71 results about "Vaccine strain" patented technology

The invention discloses a toxoplasma gondii attenuated vaccine strain RH delta rop67 as well as a construction method and application thereof, and belongs to the technical field of parasitic disease prevention and control and biological product preparation. The attenuated vaccine strain is constructed by performing targeted knockout on the ROP67 gene in a toxoplasma gondii strain RH delta ku80 through a CRISPR / Cas9 mediated gene editing technology. Compared with a wild type strain, the attenuated vaccine strain shows remarkable attenuation characteristic and good immunogenicity. A test result shows that the attenuated vaccine strain can induce a host to generate specific immune response mainly based on cellular immunity, maintains a protection effect on toxoplasma gondii infection in a relatively long immune period, and has a protection effect on tachyzoite infection and a chronic infection stage of toxoplasma gondii strains with different virulence; the survival ability of a host to tachyzoite infection can be improved, and the formation level of cysts in tissues is reduced. The invention provides a technical scheme with long-term immune potential for research and development of toxoplasma gondii attenuated vaccines.

The invention provides a nucleic acid probe, a primer group, a kit, a detection method and application, and relates to the technical field of biology. The nucleotide sequence of the nucleic acid probe is as shown in SEQ ID NO. 1; wherein the 3'end of the nucleic acid probe is modified with MGB, and locked nucleic acid is modified at a base position corresponding to the difference between the swine fever wild strain and the swine fever vaccine strain in the nucleotide sequence. According to the nucleic acid probe, a specific sequence is utilized to precisely target a swine fever wild strain, and locked nucleic acid modification is introduced at a differential site, so that the recognition capability on single-base mismatch is remarkably enhanced, non-specific binding to a vaccine strain is thoroughly blocked, and false positive interference is eliminated; and 3 '-terminal MGB modification is matched to improve the binding stability and sensitivity, so that the efficient and accurate identification of the swine fever wild strain under the immune background is ensured.

This invention belongs to the field of biodetection technology, specifically relating to a monoclonal antibody combination for detecting the N protein of porcine reproductive and respiratory syndrome virus (PRRSV) and its application. The combination consists of monoclonal antibodies 1D7 and 5C7. Sequence analysis has clarified the CDR amino acid sequences of the heavy and light chain variable regions, as shown in SEQ ID NO.1-SEQ ID NO.12, and a double-antibody sandwich ELISA detection method has been established based on this. This method uses 1D7 as the coating antibody and 5C7 as the labeling antibody, achieving a sensitivity of up to 100 pg / mL, high specificity, no cross-reactivity with irrelevant antigens such as PEDV, and effectively detecting the N protein in PRRSV vaccine strains such as JXA1-R and R-98. This invention can be used for rapid detection of PRRSV antigen in clinical samples and for vaccine quality control.

The invention belongs to the field of biology, and discloses an mRNA (messenger ribonucleic acid) with a nucleotide sequence as shown in SEQ ID NO.3. Antiserum of a strain (A / chick / Gansuu / 28 / 2024) corresponding to the mRNA has relatively good reactivity with other strains and poorer reaction with a current vaccine strain RE-13, the branched strain is a current epidemic strain, and the mRNA prepared from the HA gene of the strain has the advantage of strong protection; the invention also aims to provide the mRNA, application thereof and a vaccine.

The invention relates to a primer-probe set, comprising a forward primer having the nucleotide sequence of SEQ ID NO:1 and a reverse primer having the nucleotide sequence of SEQ ID NO:2, and a peptide nucleic acid (PNA) probe having the sequence of HEX-OO-(SEQ ID NO:3)-Lysine-BHQ1, which are used for differentiating the Peste des Petits Ruminants (PPR) virus vaccine and field strains and for preventing false positive results arising from the PPR vaccine, as well as to their operating temperatures. Said primer-probe set can differentiate between the vaccine strain containing the nucleotide sequence of SEQ ID NO:4 and the field strain containing the nucleotide sequence of SEQ ID NO:5. Thus, by means of said primer-probe set, false positive results arising from the PPR vaccine are prevented, and accordingly, unnecessary quarantine measures are also avoided.

