Goose-derived muscovy duck reovirus, inactivated vaccine and application of goose-derived muscovy duck reovirus

Abstract

The invention discloses a goose-derived muscovy duck reovirus, an inactivated vaccine and an application of the goose-derived muscovy duck reovirus, and belongs to the field of separation and application of avian reovirus strains, the goose-derived muscovy duck reovirus is preserved in China Center for Type Culture Collection on October 30, 2024, and the preservation number of the goose-derived muscovy duck reovirus is CCTCC NO: V202491. The goose-derived muscovy duck reovirus provided by the invention has very good immunogenicity on the goose-derived muscovy duck reovirus which takes a large number of white necrotic spots and articular hemorrhage in tissues and organs such as liver and spleen as main diseases. An inactivated vaccine prepared from the goose source muscovy duck reovirus strain is good in safety, the protection rate reaches 100%, and complete protection can be provided for a newly separated goose source muscovy duck reovirus variant.

Description

Technical Field

[0001] The invention relates to the separation and application field of avian reovirus strains, and in particular to a goose-derived Muscovy duck reovirus, an inactivated vaccine and applications thereof. Background Art

[0002] The information disclosed in this background technology section is only intended to enhance the understanding of the overall background of the invention, and should not necessarily be regarded as an admission or any form of suggestion that the information constitutes the prior art already known to a person skilled in the art.

[0003] Avian orthoreovirus (ARV) is a type of non-enveloped, icosahedral, double-layer capsid structure, and segmented double-stranded RNA virus with a diameter of 50-80 nm. ARV belongs to the Reoviridae, Spikereovirinae, and Orthoreovirus genus. ARV can cause a variety of diseases in a variety of poultry species, and its clinical manifestations vary depending on the virus strain, virulence, or infected host, which seriously endangers the development of my country's poultry industry.

[0004] As it is a new disease, there is a lack of in-depth research on the epidemiology and pathogenic mechanism of the disease, and there is no effective vaccine or drug for prevention and treatment. Therefore, starting from the pathogen, further studying the molecular pathogenic mechanism and viral mutation mechanism, and developing corresponding vaccines are the key to preventing and controlling this infectious disease. Therefore, it is urgent to develop a safe and efficient inactivated vaccine to prevent the goose-derived Muscovy duck reovirus. Compared with attenuated vaccines, inactivated vaccines are safer, simple to produce and easy to store, which is also of great significance to the prevention and control of the disease and the healthy development of the goose industry. Summary of the invention

[0005] In response to the above-mentioned prior art, the present invention isolated a Muscovy duck reovirus that causes "speckled liver disease" in goslings from diseased goslings, and investigated the cellular tropism, pathogenicity and immunogenicity of the goose-derived Muscovy duck reovirus, providing a guarantee for the prevention and treatment of newly emerging infectious diseases characterized by "speckled liver disease" and severe joint cavity bleeding.

[0006] Specifically, the present invention relates to the following technical solutions: In the first aspect of the present invention, a goose-derived Muscovy duck reovirus is provided. The virus has been deposited in the China Center for Type Culture Collection (CCTCC) on October 30, 2024, and the deposited name is: Muscovy duck reovirus MDRV-JS001, and the classification name is: Muscovy duck reovirus ( Muscovy Duck Reovirus ), the deposit address is: Wuhan University, Wuhan, China, and the deposit number is: CCTCC NO: V202491.

[0007] The goose-derived Muscovy duck reovirus provided by the present invention is a variant strain of the existing avian reovirus. The liver, spleen or other tissues and organs of the poultry infected by the goose-derived Muscovy duck reovirus will show a large number of white necrotic spots, and symptoms such as mental depression, loss of appetite, movement disorders, and yellow-green loose stools will also appear. In addition, the infected poultry will also have swollen joints, and severe bleeding in the joint cavity can be seen during autopsy. The above symptoms have never appeared in previous Muscovy duck reovirus infections.

