CN116286677B

CN116286677B - African swine fever virus strain and application thereof

Info

Publication number: CN116286677B
Application number: CN202310363647.XA
Authority: CN
Inventors: 赵东明; 步志高; 孙恩成; 朱远茂; 李芳�
Original assignee: Harbin Veterinary Research Institute of CAAS
Current assignee: Harbin Veterinary Research Institute of CAAS
Priority date: 2023-04-07
Filing date: 2023-04-07
Publication date: 2023-12-12
Anticipated expiration: 2043-04-07
Also published as: CN116286677A

Abstract

The invention discloses an African swine fever virus strain, and the microorganism preservation number of the strain is CCTCC NO: V202318. The invention also discloses a culture method of the strain, application of the strain in preparing a detection reagent for African swine fever virus, application of the strain in preparing an inhibitor for African swine fever virus, application of the strain in preparing a therapeutic preparation for African swine fever, and application of the strain in preparing a preparation for preventing African swine fever. The strain is a natural recombinant virus of the gene I type and the gene II type African swine fever virus, has strong toxicity and high mortality, and can evade immune protection induced by the gene II type African swine fever attenuated live vaccine, so that the research is very important for the prevention, treatment and diagnosis technology of the strain, and the strain has important application value.

Description

African swine fever virus strain and application thereof

Technical Field

The invention belongs to the field of veterinary virology, and relates to an African swine fever virus strain and application thereof.

Background

African swine fever (African swine fever, ASF) is a devastating swine infectious disease (www.woah.org) that severely threatens the global pig industry. African swine fever virus (African Swine Fever Virus, ASFV) belongs to the family African swine fever virus, genus African swine fever virus. The ASFV B646L gene encodes the viral capsid protein P72, P72 playing an important role in viral adsorption host cell and viral particle assembly. The C-terminal sequence nucleotide identity of the B646L gene is 86.2% -99.5%, according to which ASFV is currently classified into 24 genotypes. ASFV of all 24 genotypes were detected in Africa in Saharan, but only two genotypes spread to areas outside Africa. In 1957, the gene type I african swine fever virus was transferred into europe and caused african swine fever outbreaks in many european countries. In 2007, glaujia appeared as a highly lethal gene type II ASFV (Georgia 07), spreading rapidly to neighboring countries (www.woah.org). In 2018, ASFV like Georgia07 was transmitted to china and other asian countries. Gene type II ASFV causes losses in more than 700 tens of thousands of pigs in European Asian countries (www.woah.org).

Because of the lack of an effective african swine fever vaccine, an effective control strategy cannot be formulated, resulting in the broad spread and continued evolution of ASFV in many countries. Since 2018, we have been actively monitoring changes in african swine fever virus in china. In 2020, a natural variant of the type II gene with reduced pathogenicity was detected in china. The CD2v protein is an important virulence factor for the gene type II ASFV. The reduced virulence of this strain is due to the inability of the encoded CD2v protein to be expressed normally as a result of mutation or deletion of its EP402R gene. In 2021, a low virulence genotype I ASFV was also detected in china, which strain had no blood adsorption activity and was highly similar in genome to the NH/P68 strain reported in the portugal of the sixty twentieth century. To this end, both genotype I and genotype II ASFV were present in the chinese herd.

There are no reports of natural recombinants of African swine fever virus type I and type II.

Disclosure of Invention

In order to solve the problems existing in the prior art, the first aspect of the present invention provides an african swine fever virus strain, wherein the african swine fever virus strain is selected from the group consisting of:

s1: african swine fever virus strain with a microorganism preservation number of CCTCC NO: V202318;

s2: a passaging virus strain or a mutant virus strain with unchanged clinical pathogenicity and immunogenicity relative to an African swine fever virus strain with a microorganism collection number of CCTCC NO: V202318; and

s3: a virus strain which is substantially the same as the African swine fever virus strain with the microorganism preservation number of CCTCC NO: V202318.

Regarding the virus strain (African swine fever virus strain with a microorganism preservation number of CCTCC NO: V202318, JS/LG/21 strain) claimed in the present invention, the strain of the strain JS/LG/21 which has NO mutation and has the same passage genome should be regarded as the strain JS/LG/21 which is preserved by the microorganism. The passaging virus strain or mutant virus strain with no change in clinical pathogenicity and immunogenicity mainly refers to a virus strain based on JS/LG/21 strain passaging and accumulation of minor mutations in passaging. Substantially the same virus strain is mainly referred to as the other homologous virus strain of JS/LG/21 strain.

The JS/LG/21 strain is subjected to the generation-transmission application to inevitably introduce tiny mutation, and a generation-transmission virus strain or a mutation virus strain with no change in clinical pathogenicity and immunogenicity is considered to be within the contribution scope of the invention. No change in clinical pathogenicity and immunogenicity means no substantial change, e.g., the clinical pathogenicity and immunogenicity are considered to be the same within the limits of detection techniques such as detection sensitivity, detection limits, etc., and acceptable or unavoidable errors.

The clinical pathogenicity and immunogenicity of the offspring of JS/LG/21 strain need to be measured by animals, and the expected or unavoidable systematic errors belong to the passage virus strains without substantial changes due to differences in animal varieties, ages, sexes, health conditions and the like.

The JS/LG/21 strain is passaged multiple times and inevitably introduces minor mutations which remain within the substantial technical contribution of the present invention when they occur in non-coding sequence regions or synonymous mutations of coding regions or mutations that do not affect the pathogenicity and immunogenicity of the strain (e.g., residues that may be linked amino acid residues between two domains or that are located within the higher structure of the protein and do not affect pathogenicity or immunogenicity by being not contacted by immune cells), and it is reasonably expected that these minor changes are still within the substantial technical contribution of the present invention and should be considered as mutant strains that have no change in clinical pathogenicity or immunogenicity.

The JS/LG/21 strain primary pig alveolar macrophages and other cell passage virus strains can reasonably expect that minor mutations are inevitably introduced as with other viruses, and belong to passage virus strains or mutant virus strains with no change in clinical pathogenicity and immunogenicity when the clinical pathogenicity and immunogenicity are not changed substantially.

The JS/LG/21 strain is derived from a disease-causing pig, and it is naturally possible to isolate homologous strains which have common gene I type and gene II type African swine fever virus recombinant ancestor with the JS/LG/21 strain in a plurality of places, and the genome of the homologous strains is identical to that of the JS/LG/21 strain, and the homologous strains can have minor differences.

When these homologous strains differ from the JS/LG/21 strain to an extent equivalent to that of a passaged strain or mutant strain having no change in clinical pathogenicity and immunogenicity from the JS/LG/21 strain, these homologous strains are identical to the JS/LG/21 strain or are considered to have no difference in clinical pathogenicity and immunogenicity, and these homologous strains belong to substantially the same virus strain as the JS/LG/21 strain.

In some embodiments, the protein sequence of the B646L gene in the genome of the african swine fever virus strain is shown in SEQ ID No. 1.

In some embodiments, the coding sequence of the B646L gene is set forth in SEQ ID No.2 in the genome of the african swine fever virus strain.

In some embodiments, in the genome of the african swine fever virus strain, the gene coding sequence satisfies any one, any two, or three of the following sequences:

the coding sequence of the B602L gene is shown as SEQ ID NO. 17;

the coding sequence of the C122R gene is shown as SEQ ID NO. 18; and

the coding sequence of the D345L gene is shown as SEQ ID NO. 19.

In some embodiments, in the genome of the african swine fever virus strain, the gene coding sequence satisfies any one, any two, any three, any four, any five, any six, or seven of the following sequences:

the code sequence of MGF_505-1R gene is shown as SEQ ID NO. 3;

the code sequence of MGF_505-2R gene is shown as SEQ ID NO. 5;

the code sequence of MGF_505-3R gene is shown as SEQ ID NO. 7;

the code sequence of MGF_360-12L gene is shown as SEQ ID NO. 9;

the code sequence of MGF_360-13L gene is shown as SEQ ID NO. 11;

the code sequence of MGF_360-14L gene is shown as SEQ ID NO. 13; and

the coding sequence of the EP402R gene is shown as SEQ ID NO. 15;

in some embodiments, in the genome of the african swine fever virus strain, the gene coding sequence satisfies either or both of the following sequences:

the code sequence of MGF_100-1L gene is shown as SEQ ID NO. 20; and

the coding sequence of the I9R gene is shown as SEQ ID NO. 21.

the coding sequence of the NP1450L gene is shown as SEQ ID NO. 22;

the code sequence of MGF_360-8L gene is shown as SEQ ID NO. 23; and

the coding sequence of MGF_505-5R gene is shown as SEQ ID NO. 24.

In the process of passage of African swine fever virus strains, part of the genes have synonymous mutation, and the genes do not influence clinical pathogenicity and immunogenicity, and part of genes have synonymous mutation relative to other homologous strains with gene I type and gene II type African swine fever virus recombinant ancestor, and the genes do not influence clinical pathogenicity and immunogenicity. These sequence characteristics are necessarily retained in the passage virus of JS/LG/21 strain, and minor mutations which do not affect the growth cycle, clinical pathogenicity and immunogenicity are unavoidable. They also all match the contributions of the invention.

The second aspect of the invention provides a culture method of the African swine fever virus strain of the first aspect of the invention, wherein the culture method comprises the following steps: inoculating the African swine fever virus strain into cultured cells, and performing proliferation culture of the African swine fever virus strain to obtain the proliferated African swine fever virus.

In some embodiments, the cultured cells are primary porcine alveolar macrophages.

In some embodiments, the culture environment of the culture method is: 36-39 ℃,3-5% CO ₂ 。

The third aspect of the invention provides the use of the African swine fever virus strain of the first aspect of the invention or the African swine fever virus strain cultured by the culture method of the second aspect of the invention in the preparation of a detection reagent for African swine fever virus.

The invention separates the naturally occurring gene I type and gene II type African swine fever virus recombinant, provides genetic resources for the research and development of diagnostic reagents for the recombinant, and detects the specific DNA fragments in the recombinant by a qPCR method, for example.

In a fourth aspect, the invention provides the use of an african swine fever virus strain according to the first aspect of the invention or a strain of african swine fever virus cultivated by a cultivation method according to the second aspect of the invention in the preparation of an inhibitor against african swine fever virus and/or a therapeutic formulation against african swine fever.

The invention separates the naturally occurring gene I type and gene II type African swine fever virus recombinant, the recombinant has obviously different genetic structures relative to the gene I type and the gene II type African swine fever virus and necessarily has different drug sensitivities, and the virus strain provides genetic resources for researching and developing or screening virus inhibitors of the recombinant or preparations for treating the recombinant virus.

In a fifth aspect, the invention provides an african swine fever virus strain according to the first aspect, an african swine fever virus strain obtained by genome modification of an african swine fever virus strain according to the first aspect, an african swine fever virus strain obtained by culturing according to the second aspect, or an african swine fever virus strain obtained by genome modification of an african swine fever virus strain obtained by culturing according to the second aspect, the use of the african swine fever virus strain in preparation for use alone, in combination with other immune preparations and/or drugs, or as a component of a compound preparation composed of other immune preparations and/or drugs for preventing, slowing down and/or controlling african swine fever.

The genome modification includes conventional cell passage mutation, and the genetic engineering process may be adopted to make virus weakening, such as knocking out non-lethal virulent gene in African swine fever virulent strain to obtain attenuated virus with no obvious change in immunogenicity, and the attenuated virus may be prepared into vaccine.

The invention has the advantages compared with the prior art that

1. The JS/LG/21 isolate provides new insight for the evolution trend of ASFV and provides guidance for future ASF clinical detection and epidemic prevention and control strategy formulation.

2. Compared with the traditional strain, the JS/LG/21 isolate has a unique recombination mode, can provide reference for the research of interaction among different genotype viruses of ASFV and gene functions, and promotes the research of the pathogenic mechanism, immune mechanism and the like of ASFV.

3. Provides a new idea for developing bivalent vaccine for simultaneously preventing ASFV gene I type and gene II.

Drawings

FIG. 1 shows a fluorescence photograph of JS/LG/21 strain specifically reacting with ASFV p72 polyclonal antibody (IFA).

FIG. 2 shows photographs of the HAD effect of JS/LG/21 strain.

FIG. 3 shows a phylogenetic tree of JS/LG/21 strains.

FIG. 4 shows SNPs of some JS/LG/21 strains.

FIG. 5 shows full genome maps of some JS/LG/21 strains.

FIG. 6 shows pathogenicity and transmissibility of recombinant virus isolate JS/LG/21 strain to pigs.

FIG. 7 shows the virulence and transmission of JS/LG/21-7GD after vaccination of pigs.

FIG. 8 shows the protective effect of HLJ/18-7GD vaccine against HLJ-18 or recombinant virus isolate JS/LG/21 challenge.

Detailed Description

For the purpose of making the objects, technical solutions and advantages of the present invention more apparent, the embodiments of the present invention will be described in further detail with reference to the accompanying drawings.

The materials and instruments not described in the present invention are conventional materials and instruments in the art, the details of the operations not described in the present invention are conventional operations in the art, the software used in the present invention is operated by conventional methods with reference to the instructions of the software provider, and the kits used in the present invention are operated by conventional methods with reference to the instructions of the kit used in the present invention.

