143 results about "Attenuated strain" patented technology

The invention provides an intracellular mycobacterium tuberculosis in-situ nucleic acid detection method based on CRISPR / Cas and application, and the method comprises the following steps: S1, designing crRNA and a primer pair of a mycobacterium tuberculosis target gene sequence, and synthesizing a single-stranded DNA fluorescent probe; s2, preparing a standard solution containing a target gene sequence, and incubating with a CRISPR / Cas12a system; s3, extracting nucleic acids of different types of bacteria, uniformly mixing the nucleic acids of different types of bacteria with the CRISPR / Cas12a system, and incubating; s4, incubating an attenuated strain of mycobacterium tuberculosis and the DNA fluorescent probe, infecting macrophages, and incubating to obtain infected cells; s5, electrically transferring a CRISPR / Cas12a system into the infected cells in S4 by utilizing an electroporation technology, incubating, and detecting the intensity of a fluorescence signal; and S6, performing quantitative and positioning analysis on the detected fluorescence signal to complete detection, and directly introducing a CRISPR / Cas12a system into the macrophage by adopting an electroporation technology to realize intracellular in-situ detection, thereby avoiding the operation complexity of a nucleic acid extraction link and the loss of detection sensitivity in the prior art.

The invention discloses a toxoplasma gondii attenuated strain as well as a construction method and application thereof. The toxoplasma gondii attenuated strain delta MIC1 delta MIC3 disclosed by the invention is obtained by knocking out MIC1 and MIC3 genes from a TIR1 strain by utilizing a CRISPR-Cas9 (clustered regularly interspaced short palindromic repeats-associated 9) technology. The toxoplasma gondii attenuated strain delta MIC1 delta MIC3 can effectively enhance macrophage functions including phagocytic ability, proinflammatory factor secretion and the like, and provides theoretical basis and technical support for clarification of an immunoregulation network of toxoplasma gondii-host interaction and development of vaccine design based on attenuated strains.

The invention provides a novel goose parvovirus attenuated strain as well as a construction method and application thereof, and belongs to the field of viral vaccines. Two artificial attenuating sites capable of weakening the virulence of the novel goose parvovirus are determined through research, the live vaccine prepared by taking the obtained NGPV-NMG50 attenuated strain as an immunogen does not need to add adjuvants, the defeathering protection rate of a duck group can reach 100%, the minimum lethal dose of the virus is determined by carrying out multiple dilution on an NMG21 wild strain, and the vaccine can be used for preparing the novel goose parvovirus by taking the NGPV-NMG50 attenuated strain as an immunogen. The optimal immune dose of the NGPV-NMG50 attenuated strain is screened, so that the optimal immune dose result of the NGPV-NMG50 attenuated strain in clinical use is obtained, and an immune barrier for the novel goose parvovirus is effectively established for the ducklings.

The invention discloses a fungal virus mutant as well as a construction method and application thereof, and belongs to the technical field of fungal virus modification. The fungal virus mutant is obtained by point mutation of an initiation codon ATG for coding a protein p18 in an infectious clone pSK-ABC into ACG, a coding gene of the protein p18 is located in an open reading frame of a component C at the 3533rd-5463rd sites of a complete sequence of the infectious clone pSK-ABC, and a nucleotide sequence of the infectious clone of the mutant is shown as SEQ ID NO: 1. The phenotype of the mutant virus infected strain is observed to find that the Mp18 mutant virus can reduce the growth speed of host fungi, and causes the characteristics of abnormal host colonial morphology, conidium yield and pathogenicity reduction and the like; besides, when the attenuated strain induced by the Mp18 mutant and the virulent strain are co-inoculated, scab extension on wheat leaves can be effectively inhibited, so that the effect of preventing and controlling the fusarium graminearum virulent strain is achieved.

