50 results about "Kanamycin" patented technology

The invention provides bacillus velezensis and an application of the bacillus velezensis in degradation of antibiotics. The bacillus velezensis is preserved in the Guangdong Microbial Culture Collection Center, and the preservation number of the bacillus velezensis is GDMCC No: 66277. The bacillus velezensis is named as bacillus velezensis. The invention also provides a bacillus velezensis preparation or a bacillus velezensis liquid containing the strain. The invention also provides an application of the bacillus velezensis or the microbial inoculum thereof or the bacterial liquid thereof in degradation of kanamycin antibiotics. The application comprises the following steps: degrading the residual kanamycin antibiotics in soil or sewage, or repairing the soil polluted by the residual kanamycin antibiotics.

The invention designs a preparation method of a magnetic molecular imprinting-aptamer sandwich fluorescence sensor for detecting kanamycin. And the magnetic molecular imprinting composite material Fe3O4 (at) UiO-66 (at) MIP with a specific adsorption target object KANA is prepared. When a detection target object KANA exists, the Fe3O4-coated UiO-66-coated MIP can rapidly and specifically capture the KANA in a short time. Then, a DNA single-stranded aptamer marked with FAM is added, after the aptamer and KANA captured on the surface of the Fe3O4 at-UiO-66 at-MIP are subjected to specific recognition and magnetic separation again, an aptamer probe can enter sediment along with the magnetic composite material Fe3O4 at-UiO-66 at-MIP, the fluorescence intensity of supernate is reduced, and quantitative analysis is conducted according to the fluorescence difference value delta F. When the KANA does not exist, the aptamer cannot enter the precipitate, so that the fluorescence signal intensity is not changed. Double recognition is formed through specific binding of an MIP imprinting cavity and the aptamer, matrix interference is reduced by means of fluorescence characteristics and magnetic separation capacity, the method has the advantages of being high in adsorption capacity, specific in recognition, high in sensitivity, wide in detection range, good in selectivity and the like, and rapid and accurate detection of KANA in a complex sample can be achieved.

This invention discloses a method for directed evolution of antibiotic-resistant Escherichia coli strains based on cytidine deaminase, belonging to the field of microbial directed evolution and genetic engineering technology. This method uses E. coli as the host, introducing a recombinant plasmid expressing an optimized double-stranded cytidine deaminase mutant. Utilizing the low toxicity and high mutagenicity of this mutant, continuous passage evolution is carried out under gradient concentrations of aminoglycoside antibiotics (kanamycin and streptomycin). Combined with whole-genome sequencing, molecular docking, and reverse genetics verification, the A145T missense mutation in the wcaE gene is identified as the core functional site. This invention overcomes the shortcomings of traditional spontaneous and chemical mutagenesis, which suffer from low efficiency and significant strain damage. The mutation type is controllable, the evolutionary cycle is short, and the obtained engineered strains can tolerate up to 300 mg / L kanamycin while exhibiting streptomycin cross-resistance, and the genetic stability of the tolerance trait is strong. This method is simple, highly reproducible, and suitable for industrial breeding of stress-resistant E. coli, and can be widely applied in antibiotic fermentation, industrial microbial culture, and other scenarios.

This invention provides a composite aerogel based on Eucommia ulmoides gum and MXene nanosheets, its preparation method, and its application. The aerogel is prepared by reacting a toluene solution of Eucommia ulmoides gum with Ti3C2T... x MXene aqueous solution was mixed and a water-in-oil microemulsion was formed using a combination of ultrasound-assisted shaking. This allowed MXene nanosheets to self-assemble at the microemulsion droplet interface. Following vertical freezing and freeze-drying processes, a three-dimensional network structure of Eucommia ulmoides gum-Ti3C2T was successfully constructed. x MXene composite aerogel. The preparation method of this invention is mild and requires no chemical cross-linking agents. The resulting composite aerogel exhibits excellent adsorption performance for enrofloxacin, malachite green, Congo red, rhodamine, and kanamycin in water, with adsorption equilibrium times all within 10 minutes, enabling rapid removal of organic pollutants from water. This invention provides a new approach for the high-value utilization of Eucommia ulmoides gum and has promising application prospects in the field of water environment remediation.