The nucleic acid sequences shown in the invention are written from left to right according to the 5 'to 3' direction, and the proteins are written from left to right according to the N-end to C-end direction.

Experimental facility and ethical statement

All the experiments of the live African swine fever virus are carried out in BSL-3/ABSL-3 biosafety facility of Harbin veterinary institute of agricultural sciences, china, which facility is approved by agricultural rural areas. The invention operates in compliance with the national science and technology division of the people's republic of China, instruction for nursing laboratory animals and use.

Example 1: virus isolation

(1) Case of cases

In some pig farm in China, suspected African swine fever cases occur, and the case tissues are taken for virus identification and separation.

(2) Virus isolation

The lung of a suspected African swine fever-caused pig is ground and homogenized, primary pig alveolar macrophages (Primary porcine alveolar macrophages, PAMs) are inoculated according to 5% (v/v), the culture solution is RPMI 1640 complete medium, and the ASFVs B646L gene is detected by adopting qPCR recommended by WOAH on the cell inoculation culture supernatant on the 5 th day (p.i) after inoculation, and the result is positive. Collecting positive cell inoculation culture supernatant, and performing 3 rounds of conventional virus purification in PAMs cells by adopting a conventional limiting dilution method and the qPCR detection method, and finally separating to obtain a virus which is primarily judged to be African swine fever virus and is named as Pic/Jiangsu/LG/2021, which is abbreviated as JS/LG/21 strain.

(3) Viral propagation

PAMs are combined in a 5X 10 ratio ⁷ Individual cells/75 cm ² The cell culture flask was used in an amount of 20 ml/flask of RPMI 1640 complete medium. Placing at 37 ℃ 5% CO ₂ Culturing in incubator, inoculating JS/LG/21 at MOI of 0.1 dose after cell adhesion, harvesting virus culture solution after 96 hr, and storing at-70deg.C.

Example 2: virus identification

(1) Specificity and purity identification

The separated virus strain JS/LG/21 is inoculated with a single layer of PAMs of a 96-well plate according to MOI 0.1 and placed at 37 ℃ with 5% CO ₂ Culturing in an incubator for 48 hours. Discarding the virus culture solution, adding 4% paraformaldehyde, fixing at room temperature for 30min, and soaking in PBS for 2 times; adding 0.25% Triton-X100, penetrating into membrane for 15min at room temperature, and soaking in PBS for 2 times; adding a rabbit anti-African swine fever virus p72 polyclonal antibody, incubating for 0.5h at 37 ℃, and soaking in PBS for 5 times; FITC-labeled goat anti-rabbit IgG was added, incubated at 37℃for 0.5h, and washed 5 times with PBS; and observing under a fluorescence microscope. The results showed that JS/LG/21 inoculated wells showed specific green fluorescence (FIG. 1), and uninoculated wells showed no fluorescence, indicating that the isolate was African swine fever virus.

The JS/LG/21 sample is amplified by adopting a PCR or RT-PCR method to detect porcine circovirus type 2 virus, pseudorabies virus, porcine reproductive and respiratory syndrome virus and classical swine fever virus, and the results are negative.

The JS/LG/21 samples were tested for bacteria and mycoplasma by reference to the methods of the animal pharmacopoeia of the people's republic of China (2020 edition, three parts) annex 3306 and 3308, and the results were negative.

(2) Determination of erythrocyte adsorption (HAD) titers

The JS/LG/21 culture supernatants were serially diluted 10-fold with RPMI 1640 complete medium and inoculated in respective suspensions of RPMI 1640 complete medium containing 0.1% porcine red blood cells in PBMCs (porcine peripheral blood mononuclear cells) in 96-well plates. HAD was observed under a microscope daily for 7 consecutive days. The HAD titers were calculated using the Reed-Muench method. Unlike the 2021 report that the SD/DY-I/21 strain isogenic type I ASF viruses detected in China were all HAD negative, the JS/LG/21 strain HAD an HAD effect (FIG. 2) with a titer of 1×10 ^7.20 HAD ₅₀ /ml。

Example 3: genomic sequencing and genetic analysis

A series of ASFV genome fragments covering the whole genome are amplified by PCR by using a series of specific primers conserved among strains and a high-fidelity reaction system, sequenced by using a Sanger DNA sequencing method, and then the JS/LG/21 strain whole genome sequences are spliced.

Alignment was performed on all ASFV genomes using EINS-i in the program MAFFT v7, and phylogenetic trees were constructed using Gblocks-0.91 to exclude regions with ambiguous alignment. The complete genomic sequence of JS/LG/21 strain was mapped to ASFV genome using BLAST Ring Image Generator (BRIG) software. The complete genomic sequences of the JS/LG/21 strains were compared with the recombinant regions and Open Reading Frames (ORFs) of the gene type II virus HLJ/18 strain (Pic/HLJ/2018, genBank: MK 333180.1) and of the gene type I virus SD/DY-I/21 strain (Pic/SD/DY-I/2021, genBank: MZ 945537.1), respectively. By using4.1.8 and MEGAX, and the like.

Based on B646L gene sequence analysis, JS/LG/21 strain is genotype I. The homology of the EP402R gene and the HLJ/18 strain gene of the first separated gene type II virus in China is 100%, and the homology of the EP402R gene and the SD/DY-I/21 strain gene type I virus found in China is only 81%. It was shown that the B646L gene and the EP402R gene were derived from type I and type II viruses, respectively.

Genome-wide series assays and analyses showed that JS/LG/21 had genome lengths of 185431 base pairs (bps), respectively, containing 172 Open Reading Frames (ORFs). The invention carries out systematic evolution analysis on the JS/LG/21 genome series and 56 reference viruses of 8 different genotypes available in GenBank, and the result shows that the JS/LG/21 strain forms a unique branch in a phylogenetic tree and is between the viruses of the genotype I and the genotype II (figure 3).

The 20 genomic fragments (F1 to F20) were found to be alternately arranged as genotype I and genotype II fragments on JS/LG/21 in sequence, and the starting base positions and lengths of the 20 genomic fragments on JS/LG/21 strain were shown as table 1 together with homology and genotype data of the genomic fragments of HLJ/18 strain and SD/DY-I/21 strain. ASFV of georgia 07-like gene type II and NH/p 68-like gene type I have been detected in China. Their respective representatives are the gene type II virus HLJ/18 (GenBank: MK 333180.1) and the gene type I virus SD/DY-I/21 (GenBank: MZ 945537.1), both having nucleotide homology of 97.38%. Compared with SD/DY-I/21, the HLJ/18 genome has 21062bp of insertion, 4237bp of deletion and 3840bp of mutation. Both viruses had genotype-specific Single Nucleotide Polymorphisms (SNPs) in both the coding and non-coding regions of their genomes (FIG. 4). In order to determine the genomic characteristics of recombinant virus isolates JS/LG/21, the present invention performed recombinant analysis to determine the possible parents of the different fragments based on the specific SNPs of the type I and type II ASFV genes. The detailed comparison shows that 10 large discrete genomic fragments have genotype I specific SNPs (FIG. 4), with a correspondence of 99.36% -100% with the genomic fragments of SD/DY-I/21, but 71.28% -99.15% with the genomic fragments of HLJ/18 (Table 1). The other 10 discrete genomic fragments had genotype II specific SNPs (FIG. 4), with a correspondence of 99.95% -100% with the HLJ/18 genomic fragment and 27.50% -98.32% with the SD/DY-I/21 genomic fragment (Table 1). The total length of 10 fragments from genotype I was 80648bp, accounting for 43.51% of its genome, while the total length of 10 fragments from genotype II was 104694bp. It is noted that genotype determining genes B646L of JS/LG/21 strains are both located in fragment 9 (F9) from a genotype I virus, while the EP402R gene encoding CD2v is located in fragment 6 (F6) from a genotype II virus (FIG. 5). Thus, the JS/LG/21 strain is a complex recombinant virus with chimeric genomes of genotype I and genotype II ASFV.

In FIG. 3, the recombinant virus isolates were compared with the full genome sequences of 8 different genotype 56 reference ASFVs in the GenBank database, and phylogenetic trees were constructed using the maximum similarity sum IQ-tree. In FIG. 4, specific single nucleotide polymorphisms of the junction region of two recombinant fragments are shown, wherein the genome reference is based on SD/DY-I/21 strain. The whole genome of the recombinant ASFV was compared with the whole genome of the representative strains ASFV SD/DY-I/21 and Georgia 07-like gene type II, HLJ/18, using SnapGene software. In FIG. 5, a JS/LG/21 whole genome map was constructed using BLAST Ring Image Generator software, with open circles representing that derived from genotype I and closed circles representing that derived from genotype II.

TABLE 1 nucleotide homology alignment of the Gene fragment of recombinant Virus isolate JS/LG/21 with the corresponding fragment of Gene I and Gene II African swine fever Virus

Previous studies by the inventors have found that nucleotide mutations, insertions and deletions frequently occur in ASFVs, and that some changes result in changes in ORFs. Thus, the present invention compares the genome of JS/LG/21 strain with the genomes of SD/DY-I/21 and HLJ/18. The JS/LG/21 strain had 8 single nucleotide mutations in 6 ORFs of 4 different fragments, in which the non-coding region of F1 had 1 single nucleotide mutation, 4 single nucleotide deletion and 13 nucleotide deletion, compared to the homologous fragment of SD/DY-I/21. The JS/LG/21 has C deletion of MGF_110-13/14L, and has a unique single nucleotide mutation and 36 nucleotide deletion in the coding region. The JS/LG/21 strain had 2 single nucleotide insertions compared to the homologous genomic sequence of HLJ/18.

JS/LG/21 strain typical Gene sequence:

the B646L gene is positioned at positions 99,512-101,452 (gene I type and F9 fragment) of JS/LG/21 strain genome, and the coding sequence is as follows (SEQ ID NO. 1):

ATGGCATCAGGAGGAGCTTTTTGTCTTATTGCTAACGATGGGAAGGCCGACAAGATTATATTGGCCCAAGACTTGCTTAATAGCAGGATTTCTAACATTAAAAATGTGAACAAAAGTTATGGGAAACCCGACCCCGAACCCACTTTGAGTCAAATCGAAGAAACACATTTGGTTCATTTTAATGCGCATTTTAAGCCTTATGTTCCAGTAGGGTTTGAATACAATAAAGTACGCCCGCATACGGGTACCCCCACCTTGGGAAACAAGCTTACCTTTGGTATTCCCCAGTACGGAGACTTTTTCCATGATATGGTGGGCCACCATATATTGGGTGCATGTCATTCGTCCTGGCAGGATGCTCCGATTCAGGGCACGGCCCAGATGGGGGCCCATGGTCAGCTTCAAACGTTTCCTCGCAACGGATATGACTGGGACAACCAAACACCTTTAGAGGGCGCCGTTTACACGCTTGTAGATCCCTTTGGAAGACCTATTGTACCCGGCACAAAGAATGCGTACCGAAACTTGGTTTACTACTGCGAATACCCCGGAGAACGACTTTATGAAAACGTAAGATTCGATGTAAATGGAAATTCCCTGGACGAATATAGTTCGGATGTCACAACGCTTGTGCGCAAATTTTGCATCCCAGGGGATAAAATGACTGGATATAAGCACTTGGTCGGCCAGGAGGTATCGGTGGAGGGAACTAGTGGCCCTCTCCTATGCAACATTCATGATTTGCACAAGCCGCACCAAAGCAAACCTATTCTTACCGATGAAAATGATACGCAGCGAACGTGCAGCCATACCAACCCGAAATTCCTTTCACAACATTTTCCCGAGAACTCTCACAATATCCAAACAGCAGGTAAACAAGATATTACTCCTATTACGGACGCAACGTATCTGGACATAAGACGTAATGTTCATTACAGCTGTAATGGACCTCAAACCCCTAAATACTATCAGCCCCCTCTTGCGCTCTGGATTAAGCTGCGCTTTTGGTTTAACGAGAACGTGAACCTTGCTATTCCCTCGGTATCCATTCCCTTCGGCGAGCGCTTTATCACCATAAAGCTTGCATCGCAAAAGGATTTGGTGAATGAATTTCCTGGACTTTTTATACGCCAGTCGCGTTTTATACCTGGACGCCCCAGTAGACGCAATATACGCTTTAAACCATGGTTTATCCCAGGAGTCATTAATGAAATCTCGCTCACGAATAATGAACTTTACATCAATAACCTGTTTGTAACCCCTGAAATACACAACCTTTTTGTAAAACGCGTTCGATTTTCCCTGATACGTGTCCATAAAACGCAGGTGACCCACACCAACAATAACCACCACGATGAAAAACTAATGTCTGCTCTTAAATGGCCCATTGAATATATGTTTATAGGATTAAAACCTACCTGGAACATCTCCGATCAAAATCCTCATCAACACCGAGATTGGCACAAGTTCGGACATGTTGTTAACGCCATTATGCAGCCTACTCACCACGCAGAGATAAGCTTTCAGGATAGAGATACAGCTCTTCCAGACGCATGTTCATCTATATCGGATATTAGCCCCGTTACGTATCCGATCACATTACCTATTATTAAAAACATTTCCGTAACTGCTCATGGTATCAATCTTATCGATAAGTTTCCATCAAAGTTCTGCAGCTCTTACATACCCTTCCACTACGGAGGCAATGCAATTAAAACCCCCGATGATCCGGGTGCGATGATGATTACCTTTGCTTTGAAGCCACGGGAGGAATACCAACCCAGTGGTCATATTAACGTATCCAGAGCAAGAGAATTTTATATTAGTTGGGACACGGATTACGTGGGGTCTATCACTACGGCTGATCTTGTGGTATCGGCATCTGCTATTAACTTTCTTCTTCTTCAGAACGGTTCAGCTGTGCTGCGTTACAGTACCTAA

the B646L gene protein sequence is as follows (SEQ ID NO. 2):

