28 results about "Clostridial toxin" patented technology

The invention relates to a clostridium difficile triple detection kit based on colloidal gold immunochromatography and a preparation method of the clostridium difficile triple detection kit, and belongs to the technical field of immunodetection. The clostridium difficile triple detection kit provided by the invention comprises a clostridium difficile triple detection card and a sample diluent, and the clostridium difficile triple detection card is formed by arranging and connecting three detection test strips in parallel; the detection test strip comprises a clostridium difficile toxin A detection test strip, a clostridium difficile toxin B detection test strip and a clostridium difficile glutamate dehydrogenase detection test strip. By using the clostridium difficile triple detection kit provided by the invention, three markers related to clostridium difficile can be detected at the same time, the detection limit of clostridium difficile toxin A is 0.25 ng / mL, the detection limit of clostridium difficile toxin B is 0.5 ng / mL, and the detection limit of clostridium difficile glutamate dehydrogenase is 0.5 ng / mL, so that the clostridium difficile triple detection kit has the advantages of good sensitivity, simplicity in operation, high sensitivity, high sensitivity, high sensitivity and the like. The method is suitable for large-scale popularization screening.

The invention discloses a method for preparing a Clostridium perfringens epsilon toxin-ferritin nanoparticle antigen, comprising constructing a soluble E toxin mutant and a soluble Ferritin protein respectively and purifying them, and then self-assembling the soluble E toxin mutant and the soluble Ferritin protein to form a nanoparticle antigen. The epsilon-ferritin nanoparticles prepared by the invention significantly promote the production of IgG in antigen-immunized mice and successfully induce a cellular immune response.

The invention relates to the technical field of biological medicine, in particular to a composition for blocking formation of phage treatment tolerance and application of the composition. The composition comprises a folium ilicis purpurea ethyl acetate extraction active component and a clostridium perfringens specific bacteriophage, the folium ilicis purpurea ethyl acetate extraction active component is prepared from the following components in percentage by mass: 8 to 15 percent of protocatechuic acid and 5 to 10 percent of ethyl gallate, and the mass ratio of the protocatechuic acid to the ethyl gallate is (1.5 to 1) to (2.5 to 1); the clostridium perfringens specific bacteriophage is a virulent bacteriophage capable of specifically cracking a clostridium perfringens NetB toxin positive strain. According to the invention, the shallow thought that the existing compounding technology only pursues synergistic sterilization is subverted, and a deep synergistic mode of bacteriophage splitting attack and folium ilicis purpurea component disintegration bacterial defense program is proposed and verified for the first time. And the formation of tolerance is fundamentally blocked, so that a more thorough and more lasting treatment effect is realized, and the comprehensive production performance of animals is accidentally and greatly improved on the basis of the treatment effect.

The invention belongs to the technical field of bioengineering, and discloses a monoclonal antibody specifically combined with clostridium septicum alpha toxin recombinant protein, a hybridoma cell strain and application. The invention provides a monoclonal antibody which is specifically combined with clostridium septicum alpha toxin protein and a hybridoma cell strain clostridium septicum alpha toxin-8H2 which secretes the monoclonal antibody and has the preservation number of CCTCC NO: C202535, the monoclonal antibody only reacts with the clostridium septicum alpha toxin protein, and does not have cross reaction with other pathogens which infect cattle and sheep; the specificity is extremely high; according to the kit, a competitive ELISA technology is utilized, a mouse monoclonal antibody specifically combined with clostridium septicum alpha toxin recombinant protein is taken as a competitive antibody, serum antibodies of various animal sources can be detected, and species limitation of sample sources is avoided. Besides, the kit is good in repeatability, relatively loose in technical requirements during operation, capable of being widely popularized and used in production, and applied to clostridium septicum epidemiological investigation and vaccine immune level monitoring.

Antibody-based binding agents derived from human and camelid immunoglobulins are described, as well as strains of yeast engineered to secrete the binding agents, and methods of treating and preventing Clostridium difficile infections using the engineered strains of yeast. These binding agents recognize and bind with specificity to Clostridium difficile toxin A and / or toxin B and in some cases exhibit toxin neutralizing activity. The binding agents include camelid VHH peptide monomers, linked groups of VHH peptide monomers, VHH peptide monomers joined to antibody Fc domains, and VHH peptide monomers joined to IgG antibodies.

