration of the natural component 5-indanol to staphylococcus aureus is 62.5 mu g / mL. Further research finds that commercially available 5-indanol also has antibacterial activity and can effectively inhibit growth and proliferation of bacteria. Therefore, the 5-indanol can be used as a novel natural antibiotic for treating bacterial infection.

The invention discloses an antibacterial peptide, a pharmaceutical composition and application, and belongs to the field of polypeptide medicines.The antibacterial peptide forms a novel annular conformation by introducing n-leucine and 2-aminobutyric acid to construct a parent nucleus structure. The affinity of the antibacterial peptide to the main component phosphatidylglycerol of a bacterial cell membrane is remarkably improved, is improved by 31 times or more compared with polymyxin B and is improved by 16 times or more compared with D50 peptide, and the selectivity of the antibacterial peptide to the main component phosphatidylcholine of a mammalian cell membrane is improved by hundreds of times or more compared with that of a control peptide. The polymyxin B peptide has extremely low toxicity to HK-2 kidney cells, and the biological safety of the polymyxin B peptide is obviously superior to that of polymyxin B and D50 peptide. The minimum inhibitory concentration of the antibacterial peptide to gram-negative bacteria is as low as 0.03 mu g / mL, is about 33 times higher than that of polymyxin B, and is 17-33 times higher than that of D50 peptide. The treatment effect of the antibacterial peptide is obviously superior to that of polymyxin B and D50 peptide in various infection models, and the antibacterial peptide is expected to be developed into a novel anti-infection drug and is used for preventing and treating various infections.

The invention relates to application of a bacterial metabolite in preparation of a metallo-beta-lactamase inhibitor and a drug for improving the sensitivity of bacteria to antibiotics and a pharmaceutical composition, and belongs to the technical field of biological medicines. The bacterial metabolite is N-acetyl-L-methionine and / or methyl malonic acid. The NDM-5 protein is expressed, separated and purified through a genetic engineering means, and an enzyme activity inhibition test, an enzyme inhibition ratio and semi-inhibition concentration determination prove that bacterial metabolites, namely N-acetyl-L-methionine and methylmalonic acid, can inhibit the activity of NDM-5 enzyme in a dose-dependent manner. The invention also proves that the N-acetyl-L-methionine and the methylmalonic acid can recover the antibacterial activity of the meropenem to NDM-1, NDM-5 and NDM-9 positive drug-resistant bacteria and have wide application prospects in the aspect of treating drug-resistant bacteria infectious diseases through a checkerboard method for measuring the minimum inhibitory concentration, a time-sterilization curve method and the like.

This invention belongs to the field of medical and pharmaceutical technology, and specifically relates to an antibacterial composition and its application. It comprises osimertinib mesylate and polymyxin. This invention is the first to demonstrate the novel pharmaceutical use of osimertinib mesylate as a synergistic antibacterial adjuvant for polymyxin. Experimental results show that osimertinib mesylate can significantly enhance the antibacterial activity of polymyxin against multidrug-resistant Gram-negative bacteria, effectively reduce the minimum inhibitory concentration of polymyxin, thereby reducing the clinical dosage of polymyxin and lowering the risk of its inherent nephrotoxicity and neurotoxicity. Furthermore, this invention reveals that the combined use of osimertinib mesylate and polymyxin can delay or reverse bacterial resistance to polymyxin, improve the survival rate of infected animal models, and broaden the antibacterial spectrum.

Disclosed herein are methods useful for determining the susceptibility of a bacterial strain to a siderophore beta-lactam in combination with a beta-lactamase inhibitor in an iron-containing growth medium. Disclosed herein are methods for determining the susceptibility of a bacterial strain to a siderophore beta-lactam in combination with a beta-lactamase inhibitor. In some embodiments, the method for determining the susceptibility of a bacterial strain to a siderophore beta-lactam comprises growing the bacterial strain in a growth medium having an iron concentration greater than 1 μM, treating the bacterial strain with a beta-lactamase inhibitor and a siderophore, and determining the minimum inhibitory concentration of the siderophore for the bacterial strain.

Compositions comprising 2-hydroxycarboxylic acid for dysregulating the metabolism of planktonic bacteria and their use. This disclosure provides compositions for dysregulating the metabolism of planktonic bacteria, the compositions comprising preferred enantiomers of 2-hydroxycarboxylic acid. This disclosure further provides compositions for dysregulating the metabolism of planktonic bacteria, the compositions comprising preferred enantiomers of 2-hydroxycarboxylic acid and antimicrobial compounds. Dysregulation of the metabolism of planktonic bacteria can be measured, among other examples, by a decrease in the MIC of concomitant antimicrobial agents, an enhancement of in vivo antimicrobial effects, or aerobic respiration of metabolically active cells (reduction of non-fluorescent resazurin to highly fluorescent resorphine), which can lead to sensitization of planktonic bacteria to antimicrobial compounds and / or disruption of resistance of planktonic bacteria to antimicrobial compounds.

The invention relates to the technical field of antibacterial agents, and discloses a main chain degradable type carbonic ester alternating cation antibacterial agent, the structural formula is shown in the following formulas: R1 is one of the following formulas I-XI, R2 is one of CH2CH2, CH2CH2CH2CH2 and CH2OCH2CH2OCH2, the value range of n1 is 2-7, the value range of m is 3-7, and the value range of n is 10-20. According to the antibacterial agent, a cationic sterilization group and a degradable carbonic ester group are alternately introduced into a polymer main chain, so that accurate construction of a structure is realized. The prepared carbonic ester alternate cationic antibacterial agent has broad-spectrum and efficient activity on clinically separated multi-drug-resistant bacteria, the minimum inhibitory concentration (MIC) can reach 2-8 mu g / mL, degradation products are non-toxic and have no bactericidal activity, and meanwhile, the bacteria are difficult to induce to generate drug resistance.