The invention discloses an electrochemical aptamer sensor for detecting kanamycin as well as a preparation method and application of the electrochemical aptamer sensor, and belongs to the technical field of electrochemical biosensing analysis. According to the invention, a gold electrode assembled with a kanamycin aptamer with sulfydryl is taken as a sensing interface, a target molecule kanamycin is combined to the sensing interface, and a silver nanoparticle-zirconium-based metal organic framework material signal probe is combined with kanamycin on the sensing interface, so that the sandwich type kanamycin electrochemical aptamer sensor is constructed. The kanamycin electrochemical aptamer sensor prepared by the invention has relatively high sensitivity, relatively low detection limit and relatively wide detection range, the detection limit of the sensor is 0.085 aM, and the detection range is 0.1 aM <-1 > nM. The electrochemical aptamer sensor prepared by the invention is used for quantitative detection of kanamycin, and has the advantages of good stability, strong specificity, good reproducibility and the like.

The present application relates to the technical field of biology, and discloses a construction method of a Pseudomonas putida suicide vector and application thereof.The construction method of the Pseudomonas putida suicide vector provided by the present application takes a pK18mobsacB vector as a template to obtain a vector skeleton by amplification, and then takes Pseudomonas putida KT2440 bacterial liquid as a template to obtain a strong promoter Prib, upper and lower homologous arms of a gene x to be knocked out, and connects the upper and lower homologous arms to the vector skeleton to obtain the Pseudomonas putida suicide vector.The strong promoter Prib can increase the expression amount of sacB sucrose in the Pseudomonas putida, and enhance the sucrose lethal effect.The Pseudomonas putida suicide vector obtained can be introduced into the Pseudomonas putida, and then the strain with the target gene to be knocked out deleted can be obtained efficiently and accurately through kanamycin positive screening and sucrose negative screening.

The application discloses a pesticide composition containing zhongshengmycin and kanamycin and application thereof, and belongs to the technical field of pesticides. Effective components of the pesticide composition are zhongshengmycin and kanamycin. The mass ratio of the kanamycin to the zhongshengmycin is 1:1-9. The two effective components of the application have different action sites for killing pathogenic bacteria, and can effectively alleviate the generation of drug resistance of the pathogenic bacteria. After the zhongshengmycin and the kanamycin are compounded, synergistic effect is obvious, the control effect of the pesticide on bacterial diseases, such as citrus canker, is improved, the pesticide dosage can be reduced, and agricultural residues are reduced. Meanwhile, the prepared soluble granules do not use any organic solvent, are safe to crops, and have no residues and pollution to the environment.

The application provides a nucleic acid sequence and a method for detecting biomolecules based on a self-driven hybrid chain reaction (SHCR), which comprises a priming chain AI, a blocking chain B, a hairpin probe H1, a hairpin probe H2, a hairpin probe H3 and a hairpin probe H4, the priming chain AI comprises an aptamer sequence of a to-be-detected biomolecule and a starting sequence I, the sequence of the starting sequence I is a*‑b*, wherein a* and b* are gene fragments; the 5' end of the hairpin probe H1 is connected with b*, and the 3' end of the hairpin probe H3 is connected with a*. The application further provides a kit for detecting biomolecules based on the SHCR and a method for detecting biomolecules, in particular, a method for detecting a kanamycin residual amount in food. Through ingenious design, when the to-be-detected biomolecule exists, the sequence combination of the above biomolecule can initiate the self-driven hybrid chain reaction, the priming chain can be autonomously supplemented, the self-driven reaction process is reversely activated, thereby a more significant FRET signal is generated, and the detection sensitivity is improved.

The invention relates to a kanamycin fluorescence-electrochemical dual-mode biosensor based on a three-dimensional DNAzyme walker and application of the kanamycin fluorescence-electrochemical dual-mode biosensor, and belongs to the technical field of biosensing. The biosensor comprises a gold electrode AuE modified with a capture chain CP, a three-dimensional DNAzyme walker and a target recognition probe Apt / R of kanamycin, the three-dimensional DNAzyme walker comprises a G-quadruplex substrate chain embedded with MB, a DNAzyme chain with a self-protected annular structural domain and gold nanoparticles (AuNPs); the target recognition probe Apt / R is obtained by hybridizing an aptamer chain Apt and an aptamer complementary chain R. By adopting a fluorescence-electrochemical dual-mode detection method, the problem that single signal output is easily interfered by a false positive signal and a background signal is effectively solved, and the accuracy of kanamycin detection is remarkably improved.

