424 results about "Attenuated strain" patented technology

The invention includes auxotrophic attenuated mutants of Listeria and methods of their use as vaccines.

The invention provides a bacterium attenuated by a non-reverting mutation in each of the aroC gene, the ompF gene and the ompC gene. The bacterium is useful as a vaccine. The bacterium may, for example, be an attenuated strain of E. coli useful in vaccination against diarrhoea.

A VII gene type of an attenuated strain of Newcastle disease virus A-NDV-VII and a construction method are disclosed. The invention relates to the application of reverse genetics technique. The invention uses the constructed reverse genetics platform of ZJ1 strain of Newcastle disease virus of goose origin. The invention replaces two envelope glycoprotein gene fragments F and HN of an isolated strain JS-5-05-Go of Newcastle disease virus with high reproductive performance with the corresponding fragments of the ZJ1 strain of Newcastle disease virus of goose origin, so that the recombinant virus NDV-VII is obtained. The VII gene type of Newcastle disease virus A-NDV-VII which is highly attenuated is rescued after the attenuated mutation of the F gene of the recombinant virus. And the virus has a higher reproduction titer on chicken embryo. The invention is suitable for a mass production of vaccine, which can be used for the manufacture of vaccine.

The invention discloses a infectivity bronchitis attenuated vaccine strain LDT3-A strain, and discloses application and application effect thereof in preventing and curing chicken infectivity bronchitis. The microorganism accession number of the attenuated vaccine strain is CGMCC-2902. The attenuated vaccine strain of the present invention has good safety and good immunization protection effect to the chicken infectivity bronchitis. The attenuated strain can be prepared into single vaccine or combined vaccine for preventing or curing infectivity bronchitis virus.

The method relates to an attenuated vaccine strain for avian infectious bronchitis virus and application thereof. According to the invention, avian infectious bronchitis virus (IBV) is attenuated, so as to successfully obtain an IBV attenuated strain CCTCC.V201232 and a derivative virus strain thereof. The attenuated strain and derivative virus strain provided by the invention can be used in preparation of a vaccine composition for prevention of infectious bronchitis. Experiments show that the attenuated strain and vaccine composition provided by the invention can be inoculated to immature birds, so as to effectively activate immune system in the birds and well prevent avian infectious bronchitis.

The invention discloses a mycoplasma bovis attenuated strain and application thereof. The mycoplasma bovis attenuated strain is prepared by the following steps: A. a mycoplasma bovis virulent strain is separated and determined: by pathogeny separation culture and PCR (Polymerase Chain Reaction) detection, the pathogeny is determined to be mycoplasma bovis; B. the mycoplasma bovis virulent strain is cultured: the mycoplasma bovis which is obtained by separation is inoculated with a liquid drug culture medium, and is then cultured in an incubator, wherein the culture medium becomes bright yellow from red, and the previous generation of bacterium liquid of 1mul is taken for inoculating PPLO (pleuropneumonia-like organism) culture medium and culturing; C. the full attenuation of mycoplasma bovis can be shown by the experiments, and by the detection of morphology, and the generation 150 of strain Mbov HB0801-150.2 cultured by mycoplasma bovis Mbov HB0801 can be verified by the experiment result; and D. the preservation number of the mycoplasma bovis Mbov HB0801-150.2 is CCTCC M20111102. The invention has good vaccine development prospective, wide clinic application value, low cost and small irritant to animals, and can produce huge economic benefits and social benefits.

The invention relates to canine distemper live vaccine and a preparation method thereof. The preparation method takes a canine distemper virus natural attenuated strain CGMCC No.3201 with excellent immunogenicity and obtained by the inventor through field separation as a production strain to prepare the safe, effective and single-component canine distemper live vaccine. The canine distemper live vaccine effectively reduces the risk of importing other live viruses during canine distemper vaccine immunization and provides conditions for controlling the spread of fur-bearing animal diseases.

