44 results about "Listeria" patented technology

The invention discloses a preparation method of ocimum gratissimum carbon dots and application of the ocimum gratissimum carbon dots in antibacterial drugs and food preservation. The preparation method of the ocimum gratissimum carbon dots comprises the following steps: performing steam distillation on ocimum gratissimum leaves to remove essential oil, drying in the shade, and crushing; adding an alcohol solvent into the powder, extracting, filtering, concentrating and drying to obtain an alcohol extract; dispersing the alcohol extract in distilled water, and stirring and pyrolyzing on a heating table; and diluting the pyrolysis product with distilled water, centrifuging, taking supernate, filtering with a filter membrane, dialyzing, and freeze-drying to obtain the carbon dots. The obtained carbon dots have a carbon dot-vesicle coexisting structure, and the average particle size is 5.732 + / -0.5 nm. The prepared ocimum gratissimum carbon dots can be applied to preparation of antibacterial drugs, especially drugs for inhibiting the activity of bacillus cereus and listeria, and the field of food preservation, and have the advantages of being wide in raw material source, simple in preparation method, low in cost, environmentally friendly and the like.

The invention discloses a zanthoxylum bungeanum leaf extract and a preparation method and application thereof.The preparation method includes the steps that zanthoxylum bungeanum leaves are cleaned, dried and then smashed, and zanthoxylum bungeanum leaf powder is obtained; condensing and extracting: taking the bunge pricklyash leaf powder, adding a solvent, heating, condensing and refluxing for a certain time, carrying out suction filtration after condensing and refluxing, collecting filtrate, repeatedly extracting for 2-5 times, adding the same volume of solvent each time, and combining the filtrate to obtain an extract; performing rotary evaporation: performing rotary evaporation on the extracting solution to obtain a concentrated solution; and drying: drying the concentrated solution, and grinding the dried concentrated solution into powder to obtain the bunge pricklyash leaf extract. The zanthoxylum bungeanum leaf extract prepared by the preparation method disclosed by the invention has an inhibiting effect on listeria monocytogenes, staphylococcus aureus, streptococcus agalactiae and bacillus cereus, provides a new way for preparing bacteriostatic products such as bacteriostatic drugs, bacteriostatic cleaning supplies and bacteriostatic feed additives, and is beneficial to development and utilization of zanthoxylum bungeanum leaf resources; the use value of bunge pricklyash leaves is improved, and resource waste is reduced.

The present disclosure provides variant Listeria bacteria comprising a mutation in a purA gene encoding adenylosuccinate synthetase, wherein the variant Listeria bacteria are adenosine auxotrophs. The present disclosure provides compositions comprising a subject variant Listeria bacterium, including compositions further comprising a multispecific antibody. Also provided are immunogenic compositions comprising a variant Listeria bacterium of the present disclosure and kits comprising a unit dose thereof. The present disclosure additionally provides methods of inducing an immune response in an individual, the methods comprising administering to the individual an effective amount of an immunogenic composition of the present disclosure.

To provide methods and compositions for the lyophilization of a bacterium or a Listeria strain, e.g., Listeria monocytogenes.SOLUTION: Provided are: a method for producing a lyophilized composition comprising a bacterium or a Listeria strain; a formulation for lyophilization containing a bacterium or a Listeria strain; a lyophilized bacterium or Listeria strain; and a method for preparing a frozen bacterium or Listeria strain for lyophilization. Some such methods may comprise: providing a composition comprising a bacterium or a Listeria strain in a formulation comprising a buffer; cooling the composition in a freezing step; exposing the cooled composition to a vacuum and a first temperature increase in a primary drying step; and exposing the composition from the primary drying step to a vacuum and a second temperature increase in a second drying step.SELECTED DRAWING: None