The application belongs to the technical field of microorganism detection, and particularly relates to a bifidobacterium viable count detection culture medium, a detection method and application. The application provides a culture medium for detecting bifidobacterium, wherein the culture medium comprises MRS culture medium and an antibiotic solution; the antibiotic solution comprises streptomycin, kanamycin and sodium propionate. The culture medium can ensure normal growth of bifidobacterium, has strong inhibition on lactobacillus, can effectively realize accurate detection of bifidobacterium, and avoids interference of lactobacillus.

The invention provides Kineococcus G2 and application of the Kineococcus G2 in preparation of a pigment with antioxidant activity, the Kineococcus new strain G2 is CCTCC No. M20242602, the strain is spherical, the size is 1.0 * 1.5 mu m, the optimal growth temperature is 30-37 DEG C, the pH value is 7.0-9.0, and the salt concentration is 1.0%-2.0%. The strain G2 is not sensitive to bacitracin, ciprofloxacin and norfloxacin, and is sensitive to novobiocin, polymyxin, gentamicin, piperacillin, ofloxacin, erythromycin, streptomycin, kanamycin, rifampicin, ampicillin, vancomycin, carbenicillin, chloramphenicol, tetracycline, penicillin, cefoperazone, oxacillin, amoxicillin and neomycin. Pigment generated by fermentation of the G2 strain has good antioxidant activity, and when the concentration is 10 micrograms / mL, the scavenging activity on DPPH is 25.00%, the scavenging activity on hydroxyl radicals is 80.58%, and the iron ion reducing capacity is 1.57, which are all higher than those of contrast beta-carotenoid. The application of the new Kineococcus strain G2 can lay a foundation for the research of antioxidant drugs such as medical treatment and health care product development.

The invention discloses a two-color fluorescent aptamer sensor for detecting kanamycin and aflatoxin B1 in feed by using two-color fluorescent silver nanoclusters, and belongs to the field of food safety detection. According to the invention, different DNA templates are utilized to synthesize the double-color silver nano-cluster as a fluorescent probe, and the double-color silver nano-cluster has two different fluorescent colors of 530 nm and 630 nm. And a sequence rich in guanine is used as a capture probe, so that an amplification effect on signals of two kinds of fluorescence is achieved. When KAN or AFB1 exists, a corresponding target object is selectively combined with an aptamer fragment to form an aptamer-target object-aptamer sandwich structure, and the fluorescence intensity of the silver nano-cluster is induced to be enhanced through G-rich sequence and base pairing. The'lightening 'type double-color fluorescent aptamer sensor shows excellent detection performance, the KAN detection limit reaches 0.86 nM, the AFB1 detection limit reaches 0.71 nM, the'lightening' type double-color fluorescent aptamer sensor can be used for detecting kanamycin and aflatoxin B1 in a feed sample, and the reliability and application potential of the'lightening 'type double-color fluorescent aptamer sensor in multiple detection of antibiotics and toxins in the feed sample are highlighted.

The invention discloses a method for constructing a genetic transformation system of cymbidium kanran, which belongs to the technical field of plant genetic engineering, and comprises the following steps of: carrying out monoclonal propagation on rhizomes after germination of cymbidium kanran seeds to obtain vegetative propagules with stable characters, taking the vegetative propagules as transformation receptors, taking GFP (Green Fluorescent Protein) as marker genes, and constructing the genetic transformation system of cymbidium kanran. The method comprises the following steps: adding agrobacterium EHA105 into a YEB liquid culture medium containing 50 mg / L of kanamycin and 25 mg / L of rifampicin as a dip dyeing solution; placing the injured transformation receptor in dip dyeing for transformation, and then carrying out regeneration culture. The invention relates to a method for carrying out genetic transformation on cymbidium kanran by utilizing the innovative receptor and the screening culture medium, and the method can realize efficient and stable genetic transformation without genotype dependence and can solve the problem that the genetic transformation of cymbidium kanran varieties is difficult to carry out. According to the invention, an efficient genetic transformation and regeneration system of cymbidium kanran is established for the first time, and a foundation is laid for verification of related functional genes of cymbidium kanran and further development of biological research of cymbidium transgenic breeding and the like.

