37 results about "Listeria booriae" patented technology

The invention discloses preparation and application of Clostridium butyricum and a live Clostridium butyricum preparation; Clostridium butyricum LXKJ-1 is collected in China Center for Type Culture Collection on 24 March, 2016 under CCTCC NO: M201613. A seed medium, fermentation medium formulation, culture conditions for Clostridium butyricum and a production of a preparation of live Clostridium butyricum are also disclosed. The Clostridium butyricum provided herein is tolerant to acids, bases and high temperature, is highly capable of producing butyric acid, can inhibit animal pathogens, such as Escherichia coli, Salmonella, Shigella, Staphylococcus aureus, Listeria monocytogenes, and Clostridium perfringens, and can prevent diarrhea in livestock and poultry due to Escherichia coli, Salmonella and Clostridium perfringens, improving intestinal flora balance, promoting the growth of livestock and poultry, relieving constipation in sows, improving egg weight for layers, improving eggshell quality for layers, and decreasing egg-feed ratio.

The invention relates to lactococcus lactis subsp.lactis, antibacterial peptide produced by lactococcus lactis subsp.lactis and the application of antibacterial peptide. In the invention, the collection number of the lactococcus lactis subsp.lactis LLC518 in the General Microorganism Center of China Microorganism Culture Collection Management Committee is CGMCC No. 4584. In the invention, the antibacterial peptide produced by the lactococcus lactis subsp.lactis can restrain micrococcus tetragenus, Bacillus thuringiensis, lactococcus lactis and listeria innocua, particularly, has strong restraint function to L. monocytogenes which can cause serious food poisoning. Thus, the lactococcus lactis subsp.lactis and the antibacterial peptide thereof have active function in food fresh keeping.

The present invention provides methods of treating, protecting against, and inducing an immune response against a human papillomavirus-associated oropharyngeal tumor or cancer, comprising the step of administering to a subject a recombinant Listeria strain expressing a human papillomavirus antigen.

Methods of detecting target bacteria are provided. In some embodiments the methods comprise exposing the sample to a phage capable of infecting a set of target bacteria and comprising a heterologous nucleic acid sequence encoding a marker. In some embodiments the target bacteria comprise Listeria. In some embodiments the target bacteria are all Listeria. Recombinant Listeria phage comprising a heterologous nucleic acid sequence encoding a marker are also provided as are useful combinations of such phage and articles of manufacture comprising such phage, among other things.

The invention discloses a method for detecting listeria monocytogenes in food by loop-mediated isothermal amplification (LAMP). A set of specificity detecting primers are designed and screened for the listeria monocytogenes, a food sample to be detected is detected by LAMP, whether specific gene segments of the listeria monocytogenes exist or not is confirmed, and whether the food sample to be detected is polluted by the listeria monocytogenes or not is further determined. In addition, before the LAMP detection, the food sample is treated with azide propidium bromide to remove the disturbance of dead bacteria, and only the detection signals of live bacteria can exist in the follow-up LAMP detection. The detection method disclosed by the invention has high sensitivity, strong specificity and short detection time, an expensive experimental instrument is not needed, the operation process is simple and can not be disturbed by the residual DNA or the dead bacteria in the food sample, and the method is especially suitable for self detection in the open air, and in grass-roots detecting organizations and food enterprises.

A method for rapid detection of Listeria monocytogenes viable bacteria in liquid milk relates to a detection method of Listeria monocytogenes viable bacteria in liquid milk. The method solves problems of incapability of effective distinguishing dead bacteria from viable bacteria in a prior LAMP (loop-mediated isothermal amplification) detection method, and long detection time and high costs of a traditional detection method of pathogenic bacteria in liquid milk. The method comprises steps of: a pretreatment of milk sample to be detected; extraction of sample DNA; LAMP amplification; and identification. The invention has short time consuming and high detection sensitivity, and a detection time is substantially reduced to about 1.5h, so as to substantially reduce a storage time while waiting a detection result before raw material milk processing and before finished product leaving factory. A detection limit to Listeria monocytogenes viable bacteria in liquid milk is 6.37*10<1>cfu / mL. The method can be widely applied to the field of foodborne pathogenic bacteria detection.