A hybridoma cell strain 28F6 capable of secreting a high-titer anti-PRRSV monoclonal antibody is prepared and is preserved in the China Center for Type Culture Collection (CCTCC), and the preservation number of the hybridoma cell strain 28F6 is CCTCC NO: C2022373. The antibody titer in the cell culture supernatant of the hybridoma cell strain reaches 1: 640, the hybridoma ascites titer can reach 1: 4.096 * 10 < 5 > which is far higher than that of other prepared hybridoma cell strains, the monoclonal antibody secreted by the hybridoma cell strain 28F6, the PRRSV strain and the PRRSV vaccine attenuated strain obtained through passage have good reaction activity, and the monoclonal antibody and the PRRSV strain secreted by the hybridoma cell strain 28F6 have good immunogenicity. The probe has broad-spectrum reaction activity on the American type PRRSV and can be used for detecting the American type PRRSV.

The invention provides an H9N2 avian influenza virus attenuated strain as well as a preparation method and application thereof, and belongs to the technical field of virus attenuation. The invention provides an attenuated strain of an H9N2 type avian influenza virus. The attenuated strain is obtained by modifying an M2 gene; the modification comprises the following steps: carrying out synonymous mutation on overlapped genes for coding the M1 protein and the M2 protein, replacing adjacent genes subjected to synonymous mutation with genes for coding termination codons, and carrying out deletion mutation on intracellular structural domain genes for coding the M2 protein. The H9N2 type avian influenza virus attenuated strain disclosed by the invention can be used for preparing an H9N2 type avian influenza virus attenuated vaccine. After chickens are immunized with the H9N2 avian influenza virus attenuated vaccine, a high-level hemagglutination inhibition antibody can be induced, no toxin is expelled after the chickens are immunized, safety is high, potential harm to the environment is avoided, and a new strategy is provided for prevention and control of H9N2 avian influenza.

The invention relates to the technical field of biological medicines, in particular to a tuberculosis vaccine antigen and a vaccine. In particular to application of a mycobacterium tuberculosis Rv1787 gene in preparation of a vaccine for preventing and / or treating tuberculosis, in the application, the sequence of the Rv1787 gene or an encoding product thereof is defined, and the Rv1787 gene and the encoding product thereof serve as antigens, have mycobacterium tuberculosis specificity, and can be used for preparing a vaccine for preventing and / or treating tuberculosis. According to the mycobacterium tuberculosis vaccine, identification and response of an organism immune system to mycobacterium tuberculosis can be accurately stimulated, non-specific immune response to other normal tissues is avoided, a brand new and specific molecular target spot is provided for preventing and treating tuberculosis, and the limitation that a traditional vaccine depends on a single antigen or an attenuated strain is broken through. A specific expression product of the gene can stimulate directional recognition and attack of an organism immune system on mycobacterium tuberculosis, the pertinence and effectiveness of vaccines are remarkably improved, and a new path is provided for solving the problem of tuberculosis prevention and treatment.

The invention provides a Garlu virus attenuated strain and application thereof, and relates to the field of virology and biological medicine. According to the invention, the screened Garlu virus attenuated strain is a natural attenuated strain derived from a tick sample, can grow in Vero cells, has the titer of more than or equal to 107 TCID50 / mL, does not have clinical pathogenicity to an immunodeficient host, and is safe; after the attenuated strain is used as an immunogen for pre-intervention, infection of a lethal virus strain can be avoided, the survival rate is increased to 100%, adverse effects on growth and life of experimental animals are avoided, particularly, a host can be stimulated to generate humoral immunity and cellular immunity at the same time, and the survival rate of the experimental animals is improved. And moreover, broad-spectrum cross-protection efficacy can be generated on Bandavirus lethal virus strains, and a foundation is laid for improvement of research on Bandavirus live vaccines such as the Colu virus and the like.

The invention discloses a salmonella typhimurium EN-VNP strain based on flagellin and LPS attenuation as well as a preparation method and application of the salmonella typhimurium EN-VNP strain, and particularly relates to the technical field of biology. The bacterial strain is formed by sequentially knocking out or silencing flagellin genes fliC and fljB, a phosphoethanolamine transferase gene eptA, a 4-amino-4-deoxy-L-arabinose transferase gene arnT and phosphotransferase yeiU on the basis of a salmonella VNP 20009 bacterial strain, and knocking in or overexpressing a phosphotransferase gene lpxE. The salmonella typhimurium EN-VNP strain disclosed by the invention has relatively high safety, the attenuated strain does not contain flagellin, and a lipid A molecule of LPS only retains one phosphate group, so that the safety of the strain is improved, and the strain is more suitable for serving as a vaccine and a drug delivery carrier.