In an embodiment, the present disclosure pertains to a method of treating or preventing C. difficile infections. In some embodiments, the method includes administering an anti-toxin to a subject in need thereof. In some embodiments, the anti-toxin includes a designed ankyrin repeat protein (DARPin). In an additional embodiments, the present disclosure pertains to a composition including an anti-toxin for treating or preventing C. difficile infections. In some embodiments, the anti-toxin includes a DARPin. In some embodiments, the anti-toxin is a monomeric or dimeric DARPin for the neutralization of Clostridium difficile toxin B (TcdB).

This invention belongs to the field of biotechnology and discloses a monoclonal antibody that specifically binds to the recombinant protein of Clostridium perfringens (Cp) β2 toxin, a hybridoma cell line, and its applications. This invention provides a monoclonal antibody that specifically binds to the β2 toxin protein and a hybridoma cell line CPB2-2A4 (accession number CCTCC NO: C2024312) that secretes this monoclonal antibody. The monoclonal antibody reacts only with the Cp β2 toxin protein and does not cross-react with other pathogens infecting cattle and sheep, exhibiting extremely high specificity. The kit utilizes competitive ELISA technology, using a mouse monoclonal antibody that specifically binds to the Cp β2 toxin recombinant protein as a competing antibody, enabling the detection of Cp β2 toxin antibodies in serum from various animal sources, avoiding species limitations of sample sources. Furthermore, the kit exhibits good reproducibility. The kit has relatively relaxed technical requirements during operation and can be widely used in production for applications such as Cp epidemiological surveys and vaccine immunization level monitoring.

This present invention provides C-TAB.G5 and C-TAB.G5.1 isolated polypeptides comprising the receptor binding domains of C. difficile toxin A and toxin B as set forth in the amino acid sequences of SEQ ID NO: 2 and SEQ ID NO: 4. The C-TAB.G5 and C-TAB.G5.1 isolated polypeptides may be used to neutralize toxic effects of C. difficile toxin A and / or toxin B.

The present invention relates to the technical field of vaccine preparation, and in particular to an ASP-ETX fusion protein and a Clostridium perfringens epsilon toxin nanoparticle vaccine and a preparation method thereof. The ASP-ETX fusion protein of the present invention comprises Clostridium perfringens epsilon toxin and an activation-related secretory protein; the amino acid sequence of the ASP-ETX fusion protein is shown in SEQ ID NO.1. The Clostridium perfringens epsilon toxin nanoparticle vaccine is obtained by co-incubating the ASP-ETX fusion protein with cell membrane-wrapped nanoparticles. The vaccine exhibits excellent biosafety in both cells and animals, and induces the production of up to 10 5 ETX-specific antibodies with a neutralizing antibody titer of up to 64 can protect mice against 100×LD 50 GST-ETX toxin attack has great potential to replace traditional ETX vaccines.

The present invention relates to a lipidated immunogenic Clostridium difficile toxin A and toxin B polypeptide, a pharmaceutical composition comprising the immunogenic Clostridium difficile toxin A and / or toxin B polypeptide for use as a medicament, particularly a vaccine and / or for use in a method for the prevention or treatment of C. difficile infection and / or C. difficile-associated disease.

The present invention relates to the field of molecular biology detection technology, and specifically to a probe cluster, a kit and its application in detecting Clostridium difficile, wherein the kit includes a recombinase-mediated isothermal nucleic acid amplification system, amplification primers of the conservative sequence of the toxin B gene of Clostridium difficile, four sets of locked nucleic acid-modified G-quadruplex / heme DNA enzyme probes and competitive probes. In this method, nucleic acid amplification and its hybridization with the probe are carried out under constant temperature (42°C-45°C), and there is no need to purify the amplified product, and the steps are few and the speed is fast, and all detections can be completed within 40 minutes. The method has high sensitivity, good specificity, does not rely on complex instruments, and the results can be directly observed with the naked eye, which is suitable for the rapid detection of Clostridium difficile.