The invention discloses a multivalent expression sheep listeria vaccine for cervical cancer and a preparation method thereof, and the method comprises the following steps: on the basis of replacing sheep listeria LI [delta] ilo:: hly with hemolysin, constructing to obtain auxotrophic sheep listeria LI [delta] ilo:: hly [delta] dal [delta] dat; the fusion antigen is constructed by alternately arranging amino terminal and carboxyl terminal structural domains of four types of HPV6 / 11 / 16 / 18 E6 and E7 proteins and retaining an overlapping region of 16 amino acids at a connecting site; inserting the fusion antigen into a non-resistance plasmid pCW631 which carries a dal gene and replaces an Amp gene with an asd gene, so as to obtain a non-resistance plasmid pCW636; the resistance-free plasmid pCW636 is electrically transferred into the auxotroph sheep listeria monocytogenes LIdeltailo:: hly deltadal deltadat, and the sheep listeria monocytogenes cervical cancer vaccine is obtained. The cervical cancer vaccine provided by the invention can express the E6E7 protein in a multivalent manner, so that multiple protection on cervical cancer is realized.

The invention provides a listeria monocytogenes detection kit based on iron-tannic acid network coating aggregation-induced emission nanodots and a detection method. The listeria monocytogenes detection kit comprises Cas12a protein, crRNA, a single-stranded nucleic acid fluorescent probe, an iron-tannic acid network coating aggregation-induced emission nanodot dispersion liquid, a Lamp element, a buffer solution and enzyme-free water. According to the present invention, the iron-tannic acid network coating aggregation-induced emission nano-dot is adopted as the light-emitting material, Cy5-ssDNA is adopted as the fluorescent probe, and the specific gene segment Listeria of Listeria monocytogenes is adopted as the target sequence to construct the two-color ratio fluorescent biosensor, and the two-color ratio fluorescent biosensor can be used for detection of Listeria monocytogenes in food, the method has the advantages of simplicity, no dependence on large instruments, low cost, short detection period, low background, high sensitivity, strong specificity, high efficiency, reliability and the like.

Methods and compositions are provided for lyophilization of bacteria or Listeria strains, such as Listeria monocytogenes. Provided are methods for producing a lyophilized composition comprising a bacteria or Listeria strain, formulations for lyophilization comprising a bacteria or Listeria strain, lyophilized bacteria or Listeria strains, and methods of preparing frozen bacteria or Listeria strains for lyophilization.

The invention discloses a Plusteria monocytogenes strain capable of reducing antibiotic resistance genes and promoting growth and application of the Plusteria monocytogenes strain. The strain is separated from rice soil, and is identified as Plusteria based on physiological and biochemical characteristics and 16S rRNA (ribosomal Ribonucleic Acid) analysis. The Plusteria bacteria provided by the invention have a remarkable reduction effect on antibiotic resistance genes in the organic fertilizer; pot experiment results show that the strain can effectively reduce abundance of antibiotic resistance genes at the upper part and the root part of the lettuce and can significantly promote growth of the lettuce.

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.

The present invention discloses a homologous recombinant Bacillus subtilis expressing cecropin B gene and a construction method thereof, and belongs to the field of genetic engineering technology. The present invention discloses a homologous recombinant Bacillus subtilis expressing cecropin B gene and a construction method thereof, using Bacillus subtilis 1A1 as a starting strain, knocking out the coding region of the endo-1,4-β-xylanase gene, and integrating the expression of the cecropin B gene, and using xylan induction to obtain the Bacillus subtilis genetic engineering bacteria expressing the cecropin B gene and having the antibacterial activity of inhibiting Salmonella, Escherichia coli and Listeria monocytogenes. The recombinant bacteria can be used as an animal health product for preventing and treating bacterial diseases of the digestive tract of livestock, poultry and aquatic animals.

A method for preparing a refrigerated, pre-cooked egg based product is disclosed. The method includes combining a liquid egg material with an antibacterial composition comprising nisin, citric acid, and an secondary organic acid having a pKa of from about 3.5 to about 8 to form a liquid egg formulation with surprisingly good control of Listeria growth.