[0008] Preferably, the poultry are goslings.

[0009] The second aspect of the present invention provides the use of the goose-derived Muscovy duck reovirus in the preparation of a vaccine for preventing and treating "spotted liver disease" and joint cavity hemorrhage in goslings.

[0010] The "flower liver disease" refers to the appearance of a large number of white necrotic spots in the liver, spleen or other tissues and organs of goslings caused by infection with Muscovy duck reovirus with a preservation number of CCTCC NO: V202491.

[0011] Preferably, the vaccine is any one of an inactivated vaccine, a live attenuated vaccine, a subunit vaccine or a genetically engineered vaccine.

[0012] By investigating the cell tropism and immunogenicity of the goose-derived Muscovy duck reovirus provided by the present invention, it was found that the strain has a wide range of cell tropism, can proliferate on LMH cells, and can proliferate in large quantities in a short period of time, and is very suitable for the production of high-quality inactivated vaccines with high antigen titer, and has good immunogenicity to newly emerging infectious diseases with "speckled liver disease" and joint cavity hemorrhage in goslings as main symptoms. Therefore, the goose-derived Muscovy duck reovirus provided by the present invention can be used as an excellent vaccine strain for the preparation of vaccines.

[0013] The term "cell tropism" refers to the ability to infect and / or replicate in one or more cell lines or tissue cells.

[0014] The third aspect of the present invention provides an inactivated vaccine for preventing and treating goose "spotted liver disease" and joint cavity bleeding, wherein the inactivated vaccine contains an effective amount of inactivated goose-derived Muscovy duck reovirus liquid for prevention or treatment; the deposit number of the goose-derived Muscovy duck reovirus is CCTCC NO: V202491.

[0015] The method for preparing the inactivated goose-derived Muscovy duck reovirus liquid comprises the following steps: (1) The goose-derived Muscovy duck reovirus strain with a deposit number of CCTCC NO: V202491 was inoculated into LMH cells, the goose-derived Muscovy duck reovirus was proliferated and cultured, the cells were broken by freezing and thawing, the supernatant was collected, and purified to obtain the goose-derived Muscovy duck reovirus liquid; (2) Add formaldehyde with a final concentration of 0.2% to the goose-derived Muscovy duck reovirus solution obtained in step (1), and stir and inactivate at 37° C. for 16 h to obtain an inactivated goose-derived Muscovy duck reovirus solution.

[0016] The virus titer of the goose-derived Muscovy duck reovirus liquid is 10 -6.2 TCID 50 / 0.1 mL.

[0017] Preferably, the inactivated vaccine also contains a pharmaceutically acceptable adjuvant.

[0018] The method for preparing the inactivated vaccine comprises the following steps: Take inactivated goose-derived Muscovy duck reovirus liquid, add Tween-80 to mix as the water phase, mix white oil, aluminum stearate and Span-80 as the oil phase, mix the oil phase and the water phase in a ratio of 2:1, emulsify, and obtain an inactivated vaccine for preventing and treating goose-derived Muscovy duck reovirus.

[0019] Beneficial effects of the present invention: 1. The present invention has isolated a goose-derived Muscovy duck reovirus MDRV-JS001, which has the ability to spread across species and can infect goslings. After being infected by the strain, goslings will have swollen joints. After the diseased goslings were examined, it was found that the infected goslings had symptoms with "flower liver disease" and joint bleeding as the main symptoms. In addition, the strain has a wide range of cell tropism and can proliferate on LMH cells, which is very suitable for the production of high-quality inactivated vaccines with high antigen titers; it has good immunogenicity for newly-emerged infectious diseases with "flower liver disease" and joint bleeding in goslings as the main symptoms. It can be used as an excellent vaccine strain for the preparation of vaccines.