The application discloses a fermentation method for producing thiamine pyrophosphokinase and belongs to the technical field of bioengineering. The BL21 recombinant engineering bacteria containing pET28a-TPK, pET28a-ProS2-TPK or pET28a-SUMO-TPK are constructed, the seed liquid is prepared, the isopropyl-beta-D-thiogalactoside is used for inducing expression, the bacteria are collected, the cells are broken and the supernatant is collected to obtain the TPK crude enzyme liquid. In the fermentation, the LB / TB culture medium containing 50 μg / mL kanamycin or 100 μg / mL ampicillin is used. The SUMO label is introduced to guide the correct folding of the TPK, so that the soluble expression ratio of the TPK is more than 85%, the ratio is improved by 2 times compared with the common system, the inclusion body ratio is greatly reduced, the process is stable and has good repeatability, and an effective scheme is provided for the industrialized large-scale preparation of the TPK.

This invention relates to the field of genetic engineering technology, specifically disclosing a polyclonal antibody against citrus HIPP7 protein, its preparation method, and its applications. The method includes selecting amino acid 1-246 of the HIPP7 protein sequence for prokaryotic expression, synthesizing the sequence and ligating it into the vector pET41a to construct pET41a-HIPP7, transforming it into *E. coli*, culturing it in LB liquid medium containing kanamycin, inducing expression with IPTG, isolating and purifying the protein, and preparing a polyclonal antibody against citrus HIPP7 protein by immunizing rabbits with the HIPP7 protein. The polyclonal antibody against citrus HIPP7 protein obtained by this invention can specifically detect citrus HIPP7 protein and can be used to detect the accumulation of HIPP7 protein in different citrus tissues and under different treatment conditions, as well as to detect the accumulation of HIPP7 protein in transgenic plants.

The invention discloses a stable genetic transformation method of floating moss. The genetic transformation method comprises the following steps: (1) crushing thallus tissues of the floating moss, (2) pre-culturing explants, (3) infecting and co-culturing, (4) screening and culturing for the first time, (5) screening and culturing for the second time, (6) enlarging and culturing, and (7) verifying transformation. According to the genetic transformation method, a thallus of floating moss is taken as a starting explant, an agrobacterium-mediated hygromycin and kanamycin screening transformation system of the floating moss is established for the first time, the blank of a floating moss genetic transformation system is filled, and experimental results show that after multi-generation culture, a transformed plant can still stably express a target gene. The method has the advantages of high transformation efficiency and simplicity in operation, and can be used for subsequent genetic transformation research of unknown floating moss genes. The method has a wide application prospect.

The invention discloses an SlFMO1 gene and application thereof in regulation and control of growth and development of tomato plants, and belongs to the technical field of gene engineering. According to the method, a CRISPR / Cas9 gene editing technology is utilized, firstly, a CRISPR / Cas9-gRNA vector is constructed to accurately edit an SlFMO1 gene in tomatoes, GV3101 agrobacterium tumefaciens is utilized to conduct mediated transformation on the tomatoes, and kanamycin serves as a resistance marker to conduct screening to obtain SlFMO1-deleted mutant tomatoes. Phenotype observation and analysis show that after the SlFMO1 gene is knocked out, the plant height and the plant width of a tomato plant are obviously increased, the apical development is enhanced, the stem diameter of the plant is increased, and the inflorescence spacing is increased, which indicates that the SlFMO1 gene negatively regulates the growth and development of the tomato, and meanwhile, the expression of related genes synthesized by auxin, gibberellin and brassinolide is obviously enhanced. The discovery has important theoretical significance and practical application value for follow-up cultivation of ideal tomato varieties.