The present application relates to the technical field of antibacterial peptides, in particular to IPC C07K7, more particularly to a gingival protection antibacterial peptide or its stereoisomer and a preparation method and application thereof.The present application provides a gingival protection antibacterial peptide or its stereoisomer, which comprises antibacterial peptide MOAMPV14R; the antibacterial peptide MOAMPV14R comprises a structure shown in formula 1.In the present application, a new antibacterial peptide MOAMPV14R is designed and synthesized, which can effectively inhibit the activity of Streptococcus mutans, Porphyromonas gingivalis, Staphylococcus aureus, Pseudomonas aeruginosa, Escherichia coli, Listeria, and M. maltophilia, and the MIC value is 1-8 μg / mL, the antibacterial effect is excellent, the hemolytic activity and cytotoxicity are low, and the safety is good.

To provide methods for producing mutant bacteriophages for detection of LISTERIA.SOLUTION: Methods for the production of mutant bacteriophages with altered host range are disclosed herein. Additionally, methods and systems for rapid detection of microorganisms, such as Listeria spp., in a sample are disclosed herein. A genetically modified bacteriophage comprising an indicator gene in the late gene region is also disclosed. The specificity of the bacteriophage, such as a Listeria-specific bacteriophage, allows detection of a specific microorganism, such as Listeria spp., and an indicator signal may be amplified to optimize assay sensitivity.SELECTED DRAWING: None

The invention relates to a preparation method and application of acetylated raspberry ketone, and the preparation method is characterized in that acetic anhydride is used as an acetylation reagent to realize hydroxyl acetylation of raspberry ketone in the presence of a proper catalyst and a proper solvent so as to obtain high-purity acetylated raspberry ketone. The reaction conditions are mild, and high temperature and high pressure are not needed; the product purity is high; the method is simple to operate and suitable for industrial production. Moreover, when the acetylated raspberry ketone is used for preparing an antimicrobial composition, the effect is remarkable, and microorganisms comprise Listeria bacteria or salmonella typhimurium.

The invention provides a primer and a probe group for detecting sheep abortion-causing bacteria and application of the primer and the probe group, and belongs to the technical field of biological detection. The primer and probe group is characterized in that the sequence of the primer and probe group for detecting the listeria is shown as SEQ ID NO.1-3, and the sequence of the probe group for detecting the listeria is shown as SEQ ID NO.2-3; according to the primer for detecting the salmonella abortus, the sequence of the probe group is as shown in SEQ ID NO.4-6; the sequences of the primer and the probe group aiming at Brucella detection are shown as SEQ ID NO.7-9; the sequence of a primer and a probe group for detecting chlamydia psittaci is as shown in SEQ ID NO.10-12. The invention further discloses a kit for detecting chlamydia psittaci. The method has the characteristics of visualization, high sensitivity, strong specificity, simplicity and convenience in operation, short time consumption and the like, realizes rapid differential diagnosis of four sheep bacterial abortion diseases through one-time PCR amplification, and has important advantages in the field of sheep disease diagnosis and identification.

The invention discloses a Listeria monocytogenes phage and application thereof, the Listeria monocytogenes phage is Listeria monocytogenes phage LP4H1, the Listeria monocytogenes phage LP4H1 is preserved in the China Center for Type Culture Collection, the preservation date is April 22, 2025, and the preservation number is CCTCC (China Center for Type Culture Collection) NO: M 2025849. The listeria bacteriophage disclosed by the invention can specifically split various serotypes of food-borne monocyte hyperplasia listeria including Lm high-virulence serotype strains for 4 hours, so that the generation and aggravation of the drug resistance of the listeria are prevented; the bacteriophage strain provided by the invention has a hydrophilic phase, and can be easily prepared into spraying liquid or leacheate through a traditional method to disinfect the environment or appliances. The bacteriophage strain has no virulence factor coding gene and antibiotic resistance gene, can be amplified by harmless Listeria monocytogenes, and can be used as a food additive for specifically cracking Listeria monocytogenes to prevent the Listeria monocytogenes from polluting food. Large-scale production can be realized, and a safe and efficient new way is provided for industrially producing the bacteriophage, applying the bacteriophage to food and processing equipment thereof and sterilizing the environment.

