10 results about "Campylobacter jejuni" patented technology

The invention belongs to the technical field of microbial genetic engineering, and particularly relates to an alpha-2, 3-sialyltransferase mutant and application thereof. The a-2, 3-sialyltransferase mutants V175N, P198A, G173D, D174Q, F196K and A315H are obtained by performing site-specific mutagenesis on six amino acids in an a-2, 3-sialyltransferase amino acid sequence coded by a gene derived from Campylobacter jejuni (OH4384), the yield of 3 '-sialyllactose is remarkably increased by single-point mutagenesis of the V175N, the yield of 3'-sialyllactose is remarkably increased by single-point mutagenesis of the V175N, the yield of 3 '-sialyllactose is remarkably increased by single-point mutagenesis of the P198A, the G173D, the D174Q, the F196K and the A315H, the optimal recombinant microbial strain 3 '-SL-09 (V175N / P198A / D174Q) is obtained through combination of multiple mutation sites, the yield can reach 5.91 g / L, the bottleneck problem of low catalytic efficiency of sialyltransferase is effectively solved, and an enzyme element with excellent performance is provided for high-efficiency and low-cost biological manufacturing of 3'-SL.

The invention relates to the technical field of microorganisms, in particular to a lactobacillus plantarum strain LM2 and application of the lactobacillus plantarum strain LM2. The strain has relatively high GABA (gamma-aminobutyric acid) production capacity and nitrite degradation capacity, has a bacteriostatic effect on intestinal pathogens such as staphylococcus aureus, salmonella enteritidis, listeria monocytogenes and campylobacter jejuni, has a good bacteriostatic function, also has good acid resistance and cholate resistance, and can be used for preparing a bacterial strain for treating intestinal diseases. The strain can well survive in artificial intestinal juice and artificial gastric juice; in order to increase the yield of GABA, the accelerant capable of remarkably promoting the growth of the strain LM2 is obtained by researching the accelerant, and the highest survival rate of the freeze-dried powder prepared by optimizing the accelerant and the freeze-dried powder can reach 99% or above, the nitrite degradation rate can reach 99% or above, the yield of GABA is increased to 3.0 g / L or above, and the freeze-dried powder is bacterial powder capable of being widely applied.

This invention discloses a fermented microbial preparation for inhibiting Campylobacter jejuni in calves, its preparation method, and its application. The fermented microbial preparation is a co-fermentation product of a mixture of Lygodium japonicum decoction and liquid culture medium, inoculated with Lactobacillus paracasei; the Lactobacillus paracasei is... Lacticaseibacillus paracasei KQNIU. Comparative experiments in this invention revealed that, compared to other types of traditional Chinese medicine, the inhibitory effect of fermented Lygodium japonicum on Campylobacter jejuni is significantly higher than that of other types of traditional Chinese medicine. Furthermore, the co-fermentation of the traditional Chinese medicine Lygodium japonicum and the probiotic Lactobacillus paracasei KQNIU achieves a synergistic effect between the two, overcoming the problem of limited efficacy when used alone.

An antimicrobial peptide having an amino acid sequence selected from SEQ ID NOs: 2-12 is provided. The antimicrobial peptide has antimicrobial activity against Gram-negative bacteria, Campylobacter jejuni, Escherichia coli, Salmonella enterica subsp. enterica serovar typhimurium, Salmonella enterica subsp. enterica serovar choleraesuis, Klebsiella pneumonica, and / or Enterobacter cloacae. A composition, pharmaceutical composition, food additive, cosmetic composition, or hygine product having an antimicrobial peptide including an amino acid sequence selected from SEQ ID NOs: 2-12 is also provided. A method of treating an infectious disease caused by bacteria including a step of administering a pharmaceutical composition having the antimicrobial peptide as an active ingredient is also provided.

The present application relates to the field of microbial technology, in particular to bacillus subtilis BS-1 and its application in water buffalo silage feed, the strain BS-1 of the present application has good bacteriostatic activity on escherichia coli, salmonella and streptococcus uberis, after mixing and fermenting according to a specific proportion with orange peel and cassava residue, the bacteriostatic spectrum of the obtained silage feed is significantly enhanced, which can simultaneously inhibit escherichia coli, campylobacter jejuni, salmonella, streptococcus uberis, staphylococcus aureus and streptococcus agalactiae that cause diarrhea and mastitis. In the feed, after mixing 60%-75% of orange peel and 25%-40% of cassava residue, the crude protein content of the fermentation product is significantly improved, and the fiber content is reduced. Feeding test shows that the feed can significantly improve the milk yield and milk quality of lactating water buffalo, and effectively alleviate diarrhea. The present application provides a safe, efficient and nutritious silage feed with disease prevention function.

