17 results about "Bacterial enterotoxins" patented technology

The invention belongs to the technical field of biosensors, and discloses a photoelectrochemical immunosensor based on a dendritic peptide tetramer as well as a preparation method and application of the photoelectrochemical immunosensor. The dendritic peptide tetramer is adopted to construct the photoelectrochemical immunosensor for the first time, and the method comprises the following steps: preparing an HsGDY / Cu2O photocathode, and sequentially anchoring an antibody probe and the dendritic peptide tetramer on the surface of the photocathode. Through specific binding of a target object and the antibody probe, a significant steric hindrance effect is generated on an electrode interface, interface charge transfer is hindered, photocurrent signal change is caused, and detection of the target object staphylococcus aureus enterotoxin A is realized. The photoelectrochemical immunosensor provided by the invention is simple, convenient and efficient in preparation process, has excellent food matrix biological pollution resistance, can effectively inhibit non-specific adsorption so as to significantly improve the sensitivity, specificity and accuracy of detection, is suitable for the field of food safety detection, and is suitable for market popularization and application.

The invention relates to the technical field of biological medicines, and particularly discloses a composition and application thereof in preparation of medicines for preventing and treating osteoporosis. The composition comprises enterotoxin c and a traditional Chinese medicine extract, wherein the weight ratio of the enterotoxin c to the traditional Chinese medicine extract is 1: (10-100). Researches show that the composition has the effect of treating or preventing osteoporosis; therefore, the compound has important application value when being used as an effective component for preparing the medicine with the effect of treating or preventing the osteoporosis.

The application belongs to the technical field of biological gene engineering, and discloses a lactococcus lactis carrier oral vaccine for producing enterotoxigenic escherichia coli F18 pilus type and application. Four lactococcus lactis antigen surface display strains are prepared, and are mixed to perform oral immunization. The oral immunization mode is convenient to operate, avoids the stress reaction caused by injection immunization on animals, and greatly improves the immunization effect, so that the diarrhea caused by enterotoxigenic escherichia coli on piglets can be effectively prevented. 50 The application is an oral escherichia coli vaccine, and mouse immunization challenge experiment shows that all the mice can survive under the challenge dose of LD , and piglet immunization challenge experiment shows that the piglets can be 100% protected from diarrhea, which shows that the immunization group has effective mucosal immune protection ability.

The application discloses a recombinant M13 bacteriophage, a K88-targeting antibacterial preparation containing the bacteriophage and application of the antibacterial preparation, and belongs to the field of biotechnology and veterinary medicine. The antibacterial preparation contains the recombinant M13 bacteriophage rM13; a K88-targeting element is displayed on the tail fiber pIII protein of the recombinant M13 bacteriophage, and the K88-targeting element is a nanobody NBK88 with an amino acid sequence shown in SEQ ID NO:1. The engineering in the application enables the rM13 to specifically recognize, invade and lyse enterotoxigenic Escherichia coli expressing K88 fimbriae, so that the host range of the wild-type M13 is accurately guided to pathogenic bacteria. The application also provides use of the preparation in preparation of a medicine for preventing or treating ETEC infection, and a dosage form of the medicine is preferably a freeze-dried preparation or an enteric preparation capable of releasing in the intestinal tract. The preparation provided by the application has the advantages of high targeting, self-proliferation, non-damage to intestinal microecology and overcoming of bacterial drug resistance.

The invention relates to the field of biological medicine and immunology, in particular to preparation and application of an anti-staphylococcus aureus enterotoxin B antibody. A heavy chain variable region of the antibody SEB-A8 provided by the invention comprises CDR sequences as shown in SEQ ID NO: 1-3, a light chain variable region of the antibody SEB-A8 comprises CDR sequences as shown in SEQ ID NO: 9-11, and the antibody SEB-A8 has important application value in treatment, prevention or diagnosis of staphylococcus aureus infection. Experimental data show that the antibody can effectively neutralize the superantigen activity of SEB and significantly improve the survival rate of MRSA infected mice, has a dose-dependent protection effect, can be used as a non-antibiotic treatment strategy, is used for treatment of methicillin-resistant staphylococcus aureus infection, has great significance in controlling development of bacterial drug resistance, and has a broad application prospect. And a new research direction is provided for clinical anti-infection treatment.