The invention discloses a mutation breeding method of lactobacillus plantarum and application of a strain of the lactobacillus plantarum. The collection number of the lactobacillus plantarum in China general microbiological culture collection center is CGMCC No 5297. The lactobacillus plantarum can generate bacteriocin which has a better inhibiting effect on multiple gram-positive bacteria and especially has great a high inhibiting effect on listeria monocytogenes, and the bacteriocin has the advantages of better heat stability, acid stability and the like and can be applied as a food additive and a feed preservative agent which have wide application prospect.

The invention relates to a Listeria monocytogenes monoclonal antibody hybridoma cell strain and an application thereof and belongs to the technical field of food safety immunological detection. According to the invention, a complete antigen of a specific polypeptide of Listeria monocytogenes is uniformly mixed with an equal volume of Freund adjuvant (Sigma), BALB / c mice are immunized by subcutaneous injection, after the BALB / c mice are immunized for four times, spleen cells of immunized mice are fused with mice myeloma cells of immunized mice by virtue of a PEG method, an indirect ELISA screening and three times of subcloning are carried out to obtain a monoclonal cell strain A. The monoclonal antibody secreted by virtue of the monoclonal cell strain A has cross reaction with different Listeria monocytogenes culture supernatants and no cross reaction with listeria except Listeria monocytogenes, E. coliO 157, Salmonella and Campylobacter jejuni and thus the Listeria monocytogenes monoclonal antibody hybridoma cell strain can be used in the specific detection of Listeria monocytogenes in a food.

The invention relates to the technical field of detection of pathogenic bacterium, and discloses a selective medium for multiplex proliferation of salmonella, listeria monocytogenes and vibrio parahaemolyticus. The selective medium is prepared from tryptone, peptone, sodium chloride, sodium dihydrogen phosphate, glucose, mannitol, esculin hydrate, sodium citrate, skim milk powder, sterile purified water, potassium tellurite solution, acriflavine solution and nalidixic acid solution. A preparation method of the selective medium comprises the following steps: preparation of potassium tellurite solution; preparation of acriflavine solution; preparation of nalidixic acid solution; preparation of a semi-finished product medium; addition of a sample; and addition of potassium tellurite solution, acriflavine solution and nalidixic acid solution in the medium. The selective medium can carry out multiplex proliferation on the target bacteria and inhibit non-target bacteria, is small in inhibiting effect on the target bacteria in the sub-lethal state so that the target bacteria in the sub-lethal state can realize effective proliferation. The preparation method of the selective medium is easy to operate and high in efficiency.

The invention relates to the field of food microorganisms, in particular to lactobacillus kefiranofaciens CICC 6278 and application of the lactobacillus kefiranofaciens to Xinjiang characteristic chili fermentation. Nitrite can be efficiently and quickly degraded by the lactobacillus kefiranofaciens, the lactobacillus kefiranofaciens is low in biogenic amine production, and pathogenic microorganisms can be inhibited by the lactobacillus kefiranofaciens. A bacterial strain of the lactobacillus kefiranofaciens is preserved in the China General Microbiological Culture Collection Center, and a preservation number of the bacterial strain is CGMCC 14017. The lactobacillus kefiranofaciens and the application have the advantages that the nitrite degradation rate can reach 94.8% if the bacterial strain is cultured in improved MRS liquid culture media for 24 h, and the nitrite can be completely degraded if the bacterial strain is cultured for 36 h; the bacterial strain comprises negative amino acid decarboxylase, and the pathogenic microorganisms including Escherichia coli, staphylococcus aureus, listeria monocytogenes and salmonella can be inhibited; the bacterial strain can be used for Xinjiang characteristic chili fermentation, the content of nitrite in obtained fermented chili is 1.06 mg / kg, the content of biogenic amine in the fermented chili is 5.62 mg / kg, and accordingly the edible safety of the fermented chili can be improved.