The invention discloses a campylobacter jejuni liquid-phase probe targeted capturing and library building method and a kit thereof, and belongs to the technical field of germ detection. Specific probe enrichment, magnetic bead purification and high-throughput sequencing are combined, and the problems that in the prior art, low-load detection is difficult, information is incomplete, and operation is tedious are solved. Aiming at the characteristics of wide food-borne transmission, multiple low-load samples and strong complex matrix interference of campylobacter jejuni, low-load accurate detection, whole-genome information analysis and high-throughput standardized operation are realized through a liquid-phase probe targeted capture technology; the method is suitable for large-scale sample detection in the fields of food safety detection, clinical diagnosis, public health research and the like.

This invention discloses a monoclonal antibody for detecting the surface protein SapA of Campylobacter fetus and its application. The monoclonal antibodies are named 4F6 and 7B3, and the amino acid sequences of the heavy and light chain variable regions of these two antibodies are disclosed. The monoclonal antibody prepared by this invention can specifically recognize the surface protein SapA of Campylobacter fetus. The prepared monoclonal antibody has good specificity, showing no cross-reactivity with non-Camplybacteria such as standard Escherichia coli, Salmonella, Listeria, Klebsiella pneumoniae, Staphylococcus aureus, and Streptococcus, and also with Campylobacter jejuni and Campylobacter coli. The test strip prepared by combining the monoclonal antibody of this invention with colloidal gold can achieve rapid on-site detection of Campylobacter fetus with a low detection limit and high sensitivity, successfully developing an immunological method for the specific detection of Campylobacter fetus.

The invention discloses a method for detecting campylobacter jejuni cell swelling toxin CdtB in food, and provides application of a campylobacter jejuni cell swelling lethal toxin CdtB monoclonal antibody to detection of campylobacter jejuni in food for the first time. The invention aims to establish the detection kit and the detection method based on the campylobacter jejuni cell swelling toxin CdtB monoclonal antibody, and the detection kit and the detection method have relatively strong specificity and sensitivity. The CdtB monoclonal antibody prepared by the invention can be combined with CdtB protein secreted by campylobacter jejuni in food, so that the detection of the campylobacter jejuni is realized. The detection speed is high, semi-quantitative detection can be achieved, the detection sensitivity is high, and the lowest CdtB mass of 0.01 microgram can be detected.

The use of Campylobacter jejuni and its toxin in the preparation of drugs for preventing, diagnosing, predicting, treating colorectal cancer and extra-intestinal tumor metastasis. Campylobacter, especially Campylobacter jejuni and toxin CDT, can be used as a marker to distinguish whether a colorectal cancer patient has metastasis. Experiments have proved that Campylobacter jejuni has the ability to promote metastasis and invasion. Campylobacter jejuni promotes the invasion and metastasis of colon cancer cells by CDT protein and the up-regulated JAK2 / STAT3 / MMP9 signaling pathway activated by CDT protein. When the process is blocked, the tumor metastasis-promoting ability of Campylobacter jejuni is weakened or lost. Campylobacter jejuni also promotes the metastasis of extra-intestinal tumors. Based on drugs or agents that can block this process, the metastasis of colorectal cancer cells and extra-intestinal tumors can be prevented and inhibited. Based on Campylobacter jejuni and its toxin, corresponding reagents or methods are developed for diagnosing or predicting the metastasis of colorectal cancer and extra-intestinal tumors. Through the marker provided in the present application, it is expected to inhibit tumor metastasis and prolong the survival of patients.

The invention discloses a novel cyclic antibacterial peptide with a broad-spectrum antibacterial effect and application of the novel cyclic antibacterial peptide, the obtained novel antibacterial peptide is named as N1-7567, and the novel cyclic antibacterial peptide belongs to the technical field of antibacterial peptides. The amino acid sequence of the novel antibacterial peptide N1-7567 is AFLKRFSCRLIRAGKYLSCLLQPAA, and the C at the 8 site and the C at the 19 site are S-S. The invention also discloses a preparation method of the novel antibacterial peptide N1-7567. The obtained antibacterial peptide has a broad-spectrum antibacterial effect, the minimum inhibitory concentration (MIC) of the antibacterial peptide N1-7567 to campylobacter jejuni 81-176 is 22.13 mu M, and the novel antibacterial peptide is expected to become a novel prevention and control product for campylobacter jejuni.