The invention discloses a toxoplasma gondii attenuated strain with deletion of a Tgsrs51 gene and application of the toxoplasma gondii attenuated strain, and belongs to the technical field of gene engineering. A Tgsrs51 gene is deleted in a genome of the toxoplasma gondii attenuated strain; and the ID (Identity) number of the Tgsrs51 gene on a ToxoDB (Database) website is TGME49308840. A Tgsrs51 gene deleted strain of a toxoplasma gondii type II Pru strain is constructed by utilizing a CRISPR-Cas9 technology, and experiments prove that the Tgsrs51 gene deletion can remarkably reduce the invasion efficiency of the toxoplasma gondii Pru strain, the secretion capacity of micronematosome MIC2 and the tachyzoite proliferation rate, lead to in-vitro growth limitation, remarkably improve the survival rate of infected mice and remarkably reduce the number of intracerebral cysts. The invention provides a theoretical basis for researching a molecular mechanism and an immune mechanism of toxoplasma gondii pathopoiesis, and provides a new strategy for prevention and control of toxoplasmosis.

The present invention relates to an attenuated virus strain derived from a human metapneumovirus strain, which comprises a genome sequence shown in SEQ ID NO: 1. The attenuated strain comprises one or more genetic modifications of the sequence SEQ ID NO: 1, and the genetic modifications reduce the virulence of the strain.

The invention belongs to the field of strains, and particularly relates to a botryosphaeria dothidea attenuated strain ZMXX551-1 containing a penicillium-producing virus BdCV2 and application of the botryosphaeria dothidea attenuated strain. The attenuated strain ZMXX551-1 is preserved in the China General Microbiological Culture Collection Center on June 25, 2025, the preservation number is CGMCC NO.42040, the genome of the penicillium virus BdCV2 is composed of four dsRNAs, the penicillium virus BdCV2 has a remarkable effect in the aspect of weakening the pathogenicity of botryosphaeria dothidea, the attenuated strain ZMXX551-1 is used for treating peach seedlings, the length of scabs is inhibited by 8.63%, and the length of the scabs is inhibited by 8.63%. After 3 months, the scab of the treatment group begins to heal, and the scab of the control group is continuously increased, which indicates that the peach seedling inoculated with the strain ZMXX551-1 grows well; therefore, the strain ZMXX551-1 can inhibit expansion of peach gummosis scabs and improve plant growth, and has biological control potential.

The present invention provides a novel attenuated strain of goose parvovirus and its construction method and application, belonging to the field of virus vaccines. The present invention has determined two artificial attenuation sites that weaken the virulence of the novel goose parvovirus through research. The NGPV-NMG50 attenuated strain obtained in this application is used as a live vaccine prepared as an immunogen, and the feather loss protection rate of ducks can reach 100% without the addition of adjuvants. The minimum lethal dose of the virus is determined by diluting the NMG21 wild strain in multiples, and then the optimal immune dose of the NGPV-NMG50 attenuated strain is screened, and the optimal immune dose results of the NGPV-NMG50 attenuated strain in clinical use are obtained, so that ducklings can effectively establish an immune barrier against the novel goose parvovirus.