MASGGAFCLIANDGKADKIILAQDLLNSRISNIKNVNKSYGKPDPEPTLSQIEETHLVHFNAHFKPYVPVGFEYNKVRPHTGTPTLGNKLTFGIPQYGDFFHDMVGHHILGACHSSWQDAPIQGTAQMGAHGQLQTFPRNGYDWDNQTPLEGAVYTLVDPFGRPIVPGTKNAYRNLVYYCEYPGERLYENVRFDVNGNSLDEYSSDVTTLVRKFCIPGDKMTGYKHLVGQEVSVEGTSGPLLCNIHDLHKPHQSKPILTDENDTQRTCSHTNPKFLSQHFPENSHNIQTAGKQDITPITDATYLDIRRNVHYSCNGPQTPKYYQPPLALWIKLRFWFNENVNLAIPSVSIPFGERFITIKLASQKDLVNEFPGLFIRQSRFIPGRPSRRNIRFKPWFIPGVINEISLTNNELYINNLFVTPEIHNLFVKRVRFSLIRVHKTQVTHTNNNHHDEKLMSALKWPIEYMFIGLKPTWNISDQNPHQHRDWHKFGHVVNAIMQPTHHAEISFQDRDTALPDACSSISDISPVTYPITLPIIKNISVTAHGINLIDKFPSKFCSSYIPFHYGGNAIKTPDDPGAMMITFALKPREEYQPSGHINVSRAREFYISWDTDYVGSITTADLVVSASAINFLLLQNGSAVLRYST

the MGF_505-1R (called MGF505-1R for short) gene is located at 23250-24845 (gene II type F2 fragment) of JS/LG/21 strain genome, and the coding sequence is as follows (SEQ ID NO. 3):

ATGTTCTCTCTCCAGAACTTATGTCGAAAAACATTACCTAACCGTAAACTTCCTGAATTTTTTGACGAATATATATTACAACTGCTGGGATTATACTGGGAAAACCATGGAACTATTCAACGAGCAGGAAACAACTGTGTGCTTATACAGCAACATACCCTCATTCCCGTAAATGAAGCCCTGAGAACAGCAGCATCTGAAGAAAATTATGAGATCGTGAGCCTTTTATTAGCGTGGGAGGGGAACCTTTACTATGCTATTATAGGGGCTCTAGAGGGCAACCGCCACGACTTAATTCGTAAATATGATGACCAAATCAAGGACCATCATGAAATTCTGCCATTCATTGACGATCCAGTCATATTTCACAAATGCCATATCATGCGGCAATGCTTTTTTGATTGTATTTTATATCAAGCTGTAAAATATAGTAAGTTTCGCGTTCTTCTTTACTTTAAACATAGATTAGAGGATGATTTGCCCTTCACTCATTTACTTATTGAAAAGGCATGTAAAGATCATAATTATGAAGTTATTAAATGGATATATGAAAACCTACATATCTACAATATGATAGATACCTTTGAATGTGCTATTGCCCATAAGGATCTACATCTATATTGTTTGGGGTATAGATTTATATATAACAGAATCGTACCCGATAAGTATCATCATTTAGATATTCGCATGCTTTCAAGCCTACAACTCCTACATAAGGTGGCAGCCAAAGGATACTTAGATTTTATCCTAGAAACCTTAAAGTATGATCATAATAAAGATAATATAAATATTATTCTAACACAAGCTGCAACCTATAACCATAGAAAAATTTTAATCTATTTCATTCCTCAATCAACCCACGCACAGATAGAACAATGTTTACTAGTGGCGATAAAAGCAAAATCTTCCAGGAAAACCTTGAACTTACTACTGTCTCACCTAAACCTTTCCATCAACCTCATCAAAAAAATAAGCCATTATGTTGCCACTTACAATTCAACAAATATAATAGGCATTCTGAGTATGCGGCGGAAAAAGAAGATATATTTAGATATCATATTGACAAAATTTGTAAAAAAAGCTATTTTTAATAAGTTTGTCGTTCGATGTATGGATACATTTTCTATAAACCCGGAAAGAATCCTTAAAATAGCCGCGCGAATAAATAGGATGATGTTAGTGAAAAAAATATCTGAACATGTTTGGAAAAATCATGCGGTTAGACTTAAATACCTTAAACATGCGGTACACACGATGAAGCATAAAGATGGGAAAAATAGACTCATGAACTTTATCTATGATCGCTGTTATTACCATATGCAAGGGGAAGAAATCTTTAGCCTCGCAAGATTTTATGCAATCCATCATGCACCAAAGTTGTTTGACGTTTTTTATGATTGTTGTATCCTAGATACGATACGATTCAAAAGCCTTCTTTTAGATTGTTCACATATCATAGGTAAAAACGCTCATGATGCTACCAATATCAACATCGTGAACAAGTATATCGGCAACCTGTTTGTTATGGGAGTTCTTAGCAAAAAAGAAATCTTACAGGACTATCCATCCATTTATTCTAAACAATACATGCCTTAG

the MGF_505-1R gene protein sequence is as follows (SEQ ID NO. 4):

MFSLQNLCRKTLPNRKLPEFFDEYILQLLGLYWENHGTIQRAGNNCVLIQQHTLIPVNEALRTAASEENYEIVSLLLAWEGNLYYAIIGALEGNRHDLIRKYDDQIKDHHEILPFIDDPVIFHKCHIMRQCFFDCILYQAVKYSKFRVLLYFKHRLEDDLPFTHLLIEKACKDHNYEVIKWIYENLHIYNMIDTFECAIAHKDLHLYCLGYRFIYNRIVPDKYHHLDIRMLSSLQLLHKVAAKGYLDFILETLKYDHNKDNINIILTQAATYNHRKILIYFIPQSTHAQIEQCLLVAIKAKSSRKTLNLLLSHLNLSINLIKKISHYVATYNSTNIIGILSMRRKKKIYLDIILTKFVKKAIFNKFVVRCMDTFSINPERILKIAARINRMMLVKKISEHVWKNHAVRLKYLKHAVHTMKHKDGKNRLMNFIYDRCYYHMQGEEIFSLARFYAIHHAPKLFDVFYDCCILDTIRFKSLLLDCSHIIGKNAHDATNINIVNKYIGNLFVMGVLSKKEILQDYPSIYSKQYMP

the MGF_505-2R (called MGF505-2R for short) gene is located at 28637-30217 (gene II type F2 fragment) of JS/LG/21 strain genome, and the coding sequence is as follows (SEQ ID NO. 5):

ATGTTTTCCCTTCAAGACCTTTGCCGAAAGCATCTTTTTATTCTTCCCGATGTTTTTGGCGAGCATGTACTACAACGATTAGGACTGTATTGGAGATGTCACGGCTCCCTTCAACGCATAGGAGACGACCACATACTCATACGACGGGATCTCATCCTTTCCACCAACGAGGCCTTAAGAATGGCGGGAGAGGAAGGAAACAATGAAGTAGTAAAGCTCTTGTTACTGTGGAAGGGAAATCTTCATTACGCCGTCATAGGAGCCTTGCAGGGTGATCAATATGACCTGATCCATAAGTATGAAAACCAAATCGGCGACTTTCATTTTATCTTACCATTGATTCAAGACGCGAATACGTTTGAAAAATGCCACGCTTTAGAACGTTTTTGTGGTGTTTCATGTCTGCTAAAACATGCTACAAAATACAACATGCTCCCTATTCTCCAAAAATACCAAGAAGAGCTGTCTATGAGAGCGTATCTTCACGAAACCCTATTTGAACTAGCATGCCTATGGCAGAGGTATGATGTCCTTAAATGGATAGAGCAAACCATACATGTTTACGACCTAAAGATTATGTTTAATATTGCCATCTCCAAGAGGGATCTGACTATGTACTCCTTAGGATATATTTTCCTTTTTGATAGAGGGAACACCGAAGCTACGTTGCTAACGCAACATCTCAAGAAGACAGCGGCCAAAGGGCTCCTCCACTTTGTGCTAGAAACGTTAAAATACGGCGGCAaCATAGATACCGTCCTGACCCAAGCCGTaAAGTACAATCATAGAAAACTTTTAGATTATTTTCTGCGTCAaCTACCTCGTAAACATATTGaAAAACTTTTGTTGCTGGCCGTGCAGGAAAAGGCTTCTAAAAAAACATTGAACTTACTGTTGTCACATTTAAACTACTCCGTGAAACGCATCAAAAAACTACCGCGCTATGTGATAGAGTACGAGTCCACCTTGGTGATAAAGATTTTATTAAAAAAAAGAGTGAACCTGATAGATGCCATGTTGGAAAAGATGGTAAGATATTTTTCTGCGACGAAAGTGAGGACGATCATGGATGAGCTTTCGATTAGTCCGGAAAGAGTCATTAAGATGGCTATACAGAAAATGAGAACGGATATCGTAATCCATACTTCTTATGTTTGGGAGGATGATCTAGAACGTCTTACTCGTCTTAAAAATATGGTATACACCATAAAGTACGAACATGGGAAAAAAATGTTAATTAAAGTCATGCACGGCATATACAAAAACTTAtTATACGGCGAAAGGGAAAAAGTCATGTTTTATTTAGCCAAGCTCTATGTTGCTCAAAACGCGGCCACCCAATTCAGAGACATTTGTAAGGACTGTTACAAACTGGATGTGGCACGGTTTAAACCGCGGTTTAAGCAACTAATATTAGACTGTTTAGAAATTATTACTAAAAAATCTTGCTATAGTATCCTGGAAATCTTAGAAAAACATATTATTTCCCTGTTTACTATGAAAGTTATGACTGAAGAAGAAAAAAACCTATGTTTAGAAATATTATATAAAGTAATTCATTATAAAACAATACAATGTTAA

the MGF_505-2R gene protein sequence is as follows (SEQ ID NO. 6):

MFSLQDLCRKHLFILPDVFGEHVLQRLGLYWRCHGSLQRIGDDHILIRRDLILSTNEALRMAGEEGNNEVVKLLLLWKGNLHYAVIGALQGDQYDLIHKYENQIGDFHFILPLIQDANTFEKCHALERFCGVSCLLKHATKYNMLPILQKYQEELSMRAYLHETLFELACLWQRYDVLKWIEQTIHVYDLKIMFNIAISKRDLTMYSLGYIFLFDRGNTEATLLTQHLKKTAAKGLLHFVLETLKYGGNIDTVLTQAVKYNHRKLLDYFLRQLPRKHIEKLLLLAVQEKASKKTLNLLLSHLNYSVKRIKKLPRYVIEYESTLVIKILLKKRVNLIDAMLEKMVRYFSATKVRTIMDELSISPERVIKMAIQKMRTDIVIHTSYVWEDDLERLTRLKNMVYTIKYEHGKKMLIKVMHGIYKNLLYGEREKVMFYLAKLYVAQNAATQFRDICKDCYKLDVARFKPRFKQLILDCLEIITKKSCYSILEILEKHIISLFTMKVMTEEEKNLCLEILYKVIHYKTIQC

the MGF_505-3R (called MGF505-3R for short) gene is located at the 30304-31146 (gene II type F2 fragment) of JS/LG/21 strain genome, and the coding sequence is as follows (SEQ ID NO. 7):

ATGTCCTCTTCTCTTCAGGAACTTTGTCGAAAAAAGCTGCCTGACTGCATACTTCCAGAGTTTTTTGACGACTATGTATTGCAACTGTTAGGACTGCACTGGCAAGATCATGGTTCCCTTCAGCGTATCGAGAAGAACCAGATACTTGTTCAACAGGAACCCATCCATATCAATGAAGCACTCAAAGTAGCAGCATCGGAAGGGAACTATGAAATCGTAGAGCTGTTGTTGTCATGGGAGGCAGATCCCCGCTACGCCGTCGTAGGAGCCCTAGAAAGCAAATACTATGACCTGGTTTACAAATACTATGACCAAGTTAAAGACTGCCATGATATCTTGCCGCTGATTCAAAATCCGGAAACATTCGAAAGATGTCATGAGTTAAACAGCACCTGTTCACTGAAATGCTTATTCAAGCATGCTGTGATAAATGACATGCTGCCGATTCTTCAAAAATATACAGACTATCTGGATAGGTGGGAGTATTGCAGCCAGATGCTGTTCGAACTGGCATGTAGTAAAAAAAAATATGAGATGGTTGTGTGGATAGAGGGAGTTCTAGGCGTCGGCAAAGTTACATCTCTTTTCACCATTGCGATTAGCAACAGAGACCTACAGCTGTATTCTCTGGGCTACTCAATTATCCTTGAGAATTTGTACTCCTGTGGACAGGACCCCAAGTTTTTACTAAATCATTTCCTGCGAGACGTTTCAATAAAAGGGCTTCTACCCTTTGTAATCAAAACCATAGAATATGGTGGAAGCAAGGAGATAGCCATAACTCTGGCTAAAAAATATCAGCATAAACATATTTTGAAATACTTCGAAACCTGGGAAAGCTAG

the MGF_505-3R gene protein sequence is as follows (SEQ ID NO. 8):