This invention discloses a candidate strain of *R. anatipestifer* double-gene deletion attenuated vaccine, its construction method, and its application. The candidate strain of *R. anatipestifer* double-gene deletion attenuated vaccine is *R. anatipestifer* strain CH-1. B739_RS01935-B739_RS07625 A candidate attenuated live vaccine strain with double gene deletion, deposited at the China Center for Type Culture Collection (CCTCC) on May 22, 2025, with accession number CCTCC NO: M20251080, at Wuhan University, Wuhan, China, has been deposited on that date. The attenuated live strain constructed in this invention showed no significant impact on the weight gain of ducklings after immunization, demonstrating good safety. Furthermore, the protection rate against challenge with the wild-type virulent RACH-1 strain reached 83.3% after immunization, indicating excellent immunoprotective efficacy.

This invention relates to the field of molecular biology detection technology, specifically disclosing a quadruple fluorescent PCR primer-probe combination, reaction system, and detection method for identifying wild-type and vaccine strains of Mycoplasma gallisepticum. The quadruple fluorescent PCR primer-probe combination for identifying wild-type and vaccine strains of Mycoplasma gallisepticum includes a universal primer-probe set for detecting Mycoplasma gallisepticum and specific primer-probe sets targeting three vaccine strains, F-36, TS-11, and 6 / 85, respectively. The quadruple fluorescent PCR primer-probe combination, reaction system, and method of this invention for identifying wild-type and vaccine strains of Mycoplasma gallisepticum can simultaneously detect and differentiate the DNA of wild-type Mycoplasma gallisepticum and its three different vaccine strains (F-36, TS-11, and 6 / 85), making detection and differential diagnosis more efficient, economical, and convenient; it has advantages such as high sensitivity, good specificity, rapid high throughput, and simple operation.

The application discloses a Toxoplasma gondii DAHPS gene deletion vaccine strain and application thereof. The application provides a Toxoplasma gondii gene knockout strain, which is obtained by directly knocking out a 3-deoxy-D-arabino-heptulosonate-7-phosphate synthase TgDAHPS gene of the Toxoplasma gondii through a gene editing technology, the gene ID of the TgDAHPS gene is TGGT1_221260, and the nucleotide sequence is shown as SEQ ID NO. 1. The gene deletion strain Δdahps provided by the application can grow normally in vitro, does not reproduce in a host in vivo, and is almost non-toxic. After immunization of the Δdahps strain, the host can be induced to have good immune protection. The Δdahps has the advantages of weak virulence and almost no reproduction in vivo as the attenuated vaccine strain of the Toxoplasma gondii, can improve the resistance of the host to wild Toxoplasma gondii, and can be used for preventing the infection of the Toxoplasma gondii in humans and animals, and has important significance for developing more Toxoplasma gondii vaccines.

The invention relates to the technical field of virus detection, in particular to a fluorescent RT-PCR (Reverse Transcription-Polymerase Chain Reaction) detection probe 1106VP and / or 1106WP and primers 1106VWF and 1106VWR. The invention also discloses a fluorescent RT-PCR detection reagent, a fluorescent RT-PCR detection kit, a fluorescent RT-PCR detection probe, a primer, the fluorescent RT-PCR detection reagent and the application of the fluorescent RT-PCR detection kit in identification of a porcine reproductive and respiratory syndrome NJ-1106R strain and a porcine reproductive and respiratory syndrome non-NJ-1106R strain. The probe and the primer disclosed by the invention are high in specificity and high in sensitivity; the accuracy is high, and the accuracy rate of blind sample detection is 100%; the kit is high in universality, can be used for detecting virus liquid for cell culture in a laboratory, and can also be used for detecting porcine serum and tissue samples in clinical samples. The method is an effective method for identifying the PRRSV NJ-1106R vaccine strain and other PRRSV wild strains.

