12 results about "Pilus" patented technology

The invention relates to molecular glue for forming fimbriae related protein based on SpaA isopeptide bonds of Vinci bacteria. The invention also relates to a nanoparticle vaccine composition formed by the molecular glue, and the immunogen is covalently displayed on the surface of the nanoparticle by the molecular glue.

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 belongs to the field of microbiology and veterinary microbiological technology, and relates to a strain of enterotoxigenic Escherichia coli carrying F5 and F41 fimbriae and application thereof. The strain is isolated from a fecal sample of a diarrheal calf, and is confirmed to be enterotoxigenic Escherichia coli carrying F5 fimbriae-related genes, F41 fimbriae-related genes and ST enterotoxin estA gene through isolation and culture, morphological identification, biochemical identification, fimbriae gene and virulence gene PCR detection and whole genome sequencing analysis. The strain has been preserved in the China General Microbiological Culture Collection Center on June 13, 2022, and the preservation number is CGMCC No. 25077. Pathogenicity tests show that the strain has strong virulence and can stably establish an animal infection model. Drug sensitivity tests show that the strain has a specific sensitivity spectrum to a variety of antibacterial drugs. The strain can be used for animal infection model establishment, antibacterial drug evaluation, calf diarrhea pathogenesis research, prevention and control technology research, and can also be used for preparing biological agents for preventing or diagnosing calf diarrhea.

To provide compositions and methods for preventing, inhibiting, disrupting, or treating polymicrobial biofilms.SOLUTION: For example, methods are provided for one or more of the following: preventing, inhibiting, disrupting, dispersing, or treating invitro and / or invivo a polymicrobial biofilm comprising Haemophilus bacteria in a subject in need thereof. The method comprises or consists essentially of or yet further consists of contacting a multi-microbial biofilm with (i) an anti-DNA binding and bending protein (DNABII) antibody or a biologically active fragment thereof and (ii) an anti-type IV pilin (T4P) majority subunit (PII A) antibody or a biologically active fragment thereof.SELECTED DRAWING: None

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.

This invention discloses a method and application for detecting F17 Escherichia coli. Using the fimbrial virulence gene ctg_04543 or ctg_04549 of F17 E. coli as a target, a fluorescent quantitative probe is designed based on the nucleotide sequence. Using F17 E. coli genomic DNA as a template, the F17 fimbrial gene ctg_04543 or ctg_04549 is detected by fluorescent quantitative PCR. Based on the fitted standard curve, F17 E. coli in the sample can be quantitatively detected. The F17 E. coli detection method provided by this invention is simple, rapid, quantitative, highly sensitive, and highly specific. It can achieve quantitative detection of F17 E. coli within 2-3 hours, meeting the detection needs of various situations such as laboratory research and animal pathogen diagnosis, and has broad application prospects and extremely high market implementation potential.

Method for detecting pathogenic strains of Escherichia coli expressing the f17g gene of the F17 fimbria gene. The invention relates to a detection method based on the amplification of the genomic DNA of the pathogenic strain using LAMP technology with specific primers at a temperature of 62°C. This reaction is carried out with the Cas12a enzyme, previously activated with a guide RNA specific to the F17g gene. This method allows for the rapid detection of pathogenic strains with rudimentary equipment and can be associated with a rapid diagnostic device in the field.

The invention relates to the technical field of bioengineering and protein engineering, in particular to an escherichia coli genetically engineered bacterium and a high-throughput screening method of an enzyme. According to the high-throughput screening method of the enzyme, the enzyme is displayed on the surface of escherichia coli, and the surface display efficiency of the enzyme is remarkably improved by optimizing an escherichia coli curli fimbriae system, so that the screening efficiency of the enzyme is improved, the screening steps are reduced, and the screening cost is reduced. The method solves the problems of need of cell disruption, complex operation, easy reduction of protein activity and low screening efficiency of a traditional screening method in an enzyme directed evolution process, and has the advantages of no need of cell disruption, simple and easy operation, high flux, specific and accurate enzyme activity determination, wide enzyme activity detection range, high screening efficiency and the like; good application prospects are realized.