The invention relates to a duplex PCR detection kit for Listeria monocytogenes and Enterococcus faecium and a detection method using the kit. The kit detects a primer pair of Listeria monocytogenes hlyA and a primer pair of the dd1 gene of an Enterococcus faecium strain; if specific amplification bands are obtained at 174 bp and 557 bp, Listeria monocytogenes and Enterococcus faecium are positive; and the kit can simultaneously detect Listeria monocytogenes and Enterococcus faecium. The lower limit of the detection sensitivity of the is lower than a minimum infective dose of pathogenic bacteria, which is of great significance to later clinical application and to monitoring of Listeria monocytogenes and Enterococcus faecium.

The invention discloses a molecular marker for rapidly detecting the listeria monocytogenes. The primers of the molecular marker are as follows: RliB(F)gAAATAgCTCTTTgAggTAAgATggg; RliB(R)gCATAATCCTATgTATAACAggTTTTC. The invention further discloses a method for rapidly detecting the listeria monocytogenes by using the molecular marker. The method comprises the following steps: performing PCR amplification by taking the bacterium liquid to be tested as a template and performing agarose gel electrophoresis on the obtained PCR amplified product; when the electrophoresis result shows that a specific strip is generated in about 500 bp, judging whether the sample to be detected contains the listeria monocytogenes; and otherwise, the sample does not contain the listeria monocytogenes.

The invention relates to a Lactobacillus plantarum plant subspecies and a preparation method for producing anti-Listeria monocytogenes bacteriocin, which are suitable for the preservation of meat and meat products, milk and dairy products, fruits and vegetables, and ready-to-eat food. In the present invention, Lactobacillus plantarum subsp. plantarum Zhang-LL (CGMCC No. 6936) is obtained by screening the bacon in the Fujian farmers market. Bacteriocin-producing fermentation broth was obtained by fermentation of Zhang-LL strain, and the bacteriocin of Zhang-LL strain was extracted and purified by pH-dependent adsorption-desorption method, cation exchange chromatography, and reversed-phase high performance liquid chromatography. It is 32 times higher and the purity is 36.65 times higher. The bacteriocin can inhibit various food-borne pathogens such as Listeria monocytogenes, has high antibacterial activity, is stable to heat and acid and alkali, and is degraded by human protease, so it is a natural and safe biological preservative. The method has the advantages of simple operation, stability, high efficiency, convenient source and low cost, and is suitable for industrial production.

The invention discloses primers capable of simultaneously detecting various diarrhea pathogenic bacteria and an application of the primers, and belongs to the field of nucleic acid detection of pathogenic bacteria. The invention discloses primers and probes as shown in SEQ ID NO: 1-39; and the primers and the probes can be used for rapidly and accurately detecting staphylococcus aureus, shigella, vibrio parahaemolyticus, yersinia enterocolitica, clostridium difficile, plesiomonas sp, listeria monocytogenes, escherichia coli O157:H7, aeromonas, salmonella, clostridium perfringens, bacillus cereus and campylobacter jejuni; therefore, great convenience is brought to clinical microorganism detection.

The invention discloses a bacillus subtilis YSJB-30 which is separated and screened from fresh excrement of a healthy sow. The bacillus subtilis YSJB-30 is primarily identified as bacillus subtilis by combining morphology with a16SrDNA sequence alignment result. The bacillus subtilis is capable of secreting extracellaluar proteases and an in vitro test proves that the bacillus subtilis is capable of inhibiting pathogenic entero becteria such as salmonella and listeria monocytogenes; the bacillus subtilis is applied to solid fermentation of raw material such as straw, rice hull and bean pulp to prepare a probiotic; the optimal raw material proportion is determined by combining the raw material cost and viable count; technological parameters are optimized by adopting a Plackett-Burman design, a steepest ascent and a response surface analysis method; when the fermentation lasts for 36 hours under the optimized culture condition, the viable count of the bacillus subtilis reaches 5.35*10<9>CFU / g. According to the invention, basic data are provided for the feed probiotic which is prepared by solid fermentation to replace an antibiotic; and meanwhile, the bacillus subtilis is of great significance for comprehensive utilization and resource development of grain and oil by-products in the northern area in China.