The invention discloses a toxoplasma gondii double-gene deletion attenuated vaccine strain as well as a construction method and application thereof. The toxoplasma gondii double-gene deletion attenuated vaccine strain is constructed by deleting a ku80 gene and a CDC14 gene on the basis of a toxoplasma gondii type II PLK strain, and is named as PLK [delta] TgKu80 [delta] TgCDC14 ([delta] CDC14 for short), and experimental results show that the pathogenicity of the strain is remarkably reduced after the CDC14 gene is knocked out. In order to further explore the immune protection effect on toxoplasma gondii acute infection mice, secondary acute infection is carried out on mice immunized with delta CDC14 strains, and the result shows that compared with non-immunized group mice, no immunized mice die within 30 days, and all non-immunized mice die within 13 days. Therefore, the double-gene deletion attenuated vaccine strain has the potential of being used as a vaccine, and an effective technical means is provided for preventing toxoplasma gondii infection.

This invention relates to the field of biotechnology, and aims to provide a monoclonal antibody 7A12 for identifying genotype 2 classical swine fever, along with its preparation and application methods. This monoclonal antibody contains an Ig domain V of the antibody heavy chain. H CDR1, V H CDR2 and V H CDR3, and the Ig domain V of the antibody light chain L CDR1, V L CDR2 and V L CDR3; wherein, the V H CDR1, V H CDR2 and V H The amino acid sequences of CDR3 are shown in SEQ ID NO:1-3, respectively; the V L CDR1, V L CDR2 and V L The amino acid sequences of CDR3 are shown in SEQ ID NO:4-6. The antibody provided by this invention has advantages such as high titer, strong specificity, and high affinity; it also has high sensitivity and specificity, and shows no cross-reactivity with type 1 classical swine fever vaccine strains. Serologically, it can differentiate and diagnose infection and vaccine immunization with genotype 2 classical swine fever wild-type strains. Furthermore, it can be used to develop a blocking ELISA kit for identifying genotype 2 classical swine fever, effectively diagnosing and purifying genotype 2 classical swine fever virus.

This invention provides a live attenuated Brucella vaccine strain M5Δ pyrE Its construction methods and applications belong to the field of biotechnology. The M5... pyrE The strain was obtained by knocking out Brucella mesenteriae strain M5. pyrE Genetically constructed and deposited at the China Center for Type Culture Collection. This invention discovers that... pyrE The gene is associated with Brucella virulence; knocking out this gene significantly weakens Brucella virulence and reduces its intracellular and mouse viability. Compared to the existing vaccine strain M5-9026, M5... pyrE The strain exhibits superior immunoprotective effects, effectively inducing humoral and Th1 cellular immune responses, and demonstrates good safety. The M5 strain constructed in this invention... pyrE This strain has promising potential as a candidate strain for a live attenuated vaccine to prevent brucellosis in animals.

The application belongs to the field of vaccines and genetic engineering technology, and relates to an H3N2 canine influenza recombinant virus strain and application thereof. Specifically, the application relates to a recombinant canine influenza vaccine strain which is obtained by recombination of the following genes: an HA gene, an NA gene, a PB1 gene, a PB2 gene, a PA gene, an NP gene, an M gene and an NS gene; wherein the sequence of the HA gene is shown as SEQ ID NO:1; and / or the sequence of the NA gene is shown as SEQ ID NO:2. The application also relates to an H3N2 canine influenza recombinant vaccine and a method for preparing the H3N2 canine influenza recombinant vaccine.

The invention relates to the technical field of virus detection, and particularly discloses a fluorescent RT-PCR (Reverse Transcription-Polymerase Chain Reaction) detection kit for identifying a classical swine fever virus vaccine strain and a wild strain. The kit comprises a specific primer combination, a specific fluorescent probe, a fluorescent RT-PCR (Reverse Transcription-Polymerase Chain Reaction) reaction solution, a positive control and a negative control, the primer combination comprises a vaccine strain and wild strain specific primer pair targeting a virus 5 '-UTR region and an E2 gene; the fluorescent probes comprise probes corresponding to the targets respectively and are marked with fluorophores; verification is carried out through double gene targets, missing detection caused by single site mutation is effectively avoided, and the method has the advantages of high specificity, high sensitivity and high accuracy; the invention further provides a non-diagnostic purpose detection method of the kit, detection can be completed within 2 h, and the kit is suitable for rapid identification, epidemic situation monitoring and purification effect evaluation of classical swine fever virus vaccine strains and wild strains in clinical samples.