The invention relates to the technical field of biological medicines, and discloses a construction method and expression application of an Hcp gene deleted strain of a rahnella aqua KCL-5 strain for fish. The Hcp 0186 gene deletion strain is constructed by using a homologous recombination method, the comparison between the deletion strain and a wild strain is carried out, and the result shows that the deletion of the Hcp 0186 gene has an influence on the growth speed, the pathogenicity of the Hcp 0186 gene to the zebra fish is obviously reduced, the survival rate of the infected zebra fish is increased from 0% to 52%, and the Hcp 0186 gene deletion strain can be used as a fish attenuated live vaccine. A recombinant prokaryotic expression vector pET32a-Hcp and expression and purification of fusion protein of the recombinant prokaryotic expression vector pET32a-Hcp are further constructed, and Hcp 0186 rabbit polyclonal antibody serum is prepared as a primary antibody and can be applied to localization expression analysis of fish tissues infected by the bacterium and detection of WB and IHC. Results prove that the Hcp 0186 gene deletion of the strain provides an attenuated strain vaccine and clinical diagnosis and detection application of infected fish of the attenuated strain vaccine, and a scientific basis can be provided for revealing a molecular pathogenic mechanism of the strain and development and application of a mutant strain of the strain.

The invention discloses a bovine virus diarrhea live vaccine based on suspension culture and a preparation method thereof, and relates to the field of animal vaccines. The bovine viral diarrhea virus vaccine is a freeze-dried vaccine, and each vaccine contains a bovine viral diarrhea virus BVDV attenuated strain antigen and a freeze-drying protective agent; wherein the virus content of the antigen of the BVDV attenuated strain is 105-107 CCID50 / piece, and the BVDV attenuated strain is a cytopathic effect type attenuated strain suitable for suspension culture; the freeze-drying protective agent comprises trehalose, cane sugar, gelatin hydrolysate, sodium glutamate and polyvinylpyrrolidone. The suspension culture technology is adopted, large-scale, efficient and stable production of BVDV antigens is achieved, an optimized freeze-drying formula is combined, the obtained vaccine is high in virus titer, good in immunogenicity, high in stability, good in safety, advanced in production process, controllable in cost and suitable for industrial large-scale production.

The present invention discloses a live attenuated strain of Zika virus (ZIKV) having a deletion in the 3′ untranslated region (3′UTR) of the viral genome, which may affect viral RNA synthesis and sensitivity to type I interferon inhibition, but may not affect viral RNA translation. The present invention also discloses the use of these live attenuated ZIKV strains in the preparation of ZIKV vaccines and for providing immunoprotection against ZIKV infection and congenital ZIKV syndrome, particularly in pregnant females.

The invention belongs to the technical field of biological medicine, and discloses a toxoplasma gondii in-vitro merozoite induction model and a construction method thereof. The invention discloses application of a glutamine antagonist to induction of differentiation of toxoplasma gondii tachyzoite to merozoite or preparation of a product for induction of differentiation of toxoplasma gondii tachyzoite to merozoite, and finds that the glutamine antagonist JHU083 can induce differentiation of toxoplasma gondii virulent strain RH and attenuated strain ME49 tachyzoite into merozoite under in-vitro conditions for the first time. A reliable in-vitro model is provided for researching the key initial stage of sexual reproduction of the toxoplasma gondii, and an irreplaceable research foundation is laid for the key link of targeted blocking of parasite transmission.

The present invention relates to an attenuated strain of avian infectious bronchitis virus and a vaccine composition containing same. With weak pathogenicity and high immunogenicity, the attenuated strain of the present invention can induce defensive capabilities against the avian infectious bronchitis virus and thus can be advantageously used as an attenuated live vaccine.

The invention discloses a gene VII type Newcastle disease attenuated marker vaccine strain rMG7-HN-G256E, the preservation number of the gene VII type Newcastle disease attenuated marker vaccine strain is CGMCC (China General Microbiological Culture Collection Center) No.46292, and the whole-genome nucleotide sequence of the vaccine strain is as shown in SEQ ID No: 1; wherein the 256th amino acid glycine (G) of the HN protein is replaced by glutamic acid (E). A Newcastle disease virus reverse genetic manipulation platform is utilized, different sites are mutated on the basis of a Newcastle disease virus MG7 strain, a gene VII type Newcastle disease virus marker vaccine attenuated strain rMG7-HN-G256E which is low in pathogenicity, good in growth characteristic, high in virus titer, stable in passage and excellent in immunogenicity is rescued, and the marker vaccine strain is good in immunogenicity, high in immunogenicity, high in immunogenicity, high in specificity, high in specificity and high in specificity. The vaccine can induce a high-level protective antibody, completely protects immunized chickens, can be used for preventing and controlling the current epidemic gene VII type Newcastle disease virus, and lays a foundation for identifying vaccine immunity and wild virus infection.