The invention belongs to the technical field of molecular biological detection, and provides a method for detecting and identifying six pairs of PCR (polymerase chain reaction) primers of six kinds of Listeria bacteria from an environment respectively. The PCR primer pairs are designed according to a specific target gene iap (inhibitor of apoptosis protein) of the Listeria bacteria, the target gene is high in stability and specificity, and the six kinds of Listeria bacteria existing in the environment can be rapidly and accurately identified by virtue of a reasonable PCR system and a gel electrophoresis detection means. The detection method comprises the following steps of (1) extracting a sample DNA (deoxyribonucleic acid), and performing PCR amplification by adopting different primer pairs respectively; (2) judging whether a sample to be detected contains the Listeria bacteria or not according to the length of a PCR amplification product fragment. According to the method, the six kinds of Listeria bacteria in the environment and a food sample can be rapidly, accurately and sensitively detected and identified, so that the efficiency is improved, time is saved, and moreover, the detection cost is lowered.

The invention relates to a cervical cancer therapeutic vaccine based on recombinant attenuated Listeria monocytogenes. Attenuated Listeria monocytogenes (hereinafter referred to as Lm) is used as a vector, and the unique ability of Listeria to grow in a host phagocytic cell is the characteristic of a natural T cell immune activation adjuvant, and is used to effectively improve the specific immuneresponse in a tumor microenvironment and break the immune tolerance of bodies, so persistent viral infection of the bodies is removed, and good therapeutic effects of clearing focus and restraining tumor development are achieved. The cervical cancer therapeutic vaccine makes up for the shortcoming of low immunogenicity of nucleic acid and protein peptide vaccines, and the attenuated Listeria reserves the intracellular growth and antigen presentation completion characteristics of an original strain, and has a high safety.

The invention belongs to the technical field of biology, and particularly discloses an escherichia coli and / or salmonella and / or listeria monocytogenes enzyme production co-culture medium. The culture medium comprises 17 g of casease digesta, 6 g of yeast paste, 2.5 g of glucose, 3 g of soytone, 5 g of sodium chloride, 1.35 g of monopotassium phosphate, 2.5 g of dipotassium phosphate, 9.6 g of disodium phosphate and 1.1 g of sodium pyruvate in one liter of sterile distilled water. The substances are dissolved into the sterile distilled water, sterilized for 15 min at high pressure at the temperature of 121 DEG C, cooled to the room temperature and stored in a refrigeration mode to prepare the culture medium. In the practice, the detection speed is greatly increased, reliability of detection results is ensured, and the effect is remarkable.

The invention discloses a double-antibody sandwich method for detecting beta-glucuronidase in escherichia coli cells of food, belonging to the technical field of immunoassay. The double-antibody sandwich method provided by the invention comprises the following steps of carrying out immune on seven-week BALB / c mice by using escherichia coli beta-glucuronidase (EC3.2.1.31), and fusing and screening to obtain ten monoclonal antibodies, respectively marking HRP and carrying out pairing; and establishing an sandwich ELISA analytical method by utilizing CGMCC No.7209 as a coating antibody, utilizing a CGMCC No.7211 as an enzyme labelled antibody, and utilizing the recombination expressive escherichia coli beta-glucuronidase as a standard substance. According to the double-antibody sandwich method provided by the invention, the beta-glucuronidase in escherichia coli ATCC 25922 detection cells is cracked, the escherichia coli is detected, and the LOD is 3.27*10^4cfu / mL; according to the method, the monoclonal antibody of a landmark of the escherichia coli, namely beta-glucuronidase, is prepared, the double-antibody sandwich method for detecting the escherichia coli is established, the method and salmonella, E.coli, enterobacter sakazakii, staphylococcus aureus and listeria monocytogenes do not have cross reaction, and the new detection method is provided for detecting the escherichia coli in food.