The invention provides a mycobacterium tuberculosis attenuated live vaccine strain solid culture medium as well as preparation and application thereof, and the raw material of the solid culture medium comprises supernate obtained by filtering potato water prepared from selenium-enriched yellow-core potatoes with the total selenium content of 15-150mu g / kg. A solid culture medium without animal-derived components is obtained; and the culture method is further optimized, so that the mycobacterium tuberculosis is high in thallus proliferation speed and not easy to be infected by infectious microbes when being cultured. The solid culture medium disclosed by the invention is simple in manufacturing process, low in implementation cost and high in conversion efficiency, and has a prominent popularization prospect.

This study describes the construction, identification, and application of a pseudorabies virus (PRV) triple-gene deletion vaccine strain (gI / gE / TK). Based on the JS-2012-ΔgI / gE double-gene deletion strain, the TK virulence gene was further deleted using CRISPR technology. Its pathogenicity was evaluated in KM mice and piglets, and its immunoprotective efficacy was verified in piglets. This provides theoretical support for the clinical prevention and control of pseudorabies; establishes experimental models in mice and pigs to study the immunoprotective efficacy of the triple-gene deletion strain; and prepares for the subsequent development and evaluation of vaccines using PRV strains as vectors.

This invention belongs to the field of biomedical technology, specifically relating to a method for constructing a highly cell-adaptive PEDV GIIc recombinant chimeric virus. Specifically, this invention, based on the PEDV viral S protein determining PEDV's cell adaptability, innovatively elucidates that S2 is the key subunit determining its cell adaptability. On this basis, this invention proposes a scheme that can increase viral titer and thus reduce vaccine production costs when preparing candidate vaccine strains of circulating PEDV strains (especially GIIc). This involves retaining the S2 subunit of the highly cell-adaptive strain and replacing the S1 subunit of the highly cell-adaptive strain with the S1 subunit of the circulating strain, or replacing the S2 subunit of the circulating strain with the S2 subunit of the highly cell-adaptive strain. This scheme can both preserve the immunogenicity of the circulating strain and improve the efficiency of high-titer vaccine production.

This invention belongs to the field of bioengineering technology, specifically relating to the construction of a double-gene-deleted attenuated African swine fever virus strain and its application as a vaccine. This invention combines the deletion of the MGF505-7R and I267L genes in the ASFV CN / GS 2018 virus, reducing the virulence of the parent strain and obtaining an attenuated African swine fever vaccine strain. The attenuated African swine fever vaccine strain completely attenuates pigs after immunization, with 100% survival rate, and provides immune protection against challenge with the virulent ASFV CN / GS / 2018 strain. It can serve as a safe and effective candidate vaccine for the prevention and control of African swine fever, possessing significant social value.

This invention belongs to the field of genetic engineering technology and relates to... REXO2 This invention relates to the application of its siRNA in inhibiting PRRSV replication. By establishing a cell model and using RNA interference technology and a live attenuated PRRSV vaccine strain for challenge, this invention detects… REXO2 The effect of silencing on PRRSV replication in cells was found. REXO2 Silencing can significantly inhibit PRRSV replication. This invention provides a new approach for the prevention and treatment of porcine reproductive and respiratory syndrome (PRRS).