MSSSLQELCRKKLPDCILPEFFDDYVLQLLGLHWQDHGSLQRIEKNQILVQQEPIHINEALKVAASEGNYEIVELLLSWEADPRYAVVGALESKYYDLVYKYYDQVKDCHDILPLIQNPETFERCHELNSTCSLKCLFKHAVINDMLPILQKYTDYLDRWEYCSQMLFELACSKKKYEMVVWIEGVLGVGKVTSLFTIAISNRDLQLYSLGYSIILENLYSCGQDPKFLLNHFLRDVSIKGLLPFVIKTIEYGGSKEIAITLAKKYQHKHILKYFETWES

the JS/LG/21 strain MGF_360-12L (called MGF360-12L for short) gene is located at 24898-25950 (gene II type F2 fragment) of JS/LG/21 strain genome, and the coding sequence is as follows (SEQ ID NO. 9):

ATGTTGCCTTCCCTGCAATCTCTGACCAAAAAGGTGTTGGCTGGACAATGCGTGCCCACGAACCAACATTATCTTTTAAAGTGTTATGACCTATGGTGGCATGATGCTCCGATCACGTTTGATCATAACCTAAGGCTCATAAAATCAGCAGGTATTAAAGAGGGCTTAAACCTAAATACGGCGTTAGTGAAGGCTGTAAGGGAAAACAACTACAACCTTATAAAACTGTTTGCAGAGTGGGGGGCGGACATCAACTACGGGCTGGTATCTGTCAACACGGAGCACACCTGGGACCTCTGTCGAGAGCTAGGTGCCAAGGAAACCTTGAATGAAGAAGAAATTTTACAAATTTTTATAGATCTAAAGTTTCATAAAACTAGTAGTAACATTATTTTATGCCATGAGGTGTTTTCCAACAATCCGATATTACAAAAAGTAAATAATATAAAAATGAGGATAGAAATTTTCTGGGAGTTAAGGGAGTTAATAGTAAAAACCGATCTGCTAAATAATGAGTTTTCGCTCAGTACATTACTACTCAAATACTGGTACGCTATAGCCATACGCTATAACCTGAAAGAGGCCATACAGTATTTTTACCAAAAATATACACACCTGAATACGTGGCGGTTAACATGTGCTCTTTGTTTTAATAATGTGTTTGACCTTCATGAGGCGTATGAAAAGGACAAGATCCATATGGACATAGAAGAGATGATGCGGATCGCCTGCATCAAAGACCACAACCTTTCAACCATGTACTACTGCTATGTCCTGGGCGCCAACATCAATCAAGCCATGCTTAGCTCAATACAGTACTATAATATAGAAAACATGTTCTTTTGTATAGATCTGGGGGCTGATGTTTTCGAAGAGGGTACTACAGCTTTAGGGGAAGGGTATGAGCTTATAAAGAACATTTTATCCCTAAAGATTTATAGTCCGGCCACCACCCCGTTGCCTAAAAGCACGGACCCTGAAATCATAGATCATGCGTTAAAAAATTACGTTTCAAAAAATATGATGATCTTCCTTACCTATGATTTAAGATGA

the MGF_360-12L gene protein sequence is as follows (SEQ ID NO. 10):

MLPSLQSLTKKVLAGQCVPTNQHYLLKCYDLWWHDAPITFDHNLRLIKSAGIKEGLNLNTALVKAVRENNYNLIKLFAEWGADINYGLVSVNTEHTWDLCRELGAKETLNEEEILQIFIDLKFHKTSSNIILCHEVFSNNPILQKVNNIKMRIEIFWELRELIVKTDLLNNEFSLSTLLLKYWYAIAIRYNLKEAIQYFYQKYTHLNTWRLTCALCFNNVFDLHEAYEKDKIHMDIEEMMRIACIKDHNLSTMYYCYVLGANINQAMLSSIQYYNIENMFFCIDLGADVFEEGTTALGEGYELIKNILSLKIYSPATTPLPKSTDPEIIDHALKNYVSKNMMIFLTYDLR

the MGF_360-13L (called MGF360-13L for short) gene is located at the 26111-27172 positions (gene II type F2 fragments) of the JS/LG/21 strain genome, and the coding sequence is as follows (SEQ ID NO. 11):

ATGTCGTTGCCGCTCTCTCTGCAGACCCTCGTCAAAAAGACGATAGCCAGCCAGTGTTTGTCAATAGATGAACACTGCATTTTGAAATATTGTGGCCTATGGTGGCATGATGCTCCTCTCAAGCTTTGTATGGATCGTGGCCGAATACAAATAAAATCAGGATTTTTAGGAGAAGATATAGACCTTCGTGTGGCATTAATAATAGCTGTTAAGGAAAACAACTATAGTCTGATAAAGCTCTTTACAGAGTGGGGCGCAAATATCAACTATGGTTTGCTTTCTATCAATACGAAGCACATCCGAGAGTTGTGTAGACAGCTAGGCGCCAAAGAAACTCTAGAGGACAACGATATTTTCCGTATTTTTACCAGGATAATGCACAATAAAACCAGCGGCAGTATTATTTTGTGCCATGAAATTTTTATGAATAATCCTATTTTAGAAAACAAATTTGTTATACAATTAAGGGGCTTAATTTATAAAAGACTATGGGGGCTCATAGAAATAAAAGAAACGGACGAGTTAAATGGTTTACTAGTGAAGTATTGGTACGCCAAAGCAGTACAATACGATTGTAAGGACGCCATTTGTTTTCTAGATGAGAAATATACGGATCTTAATGAATGGCGATTAAAATGTCTCCTGTATTATAACAAAATATATGAGCTTCATGAGATGTACCACAAGGAAAACATCCAAATAGACGTCCATGACATGATATGTCTGGCTTCTACCAAGGATAACAATCCATTAACAATATATTACTGTTACGCGCTGGGGGGCAACATCAACCAAGCTATGCTTACTTCAGTACAATATTATAACATCGGTAATATATTTTTCTGTATAGATTTGGGTGGTAATGCCTTtGAAGAGGGTCGTGCCATAGCGGAACAAAAAGGTTATAATTTTCTGAGCCATAGTTTGGCTTTGGATATTTACAGCTCAGATGCTTCCTTGCCACTAAACTTAAAGGACCCCGAAGAAATAAGCAGTTTATTAAAAGATTATAAATCAAAAAACTTATCCATCATTTGGGAATATTCTCATAATATACTATAG

the MGF_360-13L gene protein sequence is as follows (SEQ ID NO. 12):

MSLPLSLQTLVKKTIASQCLSIDEHCILKYCGLWWHDAPLKLCMDRGRIQIKSGFLGEDIDLRVALIIAVKENNYSLIKLFTEWGANINYGLLSINTKHIRELCRQLGAKETLEDNDIFRIFTRIMHNKTSGSIILCHEIFMNNPILENKFVIQLRGLIYKRLWGLIEIKETDELNGLLVKYWYAKAVQYDCKDAICFLDEKYTDLNEWRLKCLLYYNKIYELHEMYHKENIQIDVHDMICLASTKDNNPLTIYYCYALGGNINQAMLTSVQYYNIGNIFFCIDLGGNAFEEGRAIAEQKGYNFLSHSLALDIYSSDASLPLNLKDPEEISSLLKDYKSKNLSIIWEYSHNIL

the MGF_360-14L (called MGF360-14L for short) gene is located at 27568-28431 (gene II type F2 fragment) of JS/LG/21 strain genome, and the coding sequence is as follows (SEQ ID NO. 13):

ATGTTGTCTTTACAAACGTTGGCCAAAAAAGTTGTGGCATGCAATTATCTTTCAAGTGACTATGATTATACGTTGCAGCGTTTTGGTTTGTGGTGGGATTTAGGTCCTATTCACCTATGTAACAATTGTAAGCAAGTTTTTTCGTATAAACATTTACAGTGTTTTTCTGAGGATGATCTTTGTCTCGAAGCGGCGCTAGTAAAGGCCGTGAAGAGCGATAATCTTGAACTTATACGTTTATTTGTGGATTGGGGCGCAAATCCTGAATATGGGCTTATACGTGTTCCTGCCGTGTATCTAAAGCGGCTGTGTGCGGAACTGGGAGGCTTAACGCCTGTATCCGAACCCCGTCTTCTGGAAATTTTAAAAGAAGTGGCCAGGCTAAAATCCTGTGCAGGAGTTCTGCTGGGTTATGACATGTTTTGTCATAATCCACTCTTGGAAACCGTAACTAGAACCACTTTAGACACAGTTACGTACACCTGTTCAAACATTCCGTTGACGGGGGATACGGCGCACCACCTATTAACAAAGTTTTGGTTTGCCCTGGCATTACGACATAATTTTACAAAGGCTATTCACTATTTCTATAAAAGGCATAAAAATCACCTCTATTGGCGGGTAGCTTGTAGCCTTTATTTTAATAACATTTTTGACATACACGAGTTGTGTCGTGAAAAAGAGATTTGCATCAGCCCTAATCTGATGATGAAATTTGCTTGCTTGCGGGAAAAAAATTACGCGGCCATTTATTACTGTCATAGGTTGGGGGCTAGTCTCGATTATGGCATGAATCTTTCTATCTATAACAATAATACTTTAAACATGTTTTTCTGTATTGATTTGGGGGGCTGCCGATTTTGAMGF-360-14L Gene protein sequence the following (SEQ ID NO. 14):

MLSLQTLAKKVVACNYLSSDYDYTLQRFGLWWDLGPIHLCNNCKQVFSYKHLQCFSEDDLCLEAALVKAVKSDNLELIRLFVDWGANPEYGLIRVPAVYLKRLCAELGGLTPVSEPRLLEILKEVARLKSCAGVLLGYDMFCHNPLLETVTRTTLDTVTYTCSNIPLTGDTAHHLLTKFWFALALRHNFTKAIHYFYKRHKNHLYWRVACSLYFNNIFDIHELCREKEICISPNLMMKFACLREKNYAAIYYCHRLGASLDYGMNLSIYNNNTLNMFFCIDLGGCRF

EP402R gene (encoding CD2v protein) is located at positions 68885-69967 (gene type II F6 fragment) of JS/LG/21 strain genome, and the encoding sequence is as follows (SEQ ID NO. 15):

ATGATAATACTTATTTTTTTAATATTTTCTAACATAGTTTTAAGTATTGATTATTGGGTTAGTTTTAATAAAACAATAATTTTAGATAGTAATATTACTAATGATAATAATGATATAAATGGAGTATCATGGAATTTTTTTAATAATTCTTTTAATACACTAGCTACATGTGGAAAAGCAGGTAACTTTTGTGAATGTTCTAATTATAGTACATCAATATATAATATAACAAATAATTGTAGCTTAACTATTTTTCCTCATAATGATGTATTTGATACAACATATCAAGTAGTATGGAATCAAATAATTAATTATACAATAAAATTATTAACACCTGCTACTCCCCCAAATATCACATATAATTGTACTAATTTTTTAATAACATGTAAAAAAAATAATGGAACAAACACTAATATATATTTAAATATAAATGATACTTTTGTTAAATATACTAATGAAAGTATACTTGAATATAACTGGAATAATAGTAACATTAACAATTTTACAGCTACATGTATAATTAATAATACAATTAGTACATCTAATGAAACAACACTTATAAATTGTACTTATTTAACATTGTCATCTAACTATTTTTATACTTTTTTTAAATTATATTATATTCCATTAAGCATCATAATTGGGATAACAATAAGTATTCTTCTTATATCCATCATAACTTTTTTATCTTTACGAAAAAGAAAAAAACATGTTGAAGAAATAGAAAGTCCACCACCTGAATCTAATGAAGAAGAACAATGTCAGCATGATGACACCACTTCCATACATGAACCATCTCCCAGAGAACCATTACTTCCTAAGCCTTACAGTCGTTATCAGTATAATACACCTATTTACTACATGCGTCCCTCAACACAACCACTCAACCCATTTCCCTTACCTAAACCGTGTCCTCCACCCAAACCATGTCCGCCACCCAAACCATGTCCTCCACCTAAACCATGTCCTTCAGCTGAATCCTATTCTCCACCCAAACCACTACCTAGTATCCCGCTACTACCCAATATCCCGCCATTATCTACCCAAAATATTTCGCTTATTCACGTAGATAGAATTATTTAA

the EP402R gene protein sequence is as follows (SEQ ID NO. 16):

MIILIFLIFSNIVLSIDYWVSFNKTIILDSNITNDNNDINGVSWNFFNNSFNTLATCGKAGNFCECSNYSTSIYNITNNCSLTIFPHNDVFDTTYQVVWNQIINYTIKLLTPATPPNITYNCTNFLITCKKNNGTNTNIYLNINDTFVKYTNESILEYNWNNSNINNFTATCIINNTISTSNETTLINCTYLTLSSNYFYTFFKLYYIPLSIIIGITISILLISIITFLSLRKRKKHVEEIESPPPESNEEEQCQHDDTTSIHEPSPREPLLPKPYSRYQYNTPIYYMRPSTQPLNPFPLPKPCPPPKPCPPPKPCPPPKPCPSAESYSPPKPLPSIPLLPNIPPLSTQNISLIHVDRII

the B602L gene, blast per identity, is 98.21% at the highest and is located at positions 96,225-98 and 201 (gene I and F9 fragments) of the JS/LG/21 strain genome, and the coding sequence is as follows (SEQ ID NO. 17): .