The invention discloses a method for enriching listeria monocytogenes in meat and meat products. The method comprises the following steps: firstly, homogenizing meat and meat product samples, combining low temperature static pretreatment with low-temperature high-speed centrifugation to remove large molecular component disruptors such as rich fat and protein in the samples; enriching target bacteria in the samples on a microfiltration membrane by adopting a microfiltration membrane filtration method. The detection limit of the listeria monocytogenes in the meat and meat products is improved, so that the detection problem of low level of the listeria monocytogenes in the meat and meat products is solved. Target bacteria in a filter membrane and filter membrane aperture are eluted by using eluent favorable for growth and protection of the listeria monocytogenes; by using specific combination of listeria monocytogenes immunomagnetic beads with listeria monocytogenes in bacterial suspension, the aim of enriching the listeria monocytogenes in the meat and meat products is achieved and the detection rate of the listeria monocytogenes is increased.

The invention relates to application of recombinant attenuated Listeria in preparation of a therapeutic vaccine for cervical cancer. Attenuated Listeria monocytogenes (hereinafter referred to as Lm) and attenuated Listeria ivanovii (hereinafter referred to as Li) are used as vectors, by use of the unique characteristic that the Listeria can grow in phagocytose cells in a host, and is a natural T cell immune activation adjuvant, specific immune response in tumor microenvironment can be effectively enhanced, body's immune tolerance can be broken, body's persistent viral infection can be eliminated, and good treatment results of clearing focuses and curbing tumor development can be achieved. The Listeria has the advantages that shortcomings of low immunogenicity of nucleic acid and protein peptide vaccines can be made up, the attenuated Listeria retains the characteristic that an attenuated original strain can grow intracellularly to complete antigen presentation, and meanwhile the attenuated Listeria has higher safety.

The invention relates to a PCDR (polymerase chain displacement reaction) detection reagent for food-borne pathogenic bacterium listeria monocytogenes, which can effectively realize quick and accuratedetection of the food-borne pathogenic bacterium listeria monocytogenes by a high-sensitive PCDR method. The PCDR detection reagent is prepared by an SD buffer solution, dNTPs, Mg<2+>, one pair of upstream and downstream inner primers, one pair of upstream and downstream outer primers and SD DNA polymerase through uniformly mixing by adding ultrapure water; when being used, the genomic DNA of thelisteria monocytogenes is dissolved in ddH2O, the DNA and the detection reagent provided by the invention are taken to be mixed and are uniformly mixed in an EP tube; the reaction tube is placed in aPCR (polymerase chain reaction) amplifier for reaction, predegeneration, annealing and extending, the steps are cycled, then agarose gel electrophoresis detection is performed, thereby realizing the detection of the food-borne pathogenic bacterium listeria monocytogenes by the PCDR method. The detection reagent provided by the invention is scientific and reasonable in components, easy to produce and prepare, convenient to use, and can quickly detect the food-borne pathogenic bacterium listeria monocytogenes with sensitivity and specificity, so as to ensure the food safety and realize obvious economic and social benefits.

The invention relates to a mesothelin high-expression cancer treatment vaccine based on recombinant attenuated listeria monocytogenes. The attenuated listeria monocytogenes (Lm) is used as a carier, the characteristics that the Lm can specifically grow in a host phagocyte and is a natural T cell immune activated reagent are utilized, specific immune response in a tumor microenvironment can be effectively improved, the immune tolerance of a body can be broken, persistent viral infection of the body can be cleaned, and an excellent treatment effect for cleaning the focus and inhibiting tumor development can be achieved. The mesothelin high-expression cancer treatment vaccine has the advantages of overcoming the defect of relatively low immunogenicity of nucleotide and protein polypeptide vaccines, the attenuated listeria remained with original strains can grow in cells, so that higher safety is achieved while the characteristic of antigen presentation can be completed.

The invention relates to the technical field of microbial detection, in particular to a method for promoting growth of listeria monocytogenes. According to the method, it is found that by means of saccharomycetes, the growth of the food-borne pathogenic bacterium, namely listeria monocytogenes, can be effectively promoted, the growth rate of listeria monocytogenes is increased, the time for enrichment culture is effectively shortened, and the culture and inspection work efficiency of listeria monocytogenes is improved. The saccharomycetes serve as a growth promoter and have general applicability to different listeria monocytogenes strains, and the method for promoting the growth of listeria monocytogenes lays a foundation for achieving rapid detection of listeria monocytogenes.