The invention relates to a construction method of an Agrobacterium rhizogenes mediated acacia melanoxylon genetic transformation system, which comprises the following steps: by taking an acacia melanoxylon SR17 sterile single plant as an explant, selecting an Agrobacterium rhizogenes strain Ar1193, infecting for 45 minutes in a heavy suspension of which the bacterial liquid concentration OD600 is equal to 0.9 and the acetosyringone concentration is 100 [mu] mol.L <-1 >, co-culturing for 3 days, and then transferring into a bacteriostatic culture medium to induce hairy roots; and taking the transgenic hairy roots obtained by induction as explants, and inoculating the explants into a WPM culture medium containing 0.05 mg.L <-1 > TDZ and 200 mg.L <-1 > casein hydrolysate to induce regeneration of adventitious buds so as to obtain complete transgenic plants. The screening concentrations of the four antibiotics, namely kanamycin, hygromycin, glyphosate and glufosinate-ammonium, are determined; a stable and efficient acacia melanoxylon genetic transformation system is established, the hairy root induction rate reaches 63.17%, the transgenic positive rate reaches 15.42%, and the adventitious bud regeneration rate reaches 52%.

The invention belongs to the technical field of biology, and particularly relates to a bifidobacterium longum subsp. Longum FMBL B241768LS, a microbial inoculum and application of the microbial inoculum in hypoglycemic products, the bifidobacterium longum subsp. Longum FMBL B241768LS is preserved in China Center for Type Culture Collection on October 14, 2024, and the preservation number is CCTCC NO: M 20242173; the inhibitory activity of the compound on dipeptidyl peptidase IV is as high as 79.17%; the compound has a relatively good inhibition effect on the activity of alpha-glucosidase and alpha-amylase; the compound shows drug resistance to ciprofloxacin, ampicillin, penicillin G, clindamycin, kanamycin and polymyxin B; a good inhibition effect is achieved on pathogenic bacteria; the strain can be used for preparing medicines, fermented foods, health-care products and food additives for reducing blood sugar and inhibiting pathogenic bacteria, and has a wide application prospect.

The invention discloses an SlFMO1 gene and application of the SlFMO1 gene in regulation and control of resistance of tomato fruits to gray mold, and belongs to the technical field of gene engineering. A CRISPR / Cas9 gene editing technology is utilized, firstly, a CRISPR / Cas9-gRNA vector is constructed to accurately edit the SlFMO1 gene in tomatoes, GV3101 agrobacterium tumefaciens is utilized to conduct mediated transformation on the tomatoes, kanamycin serves as a resistance marker to conduct screening to obtain SlFMO1-deleted mutant tomatoes, it is found that when the SlFMO1 gene in the tomatoes is deleted, the resistance of tomato fruits to gray mold is remarkably reduced, and when the SlFMO1 gene in the tomatoes is deleted, the resistance of the tomato fruits to gray mold is remarkably reduced. The result shows that the SlFMO1 gene positively regulates and controls the resistance of the tomato to the gray mold. The discovery provides a new target for subsequent improvement of tomato varieties and creation of materials for resisting gray mold of fruits, and has important application prospects in molecular breeding for improving disease resistance of tomato fruits.

The application discloses a gene expression vector pJXNU for actinomycetes, a construction method and application thereof. The sequence of the vector is shown as SEQ ID NO. 2. The vector is based on a pSET152 plasmid, and loaded with kanamycin and thiostrepton antibiotic resistance genes, and a 533bp DNA fragment containing three gene expression element sequences and two sets of multiple cloning sites (MCS) shown as SEQ ID NO. 1. The vector has two autonomously expressed strong gene expression elements and one thiostrepton-induced expression element, can realize autonomous high-efficiency expression of two or two groups of genes and / or induced expression of one or one group of genes on one vector, and can realize multi-type functional gene research and application in an actinomycete host.

The invention discloses a preparation method and application of a molecularly imprinted polymer and aptamer double-recognition gold nanoparticle-laser induced graphene composite material modified electrode, and belongs to the technical field of flexible electrochemical sensors and kanamycin detection. According to the invention, a gold nanoparticle-laser-induced graphene composite material modified electrode is used as a base material, a kanamycin aptamer is fixed through a gold-sulfur bond by using gold nanoparticles on the surface of the base material, and a molecularly imprinted polymer layer is further modified; therefore, an electrochemical sensing electrode with a molecularly imprinted polymer and aptamer dual recognition interface is constructed, and the electrochemical sensing electrode is used as a high-performance sensitive element of a sensor and shows good analysis performance in actual fish meat sample kanamycin detection. The prepared modified electrode can be used for sensitively detecting KANA in a concentration range of 10.0 pmol / L-1. 0mmol / L, the detection limit is as low as 3.3 pmol / L, and the modified electrode is good in selectivity and stability.