Described herein is an extract of a herbal composition comprising at least two different dry plants, the compounds are useful as antimicrobial and / or antibiotic film agents in the treatment or prevention of microbial infections caused by bacteria (e.g., Escherichia, Klebsiella, Listeria, Pseudomonas, Salmonella, Streptococcus, or Staphylococcus) or by fungi, as well as in the treatment or prevention of microbial infections caused by bacteria (e.g., Escherichia, Klebsiella, Listeria, Pseudomonas, Salmonella, Streptococcus, or Staphylococcus). It has been found that in such an extract, the active ingredients exert their biological effects in a synergistic manner. The extracts may form active ingredients of food supplements, nutraceuticals, pharmaceutical or cosmetic compositions or functional foods or food additives. Also described herein are methods for preparing the extracts.

The invention discloses application of salinomycin to prevention and treatment of pathogenic microorganisms. According to the present invention, the compound provides significant inhibition activity for agricultural fungi such as Sclerotinia sclerotiorum, Botrytis cinerea, Pyricaria oryzae, Moniliniafacticola ACCC 36263, food-borne bacteria such as Escherichia coli O157: H7ATCC 35150, Bacillus cereus BN CC 103930, Listeria monocytogenes ATCC 19115 and Salmonella enteritidis ATCC 14028, and further provides a certain inhibition effect on other agricultural pathogenic bacteria, such that the compound is expected to be developed into the one type of the compound,

Embodiments of the present disclosure generally relate to compositions of a lyophilized (freeze dried) Listeria strain based therapeutics and a method for lyophilizing compositions of the therapeutics. A Listeria monocytogenes (LM) based vaccine formulation contains a lyophilized powder including a LM bacteria, the LM bacteria comprising at least one therapeutic agent and a lyophilization medium and a delivery composition. A method of forming a Listeria monocytogenes (LM) based vaccine formulation is disclosed. The LM based vaccine formulation includes resuspending an LM stock in a lyophilization medium to form a lyophilization composition, wherein the lyophilization medium comprises at least a lyoprotectant and a buffer component, freezing the lyophilization composition, lyophilizing the lyophilization composition, and forming a lyophilized powder, the lyophilized powder contains a LM bacteria, a lyoprotectant, and a buffer component.

The invention discloses a novel broad-spectrum antibacterial peptide and application thereof, the novel broad-spectrum antibacterial peptide is a polypeptide obtained by 3-5 times of recombination and series connection of an amino acid sequence SEQ ID NO.1, or a chimeric peptide formed by connecting the amino acid sequence SEQ ID NO.1 and a cell penetrating peptide containing 2-10 arginine, and the chimeric peptide is named TN3. The antibacterial peptide has certain broad-spectrum antibacterial activity, and has an obvious antibacterial effect on staphylococcus aureus, escherichia coli, listeria monocytogenes and pseudomonas fluorescens. In addition, the broad-spectrum antibacterial peptide is low in cytotoxicity, has good biocompatibility and has clinical application potential.

The invention discloses laggera pterodonta carbon dots as well as a preparation method and application thereof, and belongs to the technical field of medicines. The preparation method of the laggera pterodonta carbon dots comprises the following steps: dispersing laggera pterodonta fine powder in distilled water, and stirring and pyrolyzing on a heating table; and diluting the pyrolysis product with distilled water, centrifuging, taking supernate, filtering with a filter membrane, dialyzing, and freeze-drying to obtain the carbon dots. The average particle size of the obtained carbon dots is 4.51 + / -1.04 nm. The laggera pterodonta carbon dots prepared by the invention show strong inhibitory activity on various gram-positive bacteria (such as Listeria monocytogenes and methicillin-resistant staphylococcus aureus MRSA) and fungi (such as Candida albicans), and are particularly effective on clinically-difficult drug-resistant strains, such as vancomycin-resistant enterococcus (VRE) and MRSA; the compound can be applied to preparation of novel antibacterial drugs, antibacterial dressings, disinfectants or preservatives, and has the advantages of wide raw material sources, simple preparation method, low cost, environmental friendliness and the like.