ATGGCAGAATTTAATATTGATGAGCTTCTCAAAAACGTATTGGAGGATCCCTCTACTGAAATATCCGAAGAAACGCTTAAACAGCTTTATCAAAGGACGAACCCTTACAAACAGTTCAAAAATGATAGCAGGGTGGCCTTTTGCTCTTTTACAAATTTGCGGGAGCAGTATATTCGACGTCTTATAATGACTAGCTTTATTGGATATGTCTTCAAAGCTCTGCAGGAATGGATGCCTTCCTATTCAAAACCTACCCACACGACCAAAACTCTTCTCAGTGAGCTAATAACGTTAGTTGATACTTTGAAACAGGAAACTAATGATGTTCCCTCTGAATCGGTAGTAAATACAATTTTATCTATAGCGGATAGCTGCAAAACCCAGACGCAGAAAAGCAAGGAAGCTAAAACAACGATCGATAGCTTTTTACGAGAACATTTTGTGTTTGATCCTAATCTTCATGCTCAAAGTGCGTATACTTGTGCAAGCACTTGTGCAGATACCAATGTAGACACCTGTGCAAGCACTTGTGCAAGCACTTGTGCAAGCACTTGTGCAAGCACTTGTGCAAGCACTTGTGCAAGCACTTGTGCAAGCACTTGTGCAAGCACTTGTGCAAGCACTTGTGCAAGCACTTGTGCAAGCACTTGTGCAAGCACAGGTGCAAGCACAGGTGCAAGCACTTGTGCAGATACCAATGTAGACACCTGTGCAAGCACTTGTGCAGATACCAATGTAGACACCTGTGCAAGCACTTGTGCAAGCACTTGTGCAAGCACTTGTGCAAGCACTTGTGCAAGCACAGGTGCAAGCACTTGTGCAGATACCAATGTAGACACCTGTGCAAGCACTTGTGCAGATACCAATGTAGACACCTGTGCAAGCACTTGTGCAGATACCAATGTAAACACTTGTGCAAGCATGTGTGCAGATACCAATGTAGACACCTGTGCAAGCACCTGTGCAAACACCTGTGCAAGCACAGAATACACCGATTTAGCAGATCCTGAGCGCATCCCTTTACACATCATGCAAAAAACATTAAATGTGCCTAATGAGCTTCAGGCCGATATTGATGCAATTACCCAAACCCCACAGGGCTATAGGGCAGCAGCCCACATATTACAAAATATAGAACTTCATCAAAGCATTAAACATATGCTTGAAAATCCGAGGGCGTTTAAACCCATTCTCTTTAACACAAAAATTACTAGATATCTTTCGCAGCATATTCCACCTCAGGATACTTTTTATAAGTGGAATTATTACATTGAGGATAATTACGAAGAGTTGCGGGCCGCTACGGAAAGCATCTACCCAGAAAAGCCCGACCTAGAGTTTGCCTTCATTATTTATGATGTGGTGGATAGCAGCAACCAACAAAAGGTTGATGAATTTTATTATAAATATAAAGACCAGATTTTCTCAGAGGTTTCATCCATTCAATTAGGCAACTGGACACTCCTGGGAAGCTTTAAGGCCAACAGAGAGCGCTACAATTATTTTAATCAAAATAATGAAATAATAAAACGGATTTTGGACCGTCATGAGGAAGACCTAAAGATAGGAAAAGAGATTCTACGAAATACCATTTACCACAAAAAAGCAAAAAATATACAAGAAACCGGCCCGGATGCTCCGGGGCTCTCCATCTATAATTCAACCTTTCACACGGATAGCGGGATTAAGGGACTGCTTTCCTTTAAGGAGCTAAAAAACCTAGAAAAAGCATCTGGAAATATCAAAAAAGCTCGAGAGTATGATTTTATAGACGACTGCGAAGAAAAAATTAAGCAACTGCTTAGTAAAGAAAATTTAACCCCCGATGAAGAAAGCGAGCTGATAAAAACAAAAAAACAGTTAAATAATGCGCTTGAAATGCTCAATGTGCCTGATGATACGATACGGGTAGATATGTGGGTCAACAATAATAATAAACTCGAAAAAGAAATTTTATATACAAAAGCAGAATTGTAA

The C122R gene, blast per identity, is up to 99.69%, and is located at positions 79,743-80,060 (genotype I, F7 fragment) of the JS/LG/21 strain genome, and the coding sequence is as follows (SEQ ID NO. 18):

ATGAAAATTTGTAAGGCTTGCAGTTCTTGTATGGTCAGAACCTATGTCGATGGAAACATTATTTTTCGCTGCAGCTGCGGCGAAAGCGTTCAAGGGGATAGTCAAAACTTGCTCGTCTCTAGCAAGGTGTACCACACCGGGGAAATGGAAAATAAGTACAAGATTTTTATTAAAAATGCACCCTTTGACCCCACGAATTGCCAAATAAAAAAGGATTGCCCGAATTGTCATTTAGACTATTTGACACAAATCTGTATTGGAAGCCAAAAAATCATTATATTGGTGTGCCGCTGTGGCTATATGAGCAACAGAGGATAA

the JS/LG/21 strain D345L gene, blast per identity is up to 99.81%, is located at 140,959-141,996 (genotype I, F17 fragment) of the JS/LG/21 strain genome, and has the following coding sequence (SEQ ID NO. 19):

ATGGAAACCTTTGTACGCCTGTTTAAAGACTCTCCTCAGCAGCGCTCCGATGCCTGGCATGCTATTCGTCGCACTCAGGTGGGTGGCTCTGACCTTGCTAGCGTTTTAGGTTTAAACCCTTACAAAAGCTATTATATAATCTTGGCGGAAAAAGCAAATCTTTTTAAGAAGAATTTGAACCGCGCTGCTTGTAGCTGGGGAACCCTTTTTGAGCGAGTTAGTAAAGATCTGCTTGAGTTGTTCTGCCAAACCACCGTCATAGGTGACAATATTCATATTGATGGGACCTATTTGGGATACCCCGGACATAGTAATAGCCCCGATGGGTTTTGTCACCTAACGCTGGGATACACTCAACAGTCCTGGGAAATCAAAACAATTTTTAACAACGTACGCTATGAGGCCACGAAACGCATCCCCGTGCTGGTAGAAATAAAGTCCCCATTCAACCGAAAAATAAAAAACTCGGTGCCCTCCTACTATATGCCGCAAATACAATCCGGTCTTGCCCTTTCGCCGCCTATCTCTATGGGCATCTACGTCGAGGCCATGTTTCGCGTGTGCGGCATTCATCAGCTGGGATCGAATAATGAGACCAATACGGATATCCACCCTCCAGAGTCCATGCTCCCGCTTGCCTGGGGAATCATCACGATCTGCTCTACACAGGAGCACACCGAGGCTCCTCAAGATTTTGGCACGCTCGACGCGGAAACATTTCGCCAACTACTTGAAACGCTGTATCAAAAAGATCAGTACACTATTCACTATTCTATGCCTTATGAAACCGCGTGTCCCGAAATGCCAAATGTGGTTGGCTACTTTGGATGGAAGGTCTTTATCTTTCAAATAATTCCAGTTATGAAACATCCCCAGTTTTTAAAAGACAAATATCCCATCATACAACAGTTCTTACGTGACCTACATACTATTAAAGCCTCGCCATCTCCCATGGAGACGTATGAAAAAATCTGCTGCTCAGAGGAAAGCGCTCTATCCACAGAGGACATCGACAATTTTACAGATATGCTTACTTAG

MGF_100-1L gene, blast per identity, up to 99.77%, located at 175,428-175,853 (genotype II, F20 fragment) of the JS/LG/21 strain genome, encoded by the following sequence (SEQ ID NO. 20):

ATGGGAAACAAAGAAAGTAAGTATCTGGAGATGTGCTCGGAAGAAGCATGGTTAAACATTCCCAATATTTTCAAATGCATTTTCATAAGAAAACTGTTTTATAACAAATGGCTTAAATACCAGGAAAAAAAACTAAAAAAGAGTTTGAAACTGCTGAGTTTTTACCATCCCAAAAAAGATTTTGTAGGAATAAGAGACATGCTACAAATGGCTCCAGGAGGATCTTATTTTATTACAGATAATATGACTGAGGAGTTTTTAATGTTAGTTGTAAAGCATCCAGAAGATGGGAGTGCTGAGTTTACTAAATTATACCTTAAAGGAAGTTGCATTGTGATTGATGGATACTACTATGATAATCTTCATATCTTTATTTCAGAAACTCCTGATATATACAAATATCCCTTGATTCGTTATGATAGATAA

the I9R gene, blast per identity, is up to 99.68%, located at 177,653-177,964 (genotype II, F20 fragment) of the JS/LG/21 strain genome, and has the following coding sequence (SEQ ID NO. 21):

ATGGGAACTTTTTCAGTAACTGCCTCTGCAAAAAGTGACGATGCTGTTTGTAAGTATTTAGAAGAACCAATAGATGAAAATTACAGAAACATATTAAGAAATGAGCATGTTAAAAAAAATTTAAATGAGGCTCTGAATCGACATATTACTACCTATAATCCAGTAGTTGATTGGTGTAATAACTATTCAACATTTTCATCTCAGGATTTCGATGAATATAAAATTTATATACATAGCGATCTTATGGATGGACGACCTCGTCCAAAAAAAAACATGGTGTGTCATCATGTAATGTTTGTTAGTTTTATATAA

the NP1450L gene, blast per identity, was 99.86% at the highest, located at position 124,998-129,350 (genotype I and genotype II linker portions spanning F12 and F13) of the JS/LG/21 strain genome, and the coding sequence was as follows (SEQ ID NO. 22):