The invention relates to the technical field of biology, and discloses a Zika virus non-structural protein 1 functional site and application thereof in design of a Zika virus attenuated strain. According to the invention, a new Zika virus virulence site is innovatively found, and a basis is provided for research of Zika virus and research and development work of related drugs. The invention also provides an attenuated mutant strain constructed on the basis of the virulence site, and the attenuated mutant strain has obvious attenuated characteristics and higher genetic stability, and can be used as an alternative strain of a Zika virus attenuated live vaccine.

The invention discloses a riemerella anatipestifer double-gene deletion attenuated vaccine candidate strain, a construction method and application, the riemerella anatipestifer double-gene deletion attenuated vaccine candidate strain is a riemerella anatipestifer CH-1 strain B739RS01935-B739RS07625 double-gene deletion attenuated vaccine candidate strain, the preservation number is CCTCC NO: M20251080, the preservation date is May 22, 2025, and the preservation number is CCTCC NO: M20251080. The strain is preserved in China Center for Type Culture Collection, and the address of the preservation unit is Wuhan University, Wuhan, China. After ducklings are immunized by the low virulent strain, the low virulent strain has no obvious influence on weight proliferation of the ducklings and has good safety. And after the ducklings are immunized, the challenge protection rate on RACH-1 wild virulent strains reaches 83.3%, and the immune protection effect is good.

The invention provides a method for reducing PRV virulence through gene insertion and application of the method in vaccine preparation, and belongs to the technical field of gene engineering. The invention provides a method for reducing the virulence of a pseudorabies virus. An EGFP (Enhanced Green Fluorescent Protein) protein expression cassette is inserted into the upstream of a UL40 gene. According to the invention, after the PRV is subjected to the genetic engineering modification, the pseudorabies virus attenuated strain EGFP-PRV can be obtained through virus rescue. Compared with a wild type PRV-DX, the pathogenicity is weakened, no pathological clinical symptom appears after a Balb / c mouse is infected with the pseudorabies virus, and the pseudorabies vaccine has the prospect of preparing the pseudorabies vaccine.

The invention relates to the field of veterinary biological products, in particular to a porcine epidemic diarrhea virus attenuated strain and a vaccine and application thereof. The porcine epidemic diarrhea virus attenuated strain provided by the invention is obtained through in-vitro separation culture and continuous five rounds of plaque purification and screening technology, and has stable culture characteristics. Meanwhile, the virulence of the strain on newborn piglets and weaned piglets is remarkably reduced, and the virulence does not have the phenomenon of reversion after continuous passage for five times in a pig body. The strain has good immunogenicity, and mucosal immunity and systemic immune response of an organism can be activated at the same time by adopting an oral immunization mode. A neutralizing antibody of 1: 8-1: 16 can be detected in oral fluid and serum after the piglets are immunized for 14 days, and a large amount of sIgA is generated in milk after the pregnant sows are immunized, so that the piglets obtain effective passive immune protection.

The invention discloses a streptococcus agalactiae attenuated strain, a vaccine and application of the streptococcus agalactiae attenuated strain, and belongs to the technical field of veterinary biological products. The streptococcus agalactiae attenuated strain is obtained by knocking out a marR gene of a streptococcus agalactiae virulent strain HN016; wherein the nucleotide sequence of the marR gene is as shown in SEQ ID NO: 1. After the marR gene of the streptococcus agalactiae virulent strain HN016 is knocked out, the streptococcus agalactiae attenuated strain of which the virulence is remarkably reduced is obtained, and after the streptococcus agalactiae attenuated strain is prepared into the vaccine, the survival rate of aquatic animals infected with streptococcus agalactiae can be remarkably improved, so that the survival rate of the aquatic animals infected with streptococcus agalactiae is improved. The streptococcus agalactiae attenuated strain has a good application prospect in preparation of drugs for preventing and / or treating streptococcus agalactiae infection of aquatic animals.