The invention relates to the technical field of vaccine preparation, in particular to ASP-ETX fusion protein, a clostridium perfringens epsilon toxin nano-particle vaccine and a preparation method of the clostridium perfringens epsilon toxin nano-particle vaccine. The ASP-ETX fusion protein disclosed by the invention comprises epsilon toxin of clostridium perfringens and secretory protein related to activation; the amino acid sequence of the ASP-ETX fusion protein is as shown in SEQ ID NO. 1. The clostridium perfringens epsilon toxin nano-particle vaccine is obtained by co-incubation of ASP-ETX fusion protein and nano-particles wrapped by cell membranes, the vaccine shows excellent biological safety in cells and animal bodies, ETX specific antibodies as high as 105 are generated through induction in mouse bodies, the neutralizing antibody titer is as high as 64, mice can be protected against 100 * LD50GST-ETX toxin attack, and the vaccine can be used as a vaccine for treating the epsilon toxin of the clostridium perfringens. The vaccine has a huge potential of replacing a conventional ETX vaccine.

The present application relates to recombinant Clostridium difficile antigens based on a fusion protein that consists of or comprises a first amino acid sequence and a second amino acid sequence, wherein: a) the first amino acid sequence is provided by an amino acid sequence that has at least 80% sequence identity with an amino acid sequence consisting of residues 1500-1850 of a C. difficile Toxin A sequence or residues 1500-1851 of a C. difficile Toxin B sequence; and b) the second amino acid sequence is provided by an amino acid sequence that has at least 80% sequence identity with an amino acid sequence consisting of a long repeat unit located within amino acid residues 1851-2710 of a C. difficile Toxin A sequence or within amino acid residues 1852-2366 of a C. difficile Toxin B sequence; though with the proviso that the fusion protein is not a polypeptide comprising amino acid residues 543-2710 of a C. difficile Toxin A and with the proviso that the fusion protein is not a polypeptide comprising amino acid residues 543-2366 of a C. difficile Toxin B. Also provided is the use of said antigens for the prevention / treatment / suppression of Clostridium difficile infection (CDI), together with methods for generating said antigens, methods for generating antibodies that bind to said antigens, and the use of said antibodies for the prevention / treatment / suppression of CDI.

The invention provides a purification and preservation method of clostridium septicum alpha toxin, a composition and application, and relates to the technical field of biology. The purification method comprises the following steps: in the process of purifying the clostridium septicum alpha toxin, enabling a liquid phase environment contacted with the clostridium septicum alpha toxin in each step to at least contain 5mM of EDTA (Ethylene Diamine Tetraacetic Acid); the preservation method comprises the step of preserving the clostridium septicum alpha toxin obtained by the purification method in a reagent containing at least one of EDTA (Ethylene Diamine Tetraacetic Acid), glycerol, glucose, cane sugar and sorbitol. The purification and preservation method can effectively avoid degradation of the clostridium septicum alpha toxin.

The invention provides a clostridium septicum alpha toxin mutant as well as a preparation method and application thereof, and relates to the technical field of biology, leucine at the 403rd site of an amino acid sequence as shown in SEQ ID NO.1 is mutated into amino acid X, the amino acid X is any one of isoleucine, valine or methionine, and the amino acid X is any one of isoleucine, valine or methionine. Compared with the existing recombinant clostridium septicum alpha toxin, the clostridium septicum alpha toxin mutant has the advantages that the protein expression quantity is further improved, the storage life is longer, and the stability is better.

This present invention provides C-TAB.G5 and C-TAB.G5.1 isolated polypeptides comprising the receptor binding domains of C. difficile toxin A and toxin B as set forth in the amino acid sequences of SEQ ID NO: 2 and SEQ ID NO: 4. The C-TAB.G5 and C-TAB.G5.1 isolated polypeptides may be used to neutralize toxic effects of C. difficile toxin A and / or toxin B.