The invention relates to a marker-free gene deletion attenuated mutant strain of an Edwardsiella tarda wild strain. The marker-free gene deletion attenuated mutant strain is an attenuated live vaccine of an Edwardsiella tarda virulent strain, which deletes the chorismic acid synthase gene aroC of the Edwardsiella tarda virulent strain, three types of secretion system response element genes of eseB, escA, eseC and eseD and an endogenous plasmid, preferably, the Edwardsiella tarda virulent strain is an Edwardsiella tarda virulent strain EIB202 with the preservation number of CCTCC No:M208068; the endogenous plasmid is a plasmid of pEIB202; and the marker-free gene deletion attenuated mutant strain of the Edwardsiella tarda virulent strain is an attenuated strain WED with the preservation number of CCTCC No:M2010278. The invention also provides relevant preparations and application of the marker-free gene deletion attenuated mutant strain. The attenuated mutant strain or relevant preparations eliminate the potential environment and safety risk of products existing in the traditional attenuated live vaccines generally and is a safe, effective and economic vaccine aiming at Edwardsiella tarda diseases of cultured fishes.

Differentially expressed Leishmania genes and proteins are described. One differentially expressed gene (A2) is expressed at significantly elevated levels (more than about 10 fold higher) in the amastigote stage of the life cycle when the Leishmania organism is present in macrophages than in the free promastigote stage. The A2 gene encodes a 22 kD protein (A2 protein) that is recognized by kala-azar convalescent serum and has amino acid sequence homology with an S-antigen of Plasmodium falcilparum Vietnamese isolate VI. Differentially expressed Leishmania genes and proteins have utility as vaccines, diagnostic reagents, as tools for the generation of immunological reagents and the generation of attenuated variants of Leishmania.

The invention discloses a pseudorabies virus gene-deleted attenuated strain. The deleted gene sequences of the attenuated strain include a nucleotide sequence for coding No.198 to No.366 amino acids of gI protein of a pseudorabies virus and a nucleotide sequence for coding No.1 to No.404 amino acids of gE protein of the pseudorabies virus. The invention further discloses a preparation method and an application of the pseudorabies virus gene-deleted attenuated strain. The pseudorabies virus gene-deleted attenuated strain has a good immune protection effect on the pseudorabies virus and can be used as a vaccine candidate strain for preventing and treating pseudorabies.

The present invention discloses development of a model live vaccine for HIV, using an attenuated strain of Salmonella engineered to surface express specific HIV proteins and testing of this vaccine in mice. There are provided two recombinant plasmids, containing the Lpp-OmpA genes required for surface exposure, followed by the genes for the HIV-1 proteins, Reverse Transcriptase or Transactivating protein (Tat). These plasmids are electroporated into an attenuated strain of Salmonella, and antigen expression is verified. These live vaccines are then used to orally inoculate mice and the vaccinated mice are tested for fecal IgA response and helper T cell response specific for the HIV antigens.

The invention discloses a transmissible gastroenteritis virus (H) attenuated vaccine strain and the application. The microorganism preservation number of the attenuated vaccine strain of the invention is CCTCC-V200609. The safety of attenuated strain TGEV of the invention is excellent, which has excellent immune protective rate. The attenuated strain of the invention can be applied in preparing diagnostic reagent for diagnosing transmissible gastroenteritis, and also can be applied in preparing single vaccine or mixed vaccine (active or inactivated vaccine) and the like.

The invention relates to a mycoplasma hyopneumoniae culture medium and a preparation method thereof. The mycoplasma hyopneumoniae culture medium consists of a basic culture medium and an auxiliary culture medium, wherein the basic culture medium has major components of Hank's liquid, lactoprotein hydrolysate, a yeast extract and an ox heart extract, sterilization can be performed through autoclaving, and a pollution risk caused by filtration sterilization is greatly reduced; and the auxiliary culture medium comprises pig serum, argenine, cysteine, phenol red solution, penicillium and the like, the pig serum is sterilized through cobalt radiation, and the rest components are mixed with inactivated pig serum after filtration sterilization. The titer of a lapinized attenuated strain of the mycoplasma hyopneumoniae cultured with the culture medium provided by the invention is 109-1010 CCU, the minimum culture time may be 40 h, the generation of old bacteria and aged bacteria is greatly reduced, the usage amount of the pig serum can be as low as 8%, the allergic stress reaction caused by the pig serum is reduced, and the production cost of an enterprise is lowered.