The invention belongs to the technical field of animal pathogen molecular biology, and particularly relates to a dual quantitative fluorescent primer probe composition, a kit and an identification method for identifying hog cholera virus. Aiming at the current popular strains covering 3 genotypes, 11 gene subtypes and the like of the hog cholera gene, the invention selects 5UTR and NS3 gene sequences of hog cholera virus to design and synthesize specific primers and probes aiming at the two fragments; the specific primer has no non-specific amplification on African swine fever virus, pseudorabies virus, porcine reproductive and respiratory syndrome virus, porcine circovirus type II, porcine epidemic diarrhea and bovine viral diarrhea. The invention establishes a method for identifying the classical swine fever virus wild strain and the vaccine strain and develops a kit convenient for diagnosis, and the kit and the identification method can simultaneously identify the classical swine fever virus wild strain and the vaccine strain, have the characteristics of high sensitivity, strong specificity, good repeatability and good stability, and have extremely strong application prospects.

The invention relates to the technical field of gene engineering, and particularly discloses a serum type 5 haemophilus parasuis attenuated vaccine strain without antibody polygene deletion as well as a construction method and application of the serum type 5 haemophilus parasuis attenuated vaccine strain. According to the invention, crp, cpxAR and OmpP2 genes related to toxicity are deleted from a clinical isolated strain of a haemophilus parasuis serum type 5 virulent strain HN1570 by means of molecular biology to obtain a non-resistant polygene deleted strain HPS5 [delta] OmpP2 [delta] crp [delta] cpxAR, and the deleted strain is preserved; tests find that the attenuated live vaccine prepared by using the HPS5deltaOmpP2 deltacrp deltacpxAR strain haemophilus parasuis as a strain antigen not only has 100% protection rate on infection of type 5, but also has better cross protection force on infection of other serotype haemophilus parasuis and haemophilus parasuis incapable of being classified, and a good immune protection effect can be achieved by using a small immunization amount; the result shows that the haemophilus parasuis HPS5 [delta] OmpP2 [delta] crp [delta] cpxAR strain has good immunogenicity; the vaccine is simple in preparation process, free of resistance genes, free of toxic and side effects, good in safety, long in immune period and good in immune effect, and can be used for industrial production.

The application provides a construction and application of a recombinant pseudorabies virus strain stably and efficiently expressing green fluorescent protein, in the research, a green fluorescent protein gene (EGFP) is inserted into different positions of a double gene deletion vaccine strain (JS-2012-△gE / gI) of a pseudorabies virus mutant strain by using a homologous recombination method. Finally, it is proved that the recombinant virus JS-2012-△gE / gI-VP1 / 2-EGFP has good genetic stability, and the EGFP gene can also be stably and efficiently expressed, and the growth rate on cells is also comparable to that of the parent virus, so that the VP1 / 2 gene is the best exogenous gene insertion site. Subsequently, the classical swine fever virus E2 gene, the parvovirus VP2 gene, the cap gene of the circovirus type 2 and the VP1 gene of the foot-and-mouth disease virus can be replaced or inserted into the EGFP expression frame in a single or combined manner to construct different types of multi-vaccines, and the multi-vaccines have extremely high research value and platform significance.

The invention relates to the technical field of immunology and biology, and discloses a porcine epidemic diarrhea virus monoclonal neutralizing antibody which is named as PEDV-4C4F6. The antibody comprises a heavy chain and a light chain, and variable region amino acid sequences are respectively SEQ ID NO: 3 and SEQ ID NO: 4; wherein the heavy chain CDR is GYTFANYW, IFPGSGNT and TRTGAFAY in sequence, and the light chain CDR is ENVGTY, YGASK and GQSFTYPLT in sequence. The corresponding coding nucleic acids are respectively SEQ ID NO: 1 and SEQ ID NO: 2. The antibody can be obtained through immune recombination of PEDV S protein and hybridoma screening; the VH / VL can also be cloned to a eukaryotic expression vector for recombinant expression in 293S cells. An in-vitro neutralization test shows that the antibody has remarkable neutralization activity on a classical strain CV777, a vaccine strain AJ1102 and an epidemic strain ZL29, and the neutralization titer is greater than or equal to 1: 512; the subtype identification shows that the monoclonal antibody is IgG2a / kappa. The antibody is clear in sequence, high in specificity and easy to recombine and produce.