The present invention relates to a method for improving the yield of attenuated Listeria monocytogenes membrane vesicles and its application. Starting from the attenuated Listeria monocytogenes LMΔactAplcB, an attenuated strain LMΔactAplcBdaldat with dal and dat genes knocked out is constructed, and a complementing plasmid pCW633 carrying the dal gene is constructed, and the plasmid is electrotransferred into the attenuated nutrient-deficient strain LMΔactAplcBdaldat to construct a stable recombinant strain LMΔactAplcBdaldat::pCW633. Compared with the method of antibiotic treatment, the yield of secreted MVs of the recombinant strain LMΔactAplcBdaldat::pCW633 constructed by the present invention is more significantly increased. The present invention can solve the problem of low yield of attenuated LM MVs and can be used for basic and applied research related to attenuated LM MVs.

The invention discloses lactobacillus mucilaginosus for inhibiting the growth of aspergillus ochraceus and application of the lactobacillus mucilaginosus. The lactobacillus fermentum is named as the lactobacillus fermentum A119, and the strain is preserved in the China Center for Type Culture Collection (CCTCC), and has the preservation number of CGMCC NO. The preservation number of the strain is CCTCC NO: M 2025001. According to the present invention, the bacterial strain can provide a strong antibacterial effect on pathogenic microorganisms such as Aspergillus ochraceus BNCC144159, Penicillium expansum BNCC117714, Staphylococcus aureus ATCC25923, Listeria monocytogenes CMCC21633, Escherichia coli CICC10389, Salmonella WX29, Pseudomonas aeruginosa ATCC27853 and the like, and can be used for food fresh keeping, and the bacterial strain can be used for food fresh keeping,

The invention relates to the technical field of pet food, in particular to natural antibacterial wet food for pets and a preparation method thereof.The natural antibacterial wet food for pets comprises fermented pea protein, fresh meat / fish, fermented hibiscus cannabinus seed protein and the like, and antibacterial and fresh-keeping effects are achieved through lactic acid bacteria fermentation products and microcapsule herbal compounds; the formula also contains organic acid, a natural chelating agent, vitamins, cranberry extract and the like, the total water content reaches 75-78%, lactobacillus plantarum produced by pea protein under the action of lactobacillus plantarum can destroy cell membrane structures of various gram-positive bacteria, and pediococcus produced by pediococcus has a specific inhibition effect on pathogenic bacteria such as listeria monocytogenes. Through the synergistic effect of the two types of bacteriocin, the antibacterial spectrum is expanded, and respective antibacterial blind areas are filled up.

This document relates to a method for detecting and / or counting Listeria in a sample, such as Listeria monocytogenes, the method comprising culturing a sample that may contain Listeria in a medium comprising rhamnose, one or more antibiotics, a pH color indicator, and LiCl.

The invention relates to liquid antimicrobial composition comprising: • bacteriocin in a concentration of 2-50 ppm; • acetate in a concentration of 0.4-4 mol / L; • alkali metal cation in a concentration of at least 0.7 mol per mol of acetate; and • at least 70 wt.% of water; wherein the antimicrobial composition has a pH in the range of 4.5-7.5. The antimicrobial composition that is particularly suitable for reducing the bacterial load of Listeria on pieces of raw meat. The invention also relates to method of treating pieces of animal meat, said method comprising applying the antimicrobial composition of the present invention onto the surface of the pieces of animal meat.