The invention relates to gene VIb subtype Avian pneumo-encephalitis virus attenuated strain VIbI4 and a construction method thereof. The preserving number of the gene VIb subtype scriber set Avian pneumo-encephalitis virus attenuated strain VIbI4 is CGMCCNo: 6149. The gene VIb subtype Rubulavirus Newcastle disease virus attenuated strain VIbI4 and the construction method thereof relate to a technology for applying reverse genetics; and the method comprises the following steps: carrying out mutation on an F gene by using a transcription carrier Ptvt/071204 containing Avian pneumo-encephalitis virus JS/07/04/Pi full gene genome from pigeons so as to obtain to a transcription carrier ApTVT/071204, and then substituting corresponding parts on the ApTVT/071204 by the NP, P and L genetic fragments of Avian pneumo-encephalitis virus rNDV/I4 so as to obtain recombinant plasmids ApTVT/VIbI4, wherein the plasmids successfully save a recombinant virus VIbI4 after transfecting a BSR-T7/5 cell together with auxiliary plasmids. The virus is relatively high in propagating titre, is suitable for large-scale production of vaccines and can be used for manufacturing vaccines.

The invention relates to an adjuvant for improving the immunization effect of Edwardsiella vaccine and a use method of the adjuvant. The adjuvant is characterized by being extracted from raw materials including grain, yeast and a part of fungi or algae. The effective component of the adjuvant is beta-1,3-glucan or the natural, artificially modified or synthetic product of the beta-1,3-glucan. The adjuvant can be used for increasing the specific immune protection ratio of any one or more inculcated Edwardsiella vaccine antigens including the inactivated bacteria, the bacteria disintegration component, the less-virulent strain, the attenuated strain, the protective antigen, the antigen subunit, the antigenic determinant clusters or the expression product of the antigen cell expression vector of the Edwardsiella, can be used together or not together with the vaccine antigen and can be prepared into a single preparation which is used together with the vaccine antigen.

The invention discloses an attenuated strain YN150 of variant porcine epidemic diarrhea virus and applications thereof. The attenuated strain is prepared by consecutively passing strain YN144 (microbial preservation number: CCTCC V201547) for six generations in Vero cells in the presence of pancreatin (10 [mu]g/mL). The PEDV attenuated strain is originated from variant porcine epidemic diarrhea virus, has good safety, and is safe to various pigs. The provided vaccine can stimulate the pigs to generate protective immune response so as to resist variant porcine epidemic diarrhea virus and effectively prevent the infection caused by variant porcine epidemic diarrhea virus.

The invention relates to a Newcastle disease chimeric virus marker vaccine strain as well as a construction method and application thereof, and belongs to the field of rescue and application of Newcastle disease chimeric vaccine strains. A Newcastle disease virus reverse genetic operation platform is utilized to mutate an F protein cleavage site of a Newcastle disease gene GVII type strain into acleavage site of an attenuated strain, F and HN genes of a mutated gene VII type Newcastle disease strain and NP, P, M and L of a gene II type NDV La Sota strain construct a full-length chimeric cDNAsequence, and a 18bp nucleotide marker sequence is inserted into a non-coding region between P and M. A Newcastle disease chimeric virus NDV DC strain is obtained through transfection cell rescue. Theconstructed chimeric virus can reach relatively high culture titer in chick embryos and cells. The chimeric strain contains envelope surface glycoprotein of the gene VII type Newcastle disease strain, contains a skeleton of the gene II type strain, and has immunogenicity of the Newcastle disease gene VII type strain and high reproduction and high safety characteristics of the gene II type La Sotastrain.