ATGGAGGCTGGATATGCCGAAATAGCCGCCGTTCAGTTCAATATTGCCGGTGACAATGACCATAAGAGGCAAGGCGTTATGGAGGTTACCATTTCTAATTTATTTGAGGGCACCCTTCCCGCCGAGGGGGGTATCTATGATGCGCGAATGGGAACCACCGATCACCATTATAAATGCATCACTTGCTCACACCAGCGCAAGCAATGTATGGGACACCCTGGGATACTGCAGATGCATGCTCCGGTGCTTCAGCCGCTCTTCATCGCCGAAATACGACGATGGTTAAGGGTTATATGCCTCAACTGCGGGGCTCCCATTGTTGACCTAAAGAGGTACGAGCATCTTATTAGGCCTAAGCGTCTTATTGAAGCGGCTTCAAGCCAAACCGAAGGAAAGCAGTGCTACGTCTGTAAGGCAGTACACCCCAAAATTGTTAAGGACTCGGAAGATTATTTTACCTTTTGGGCGGATCAGCAGGGCAAGATTGACAAACTGTACCCGCAGATCATCAGAGAGATTTTTTCGCGCGTAACCTACGACACCGTTGTAAAACTGGGGCGAAGTAAAAACTCCCATCCCGAAAAACTTGTGCTTAAGGCCATTCAGATCCCCCCCATCAGCATACGACCTGGCATCAGATTGGGAATCGGGTCAGGCCCCCAAAGCTTTCACGACATTAACAACGTGATTCAGTATCTGGTTCGAAAGAATCTGCTGATCCCGAAGGACCTACAAATCGTGCGCGGCCAAAAAATACCTTTAAATATTGACCGCAATTTGCAAACCATACAGCAACTTTACTATAACTTTTTGTTGGATTCCGTTTCCACCACCGCAACCCAGGGAGGCACGGGAAAGCGTGGGATCGTCATGGGGGCACGCCCTGCTCCCTCCATCATGCGAAGACTTCCTCGCAAGGAGGGAAGAATTCGTAAATCCCTACTGGGCAGCCAGGTATGGTCGATCAGCCGGTCCACCATCTGCGGGAACTCAGACCTTCACCTGGACGAGGTTGGCTATCCCATTTCCTTTGCACGAACGCTGCAAGTTGCGGAAACAGTGCAACATTATAATATTAATAGATTAATGCCCTATTTTTTAAATGGAAAGCGCCAGTACCCTGGTTGTTCAAGAGTGTATAAGCAAATAACACAATCCGTTCACGACATTGAGGGTCTCAAACAAGACTTTAGGCTGGAGGTAGGAGACATCCTTTACCGTGACGTCGTCACTGGCGACGTCGCGTTTTTTAATCGCCAGCCTTCTCTCGAACGAAGCAGCATAGGGGTTCACCGGATTGTCGTTTTTGAAAACCCAAAAATTTCTACGTTTCAAATGAATGTCAGCGCATGTGCCTGGTATAATGCGGACTTTGACGGGGATCAGATGAATCTCTGGGTTCCCTGGAGCGTCATGAGCCGCGTTGAGGCCGAACTACTTTGTTCTGTGCGAAACTGGTTCATTTCCACAAAGAGCTCGGGTCCCGTTAATGGGCAGGTGCAGGACTCCACGGTGGGAAGCTTTTTGCTTACACGCACGAACACCCCCATGGGGAAAAATGTGATGAACAAGCTGCACGCCATGGGGTTGTTTCAAACAACCCAAACCGACCCACCTTGTTTTGCCAACTACTCCCCAACTGACCTGCTGGATGGCAAATCGGTTGTATCTATGCTACTGAGGCAGACCCCCATCAATTATCAACGAGCCCCCACATGGTACTCAGAAGTGTATGCACCCTACATGCATTATAACAAGCAGGACATCTCTACACAAATACGCAACGGCGAACTCATTGAAGGCGTCCTTGACAAAAAGGCCGTCGGAGCGGGTTCCTCCGGTGGAATCTATCACCTTATTTCGCGTAGGTATGGGCCGCAGCAGGCCTTGAAAATGATATTTGCGACCCAGCAGCTCGCCCTAAACTACGTGCGCAACGCCGGATTCACAGTGTCCACGGCCGACATGCTCCTAACCCCGGAGGCACATCAGGAGGTCCAAGAAATTATCAATGAACTGCTGCTTGAGTCGGAGGAAATAAACAACCGGCTGCTTCATGGAGACATCATGCCGCCTATAGGCCTGACAACGCATGACTTCTACGAAAAATTGCAGCTGAATGCGCTTAAATTTCCCGATAGAATTTTAAAGCCGATTATGAATTCCATTAATCCGGAAACCAATGGGCTTTTTCAGATGGTGGCCACTGGCGCCAAGGGCTCAAACCCCAATATGATTCACATCATGGCGGGCATCGGCCAAATTGAAATTAATACACAACGCATTCAACCCCAGTTTTCCTTCGGTAGGACCCTGGTGTACTACCCCAGGTTTGCCCTGGAGGCGCAGGCCTACGGGTTCATCTGCAACAGCTATATTGCGGGCCTTACCTCCCCTGAATTTATCTTTGGGGAAATGAATGGAAGATTCGACTTGATCAACAAAGCATTATCGACATCATCCACAGGCTATGCCAACCGTAAAGCCATCTTTGGCCTTCAATCCTGTATTGTGGATTATTACCGACGGGTTTCCATCGATACGCGTCTTGTGCAGCAGTTGTACGGAGAGGACGGCCTTGATGCGCGCCAGCTTGAAACCGTACGGTTTGAAACCATCATGCTGTCGGACCAGGAACTTGAAGACAAATTCAAGTACACCGGGATACAATCGCCCTTGTTTGAAGAAGAATTTTCACGCCTTAAAAAGGATAGAGATAAATATCGACAGATCTTCCTAAACGTCGAAAATTTTAATTTCAGTCAGCTGCTTACAGATGTTAGACAGGTGCCGGTAAACGTGGCCAGCATCGTAAAAAACATTCTACTGAGCTCCACCAGTGGCGTGCTTCCCTTCGACGAAAAAAGTATTCTACAAAAATACGCGATGGTCAAAACGTTTTGCAAAAATCTTCCATACGTGTTTATTAACAACATTCAGGAACGACTACAAACGCCCATACCCGTTTATCTTAAACGGGCTGCCTCTCTGATGCGCATGCTTATTCGCATCGAACTGGCAACCGTTAAAACATTAAACATTACCTGCGAGCAGATGAGTGCCATCCTGGACCTCATAAGGCTACAATATACTCAAAGTCTTATTAACTACGGTGAGGCAGTGGGAATCCTGGCGGCGCAGTCCGTATCAGAGCCCTTGACACAATATATGCTGGACTCCCACCACCGGTCCGTGGCCGGGGGAACCAACAAGTCGGGAATTGTGCGGCCCCAGGAGATCTTTAGCGCGAAGCCCGTAGAGGCTGAACAATCCTCTGAAATGCTTTTACGTCTAAAGAACCCGGAAGTGGAAACAAATAAAACATATGCGCAAGAAATTGCTAACAGCATAGAGCTTATAACGTTCGAACGGTTGATATTGCAGTGGCACCTATTGTACGAAACGTATTCAAGCACAAAAAAAAATGTGATGTACCCCGATTTTGCAAGTGATGTGGAATGGATGACGGATTTTCTGGAAAACCATCCTCTACTACAGCCCCCAGAGGATATTGCAAACTGGTGTATCCGCTTGGAATTAAACAAAACAACCATGATATTAAAAAGCATTAGTCTAGAAAGTATTATTAATAGTCTAAGAGCTAAACACCCCAACACCTACATCATGCATTCTGTGGAAAACACGGCCTCAGGGATTCCCATCATTATTCGCATATACCTACGGGAAAGCGCCTTTAGACGCAGTACCAATACCCGAATGGCTACGGATGAAAAAATTGCCGTAAATGTGGTGGATAAACTATTAAATAGCACGATTAGAGGAATACCAGGCATCAAAAATGCGAATGTTGTTAAGCTTATGCGCCACCGTGTGGATGCCCAGGGGAAACTGGTAAGACTAGACAATATCTACGCCATCAAAACAAACGGGACTAATATTTTTGGCGCAATGCTTGATGATAACATCGACCCATACACCATCGTATCGTCCTCTATAGGAGACACCATGGAGCTTTACGGCATAGAAGCGGCACGGCAAAAAATTATTAGTGAAATTAGAACGGTTATGGGGGACAAGGGTCCCAACCATCGTCATTTACTCATGTACGCAGATCTCATGACAAGAACGGGACAGGTTACCTCTCTAGAAAAGGCAGGGCTTAATGCAAGAGAGCCTTCCAACGTGTTGTTGCGAATGGCCTTGTCGTCTCCAGTCCAGGTCTTGACAGATGCTGCGGTTGACTCCGCCGTGAATCCCATTTACGGTATTGCCGCGCCTACCCTTATGGGCTCTGTTCCTCGCATAGGGACCATGTACTCTGACATCATTATGGATGAAAAATATATTACGGAAAATTATAAAAGTGTTGATTCCTTGATTGATATGTTATAG

MGF_360-8L gene, blast per identity up to 99.69%, located at positions 18,557-19,516 (genotype I and genotype II linker portion, spanning F1 and F2) of the JS/LG/21 strain genome, the coding sequence is as follows (SEQ ID NO. 23):

ATGCTCTCCTTGCAAACCCTGGCCAAAAAGGCTGTGGCCAAACAGAGCGTGCCTGAGGAGTATCATTATATTTTAAAATATTGTGGCTTATGGTGGCAAAACAAGCCCATTAGCTTATGTCACTACTGTAATTACGTTATTTTAAGCTCAACCCCCTTTAAGGGGGAACTTCTTCATCTTGATGTGGCATTAATCATGGCCATAAAAGAAAATAACTATGACGTAATAAGGCTGTTCACCGAGTGGGGAGCAAACATTTATTATGGGCTGACCTGTGCTAGGACGGAACAAACTCAGGAGCTGTGTCGAAAGTTAGGAGCTAAAGATGGTTTAAATAATAAGGAAATTTTCGCCGGTTTAATGCGTCATAAAACGAGTAATAACATTATTTTATGTCATGAAATATTTGATAAAAATCCTATGTTGGAAGCTCTAAATGTGCAGGAAATGGGAGAGGAGATTCATCGAGAGTTAAAGCTTTTCATATTTTATATCTTGGATAATGTACCCATGAACATATTCGTTAAATACTGGTATGCCATAGCAGTAAAATATAAGCTTAAAAGAGCTATCTTCTTTTTCTATCAAACATATGGGCACCTTAGTATGTGGCGACTCATGTGCGCCATTTACTTCAACAATGTATTTGACCTTCATGAAATATACGAGCAAAAGATCGTTCATATGGACATCGATAAAATGATGCAGTTGGCTTGTATGCAAGATTACAACTTTTTAACGATATACTACTGTTTTGTCTTGGGAGCTGATATTGATCAAGCCATCACTGTAACACAGTGGCATTATCATACGAACAATCTATATTTTTGTAAGGATTTAAAGGATCTTAAGCAAAATACTTTAACGGCACGTCCTCTTTTATTACCTAATATAACGGATCCTAAAAAAATATATACCATGTTAAAAAATTACCTACCAACATCGTCAAATTCTCTATGA

MGF_505-5R gene, blast per identity, 99.53% at the highest, is located at positions 32,863-34,359 (the junction part of genotype I and genotype II, spanning F2 and F3) of the JS/LG/21 strain genome, and has the following coding sequence (SEQ ID NO. 24):

ATGTTCTCCCTCCAGGAGATCTGTCGAAAGAACATCTACTTTCTACCTGACTGGCTCGGTGAGCATGTGATTCAGCGACTAGGTCTGTACTGGGAAAAACATGGTTCTCTTCAGCGAATCGGAGACAACTATGTACTTATACAACAGGACCTCATCATCCCCATCAATGAAGCCCTAAGAATGGCAGGGGAGGAGGGGAATGATGAGGTGGTACAACTCCTATTACTATGGGAGGGAAACATTCATTATGCCATCATAGGAGCTTTGGAGAGTGACCATTATAGCCTAATACGTAAGCTCTATGACCAAATCGAAGACTGTCACGACATCCTTCCCTTGATTCAAGACCCAAAACTCTTTGAAAAATGCCATGAATTAGATAAATCTTGTAACATTTTATGTCTCGTATTACACGCCGTAAAAAACGATATGCTTTGCATTCTTCAAGAGTATAAAATGCATCTAAGTGGAGAGGATATTCAAGTGGTGTTTGAAACAGCATGCCGTTCACAAAAAAACGATATTGTGTCATGGATGGGACAAAATATTGCAATATACAACTCCGGAGTTATTTTTGATATTGCCTTTGATAAGATGAATGTGTCCTTATTATCTATAGGGTACACGCTTCTTTTCAATCATCATATAAATAATACGAACGAAAATATTAATTCTTTATTGACACAACATCTTGAATGGGCTGCCGGCATGGGCCTTCTTCATTTTATGCTGGAAACTTTAAAGTATGGCGGGGATGTAACGATAATAGTTTTGTCTGAGGCCGTAAAATATGACCACAGAAAGATTTTAGATTATTTTCTCCGTCGAAAAAACTTGTACCAAGAAGATCTTGAAGAACTATTATTGTTGGCGATACGTGCAGATTGTTCTAAAAAGACCTTAAACTTGTTATTATCTTACTTAAACTATTCCATAAACAATATCCGTAAAAAAATATTACAATGTGTAAAAGAATATGAAACGACCGTTATTATAAAAATTCTATGGAAAAGAAAGATAAATCTGATAGAGCCCATTTTGGCAGACTTTATAGGATATCATAGCTATACCTATATGGTAGATTTTATGCGCGAGTTTTCCATCCATCCGGAAAAAATGATCAAAATGGCTGCGCGAGAATCGAGGGAGGACTTAATCATAAAATTTTCCAAAAAAGTTTGCAAAGAGCCTAAAGATAGACTTCACTATCTCAAAAGCTTAGTGTATACTATGCGACATAAAGAAGGCAAACAACTGTTAATTTATACAATCCATAACTTATACAAAGCTTGTCATCTAGAGAGTAAAGAAATGTTTAATTTGGCACGATTTTATGCACGGCATAATGCAGTGATCCAGTTCAAATCGATTTGTCACGATCTCTCCAAGCTGAATATTAATATCAAAAACTTGTTGTTAGAATGTTTAGGTATTGCTATTAAAAAAAATTACTTTCAACTTATCAAAACAATAGAAACGGATATGCGTTATGAGTAA

the separated and cultured African swine fever virus JS/LG/21 strain is submitted to a patent program approval preservation agency for preservation. The preservation unit is China center for type culture Collection; addresses are China, wuhan, university of Wuhan; the microorganism has a preservation number of CCTCC NO: V202318; the culture is named African swine fever virus ASFV JS/LG/21ASFV Pig/Jiangsu/LG/2021; the preservation time is 2023, 3 and 29 days; survival time was identified as 2023, 3 and 29 days.

Example 4: pathogenicity analysis

To evaluate the virulence of JS/LG/21 strain on pigs, SPF-grade pigs of 7 weeks old were selected from the national academy of agricultural sciences Harbin veterinary institute laboratory animal center and intramuscular injected 10 ³ HAD ₅₀ Or 10 ⁶ HAD ₅₀ Each dose was vaccinated with 6 pigs. Starting on day 1 of infection, 2 additional SPF-grade pigs were selected for each group and raised with infected pigs to assess JS/LG/21 transmission. All pigs were monitored daily for survival and clinical signs. At designated times post inoculation (p.i) or post exposure (p.ct), oral swabs, rectal swabs and EDTA anticoagulated blood were collected, and qPCR was used to detect p72 gene to reflect viral load using qPCR. The dead or euthanized pigs were dissected and brains, hearts, livers, spleens, lungs, kidneys, tonsils, inguinal, mandibular and mediastinal lymph nodes were collected and qPCR was used to examine the p72 gene to reflect viral load.

