13 results about "Enterotoxin" patented technology

The present invention discloses an intestinal microbiota Bacteroides fragilis toxin-neutralizing nanobody and its application. By deeply studying the enterotoxigenic Bacteroides fragilis and the toxin BFT secreted by it in the bodies of patients with colorectal cancer and breast cancer, nanobodies against BFT are expressed by phage display technology; nanobodies with high binding affinity to the antigen are screened out through biopanning technology; a nanobody with the ability to neutralize the toxicity of BFT, also known as Nb2.43, is obtained. The present invention expresses and optimizes to obtain a BFT nanobody protein with high affinity, stability and uniformity, opening up a new field for the treatment of colorectal cancer and breast cancer with nanobodies targeting BFT, and having good research value and application prospects.

The invention discloses a bacteriophage capable of splitting pathogenic escherichia coli and application of the bacteriophage. The phage is named as Escherichia coli phage vBEcoMYS1, and is preserved in the Guangdong Microbial Culture Collection Center, and the preservation number of the phage is GDMCC No: 67465-B1vBEcoMYS1. Experiments prove that the bacteriophage has relatively strong splitting capacity, relatively strong thermal stability and relatively strong pH stability, and can keep high titer under the conditions that the temperature is 4-40 DEG C and the pH is 5-9. The bacteriophage can be used for splitting multiple escherichia coli, including enterotoxigenic escherichia coli (ETEC) and shiga toxin-producing escherichia coli (STEC), has a relatively wide splitting spectrum, and can be used as an antibiotic substitute. In addition, the genome of the bacteriophage does not contain virulence genes and antibiotic resistance genes, so that the bacteriophage has good biological safety.

The invention discloses a primer probe composition for detecting staphylococcus aureus and enterotoxin based on an LAMP technology and application of the primer probe composition, and belongs to the technical field of molecular diagnosis. The primer probe composition provided by the invention can specifically recognize staphylococcus aureus and simultaneously identify enterotoxin entA, entB, entC, entD and entE genes of staphylococcus aureus, a high-sensitivity and high-specificity detection kit is formed on the basis, multiple LAMP reactions can be simultaneously carried out in one tube, and the primer probe composition has the advantages of low cost, convenience in operation, short detection time, high sensitivity, high specificity and the like. The method has the advantages of being simple in result judgment, meeting the requirements of basic-level detection departments for rapidness and convenience, and facilitating enterprises to carry out real-time on-site detection in a production line.

The application discloses a recombinant bacillus subtilis of surface display of a fusion protein of Edwardsiella tarda outer membrane protein OmpA and Vibrio cholerae enterotoxin CTB, a construction method and application. A homologous double cross recombinant of coding genes of OmpA and CTB is carried out into a genome of the bacillus subtilis 168 by taking the spore coat protein CotY as an anchor point, so that the recombinant bacillus subtilis capable of stably inheriting in the bacillus subtilis and displaying the Edwardsiella tarda outer membrane protein OmpA and the Vibrio cholerae enterotoxin CTB on a spore surface is obtained. After fish and mammals orally immunize the bacillus subtilis, the survival time and survival rate of the fish and mammals after infection of the Edwardsiella tarda are obviously improved. The recombinant bacillus subtilis is used as an oral vaccine type micro-ecological immunization preparation for preventing and treating the Edwardsiella tarda infection of the fish and mammals, so that the immunization procedure is obviously simplified, the immunization stress is reduced, the labor cost is saved, the effective concentration in the intestinal tract is ensured, and the specific immune response of the body is induced.

The invention discloses a transgenic animal antibody high-yield expression system based on double-copy site-specific integration and application of the transgenic animal antibody high-yield expression system. According to the invention, dual-copy anti-staphylococcus aureus enterotoxin B (SEB) monoclonal antibody genes are integrated at safe sites of mouse ROSA26 and H11 in a targeting manner, so that the whole-body high-level stable expression of the antibody in a mouse body is realized, and the yield and neutralizing activity of the antitoxin antibody are remarkably improved. The invention provides a new thought and a new strategy for the development of a low-cost and high-efficiency therapeutic antibody bioreactor. Besides, the constructed SEB antibody gene animal model provides an important tool for research on staphylococcus aureus infection resistance, provides a potential model animal solution for disease prevention and control of animal husbandry, and has good application value and industrial transformation prospect.

The invention provides a feed for improving disease resistance of Songliao black piglets and application of the feed, and belongs to the technical field of healthy breeding of livestock. The feed comprises a basic ration and the compound polysaccharide of the cortex dictamni and the sambucus williamsii, wherein the compound polysaccharide is preferably prepared by mixing and extracting the cortex dictamni and the sambucus williamsii according to the weight ratio of 3: 2. The preparation method of the compound polysaccharide comprises the steps of raw material pretreatment, ultrasonic mixing extraction, deproteinization and 10 kDa and 300 Da membrane separation and purification. Experimental results show that in an enterotoxigenic Escherichia coli challenge model, Songliao black piglets fed with the feed (in a ratio of 3: 2) show significant unexpected synergistic interaction, the diarrhea rate can be significantly reduced, and intestinal barrier injury can be effectively repaired. Therefore, the invention provides an efficient and green anti-diarrhea and growth-promoting solution for the Songliao black piglets, and has important application value.