[0020] (2) Through the analysis of the σC gene sequence of the strain, it was found that the σC gene sequence of the MDRV-JS001 isolate had a homology of more than 95% with the nucleotide and amino acid of the classic Muscovy duck reovirus ZJ2000M strain, and was distantly related to other waterfowl reovirus isolates and was in a different genetic evolutionary branch. The inactivated vaccine prepared with the goose-derived Muscovy duck reovirus strain with the deposit number of CCTCC NO: V202491 has good safety and a protection rate of 100%. In addition, the inactivated vaccine of the present invention can quickly reach a high concentration of antibody levels in a short period of time, and has a long immunity duration, which can provide rapid and long-term immune protection for goslings. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 This is a lesion image of a virus cultured in LMH cells; Figure 1 A in the figure is a picture of goose-derived Muscovy duck reovirus JS001 inoculated into LMH cells 48 hours later. Figure 1B in the figure is a picture of control cells that were not inoculated with the virus.

[0022] Figure 2 PCR identification results; in the figure, lane 1 is duck reovirus, lane 2 is duck Tembusu virus, lane 3 is duck astrovirus, lane 4 is duck circovirus, lane 5 is duck plague virus, lane 6 is duck hepatitis A virus, lane 7 is blank control, lane 8 is goose-derived Muscovy duck reovirus, and M is a 2000bp Marker.

[0023] Figure 3 This is the growth curve determination of goose-derived Muscovy duck reovirus JS001. DETAILED DESCRIPTION

[0024] It should be noted that the following detailed descriptions are illustrative and are intended to provide further explanation of the present application. Unless otherwise specified, all technical and scientific terms used herein have the same meanings as those commonly understood by those skilled in the art to which the present application belongs.

[0025] The following detailed description is for illustrative purposes only and is intended to provide further explanation of the present application, rather than to limit the scope of the present invention.

[0026] RNA extraction kit was purchased from Beijing Kangwei Century Co., Ltd., ordinary agarose gel recovery kit was purchased from Beijing Quanshijin Company, reverse transcription kit was purchased from Bao Biotechnology (Dalian) Co., Ltd., 2×Es Taq MasterMix was purchased from Beijing Kangwei Century Co., Ltd., and DL2000 Marker was purchased from Bao Biotechnology (Dalian) Co., Ltd.

[0027] Example 1: Isolation and identification of goose-derived Muscovy duck reovirus 1. Epidemiological survey: Since March 2021, an infectious disease characterized by paralysis and a large number of white necrotic spots in tissues and organs such as the liver and spleen has broken out in goslings in Jiangsu, Liaoning and Henan provinces of my country. The disease mainly occurs in goslings aged 7 to 35 days. The diseased geese have a large number of white necrotic spots in all tissues and organs of the body. The diseased goslings also have clinical symptoms of swollen joints, and the mortality rate can be as high as 80%. The autopsy of the dead goslings showed the following main pathological changes: enlarged liver and spleen, with a large number of white necrotic spots on the surface, and severe bleeding in the joint cavity.

[0028] 2. Sample collection and processing: The liver tissue of the diseased goslings was collected, sterile PBS was added, and the tissue was ground into a homogenate. The tissue was frozen and thawed three times, and the supernatant was centrifuged and sterilized by filtration through a 0.22 μm filter. The supernatant was inoculated onto LMH cells in good growth condition and adsorbed in a cell culture incubator for 30 min. The sample treatment solution was discarded, and 2% cell maintenance solution was added to continue culturing. A negative control was set up with sterile saline and incubated at 37°C. The cell status was observed and recorded daily, and the virus solution was collected when the cell fusion phenomenon reached 80%. The virus solution was blindly propagated for three generations in the same way for subsequent testing. After three generations of subculture, the degree of cell fusion tended to be stable, and 80% of the cells showed typical cytopathic effects 48 h after inoculation ( Figure 1 A in the figure), and the negative control showed no lesions ( Figure 1 B in the figure).

[0029] 3.RT-PCR identification: (1) RNA extraction: The collected cell virus fluid was repeatedly frozen and thawed, and the supernatant was obtained by centrifugation. Viral RNA was extracted according to the instructions of the RNA extraction kit and stored at -20°C for later use.