Recombinant virus isolates JS/LG/21 were each 10 ⁶ HAD ₅₀ ，10 ³ HAD ₅₀ 6 pigs were vaccinated while each group was introduced 2 non-vaccinated companion pigs from the first day. In FIG. 6, a-f show 10 ⁶ HAD ₅₀ Corresponding indexes of vaccinated pigs and concomitant pigs are measured, and g-I shows 10 ³ HAD ₅₀ The corresponding indicators of vaccinated pigs and concomitant pigs were measured, a and g show the rectal body temperature after vaccination, and b and h show the survival rate after vaccination. c and i show oral swab viral DNA content, d and j show anal swab viral DNA content, e and k show blood viral DNA content, and f and l show 10 tissue viral DNA content. The black line dashed line represents the normal rectal body temperature (40 ℃) of the pig. LN1, inguinal lymph node; LN2, mandibular lymph nodes; LN3, mediastinal lymph nodes.

At 10 ⁶ HAD ₅₀ In the group, all 6 vaccinated pigsFever started on day 4 of p.i. and died between day 5 and day 8 of p.i. (figure 6). The 2-contact pigs began to heat up on day 9 after contact and died on day 12 (fig. 6). Viral DNA was detected in all vaccinated and contact pig oral swabs, rectal swabs and blood (fig. 6). High levels of viral DNA were also detected in organs of dead pigs, including brain, heart, liver, spleen, lung, kidney and tonsils, as well as three different lymph nodes (inguinal, submandibular and mediastinal lymph nodes) (fig. 6).

At 10 ³ HAD ₅₀ In the group, all pigs died from day 6 to day 15 (fig. 6). The 2-contact pigs began to develop fever on days 9 and 10 post-infection and died on days 12 and 14 post-inoculation, respectively (fig. 3). Viral DNA was detected in all oral swabs, rectal swabs, blood of vaccinated and contact pigs, but at levels slightly below 10 ⁶ HAD ₅₀ Group (fig. 6). These results indicate that the recombinant virus isolate JS/LG/21 has high lethality and transmissibility.

Example 5: construction of Gene knockout strains

1. Construction of homologous recombinant vector

Referring to the schematic diagram of FIG. 7a, in order to replace the MGF_505-1R, MGF _505-2R, MGF _505-3R, MGF _360-12L, MGF _360-13L, MGF _360-14L gene of the JS/LG/21 strain with the mCherry gene by homologous recombination, a homologous recombination transfer vector for MGF_505-1R, MGF _505-2R, MGF _505-3R, MGF _360-12L, MGF _360-13L, MGF _360-14L gene knockout was constructed, the replaced genomic sequence corresponding to 23202-31159 of the full length sequence of the JS/LG/21 strain genome.

The DNA sequence of the 21702-23201 th position corresponding to the full-length sequence of the JS/LG/21 strain genome upstream of the MGF_505-1R, MGF _505-2R, MGF _505-3R, MGF _360-12L, MGF _360-13L, MGF _360-14L gene is used as a homologous recombination left homologous arm (see MGF-LR below for sequences), the DNA sequence of the MGF_505-1R, MGF _505-2R, MGF _505-3R, MGF _360-12L, MGF _360-13L, MGF _360-14L gene downstream corresponding to the full-length sequence of the JS/LG/21 strain genome is used as a homologous recombination right homologous arm (see MGF-RR below for sequences), and a p72mCherry expression cassette (the promoter is the p72 promoter of the African swine fever virus p72 gene) is inserted in the middle of the gene sequence of the homologous arm left gene sequence of the recombinant transfer vector. pUC57-P72mCherry contains the mCherry gene expression cassette sequence of the viral P72 promoter sequence, which was delegated to Jilin, kumei Biotechnology Co. The left and right homology arms were cloned into pUC57-p72mCherry, and after DNA sequencing was correct, the homologous recombinant transfer vector was designated pUC57-MGF-Del. pUC57-MGF-Del uses pUC57 vector as skeleton, and the region for homologous recombination is left homology arm-p 72 promoter-mCherry gene coding sequence-right homology arm in sequence.

Lower case letters in the left and right homology arm sequences are defined as left arm, right arm.

In order to replace the EP402R gene of the JS/LG/21 strain with the Venus gene through homologous recombination, a homologous recombination transfer vector for knocking out the EP402R gene is constructed, and the replaced gene sequence corresponds to 68816-69967 th positions of the full-length sequence of the JS/LG/21 strain genome.

The DNA sequence of the 67806-68815 th site corresponding to the full-length sequence of the JS/LG/21 strain genome at the upstream of the EP402R gene is used as a homologous recombination left homologous arm (see EP402R-LR below for the sequence), the DNA sequence of the 69968-70967 th site corresponding to the full-length sequence of the JS/LG/21 strain genome at the downstream of the EP402R gene is used as a homologous recombination right homologous arm (see EP402R-RR below for the sequence), and a p72Venus expression cassette (the promoter is the p72 promoter of the African swine fever virus p72 gene and the coding sequence is the Venus gene) is inserted between the left homologous arm gene sequence and the right homologous arm gene sequence of the recombinant transfer vector. pUC57-P72Venus contains the Venus gene expression cassette sequence of the viral P72 promoter sequence, which was delegated to Jilin, kumei Biotechnology Co. The left and right homology arms were cloned into pUC57-p72Venus, and after DNA sequencing was correct, the homologous recombinant transfer vector was designated pUC57-EP402R-Del. pUC57-EP402R-Del uses pUC57 vector as skeleton, and the region for homologous recombination is left homology arm-p 72 promoter-Venus gene coding sequence-right homology arm in sequence.

2. Construction and identification of recombinant African swine fever virus JS/LG/21-7GD

The homologous recombinant plasmid pUC57-EP402R-Del was transfected into the cells of the PAMs infected with JS/LG/21 strain ASFV by using TranslT-LT1 transfection reagent (purchased from Mirus Bio Inc. USA), and the African swine fever gene-deleted virus (single deletion strain) in which the EP402R gene was deleted and the green fluorescent protein emitted by Venus was expressed was purified by plaque cloning. PCR amplification verifies that the 68816-69967 nucleotide is replaced by Venus gene under the control of p72 promoter relative to the full-length sequence of African swine fever JS/LG/21 strain.

The homologous recombinant plasmid pUC57-MGF-Del is transfected into PAMs cells infected by the single deletion strain according to the method, and viruses with double deletion of the genes of EP402R and MGF_505-R, MGF _505-2R, MGF _505-3R, MGF _360-12L, MGF _360-13L, MGF _360-14L are obtained through multiple rounds of plaque purification and are named JS/LG/21-7GD. Wherein, with respect to the full-length sequence of African swine fever virus JS/LG/21-7GD strain, based on the replacement of nucleotide 68816-69967 with Venus gene under the control of p72 promoter, PCR amplification verifies that nucleotide 23202-31159 is further replaced with mCherry gene under the control of p72 promoter.

The JS/LG/21-7GD strain was able to emit red fluorescence by mCherry and green fluorescence by Venus under fluorescence excitation, as shown in FIG. 7c.

The MGF-LR sequence is as follows (SEQ ID NO. 25):

GATGTCTGCGCCCCATTCTgtaaacagTTTTATTAACTGATAGTTGTTTTCCTTTGTAGCCAACATTAGTGCCGTATTAAGGTCCAAGCCGTCTGCAAAGCTTGGCAGCTTTATCAGCATATGTTTGCAATCAAGGGAAATTGGGGCCTTATACCACCATAGTCCGCAGCGTTCTAAGATAACATGGTACTCAATAGATACTTGCTGTCTGGCTAGTACCTTTTTGGCGAAGGATTGTAAGGAAGGAAACATCCTGTTTCTTTTTTTTTTAAAAATCAATTATCTTTGTTCATAATCAAGAAAAATCCCCATATTTATTGAGTGATAATTTTTTAACATGCAATTTATTTTTTCAGGGTCCGTAACGATCGACAACAGAGAAATAACCGGATTGTAATGCTTTAATGATAAGGCATGGGCTATCAGATAATTTTCCTTTTGTTCTGCCAAAGCTTTGCCCTCCTCAAAGGCATCGGCACCCAGGTCTATACAAAAGAACAGGTTTCCAAGATTATAGTTTTGTATGGAAACAAGCATGGCTTGATTGATGTTGGCTCCCATGATAAAACAGTAGTAAATGGCCGAATAGCTATAATCTTGGATGCAGGCTATGTGCATCATTTCATCAATATCCATGCGGACCCTTTCTATTTCGTACAGCTCGTGAAGGTCGAACACGTTGTTGTAAAAAAGGGCGCACATGAGCCGCCACCTATGTAGACGCGGGTATTTCTGGTAAAAGTAGCGGATAGCATCTTTGAGGTCATAGTCCACCGCTATCGCGTACCAGTATTTGGTTAAAACAGTGCTAAAGCTATCATCATGGTCCAGCATGAAGGTTATCTCCATGAGCCCTCTTAACTCCCACATGATTTCCCCCCTCAGATCCAGATTATCTATAATCCTTAAATTGGGGTTATTGGAAAACACCTCGTGGCAAAAGATAATATTGCTACTGGTTTTATCGCGCGTTGTATCAAAGAAAATTTTTAAAATATACTCTCTTTCTAAATATTCTTTGGCTCCCAGCTCTTTGCACAGATCACGGGTATTTTCCGTGAGAGCACAAATCATTCCATAGTTAATATCTGCACCCCATTCAGTAAACAGCTTTATCAAGTCATGATTATTCTCCTTCACGGCTTTCATCAGTCCTATGTTTAACTCGATACCTTGACTAAAACAGGTTGACCTTATAAATAATTTATTGCGTCGAATATGAAGCATAATGGGGCCATTATGCCACCACAGGCCACAACACTTCAGGACATGATATTGATCTACCGGTATACACTGCCCGGCCAGTACTTTCTTCGTGAGGGATTGCAGGGAAGGCAACATGCCTTTCCATCCTTTGACGGAAATCAAATTATCTACTAATAACTATCAGTGTTTATATTAAGTATTTAGATATTATCCCGGGCTGGATACGTAGTATCGCTATTCACATGTACTTCCAACTCTAGCCggagcCTGCAGGGTCATTTATTTTTAATATTG

the MGF-RR sequence is as follows (SEQ ID NO. 26):

TACTCACTATTGTAGTGAATCGTATCCTGTAAATTTTGTAAAAAAGCTTAAACTTTTGACCACATCATATTGTTTTAGAAATCTCAAACCAGTGAACAACAGTCTTATCATACATTAAAATTCCAGTAAAATTTATATTTTTTTTGGTAAACAAATGTTTTCTCTTCAAGACATCTGTCGGAAACATCTTTTTCAACTTCCTGACGCTTTTGATGAATATATATTACAAGCGCTAGGACTATACTGGGAAAAACACGGATCTCTTCAACGAATAAGAAAGGACGCTGTGTTTGTACAGCGAAACATCGTCCTTTCTACCAATGAGGCCCTGAGAATCGCAGCCTCAGAGGGAAACGAAAGGGTAATAAAACTTCTGTTATCATGGGAGGGAAATTTTCATTATGTGATCATAGGAGCTCTAGAGGGTGACCAATATGACCTAATTCATAAGTATGATAGTCAAATTAAAGACTACCACATGATTTTATCATTGATCCAAAATGCAAATACCTTTGAAAAGTGTCATCAGTTATCCAATAGTAATATGTGGTGTCTTATACAGAATGCTATAAAATATAATATGCTCCCTATTCTCCAAAAACACAGAAATATTCTGACACATGAGGGAGAGAATCAGGAATTGTTTGAGATGGCATGTGAGGAACAGAAATATGACATAGTTTTATGGATAGGACAAACCCTAATGTTAAATGAGCCGGAGTTTATTTTTGATATCGCCTTCGAACGGATAGATTTTTCTTTATTAACAATGGGTTATAGCCTTCTTTTTGATAACAAGATGAGTAGTATAGACATTCATGATGAAGAAGATCTTACTTCATTACCAACAGAACACCTCGAAAAAGCAGCCACTAAGGGATGTTTCTTCTTTATGCTAGAAACTTTAAAACATGGTGGAAATGTAAATATGGCAGTCTTATCTAAAGCTGTTGAGTATAATCATAGAAAAATTTTAGACCATTTTATTCGGCGGCAAAAATGTTTATCACGTGAAGAGATTGAAAACCTATTATTAACCGCCATAACCAATTGTGCATCCATAAAAACGTTAAACTTACTCTTGTCTTACCTAAACTATTCCGTAAAAAATATCATTGGAAAAATAGTACAACATGTCATAAAAGATGGTGATTATACCATCATATTACTTTTAAAAAAAAAGAAAATAAACCTAGTGGAACCTGTTTTAACAGGTTTTATAGATTATTACTATAGCTATTGTTTTATAAAACATTTTATCCAAGAGTTTGCTATTCGTCCGGAAAAACTGATTAAAATGGCCGCGCGAAAAGGTAAACTAAATATGATTATCGAATTCCTTAACGAAAAATATGTTCATAAAGATGATCTTGGAACTATATTTAAATATCTCAAAACCCTAGTATGTACCATGAAACATAAAAAAGGAAAAGAGACATTAATTGTTCTTATTCATAAAATATATCAAgatATTCATCTGGAGACTAAAGAAAAATTTAA