The invention discloses a double-antibody sandwich method for detecting beta-glucuronidase in escherichia coli cells of food, belonging to the technical field of immunoassay. The double-antibody sandwich method provided by the invention comprises the following steps of carrying out immune on seven-week BALB / c mice by using escherichia coli beta-glucuronidase (EC3.2.1.31), and fusing and screening to obtain ten monoclonal antibodies, respectively marking HRP and carrying out pairing; and establishing an sandwich ELISA analytical method by utilizing CGMCC No.7209 as a coating antibody, utilizing a CGMCC No.7211 as an enzyme labelled antibody, and utilizing the recombination expressive escherichia coli beta-glucuronidase as a standard substance. According to the double-antibody sandwich method provided by the invention, the beta-glucuronidase in escherichia coli ATCC 25922 detection cells is cracked, the escherichia coli is detected, and the LOD is 3.27*10^4cfu / mL; according to the method, the monoclonal antibody of a landmark of the escherichia coli, namely beta-glucuronidase, is prepared, the double-antibody sandwich method for detecting the escherichia coli is established, the method and salmonella, E.coli, enterobacter sakazakii, staphylococcus aureus and listeria monocytogenes do not have cross reaction, and the new detection method is provided for detecting the escherichia coli in food.

The invention discloses a method for detecting living bacteria bodies of listeria monocytogenes in a sample. The method includes following steps: (1) coupling an antibody capable of being specifically combined with the living bacteria bodies of listeria monocytogenes onto magnetic balls to obtain immune magnetic balls, wherein the antibody capable of being specifically combined with the living bacteria bodies of listeria monocytogenes cannot be combined with dead bacteria bodies; (2) mixing the immune magnetic balls with a liquid sample to obtain a mixture, wherein the mixing condition is described as that when the living bacteria bodies of listeria monocytogenes exists in the sample, the immune magnetic balls can specifically adsorb the living bacteria bodies of listeria monocytogenes; (3) placing the mixture in a separation magnetic field for immobilizing the immune magnetic balls and eluting substances being not adsorbed on the immune magnetic balls to obtain eluted immune magnetic balls; (4) performing DNA extraction to substances adsorbed onto the immune magnetic balls to obtain a template sample; (5) performing PCR amplification to the template sample with a specific primer aiming to the living bacteria bodies of listeria monocytogenes, and determining the content of the living bacteria bodies of listeria monocytogenes in the sample according to the content of targeted fragments in a PCR amplification product.

The invention relates to a transformed and attenuated Listeria monocytogenes introducing a human CD24 (cluster of differentiation 24) nucleotide sequence, and a vaccine thereof. The transformed and attenuated Listeria monocytogenes is characterized in that human CD24 nucleotide is located on a shuttle plasmid PKSV7, and is duplicated and expressed in the attenuated Listeria monocytogenes or a progeny of the attenuated Listeria monocytogenes. The vaccine provided by the invention overcomes various defects in liver cancer treatment in the prior art, is used for clinic treatment and prevention of drug resistance of liver cancer to chemo-radiotherapeutic drugs and postoperative metastasis and relapse, and is relatively high in safety and reliability.

The invention relates to a mesothelin high-expression cancer therapeutic vaccine based on recombinant attenuated Listeria ivanovii. Attenuated Listeria ivanovii (called Li for short) is used as a vector, and the unique ability of Listeria to grow in a host phagocytic cell is the characteristic of a natural T cell immune activation adjuvant, and is used to effectively improve the specific immune response in a tumor microenvironment and break the immune tolerance of bodies, so persistent viral infection of the bodies is removed, and good therapeutic effects of clearing focus and restraining tumor development are achieved. The cervical cancer therapeutic vaccine makes up for the shortcoming of low immunogenicity of nucleic acid and protein peptide vaccines, and the attenuated Listeria reserves the intracellular growth and antigen presentation completion characteristics of an original strain, and has a high safety.

The invention discloses a combination of nucleotide sequences and its application in cross constant temperature amplification reaction. The cross constant temperature amplification reaction can be used to identify Listeria monocytogenes, and has the characteristics of simple, fast, convenient, strong specificity and high sensitivity.