[0030] (2) Reverse transcription to obtain cDNA: The reverse transcription kit used was PrimeScript™ RT Master Mix with catalog number RR036A from Takara Biotech (Dalian) Co., Ltd. 5× PrimeScript RT Master Mix×2μL was added to a 200 μL PCR reaction tube, and 2 μL of RNA extracted from the virus solution was added, and RNase FreeddH2O was used to supplement the system to 10 μL. The reaction was carried out in a PCR instrument under the following conditions: 37℃ for 15min; 85℃ for 5s, and then stored at 4℃.

[0031] (3) PCR amplification: Muscovy duck reovirus belongs to the genus Orthoreovirus of the family Reoviridae. σC protein is an extremely important structural protein of Orthoreovirus and plays an important role in the pathogenicity of the virus. In addition, the gene encoding σC protein is the gene fragment most susceptible to mutation in the genome. Therefore, in this study, a pair of specific primers for amplifying a 1002 bp fragment were designed based on the σC gene sequence of Muscovy duck reovirus on Genbank, a gene sequence database established by the National Center for Biotechnology Information of the United States, and synthesized by Beijing Qingke Xinye Biotechnology Co., Ltd.

[0032] Upstream primer: 5′- CCGATTGGGCCGACATCTCAT-3′ (SEQ ID NO. 1); Downstream primer: 5′-ACTACCTCAAGTGGTCGCAA-3′ (SEQ ID NO. 2).

[0033] A 20 μL system was used for amplification: template cDNA × 2 μL, upstream and downstream primers × 1 μL each, 2 × Es TaqMasterMix × 10 μL, and ddH2O was used to supplement the 20 μL system. After mixing and centrifuging, the mixture was placed in a PCR instrument for reaction. The reaction conditions were 95°C, 5 min, followed by 30 cycles of 95°C, 45 s, 52°C, 30 s, 72°C, 25 s, and 72°C, 10 min, and then stored at 4°C for later use.

[0034] At the same time, the reported specific primers were used to detect conventional duck-origin viruses, including duck reovirus (DRV), duck Tembusu virus (TMUV), duck astrovirus (DAStV), duck circovirus (DuCV), duck plague virus (DPV) and duck hepatitis A virus (DHAV).

[0035] (4) Agarose gel electrophoresis: The PCR amplification products were detected by 1% agarose gel electrophoresis. The results showed that the products amplified by PCR using primers SEQ ID NO.1 and SEQ ID NO.2 showed a specific band with the expected size of 1002 bp after electrophoresis in 1% agarose gel, indicating that the cell culture of the isolated strain contained goose-derived Muscovy duck reovirus ( Figure 2 ), named JS001 strain. In addition, the isolates were tested for routine duck-derived viruses, including DRV, TMUV, DAStV, DuCV, DPV, and DHAV, and the results were all negative, and no other viral contamination was detected.

[0036] 4. Sequencing and sequence analysis: The amplified product was recovered from the gel and sent to Beijing Qingke Xinye Biotechnology Co., Ltd. for sequencing. The sequencing results were spliced ​​and aligned using Blast, and homology analysis was performed with other waterfowl reoviruses.

[0037] The results showed that the σC gene sequence of the strain was most closely related to the classic Muscovy duck reovirus ZJ2000M strain, with nucleotide and amino acid homology of more than 95%. It was distantly related to other waterfowl reovirus isolates and was in a different genetic evolutionary branch (Table 1). Therefore, it can be determined that it is a Muscovy duck reovirus from geese.

[0038] Table 1: Nucleotide and amino acid homology analysis of the σC gene of MDRV-JS001 isolate and waterfowl reovirus The strain was named Muscovy duck reovirus MDRV-JS001. The strain was biologically preserved, and the preservation information is as follows: Bacteria name: Muscovy duck reovirus MDRV-JS001 Collection institution: China Center for Type Culture Collection Abbreviation of depository institution: CCTCC Address: Wuhan University, Wuhan, China Deposit date: October 30, 2024 Classification name: Muscovy duck reovirus ( Muscovy Duck Reovirus ) The registration number of the Collection Center is: CCTCC NO: V202491.