The invention provides an SP-1 polypeptide and application of a coding gene of the SP-1 polypeptide in inhibition of tight reaction and antibiosis, and belongs to the technical field of polypeptides. The amino acid sequence of the spider-derived SP-1 polypeptide is as shown in SEQ ID NO: 1. According to the present invention, the SP-1 polypeptide can specifically inhibit Escherichia coli and pseudomonas aeruginosa tight reaction key small molecule (p) ppGpp synthase activity, strong antibacterial activity is represented, and the MIC of the SP-1 polypeptide on Escherichia coli and pseudomonas aeruginosa is 2.4 [mu] M and 1.5 [mu] M respectively, and is significantly lower than the MIC (14.5 [mu] M and 12.3 [mu] M) of kanamycin of a positive control group under the same experiment condition; in addition, the SP-I peptide shows efficient bactericidal activity, the minimum bactericidal concentration of the SP-I peptide to escherichia coli and pseudomonas aeruginosa is 2.0 mu M, and the SP-I peptide can effectively inhibit generation of escherichia coli and pseudomonas aeruginosa biological membranes. Therefore, the SP-1 polypeptide can be used as an active ingredient to be applied to preparation of antibacterial drugs for inhibiting multidrug resistance bacteria.

The invention provides a preparation method of spirolactone, and relates to the technical field of organic synthesis. The preparation method of spirolactone provided by the invention comprises the following steps: taking 4-androstene-3, 17-diketone as a raw material, carrying out nucleophilic addition reaction on the 4-androstene-3, 17-diketone and an organic zinc reagent 3-tert-butoxy-3-oxypropyl zinc bromide, then carrying out elimination-lactonization under the catalysis of trifluoroacetic acid, and completing lactonization while removing tert-butyl; then sequentially carrying out etherification reaction and oxidative dehydrogenation reaction to obtain canrenone, and finally carrying out addition reaction on canrenone and thioacetic acid to obtain spirolactone. The preparation method provided by the invention provides a novel construction method of 21-carboxylic acid-gamma-lactone, the method is good in specificity, the total mass yield of spirolactone is greater than 92%, and the total mass yield is high; moreover, the HPLC purity of the spirolactone prepared by the preparation method provided by the invention is greater than 99.7%, which is far higher than the purity of the spirolactone prepared by the existing process.

This invention discloses a method for introducing exogenous genes into Gynostemma pentaphyllum, comprising: S1: Selecting Gynostemma pentaphyllum seeds with seed coats within 3 months of harvest, disinfecting, and culturing to obtain aseptic seedlings from seedlings, or selecting stem segments with axillary buds after leaf removal, disinfecting, and culturing using a subculture proliferation medium containing cephalosporin to obtain aseptic rooted seedlings; S2: Selecting the aseptic seedlings or aseptic cuttings obtained in S1, culturing in a rooting medium containing cephalosporin to obtain aseptic rooted seedlings; S3: Transforming plasmid Pcambia1301-PMI into Agrobacterium and culturing in a medium containing kanamycin and rifampin to obtain an Agrobacterium resuspension; S4: Infecting the aseptic rooted seedlings obtained in S2 with the Agrobacterium resuspension, and performing co-culture, antibacterial culture, and screening culture to obtain transgenic adventitious shoots. This invention can successfully introduce exogenous genes into Gynostemma pentaphyllum, obtaining Gynostemma pentaphyllum positive plants.

