71 results about "Enterotoxigenic Escherichia coli" patented technology

The invention provides strains of bacteria, especially enterotoxigenic E. coli, attenuated by mutations in the genes encoding enterotoxins (LT, ST, EAST1) and optionally further attenuated by deletion of additional chromosomal genes. In addition the invention provides strains of attenuated bacteria expressing immunogenic but non-toxic variants of one or more of these enterotoxins. These bacteria are useful as a vaccine against diarrhoeal disease.

The invention discloses a multiple PCR detection kit for 11 intestinal pathogen nucleic acid and application of the detection kit. The detection kit comprises primers for amplifying 11 intestinal pathogens which include vibrio cholerae serotype O1, vibrio cholerae serotype O139, salmonella, Shigella, vibrio parahaemolyticus, Yersinia enterocolitica, enterophathogenic escherichia coli (EPEC), enteroinvasive escherichia coli (EIEC), enteroaggregative escherichia coli (EAEC), enterotoxigenic escherichia coli (ETEC) and escherichia coli O157:H7. The multiple PCR detection kit has the advantages that the kit is capable of performing multiple detection, high in sensitivity and fast and convenient to use; specific primer sequences are used to guarantee detecting result reliability; the detection method is simple to operate, time saving, labor saving, high in detection throughput, low in reagent consumable cost, capable of directly detecting the nucleic acid extracted from encephalitis pathogens, low in detection platform and staff technical level requirements and capable of being widely popularized in conventional detection.

Disclosed herein are antigens that stimulate protective antibodies against enterotoxigenic Escherichia coli. Also disclosed herein are proteins encoded by cssA and cssB genes as well as constructs containing the genes and methods of using thereof.

Escherichia coli strains, such as enterotoxigenic E. coli strains, genetically engineered to express from recombinant plasmids one or more colonization factors (CFs) associated with enterotoxigenic Escherichia coli bacteria (ETEC) in an increased amount compared to said CFs expressed by ETEC wild-type reference strains, as well as a method of producing such strains, and vaccine compositions against diarrhea comprising such strains, are described. Further, E. coli strains expressing unnatural combination of at least two different CFs, e.g., CFA/I+CS2, CFA/I+CS6, or CS2+CS4 are disclosed.

Genetic vaccine which comprises plasmid(s) containing genes coding for antigens of enterotoxigenic Escherichia coli (ETEC) strains is disclosed. Additionally, plasmids may consist of multiple copies of the same antigen (i.e. K88 or K99 fimbrial antigen) or multiple antigens (ie. K88 and K99 fimbrial antigens) and genetic adjuvants such as cytokines (IL-2, IL-4 & GM-CSF), costimulatory molecules (CD80 & CD86) or chemokines or immunostimulatory sequences. A method for isolating antibodies from chicken egg yolk for passive immunization of animals, as well as humans to control diarrhoeal diseases using the genetic vaccines is also disclosed.

The invention provides a preparation method and use of safe and environment-friendly enterotoxigenic Escherichia coli (ETEC) egg yolk antibody powder. The preparation method comprises: selecting a healthy commercial egg-laying chicken, immunizing the egg-laying chicken by using pig ETEC triple vaccine as an antigen and injecting through muscle according to a ratio of 0.5 to 2ml/feather, obtaining specific IgY, immunizing for 50 days for the first time, starting to collect eggs, and preparing Escherichia coli egg yolk antibody powder, wherein immunization is performed again every other 40 days for reinforcement, and high-titer IgY eggs can be obtained continuously. Fresh egg yolk pulp is quickly dewatered and dried in several seconds by a spray drying technique to form Escherichia coli egg yolk antibody powder, the spray drying temperature at an inlet is 120 to 155 DEG C, the spray drying temperature at an outlet is 60 to 80 DEG C, and the Escherichia coli egg yolk antibody powder is kept in a drying tower for 2 to 3 hours. The preparation method has the advantages that: the Escherichia coli egg yolk antibody powder can be used as a feed additive for various kinds of livestock and poultry and widely used in livestock and poultry production; and the Escherichia coli egg yolk antibody powder can improve the production performance of piglets in early weanling period, has obvious effects on prevention and treatment of diarrhea in piglets and overcomes the drawbacks of coarse egg yolk antibody.