The invention discloses an attenuated synergistic host chassis capable of being widely applied to production of pseudomonas aeruginosa bacteriophage as well as a construction method and application of the attenuated synergistic host chassis, and belongs to the technical field of microorganisms. According to 68 bacteriophages separated from the pseudomonas aeruginosa type strain PAO1, the comprehensive host range of the 68 bacteriophages can cover 97% (238 / 245) of 245 pseudomonas aeruginosa separated from multiple hospitals, and the target of amplifying clinical pseudomonas aeruginosa bacteriophages by a single host bacterium is achieved. By knocking out a phage resistance system, a prophage, a virulence factor effect protein and an antibiotic resistance related gene in the PAO1, the yield of the PAO1 phage is increased, and pollution of most secretory prophages, virulence factors and antibiotic inactivating enzymes to the phage is removed from the source. Key virulence factors such as O antigens, fimbriae and core oligosaccharides are further knocked out to synthesize related genes, pollution of the O antigens, the fimbriae and the core oligosaccharides is reduced, lipopolysaccharide is greatly truncated, and the purification problem is solved.

The application discloses construction and application of Escherichia coli with high L-threonine yield, and belongs to the field of genetic engineering and fermentation engineering. In the genome of Escherichia coli TWF001, the pilus synthesis gene clusters Ycb, Yad, Yde, Yeh, Yqi, Yra, Yfc, Type1, Yhc and Sfm are knocked out to obtain mutant TWK021. The L-threonine yield of the TWK021 strain in a fermentation medium is 15.75 g / L, which is increased by 32.4% compared to the TWF001 yield, and the L-threonine yield of 62.7 g / L is obtained in a fed-batch fermentation. The application constructs a stable Escherichia coli with high L-threonine yield, and the plasmid does not need to be maintained by antibiotics in the whole fermentation process, and a new strategy for increasing the L-threonine yield of Escherichia coli is provided.

The application discloses a broad-spectrum attenuated and synergistic host chassis for production of pseudomonas aeruginosa phage, a construction method and application thereof, and belongs to the technical field of microorganisms. 68 phages isolated from a model strain of Pseudomonas aeruginosa PAO1 can cover 97% (238 / 245) of 245 Pseudomonas aeruginosa strains isolated from multiple hospitals, and the target of amplifying clinical Pseudomonas aeruginosa phage by a single host strain is achieved. By knocking out phage resistance systems, prophages, virulence factor effector proteins and antibiotic resistance related genes in PAO1, the production of PAO1 phage is improved, and most of the secreted prophages, virulence factors and antibiotic inactivation enzymes are removed from the source to pollute the phage. Further, key virulence factor synthesis related genes such as O antigen, pilus and core oligosaccharide are knocked out, the pollution of O antigen, pilus and core oligosaccharide is reduced, the lipopolysaccharide is greatly truncated, and the problem of purification is solved.

The invention discloses a bacterial surface modification method based on a programmable hairy DNA nanowire rod and application of the bacterial surface modification method. The method comprises the following steps: firstly, constructing a DNA nanowire rod structure with a three-dimensional structure by utilizing a DNA origami technology; respectively modifying the head end and the main body of the DNA nanowire rod structure with functional molecules; incubating the bacteria modified with the coupling group and the DNA nanowire rod structure modified with the functional molecule to obtain the DNA nanowire rod structure modified with the coupling group. The DNA nanowire rod structure constructed by the invention can be used for regulating and controlling the movement of bacteria, and the behaviors of the bacteria can be regularly adjusted by adjusting the geometrical shape and density of the DNA-based pilus analogues without gene manipulation. The DNA nanowire rod has modifiability, low toxicity and low immunogenicity, can be used for analyzing how the nanoscale appendage form controls movement, and lays a foundation for application in interface adaptability, colonization or engineering probiotic systems in the future.