The chitinase 3-like 1 (CHI3L1) inhibitor, specifically kasugamycin, provided by the present invention, suppresses the expression or activation of chitinase 3-like 1 (CHI3L1), thereby effectively preventing or treating infections with acid-fast bacteria, particularly non-tuberculous mycobacteria and various diseases caused by infection with acid-fast bacteria, particularly nontuberculous mycobacteria. In addition, by measuring the expression level of chitinase 3-like 1 (CHI3L1) protein, when the expression level is higher than that of a control group, it is possible to effectively predict infection with acid-fast bacteria, particularly non-tuberculous mycobacteria, the onset of diseases caused by infection with acid-fast bacteria, particularly non-tuberculous mycobacteria, or the prognosis of diseases related to infection with acid fast bacteria, particularly nontuberculous mycobacteria.

The invention discloses construction and application of a vibrio parahaemolyticus capsular polysaccharide synthesis gene cluster and lipopolysaccharide synthesis HldE mutant strain, and belongs to the technical field of molecular biology and genetic engineering.According to the construction method, an overlapping extension PCR technology is adopted for constructing a kanamycin resistance gene knockout fusion fragment, the fusion fragment is cloned into a suicide plasmid pDS132, and the suicide plasmid pDS132 is used for preparing the HldE mutant strain of the vibrio parahaemolyticus capsular polysaccharide synthesis gene cluster and lipopolysaccharide synthesis HldE mutant strain. A recombinant suicide plasmid is introduced into vibrio parahaemolyticus through conjugational transfer, and sucrose-induced double-exchange homologous recombination and kanamycin resistance screening are utilized to efficiently obtain a capsular polysaccharide synthetic gene cluster and an HldE gene knockout mutant strain. The invention further discloses an application of the mutant strain in evaluating the exposure of the outer membrane protein, and discloses the influence of a capsule and a lipopolysaccharide layer on the accessibility of an outer membrane protein antibody. The method is easy and convenient to operate and high in screening efficiency, and an effective tool is provided for vibrio outer membrane protein function research, vaccine target screening and pathogenic mechanism analysis.

The application discloses a slow-release antibacterial composite membrane and a preparation method and application thereof. First, hectorite and model drug kanamycin are loaded in an aqueous solvent, then mixed with a polylactic acid glycolic acid solution, and a porous membrane is prepared through a phase separation method; and then the prepared porous membrane is immersed in a chitosan solution with a certain concentration to form a three-dimensional porous composite membrane coated with chitosan; the prepared composite membrane has good drug slow-release effect, antibacterial property and mechanical property, can effectively promote angiogenesis and wound healing, and reduce inflammatory reaction.

The invention belongs to the technical field of medicines, and provides application of dicentrine in preparation of a medicine for treating kanamycin drug-resistant bacterium infection. According to the invention, dicentrine and kanamycin are combined for use to inhibit drug-resistant bacteria expressing EanT-1 nucleotide transferase, such as EanT-1-producing Exiguobacterium or Escherichia coli carrying an eanT-1 gene. The dicentrine is competitively combined with an EanT-1 enzyme active center to block the modification inactivation effect of the dicentrine on kanamycin. The composition can significantly reduce the minimum inhibitory concentration (MIC) of drug-resistant bacteria to kanamycin, and shows a synergistic antibacterial effect in vitro and in a mouse septicemia model.

The invention discloses a multi-immunochromatography test strip with unified detection limit for detecting four aminoglycoside drugs and application of the multi-immunochromatography test strip. The test strip comprises a water absorption plate, a detection pad, a colloidal gold pad, a sample pad and a PVC (polyvinyl chloride) bottom plate, wherein a gold-labeled antibody is fixed on the surface of the colloidal gold pad, and when a sample flows through the colloidal gold pad, the gold-labeled antibody is dissolved and serves as a tracer molecule to migrate along with a liquid phase; four detection areas T1, T2, T3 and T4 and a quality control line area C are arranged on the detection pad, a kanamycin antigen, a gentamicin antigen, a neomycin antigen and a spectinomycin antigen are sprayed on the four detection areas respectively, and a goat anti-mouse antibody is sprayed on the quality control line area C. According to the present invention, the expensive reagent and the base material are not required, the production cost is low, the operation is simple, the professional training is not required, the detection efficiency is high, the detection cost is low, the multiple immunochromatography test strip is used for simultaneously detecting kanamycin, gentamicin, neomycin and spectinomycin, and the detection limits can achieve 5 ng / mL.