The invention relates to a diarrhea pathogenic bacteria multi-gene detection system and its kit and application. The detection system has 15 pairs of primers, wherein 13 pairs of diarrhea pathogens primers, one pair of human genome beta-actin primers and one pair of system quality controlled beta-actin primers are included. Diarrhea pathogens refer to campylobacter jejuni, shigella, clostridium difficile, salmonella enteritidis, salmonella typhimurium, enterotoxigenic escherichia coli, escherichia coli O157, vibriones, yersinia enterocolitica and the like. The diarrhea pathogenic bacteria multi-gene detection system and its kit do not require routine culture and other steps, synchronous detection and analysis of the various diarrhea pathogens can be directly conducted on a stool sample in the same reaction system, the shortcomings that a routine detection method is low in flux and low in detection rate and takes much time are made up for, a comprehensive, accurate and low-cost pathogen diagnosis is provided for clinical use for the first time, and an important reference is provided for individualized medication and accurate medical treatment.

The invention relates to the technical field of engineered antibody and provides a monoclonal antibody. The variable region of heavy chain of the monoclonal antibody contains the amino acid sequences shown in SEQ ID NO.1, SEQ ID NO.2 and SEO ID NO.3; the variable region of light chain of the monoclonal antibody contains the amino acid sequences shown in SEQ ID NO.4, SEQ ID NO.5 and SEQ ID NO.6. The invention also specifically provides a humanization single-chain antibody generated by the recombinant strain of enterotoxigenic Escherichia coli with the accession number CGMCC No.2820 and the amino acid sequence of the humanization single-chain antibody is shown in SEQ ID NO.7. The antibody of the invention can be specifically bound with A-beta oligomer, effectively inhibit the fibrosis aggregation of A-beta and obviously alleviate the toxic effect of the A-beta on cells. The invention also relates to a pharmaceutical composite containing the antibody. The antibody of the invention has strong activity, good specificity, easy preparation and wide prospect of experiment application and clinical application.

The invention provides a method for constructing a K88ac<+> enterotoxigenic escherichia coli attenuated virus strain. The method includes the following steps that 1, K88ac<+> enterotoxigenic escherichia coli enterotoxin genes are subjected to traceless point mutation, wherein TCT on the LT I gene of K88ac<+> enterotoxigenic escherichia coli without antibiotics resistance genes is mutated into AAA, and correspondingly-encoded No. 63 serine is mutated into lysine (K); 2, the K88ac<+> enterotoxigenic escherichia coli enterotoxin genes are knocked out, wherein on the basis of the first step, the ST II genes in the K88ac<+> enterotoxigenic escherichia coli are knocked out, and therefore the aim of attenuating the K88ac<+> enterotoxigenic escherichia coili is achieved accordingly. The attenuated virus strain constructed with the method is high in adhesivity and long in in-vivo planting time, infection of the pathopoiesia stain can be prevented, and the method can be used for biological preventing of colibacillosis caused by K88ac<+> ETEC.

The invention relates to a specific marking method for enterotoxigenic escherichia coli. The method includes taking a red fluorescent protein gene as a reporter gene, and utilizing a CRISPR/Cas9 system to knock a RFP gene into a genome of the enterotoxigenic escherichia coli at a fixed point. The specifically-marked enterotoxigenic escherichia coli constructed by the method can realize the specific identification and monitoring of pathogenic escherichia coli, and provide a methodological basis for studying the infection path and pathogenic mechanism of the enterotoxigenic escherichia coli in vivo.

The invention provides a visual multiplex fluorescent LAMP detection method which can detect bovine rotavirus (BRV) and enterotoxigenic escherichia coli (ETEC). According to the detection method, twofluorophores are introduced into an LAMP method, a result is directly judged by virtue of colors of a reaction product, for example, red is namely bovine diarrhea caused by the BRV, and green is namely bovine diarrhea caused by the ETEC. The detection method provided by the invention has the advantage that the two viruses can be identified and detected at the same time through once LAMP reaction in one reaction tube. The primer designed by the invention is high in sequence sensitivity, and each reaction can detect 100 copied mixed templates at least; and specificity is good, and a target genecan be efficiently amplified; and clinical detection effect is good. The detection method provided by the invention is convenient and rapid, does not need to use an expensive instrument, is low in cost and can realize field pathogeny detection.