The present application relates to a kind of antigen binding protein pair specifically binding enterotoxin SEC and its application.The antigen binding protein pair of the present application includes the first antigen binding protein 16E12 combined with enterotoxin SEC and the second antigen binding protein 9B7 combined with enterotoxin SEC combined with the first antigen binding protein 16E12.The antigen binding protein of the present application has unique variable region sequence, the minimum detection limit for enterotoxin SEC is 0.1ng / mL, and there is no cross reaction for enterotoxin SEA, SEB, SED, SEE and common microbial toxin;The antigen binding protein sequence of the present application is clear, can effectively avoid gene mutation, the batch difference of antigen binding protein is small, quality is stable, structure is complete, it is helpful to the development of stable immune analysis detection method.

The invention provides a photoelectrochemical aptamer sensor as well as a preparation method and application thereof, and relates to the technical field of biosensors, according to the photoelectrochemical aptamer sensor provided by the invention, a heterostructure of narrow-band-gap CdIn2S4 and WO3 is constructed, so that the prepared WO3 / CdIn2S4 composite material shows excellent photoelectrochemical signal response, and the photoelectrochemical aptamer sensor can be applied to the field of biosensors. According to the present invention, by combining the specific recognition effect of the aptamer, the sensitive analysis of the target object staphylococcal enterotoxin B (SEB) can be achieved, the sensor has characteristics of simple operation and strong anti-interference, the detection range is 1.0 * 10 <-17 >-1.0 * 10 <-12 > mol / L, the detection limit is as low as 1.26 * 10 <-18 > mol / L, and the sensor can be successfully used for the high-selectivity and rapid detection of the SEB in the water sample.

The invention discloses a B cell conservative epitope peptide of enterotoxigenic Escherichia coli V-type secretion system effect protein EatA and application thereof, and particularly relates to application in ETEC specific antibody diagnosis. The B cell conservative epitope peptide disclosed by the invention can be functionally displayed and expressed on the surface of an inert carrier S9H thallus, PT8 is displayed and expressed on the surface of the S9H thallus, and an agglutination test directly mediated by the PT8 and specifically recognized by an antibody is established, so that only ETEC pathogen infectious antibodies are specifically recognized, other pathogenic escherichia coli can be identified and diagnosed, and the B cell conservative epitope peptide has a good application prospect. And no cross reaction with serum antibodies of other infectious diseases exists. According to the method, the specific serum antibody can be detected 7 days after a Balb / c mouse is infected by the ETEC strain H10407. The diagnosis method is high in specificity, good in sensitivity, convenient to operate and intuitive in result judgment, and is expected to become a technical means for visual on-site accurate and convenient diagnosis of ETEC infection.

This invention relates to the fields of biomedicine and immunology, and particularly to the preparation and application of an anti-Staphylococcal enterotoxin B antibody. The antibody provided by this invention has a SEB-A8 heavy chain variable region containing CDR sequences as shown in SEQ ID NO:1-3, and a light chain variable region containing CDR sequences as shown in SEQ ID NO:9-11. It has significant application value in the treatment, prevention, and diagnosis of Staphylococcus aureus infections. Experimental data show that this antibody can effectively neutralize the superantigen activity of SEB, significantly improve the survival rate of MRSA-infected mice, and exhibit a dose-dependent protective effect. It can be used as a "non-antibiotic" treatment strategy for the treatment of methicillin-resistant Staphylococcus aureus infections, which is of great significance in controlling the development of bacterial resistance and provides a new research direction for clinical anti-infective therapy.

The invention provides an antibody SEC55, a fusion protein SEC55-vHRP, a preparation method and an application. The fusion protein comprises an IgG antibody signal peptide, a hemagglutinin tag, the antibody SEC55, a connecting peptide, horse radish peroxidase and a histidine tag. The fusion protein can be used for detecting staphylococcus aureus enterotoxin C in food. The fusion protein SEC55-vHRP is provided with a horse radish peroxidase label, so that secondary antibody incubation is not needed, subsequent chromogenic reaction can be directly carried out after primary incubation is finished, the detection time is shortened, and the fusion protein SEC55-vHRP has a wide application prospect.

The invention provides bacteroides fragilis capable of relieving enteritis and application of the bacteroides fragilis, and belongs to the technical field of microorganisms. The Bacteroides fragilis is Bacteroides fragilis NJ, the preservation number of the Bacteroides fragilis NJ in the China General Microbiological Culture Collection Center is CGMCC No.46606, and the Bacteroides fragilis NJ has the effects of inhibiting colonization of pathogenic enterobacteria, relieving host colon tissue lesions and intestinal inflammation, effectively reducing the level of inflammatory cytokines such as TNF-alpha and IL-17 in serum, and improving the immunogenicity of the serum. The abundance of enterotoxin-producing bacteroides fragilis in intestinal tracts is reduced; and a new way and method can be provided for prevention and treatment of intestinal inflammation.