The invention relates to a clostridium difficile triple detection card based on red nanospheres, and a preparation method and application thereof, and belongs to the technical field of immunodetection. The clostridium difficile triple detection card is composed of three detection test paper strips, and the preparation method comprises the following steps: processing a sample pad and a combination pad, marking clostridium difficile toxin A, clostridium difficile toxin B, clostridium difficile glutamate dehydrogenase detection antibodies and chicken IgY antibodies by using red cellulose nanospheres, preparing a marking reconstitution fluid, spraying the marking reconstitution fluid on the combination pad, and detecting the clostridium difficile glutamate dehydrogenase. The detection card has the advantages that the detection limit of the clostridium difficile toxin A is as low as 0.1 ng / mL, the detection limit of the clostridium difficile toxin B is as low as 0.25 ng / mL, the detection limit of the clostridium difficile glutamate dehydrogenase is as low as 0.1 ng / mL, and the clostridium difficile glutamate dehydrogenase detection card has good specificity and sensitivity; the generation of a false positive phenomenon is greatly avoided, and the detection effect is further improved by virtue of the nanospheres based on an immunochromatography technology.

The present disclosure relates to a mixture of HMOs with at least 85 wt% of LNFP-I, 2'FL and 3'SL of the total amount of HMOs in the mixture and the use of such a mixture to decrease Clostridium difficile and its toxins in a subject. Furthermore, the mixture of HMOs can increase microbial taxa that are diminished with aging in a mammal, including increasing Bifidobacteria such Bifidobacterium longum and / or Bifidobacterium adolescentis and Faecalibacterium such as Faecalibacterium prausnitzii in the gut of a subject, in particular an elderly.

The invention discloses a clostridium perfringens alpha toxin monoclonal antibody, a hybridoma cell strain and application. The monoclonal antibody is generated by a hybridoma cell strain CPA-3B8 with the preservation number of CCTCC NO: C2025127, the sequence of a heavy chain variable region of the monoclonal antibody is as shown in SEQ ID NO. 1, and the sequence of a light chain variable region of the monoclonal antibody is as shown in SEQ ID NO. 2. The invention also discloses a competitive ELISA method established by using the monoclonal antibody, the method optimizes key parameters such as antigen coating concentration, closing conditions, competition time and the like, and determines a positive critical value (PI is greater than or equal to 38.56%) and a negative critical value (PI is less than or equal to 30.73%). The method has the advantages of high sensitivity, strong specificity, good repeatability and the like, can be used for detecting the clostridium perfringens alpha toxin antibody in animal serum, and provides an effective tool for vaccine immune effect evaluation and disease diagnosis.

The application discloses an immunological composition, a preparation method and application thereof, and belongs to the field of animal epidemic disease prevention and control. The immunological composition comprises recombinant Clostridium perfringens alpha toxin protein, recombinant Clostridium perfringens beta1 toxin protein and recombinant Clostridium perfringens epsilon toxin protein; the preparation method comprises the following steps: respectively cloning coding genes of the recombinant Clostridium perfringens alpha toxin protein, the recombinant Clostridium perfringens beta1 toxin protein and the recombinant Clostridium perfringens epsilon toxin protein into eukaryotic expression vectors, respectively expressing the three kinds of recombinant proteins by CHO-K1 cells, and purifying the three kinds of recombinant proteins by ion exchange chromatography; compared with the prior art, the sheep clostridial disease triple four-prevention genetic engineering subunit vaccine prepared from the immunological composition produced according to the application has the following advantages: ① safe to use; ② stable quality and good immunogenicity; ③ high yield and low production cost; ④ simple process and reactor production can be realized.

The application belongs to the technical field of bioengineering, and discloses a monoclonal antibody of a recombinant protein of Clostridium perfringens toxin, a hybridoma cell strain and application. α The application provides a monoclonal antibody of a recombinant protein of Clostridium perfringens toxin, a hybridoma cell strain and application. α The application provides a monoclonal antibody of a recombinant protein of Clostridium perfringens toxin, a hybridoma cell strain and application. α The application provides a monoclonal antibody of a recombinant protein of Clostridium perfringens toxin, a hybridoma cell strain and application. α The application provides a monoclonal antibody of a recombinant protein of Clostridium perfringens toxin, a hybridoma cell strain and application. α The application provides a monoclonal antibody of a recombinant protein of Clostridium perfringens toxin, a hybridoma cell strain and application. The kit uses a mouse monoclonal antibody of a recombinant protein of Clostridium perfringens toxin as a competitive antibody, can detect serum antibodies from various animals, avoids the limitation of species of sample sources, has good repeatability, has relatively loose technical requirements in operation, can be widely used in production, and is applied to epidemiological investigation and vaccine immune level monitoring of Clostridium perfringens.

