13 results about "Clostridial toxin" patented technology

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.

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.

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 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 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 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.