This utility model relates to biotechnology and microbiology, specifically to the production of anthrax erythrocyte antigen diagnostic solution for the indirect hemagglutination assay (IHA). The technical result achieved by this utility model is increased specificity, sensitivity, and standardization of the erythrocyte antigen diagnostic solution, and reduced conjugating agent content, all while maintaining a long shelf life. A method for obtaining an anthrax erythrocyte antigen diagnosticum, including obtaining an antigen from the culture filtrate of the vaccine strain Bacillus anthracis 55, treating formalized ram erythrocytes with a conjugating preparation, followed by sensitization of the erythrocytes with anthrax antigen, to 100.0 mg of acetone-dried bacterial mass of the anthrax vaccine strain Bacillus anthracis STI-1 add 10.0 ml of a 70% phenol solution, shake and leave in the cold at 4°C for 3 hours, then the mixture is centrifuged at 6000 rpm for 90 minutes, the supernatant liquid is drained and neutralized by adding a saturated solution of sodium carbonate until a pH of 7.1±0.1 is obtained, and to remove insoluble particles the mixture is centrifuged at 6000 rpm for 30 minutes, the resulting yellowish opalescent supernatant is placed in a laboratory dialysis bag and dialyzed against running water for 2 days and then for 24 hours against distilled water, changing the water 4-5 times; the lipopolysaccharide antigen is extracted from the dialyzed solution by adding 5 volumes of 96° ethyl alcohol and acetone 1:1; the resulting mixture is shaken and left at a temperature of 4°C for 18-20 hours, After the specified period, the mixture is centrifuged at 5000 rpm for 90 min, then the supernatant is drained, and the sediment is washed twice with 3 volumes of 96° ethyl alcohol by centrifugation at 5000 rpm for 30 min, then the sediment is dissolved in distilled water, the resulting liquid lipopolysaccharide antigen in a volume of 3.0 ml is poured into glass vials with a capacity of 20.0 ml, after which the frozen antigen in the vials is transferred to a drying chamber, pre-cooled to a temperature of minus 30°C, hermetically close the lid and turn on the vacuum pump, after creating a vacuum in the chamber, after 2 hours turn on the heating of all the plates, while the temperature of the plates after 1 hour is raised to + 28°C, this heating temperature is maintained until the end of lyophilization, while the temperature in the vial with the antigen after 13 hours is also brought to a temperature of + 28°C, when this temperature is reached, lyophilization is completed after 6 hours, then the sensitized erythrocytes are washed and preserved, the residue of atkisencitin that has not bound to the erythrocyte receptors is removed, they are washed four times for 10 minutes at 3000 rpm with a solution of Tween-80 in a dilution of 1:5000 at the rate of 25-fold volume to the erythrocyte sediment, the sediment of sensitized erythrocytes after washing is diluted with a 0.9% solution of sodium chloride pH (6.8 ± 0.1) and sodium azide to a 10% concentration of erythrocytes.

The application provides a kind of construction and application of PRRSV live vector vaccine strain of recombination expression PEDV S protein receptor RBD domain, and the results show that the dominant antigen region of PEDV S protein RBD function domain can be expressed in the recombination virus rHuN4-F112-SRBD1 rescued, and the biological characteristics of recombination virus are similar to parent virus.The nucleotide sequence of SRBD1 gene introduced in each generation of recombination virus and the amino acid sequence encoded thereby are not deleted or mutated, and the IFA and Western Blot detection results show that the SRBD1 gene introduced in different generations of recombination virus rHuN4-F112-SRBD1 can be stably expressed, and does not affect the expression of parent virus itself protein, indicating that the recombination virus rHuN4-F112-SRBD1 strain has genetic stability.The immunogenicity analysis of recombination virus rHuN4-F112-SRBD1 shows that the recombination virus rHuN4-F112-SRBD1 strain can induce specific antibodies against PEDV S protein and PRRSV2 in piglets after immunization, and the antibodies induced have neutralizing effect on PEDV epidemic strain, and can be used for the development and development of PRRS and PED novel genetic engineering vaccine.