The present invention relates to mutants of an E. coli heat-stable toxin (ST) having the following wild-type sequence: NSSNYCCELCCNPACTGCY wherein the mutant has two mutations wherein the first mutation is selected from L9K, L9N and L9T and the second mutation is A14T.

The invention relates to the technical field of microorganisms, in particular to double-fermentation paraclostridium JN807 and application thereof in preparation of drugs for preventing and / or treating piglet diarrhea. The paraclostridium bifermentans JN807 is resistant to acid and bile salt, and the artificial gastrointestinal fluid is good in tolerance, so that the paraclostridium bifermentans JN807 can smoothly pass through the stomach and enter the small intestine to play a role. In addition, the paraclostridium bifermentans JN807 can be used for effectively inhibiting the escherichia coli capable of producing enterotoxins in vivo and in vitro; and the clostridium butyricum BNCC337239 and the clostridium butyricum BNCC337239 can synergistically improve the effect of preventing and / or treating piglet diarrhea.

This invention relates to the field of microbial technology, specifically to a double-fermented *Clostridium parahaemolyticus* JN807 and its application in the preparation of drugs for the prevention and / or treatment of diarrhea in piglets. Double-fermented *Clostridium parahaemolyticus* (JN807) Paraclostridium bifermentans JN807 is acid- and bile-resistant, and tolerates artificial gastrointestinal fluids well, thus it can easily pass through the stomach and enter the small intestine to exert its effects. Furthermore, the double-fermented *Clostridium paragallinarum* (… Paraclostridium bifermentans JN807 can effectively inhibit enterotoxin-producing Escherichia coli both in vivo and in vitro; and it can synergistically enhance the effect of preparing products for the prevention and / or treatment of piglet diarrhea with Clostridium butyricum BNCC337239.

This invention relates to the field of molecular biology detection technology, specifically to a dual-fluorescence quantitative PCR primer and probe for detecting *Isococcus suis* and enterotoxigenic *Escherichia coli*, and their applications. The dual-fluorescence quantitative PCR primer and probe include an upstream primer ITS1-F (SEQ ID NO. 1), a downstream primer ITS1-R (SEQ ID NO. 2), and a probe ITS1-Probe (SEQ ID NO. 3) for *Isococcus suis*, and an upstream primer ST-F (SEQ ID NO. 4), a downstream primer ST-R (SEQ ID NO. 5), and a probe ST-Probe (SEQ ID NO. 6) for *Escherichia coli*. The dual-fluorescence quantitative PCR primer and probe provided by this invention have high sensitivity, high specificity, and good reproducibility, enabling simultaneous detection of *Isococcus suis* and enterotoxigenic *Escherichia coli*, thus improving diagnostic efficiency.

The application discloses application of caprylic capric glycerides in preparation of products for relieving or inhibiting intestinal cell iron death of piglets. It is found that the caprylic capric glycerides have a regulating effect on intestinal cell iron death of piglets, and feeding piglets with products containing the caprylic capric glycerides can relieve or inhibit intestinal epithelial cell iron death of piglets, protect the intestinal morphology and function of piglets, and relieve or inhibit intestinal cell iron death of piglets induced by Escherichia coli K88. Feeding piglets with feed products containing the caprylic capric glycerides can positively regulate the jejunal villus height and the ratio of the jejunal villus height to the crypt depth of piglets, the ultrastructure of the jejunal of piglets, the protein expression amount of the tight junction protein ZO-1 of the jejunal of piglets, the contents of 4-HNE, GPX4, MDA and GSH in the jejunal of piglets, and the protein expression amount of the iron death signal path related factors (FTH1, GPX4, SLC3A2 and TFR1) of the jejunal of piglets, and can positively and comprehensively protect the intestinal health of piglets.

The application relates to a pair of antigen binding proteins specifically combined with Bacillus cereus NheA, and relates to the field of biological immunization technology. The application obtains a pair of antigen binding proteins specifically combined with Bacillus cereus NheA through screening, and the pair of antigen binding proteins are named as 5C1 and 8G7 and have unique variable region sequences. The non-hemolytic enterotoxin Nhe A of Bacillus cereus is detected by using a double-antibody sandwich detection method with 5C1 as a capture antibody and 8G7 as a detection antibody, and the minimum detection limit is 0.8 ng / mL, which indicates that the recombinant antibody has good sensitivity to Nhe A. In addition, the recombinant antibody has no cross reaction to other microbial toxins and has good specificity.

The present invention relates to mutants of an E. coli heat-stable toxin (ST) having the following wild-type sequence: NSSNYCCELCCNPACTGCY wherein the mutant has two mutations wherein the first mutation is selected from L9K, L9N and L9T and the second mutation is Al4T.