EP402R-LR sequence is as follows (SEQ ID NO. 27):

ATATTGTATGATAAATCAAACAATGTCTTATATATGTGGTTTATTATTTTAGGCGCCGCAAGATGTACTCCATTCTCATTGCATGCTTGGTGTTATTACTCTGTCTAGTTATATATGTCGGTCATCGTGCCGATCATGCACGAAAATATTTAGAAGGAATGTGGCATGGAGATCCGGTTTTTCTAAAACAGTCGGGGCTACAATCCTTTTATCTCTACATACAACCTGACCATACATGTTTTTTTAGCATTGTGAATAAAAATGGTGAAAAGCTGATGGAAACCAAAATACCTTGTACGATAACAAATAAAATATATATGTTTTTTAAACCTATTTTTGAATTTCATGTTGTGATGGAAGACATACATAGCTACTTCCCTAAGCAGTTTAACTTTCTGTTAGATAGTACAGAAGGTAAACTTATTTTAGAAAACAATCACGTTATTTATGCTGTATTGTATAAGGATAATTTCGCCACCGCACTAGGAAAAACGGTTGAAAAATATATAACACAAAATTAATCATGTTTTCTAACAAAAAGTACATCGGTCTTATCAATAAGAAGGAGGGTTTGAAAAAAAAAATAGATGATTATAGTATATTAATAATTGGAATATTAATTGGAACTAACATCTTAAGCCTTATTATAAATATAATAGGAGAGATTAATAAACCAATATGTTACCAAAATGATGATAAGATATTTTATTGCCCTAAAGATTGGGTTGGATATAATAATGTTTGTTATTATTTTGGCAATGAAGAAAAAAATTATAATAATGCAAGTAATTATTGTAAGCAATTAAATAGTACGCTTACTAATAATAATACTATTTTAGTAAATCTTACTAAAACATTAAATCTTACTAAAACATATAATCACGAATCTAATTATTGGGTTAATTATTCTTTAATTAAAAATGAGTCAGTACTATTACGTGATAGTGGATATTACAAAAAACAAAAACATGTAAGTTTATTATATATTTGTAGTAAATAA

EP402R-RR sequence is as follows (SEQ ID NO. 28):

TATGTACTATATATTAATTATTTAACCTTTCAAGCTGGTCTTCATTTAAATTTAAAATCCACTAATAAAATGTATTTTCTAGTAGCAGATCATCGAGAACATCATGTGATTCCTTTTCTTAAAACCGATTTCCATCACATGCATCAAAATCCTATACAAAAAAATCAAGCTCTCCTAGAAATCAAACAGCTTTTTACTGGAGATTATCTCATCTGCAAAAGCCCTTCTACCATTCTGGCCTGTATTGAACGAAAAACCTACAAAGACTTTGCGGCTTCTTTGAAAGATGGACGTTATAAAAATCGCCAAAAAATGCTGTCGCTGCGAGAACAAACCAACTGTCAACTTTATTTTTTTGTAGAAGGCCCGGCATTTCCTAACCCTCAAAAAAAAATTAATCACGTTGCCTATGCAAGCATTATTACTGCTATGACGCATCTTATGGTTAGAGATCATATTTTTGTCATTCAAACGAAAAATGAGGCCCACAGTTCCCAAAAGCTTGTGCAGCTTTTTTATGCCTTTTCTAAGGAAATGGTGTGCGTCGTTCCCACCTCCCTCACCCCCACGGATGAAGAGCTATGCATCAAGCTATGGTCTTCTCTTTCTGGTATTTCAGGCGTGATAGGTAAAATCTTGGCAAACACTTGTTCCGTAGCTCATTTGGTTCATGGAAAGCTTTCATCGCAGAATATTGATCAGTTAAAAACTCCCTCCAACCGACCATTCCCCAAAAAAGTAAAACGTATGCTTATAAGCATTAGCAAAGGAAATAAGGAGTTAGAAATAAAATTGCTCTCGGGGGTTCCCAATATCGGGAAAAAATTAGCTGCCGAAATTTTAAAAGATCATGCGCTTCTTTTTTTTCTAAATCAGCCCGTAGAATGCTTGGCAAATATACAAATCGTTCAAAAAACCCGTACGATTAAGTTGGGAATGAAGCGAGCCGAAGCGATTCATTATTTTTTAAACTGGTGTGGCTCTGCCCATGTAACCGATG

the p72 promoter of African swine fever virus (JS/LG/21 strain p72 gene upstream-74 nt to +1nt sequence) used in the invention is identical to the p72 promoter of African swine fever virus Pic/HLJ/2018 strain, and the sequence is as follows (SEQ ID NO. 29):

TTGTTATTATCAAGATCCTTCGCATAAACCGCCATATTTAATAAAAACAATAAATT ATTTTTATAACATTATATA

example 6: testing of knockout strains

PAMs were cultured in 24-well plates (1.25X10) ⁶ Cell/well), 100 μl/well, RPMI 1640 complete medium, and after cell attachment, JS/LG/21 and JS/LG/21-7GD (moi=0.1) were inoculated respectively. Culture at 37℃and collection of culture supernatants every 24h, characterization of viral content by qPCR detection of p72 gene was performed, see FIG. 7b.

Therefore, the growth curves of JS/LG/21 and JS/LG/21-7GD are close to overlap, which shows that after seven gene knocks of the invention are removed, the proliferation capacity and growth period of JS/LG/21 strain on primary cells are not obviously affected, JS/LG/21-7GD can normally survive, and the vaccine preparation potential is provided.

After 72h of PAM infection with JS/LG/21-7GD, green fluorescence expressed by Venus and red fluorescence expressed by mCherry could be observed with the two fluorescence positions completely coincident (fig. 7 c).

To evaluate virulence and immunogenicity of JS/LG/21-7GD strain on pigs, 7 week old SPF grade pigs were selected from the national academy of agricultural sciences Harbin veterinary institute laboratory animal center and intramuscular injection 10 ⁶ TCID ₅₀ Head, 10 pigs were vaccinated.

All pigs were monitored daily for survival and clinical signs. Rectal body temperature was normothermic, no fever was seen, see figure 7d for details, 100% animal survival, see figure 7e, within 28 days post inoculation. As can be seen, the JS/LG/21-7GD strain is safe for breeding pigs.

The antigen is African swine fever p22 protein, a detection plate is coated, the IgG antibody titer of the p22 protein is detected by a blocking ELISA method at different time after 10 pigs are inoculated, and the result shows that the specific antibody is induced after 10 days after inoculation, then the antibody titer is continuously increased until 25 days after inoculation, and the antibody titer reaches the highest, see figure 7f. Therefore, JS/LG/21-7GD strain can excite pigs to produce specific antibodies, and has good immunogenicity and potential for preparing vaccines.

In FIG. 7, (a) shows a schematic diagram of the construction of JS/LG/21-7GD gene-deleted strain. The deleted gene fragments were replaced with p72mCherry and p72Venus reporter gene expression cassettes, respectively. (b) The growth curves of JS/LG/21 and JS/LG/21-7GD in PAMs are shown. (c) fluorescence after JS/LG/21-7GD infection with PAMs for 72 h. (d) Shown 10 SPF swine vaccinations 10 ⁶ TCID ₅₀ The rectal body temperature was monitored 28 days after JS/LG/21-7GD, (e) shows survival rate, and (f) shows specific antibodies. The dashed line represents the normal rectal temperature (40 ℃) of the pig.

Example 7: immune pig toxicity test

The study data indicate that pigs surviving low virulence ASFV infection can develop protective immunity against homologous but not heterologous virus. By deleting 7 genes including 6 MGF_505/360 genes and EP402R genes encoding CD2V, an ASFV attenuated live vaccine HLJ/18-7GD (the modification process of HLJ/18-7GD strain is described in the patent document of China patent application No. 201910348878.7, corresponding to rASFV delta CD2V/360-eGFP-mCherry strain with the preservation number of CCTCC NO: V201924) is obtained, and the vaccine strain is proved to be safe and can protect the lethal attack of the gene type II ASFV by the study in pigs. To evaluate whether this HLJ/18-7GD can provide protection against JS/LG/21 strains. The invention uses 10 SPF grade pigs for intramuscular injection 10 ⁶ TCID ₅₀ HLJ/18-7GD, 5 head intramuscular injection 10 at day 28 post inoculation ³ HAD ₅₀ JS/LG/21,5 head intramuscular injection 10 ³ HAD ₅₀ HLJ/18. Each group was given 4 unvaccinated pigs as challenge.

Results referring to FIG. 8, SPF-grade pigs were 10-headed, vaccinated 10 per group ⁶ TCID ₅₀ HLJ/18-7GD, 5-head intramuscular injection 10 on day 28 post-inoculation ³ HAD ₅₀ HLJ/18 (see a-c for results), 5-head intramuscular injection 10 ³ HAD ₅₀ The recombinant virus isolate JS/LG/21 of (see d-f for results). 4 unvaccinated pigs were given to each group as challenge controls. Rectal body temperature (results see a, d) and survival (results see b, e) were monitored daily and live pigs were euthanized at the end of the observation period, virus content in tissue samples of euthanized pigs or ill dead pigs (results see c, f) were collected and qPCR was used to detect DNA for virus p 72. The black line dashed line represents the normal rectal body temperature (40 ℃) of the pig. LN1, inguinal lymph node; LN2, submaxillary lymph nodes; LN3, mediastinal lymph nodes.

Control pigs developed hyperthermia and all died within 10 days after HLJ/18 challenge, and viral DNA was detected in major organs and lymph nodes (fig. 8). In contrast, vaccinated pigs have good protection against homologous virus HLJ/18 challenge. All pigs showed no clinical symptoms during the 28 day observation period (fig. 8), and viral DNA was detected only from the lungs, kidneys, 2 lymph nodes, and tonsils of 1 pig euthanized at the end of the observation period (fig. 8). Control pigs all developed fever and died within 8 days after JS/LG/21 challenge, and viral DNA was detected in both major organs and lymph nodes (fig. 8). However, it was surprisingly found that all HLJ/18-7GD vaccinated pigs developed fever and died within 10 days after JS/LG/21 challenge (fig. 8), and that the level of viral replication in their organs was comparable to control pigs (fig. 8). The results indicate that the HLJ/18-7GD attenuated live vaccine does not provide effective protection for the novel isolate JS/LG/21.

The isolated strain JS/LG/21 can evade immunity induced by attenuated live vaccines of the gene II type ASFV due to natural recombination from the gene I type and the gene II type ASFV. This demonstrates that it is important to develop and prepare vaccine separately for recombinant JS/LG/21 strain.

As can be seen from FIG. 8e, even if the pigs are vaccinated with HLJ/18-7GD and then challenged with JS/LG/21, the challenged pigs die, indicating that JS/LG/21 is virulent. FIG. 7e shows that JS/LG/21-7GD vaccinated pigs were alive and not febrile, demonstrating that gene knockout according to the present invention effectively detoxifies the isolate JS/LG/21. Referring to FIG. 8f, the vaccinated pigs produced anti-p 22 protein antibodies well, demonstrating that JS/LG/21-7GD has immunoprotection and can be used as a vaccine.

It will be appreciated by those skilled in the art that the present invention can be carried out in other embodiments without departing from the spirit or essential characteristics thereof. Accordingly, the above disclosed embodiments are illustrative in all respects, and not exclusive. All changes that come within the scope of the invention or equivalents thereto are intended to be embraced therein.

Claims

1. An African swine fever virus strain, wherein the African swine fever virus strain is an African swine fever virus strain with a microorganism preservation number of CCTCC NO: V202318, and the encoding sequence of an NP1450L gene in the genome of the African swine fever virus strain is shown as SEQ ID NO. 22; the code sequence of MGF_360-8L gene is shown as SEQ ID NO. 23; and the coding sequence of the MGF_505-5R gene is shown as SEQ ID NO. 24.

2. The method for culturing an african swine fever virus strain of claim 1, which comprises: inoculating the African swine fever virus strain into cultured cells, and performing proliferation culture of the African swine fever virus strain to obtain the proliferated African swine fever virus.

3. The method of claim 2, wherein the cultured cells are primary porcine alveolar macrophages.

4. The culture method according to claim 2, wherein the culture environment of the culture method is: 36-39 ℃,3-5% CO ₂ 。

5. Use of an african swine fever virus strain of claim 1 or the african swine fever virus strain cultured by the culture method of any one of claims 2-4 in the preparation of a detection reagent for african swine fever virus.

6. Use of an african swine fever virus strain of claim 1 or the african swine fever virus strain cultured by the culture method of any one of claims 2-4 in the preparation of an inhibitor against african swine fever virus and/or a therapeutic formulation against african swine fever.

7. Use of an african swine fever virus strain of claim 1 or the african swine fever virus strain obtained by culturing in the method of any one of claims 2-4, in the preparation of a formulation for use alone, in combination with or as a component of a compound formulation consisting of other immune formulations and/or drugs to prevent, slow and/or control african swine fever.