The present invention discloses a canine coronavirus attenuated strain CCoVAS22 and its application, and relates to the field of biomedicine technology. The canine coronavirus attenuated strain CCoVAS22 was deposited in the China Center for Type Culture Collection on July 12, 2024, and the deposit address is Wuhan University, Wuhan, China, and the deposit number is CCTCC NO: V202413. The present invention utilizes the technical means of cross-passaging in MDCK and CRFK cell lines to obtain an independently isolated CCoVAS22 strain, which has the advantages of high toxicity and stable passage on cells. After inactivation by β-propiolactone, it has the characteristics of high safety and good immunogenicity. It can be used as a candidate strain for CCoV inactivated vaccine, which can alleviate the problem of the small number of canine coronavirus isolates in China to a certain extent, and provide technical support for the prevention of diseases caused by canine coronavirus.

The attenuated strain of Bordetella bronchiseptica (YZ01-P strain) of the present invention is genetically homologous to the pathogenic Bordetella bronchiseptica prevalent in China. After immunizing animals with the vaccine composition prepared from the attenuated strain, it can induce the animal body to rapidly produce good mucosal immunity, and its immunological efficacy can be maintained for a long time. During the period of maintaining immunological efficacy, it can effectively prevent the occurrence of canine infectious respiratory diseases caused by infection with virulent strains of Bordetella bronchiseptica. At the same time, it can also be reasonably inferred that it can greatly reduce the occurrence of canine infectious diseases characterized by respiratory diseases caused by the mixed infection of virulent strains of Bordetella bronchiseptica with canine distemper, canine parainfluenza and canine adenovirus.

The invention discloses an application of docetaxel in preparation of drugs for resisting toxoplasmosis, and belongs to the technical field of medicines. Through a series of experimental studies, it is found that docetaxel can significantly delay the onset time of mice infected with toxoplasma gondii virulent strains and effectively reduce the death rate of mice infected with toxoplasma gondii attenuated strains. Docetaxel shows a relatively strong inhibition effect in the aspect of treating related diseases caused by a virulent strain or a low virulent strain of toxoplasma gondii, and can effectively slow down the infection process and prolong the life cycle of a host. In combination with in-vitro cell experiment and in-vivo animal experiment results, the taxane drug has a good treatment prospect, can be used as a development basis of a novel toxoplasmosis-resistant drug, and promotes the realization of a novel treatment scheme.

The invention relates to a recombinant rabies virus. The recombinant rabies virus is obtained by inserting an antigen gene of feline calicivirus and an antigen gene of feline herpes virus into a genome of a rabies virus attenuated strain. The triple inactivated vaccine for preventing and treating the feline calicivirus disease, the feline herpes virus disease and / or the rabies is prepared based on the recombinant rabies virus, and after the triple inactivated vaccine is used for immunizing cats, neutralizing antibodies aiming at the feline calicivirus disease, the feline herpes virus disease and the rabies virus can be effectively induced and generated; the simultaneous immunization on the three viruses is realized.

The invention relates to the technical field of genetic engineering, in particular to a mutant of HC-Pro protein and application of the mutant to prevention and treatment of papaya malformed mosaic virus. Through papaya field virus disease investigation, a low virulent strain PLDMV-R165I is identified and found on a papaya plant without symptom infection of PLDMV, and single amino acid mutation of the 165th amino acid of the PLDMV HC-Pro multifunctional protein is found after the amino acid full-length sequence of the low virulent strain PLDMV-R165I is compared with the amino acid full-length sequence of a wild type high virulent strain PLDMV. It is further verified that after mutation of the site, replication of the virus is affected, the RNA silencing inhibition activity of HC-Pro is weakened, accumulation of the virus in the papaya body is reduced, and the site is a newly-found key amino acid for determining PLDMV disease generation and virus replication and accumulation.