The invention provides a bovine nodular dermatosis virus passage attenuating method and application thereof.The method comprises the steps that a bovine nodular dermatosis virus LSDV NM2020 strain serves as a parent strain, 25 generations of continuous passage is conducted through 9-day-old SPF chick embryo chorioallantoic membrane, 30 generations of continuous passage is conducted in Vero E6 cells in a gradual cooling mode, and finally the attenuated strain is obtained through plaque cloning and purification; the strain is named as an LSDV-Z strain. The low virulent strain shows good safety in cattle while keeping the growth titer close to that of a parent strain, does not cause clinical symptoms and does not have an external detoxification phenomenon. A virus attack protection test proves that the LSDV-Z strain can provide 100% immune protection for virulent virus attack. The method disclosed by the invention has the advantages of short attenuation period, high efficiency, no need of transgenic operation and the like, and the obtained LSDV-Z strain can be used as a safe and effective candidate vaccine strain and is used for preventing and controlling bovine nodular dermatosis.

The invention relates to the field of immunology, and discloses a polypeptide and a kit for distinguishing Brucella natural infection and vaccine immune antibodies of people. Polypeptides as shown in SEQ ID NO: 1 and SEQ ID NO: 2 are artificially synthesized according to proteome difference of a naturally infected strain of Brucella and a vaccine strain, and the polypeptides are used as antigens to coat an elisa plate and a nylon membrane or a nitrocellulose membrane chip, so that identification and detection of naturally infected Brucella and Brucella attenuated vaccine immunity of people are realized according to response difference of antibody level, and the application of the Brucella attenuated vaccine is expanded. The kit provided by the invention can be used for prevention and control of Brucella of people, and realizes prevention of human diseases and animal diseases, and gate advancement.

The application provides a construction method of a recombinant canine distemper virus strain expressing mink parvovirus VP2 protein and relates to the technical field of genetic engineering. The construction method uses a mink canine distemper virus attenuated vaccine CDV3 strain as a basis, clones mink parvovirus VP2 genes into a canine distemper virus genome cDNA, and obtains a recombinant canine distemper virus rCDV3-mVP2 strain capable of simultaneously expressing CDV proteins and MEV VP2 proteins through virus reverse genetic technology, so as to provide a candidate vaccine strain for the research and development of a mink canine distemper and parvovirus enteritis double recombinant live vaccine.

The application belongs to the technical field of biological detection, and particularly relates to a SNP site for distinguishing between MS-H vaccine strains and wild strains of synovial bursa mycoplasma, a kit and application. ktrb The application first designs specific primers and MGB probes for specific conservative gene sequences, and establishes a double qPCR kit for distinguishing between MS-H vaccine strains and wild strains. Experiments in vitro prove that the kit is simple to operate, high in sensitivity, strong in specificity, and good in repeatability. The gene site and the detection kit have the advantages of avoiding the deficiency that the commonly used genes are prone to revert mutation, can be used for clinical rapid diagnosis of MS vaccine strains and wild strains, improve the accuracy of detection, promote population purification, and have certain commercial value.

This invention relates to the field of vaccine technology and provides a CHO cell line for exocrine expression of PEDV GIIb subtype S protein and its application. The CHO cell line integrates a codon-optimized PEDV GIIb S protein encoding gene carrying the TPA signal peptide into its chromosome. The nucleotide sequence of the PEDV GIIb S protein encoding gene is shown in SEQ ID NO.1. This invention uses currently prevalent GIIb strains as the antigen source to ensure vaccine strain matching; it constructs a secretory expression structure, thereby significantly improving the exocrine expression efficiency of the S protein; it precisely truncates the transmembrane region while retaining key structural domains, maintaining the protein's native conformation and immunogenicity; and it obtains a CHO cell line with stable gene integration and long-term passage to maintain expression levels through optimized transfection conditions and an antibiotic selection system.