This document describes compositions, methods, and kits for detecting diarrheal pathogens from patient, food, or environmental samples. One embodiment described herein is primer pairs and probes for a multiplex polymerase chain reaction (PCR)-based assay for detecting gastrointestinal pathogens such as adenovirus, astrovirus, rotavirus, norovirus, zaruzin virus, Campylobacter species, Clostridium difficile, enteroaggregative Escherichia coli (EAEC), enteropathogenic Escherichia coli (EPEC), enterotoxin-producing Escherichia coli (ETEC), Shigella-like toxin-producing Escherichia coli (STEC), Shigella spp. / enteroinvasive Escherichia coli (EIEC), Escherichia coli O157, Listeria monocytogenes, Shigella-like bacteria, Salmonella spp., Yersinia enterocolitica, Vibrio species, Cryptosporidium species, Cyclospora kayanoides, Entamoeba histolytica, Giardia lamblia, or Giardia lamblia. Other embodiments include methods and kits for detecting gastrointestinal pathogens.

The invention relates to a detection reagent and a detection method for detecting bacterial cfDNA by using digital PCR and application, a bacterial cfDNA extraction reagent and a digital PCR amplification reaction reagent are adopted as the detection reagent, primers and probe compositions for detecting the bacterial cfDNA in the digital PCR amplification reaction reagent are optimized, the primers have nucleotide sequences as shown in SEQ ID NO: 1, SEQ ID NO: 2, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 7 and SEQ ID NO: 8, and the probe compositions have nucleotide sequences as shown in SEQ ID NO: 2, SEQ ID NO: 3, SEQ ID NO: 4, SEQ ID NO: 5, SEQ ID NO: 7 and SEQ ID NO: 8. The probe has nucleotide sequences as shown in SEQ ID NO: 3, SEQ ID NO: 6 and SEQ ID NO: 9, cfDNA of enterotoxin-producing bacteroides fragilis, fusobacterium nucleatum and pks + escherichia coli is subjected to qualitative detection and quantitative analysis through digital PCR, the detection method is simple, high in sensitivity, high in precision and good in stability, and the probe has important application value in detection of cfDNA of bacteria and preparation of colorectal cancer screening and early diagnosis reagents.

Provided are a tetragenococcus halophilus with an inhibitory effect on bacillus cereus and a use thereof. The preservation number of the tetragenococcus halophilus is GDMCC 64945. The tetragenococcus halophilus is isolated from fermented bean curd, and colonies of the tetragenococcus halophilus are milky white, small and round on a solid medium; The tetragenococcus halophilus is Gram-positive, and when observed under a microscope, the morphology thereof is mostly diplococci or tetrads, with no chain-like formations. The strain is sensitive to eight antibiotics such as ampicillin, gentamicin and kanamycin, and has no drug resistance gene and virulence gene. A bacterial suspension of the strain has a good inhibitory effect on a bacillus cereus strain isolated from the fermented bean curd, and when the strain is applied to a fermented bean curd fermentation system, the growth of bacillus cereus in the system can be effectively inhibited, and the content of enterotoxin in the system is reduced.

The invention relates to the technical field of genetic engineering, in particular to a recombinant specific staphylococcus aureus enterotoxin B protein as well as a preparation method and application thereof. The recombinant protein has high specificity and good immunogenicity. After the recombinant protein is used as an immunogen to immunize a mouse, a specific immune response aiming at SEB can be generated. The recombinant protein can be efficiently expressed by using the method provided by the invention. The invention effectively solves the specificity problem in SEB immune response and antibody preparation.

To detect Clostridium perfringens enterotoxin (CPE) simply, quickly and with high sensitivity.SOLUTION: An antigen liquid containing fusion protein (VT2B-C-CPE) at a verotoxin receptor binding site and a Clostridium perfringens enterotoxin C terminal, and adjuvant is inoculated into a BALB / c mouse. After inoculation, a spleen cell or lymph node cell of the mouse are fused with P3U1 to create hybridoma, from which hybridoma producing a monoclonal antibody indicating high reactivity to CPE is selected, and acquisition of 5 hybridomas producing antibody showing excellent reactivity to CPE succeeds. Next, when the monoclonal antibodies are used to detect CPE with immunochromatography, a result that CPE can be detected with high sensitivity is obtained.SELECTED DRAWING: Figure 1