Single domain antibodies which bind to Clostridium difficile toxin B and their use in the treatment and prevention of Clostridium difficile infection. Nucleic acids and vectors encoding the single domain antibodies, host cells for expression of the single domain antibodies, methods of manufacture and compositions.

In one aspect, the invention relates to an immunogenic composition that includes a Clostridium difficile toxoid A and / or a C. difficile toxoid B, and methods of use thereof. In another aspect, the invention relates to a method for eliciting an immune response in a human against a C. difficile infection. The method includes administering to the human an effective dose of a composition, which includes a C. difficile toxoid, wherein the composition is administered at least two times, and wherein the immune response against C. difficile toxin A and / or toxin B is sustained.

The present invention provides a Clostridium perfringens alpha-toxin nanobody and its application, belonging to the field of bioengineering technology. The amino acid sequence of the Clostridium perfringens alpha-toxin nanobody is shown in SEQ ID No. 1. The Clostridium perfringens alpha-toxin nanobody provided by the present invention can specifically bind to the Clostridium perfringens alpha-toxin protein with a minimum sensitivity of 0.625 μg / ml to the protein; and can detect Clostridium perfringens alpha-toxin in chicken and alpaca feces by ELISA with a sensitivity of 2 μg / ml.

The invention relates to a clostridium difficile marker combined detection card based on high-concentration colloidal gold, and belongs to the technical field of immunodetection. The high-concentration colloidal gold with the OD value of 100 is used for marking a detection antibody, the treatment process of the combination pad and the sample pad is adjusted, the marking process is optimized, the antibody concentration is accurately controlled, and the prepared detection card can detect three clostridium difficile markers including clostridium difficile toxin A, clostridium difficile toxin B and clostridium difficile glutamate dehydrogenase; the lowest detection limit for clostridium difficile toxin A is 0.1 ng / mL, the lowest detection limit for clostridium difficile toxin B is 0.25 ng / mL, and the lowest detection limit for clostridium difficile glutamate dehydrogenase is 0.1 ng / mL, so that the problems of limited sensitivity and insufficient signal amplification of a conventional colloidal gold test strip in the prior art are solved, the detection sensitivity and stability are remarkably improved, and the detection cost is reduced. The kit is suitable for clinical rapid diagnosis of clostridium difficile related diseases.

Pharmaceutical compositions that stabilize a Clostridial toxin active ingredient are described. The compositions can be liquid or solid compositions, and comprise a surfactant and an antioxidant. In some embodiments, the compositions comprise a surfactant selected from a poloxamer and a polysorbate; an antioxidant selected from methionine, N-acetyl cysteine, ethylenediaminetetraacetic acid and combinations thereof, and, optionally, a tonicity agent and / or a lyoprotector selected from, for example, trehalose, sucrose.

The present application relates to recombinant Clostridium difficile antigens based on a fusion protein that consists of or comprises a first amino acid sequence and a second amino acid sequence, wherein: a) the first amino acid sequence is provided by an amino acid sequence that has at least 80% sequence identity with an amino acid sequence consisting of residues 1500-1850 of a C. difficile Toxin A sequence or residues 1500-1851 of a C. difficile Toxin B sequence; and b) the second amino acid sequence is provided by an amino acid sequence that has at least 80% sequence identity with an amino acid sequence consisting of a long repeat unit located within amino acid residues 1851-2710 of a C. difficile Toxin A sequence or within amino acid residues 1852-2366 of a C. difficile Toxin B sequence; though with the proviso that the fusion protein is not a polypeptide comprising amino acid residues 543-2710 of a C. difficile Toxin A and with the proviso that the fusion protein is not a polypeptide comprising amino acid residues 543-2366 of a C. difficile Toxin B. Also provided is the use of said antigens for the prevention / treatment / suppression of Clostridium difficile infection (CDI), together with methods for generating said antigens, methods for generating antibodies that bind to said antigens, and the use of said antibodies for the prevention / treatment / suppression of CDI.