The present invention belongs to the field of biotechnology, and specifically relates to an antimicrobial peptide derived from deep-sea endosymbiotic methane-oxidizing bacteria and its application. The amino acid sequence of the antimicrobial peptide is shown by SEQ ID NO.1. The antimicrobial peptide of the present invention is a new type of antimicrobial peptide, which has a broad-spectrum antimicrobial activity against a variety of Gram-negative and Gram-positive pathogens, such as Pseudomonas aeruginosa, Listeria, Enterococcus faecalis and various types of Vibrio, with a minimum inhibitory concentration of 8.13-16.25 μM. In addition, the antimicrobial peptide has weak hemolytic activity and low cytotoxicity. The antimicrobial peptide provided by the present invention can replace antibiotics and is used in the prevention and treatment of various bacterial diseases, and as a safe and stable food additive or cosmetic preservative candidate.

The present disclosure relates to compounds and pharmaceutical compositions comprising same for the treatment, amelioration, and / or prevention of disease. In some embodiments, the disease is a bacterial infection. In some embodiments, the infection is caused by Acinetobacter spp., Clostridium spp., Enterococcus spp., Hemophilus spp., Legionella spp., Mycobacterium spp. (tuberculous and nontuberculous mycobacteria), Neisseria spp., Staphylococcus spp., Streptococcus spp., Listeria monocytogenes, Moraxella catarrhalis, Bacillus spp., Bacteroides spp., or any of the following: spp., Gardnerella vaginalis, Lactobacillus spp., Mobiluncus spp., Helicobacter pylori, Campylobacter jejuni, Chlamydia trachomatis, and / or Toxoplasma gondii. Preferably, the bacterial infection is caused by a bacterium belonging to the genus Staphylococcus aureus (S. aureus), A. baumannii (A. baumannii), E. faecium (E. faecalis), Staphylococcus epidermidis (S. epidermidis), Streptococcus pneumoniae (S. pneumoniae), Group A hemolytic streptococcus (S. pyogenes), Haemophilus influenzae (H. influenzae), M. abscessus (M. abscessus), M. tuberculosis (M. tuberculosis) and / or M. smegmatis (M.smegmatis), even more preferably the bacterial infection is caused by one or more bacteria belonging to the genus Acinetobacter, even more preferably by A. baumannii, even more preferably by A. baumannii having one or more resistance mechanisms to rifamycins, such as rifabutin and / or rifampicin.

A hybridoma cell line secreting an ActA monoclonal antibody and a use thereof. The hybridoma cell line was deposited on Jul. 8, 2021, at the China Center for Type Culture Collection (CCTCC) with the depository accession number of CCTCC NO: C2021174. The present invention also discloses the ActA monoclonal antibody secreted by this hybridoma cell line or its progeny cell line, a detection kit containing this ActA monoclonal antibody, immunomagnetic beads, the preparation method and use of immunomagnetic beads, and competitive ELISA and indirect ELISA detection methods. The ActA monoclonal antibody of the present invention has the advantages of high titer, good specificity, and strong affinity with the natural antigen. The Listeria competitive ELISA detection kit and immunomagnetic beads developed based on this antibody have high sensitivity and good stability, effectively monitoring the level of ActA antibodies in clinical serum samples, and can be used for labeling Listeria monocytogenes.

The present invention discloses an AIE molecule containing a carbonyl alkyne structure, an AIE molecule-modified complex, and its application; the AIE molecule-modified antibiotic complex can be directly used for antibacterial purposes, and has a stronger inhibitory effect on methicillin-resistant Staphylococcus aureus and Listeria than the unmodified original antibiotic molecule; the AIE molecule-modified complex can also be used as a photodynamic bactericidal agent for bacteria and for rapid detection of pathogens. At the same time, the AIE molecule-modified phage complex is combined with magnetic beads and antibiotic conjugates to achieve detection of pathogens. By reacting different concentrations of antibiotic molecules with AIE molecules containing a carbonyl alkyne structure, and then adding a certain amount of bacteria and magnetic bead-coupled phages, after magnetic separation, a linear equation between antibiotic concentration and fluorescence intensity is established to achieve detection of antibiotic residues.