[0039] Example 2: Investigation of the characteristics of goose-derived Muscovy duck reovirus JS001 1. Pathogenicity of the virus: Sixty healthy goslings (Zhedong white geese) aged 5 days were randomly divided into two groups: experimental group and control group. The experimental group was injected intramuscularly with 0.5 mL (TCID 50 For 10 -6.2 / 0.1mL) per goose; the control group was injected with an equal amount of sterile saline, and the clinical manifestations of goslings in each group were observed for 14 days.

[0040] On the second day after the infection, the goslings in the experimental group began to fall ill, with a 100% morbidity rate and a 50% mortality rate. The infected geese were listless, had poor appetite, motor disorders, yellow-green loose stools, and swollen joints. Autopsy revealed a large number of white necrotic spots in the liver and spleen and severe bleeding in the joint cavity.

[0041] The goslings in the control group were all healthy and had no clinical symptoms. No lesions were found in the autopsy 14 days later.

[0042] It can be seen that the goose-derived Muscovy duck reovirus JS001 of the present invention has the ability to cause "speckled liver disease" and joint cavity bleeding in goslings.

[0043] 2. Immunogenicity of the virus: The goose-derived Muscovy duck reovirus JS001 was diluted 5 times to make attenuated live virus antigen and inactivated antigen, which were used to immunize healthy 5-day-old goslings that had not been vaccinated. The sera were collected 5, 10, and 20 days after immunization and 7 and 12 days after infection, and the antibodies in the sera were detected by indirect ELISA.

[0044] The results showed that the antibody levels of goslings inoculated with live virus antigens were lower than those inoculated with inactivated antigens; that is, inactivated antigens had better immunogenicity than live virus antigens.

[0045] Adult female breeding geese were inoculated with the inactivated vaccine made from goose-derived Muscovy duck reovirus JS001. The offspring of the breeding geese immunized with the inactivated antigen were able to produce complete protection against the virus, indicating that the goose-derived Muscovy duck reovirus JS001 strain has excellent immunogenicity.

[0046] 3. Cell tropism In order to determine the cell tropism of goose-derived Muscovy duck reovirus JS001, this study used the cytopathic observation method to detect the proliferation of goose-derived Muscovy duck reovirus JS001 on LMH cells and Vero cells, and the virus growth curve of the JS001 strain was generated in LMH cells ( Figure 3 ), as follows: (1) Test method: The JS001 strain of goose-derived Muscovy duck reovirus was inoculated into LMH cells in good growth condition, adsorbed in a cell culture incubator for 30 min, the sample treatment solution was discarded, and 2% cell maintenance solution was added to continue culturing; and sterile saline was used as a negative control and incubated at 37°C. The cell status was observed and recorded daily, and the virus solution was collected when the cell fusion phenomenon reached 80%, and the virus content was calculated according to the Reed-Muench method.

[0047] (2) The results of the viral content of the goose-derived Muscovy duck reovirus strain JS001 propagated on different cells are shown in Table 2.

[0048] Table 2: Virus content of goose-derived Muscovy duck reovirus strain JS001 propagated on different cells Purification and cultivation of goose-derived Muscovy duck reovirus is a difficult point in virus and vaccine research, and whether a vaccine strain that is adapted to in vitro cell culture can be obtained is the key to vaccine development and production. The goose-derived Muscovy duck reovirus JS001 of the present invention has a wide range of cell tropism, can infect a variety of animal cells, and can produce a large number of proliferations in a short period of time. Therefore, the goose-derived Muscovy duck reovirus JS001 strain of the present invention can be used as an excellent vaccine strain for vaccine preparation.

[0049] Example 3: Preparation of inactivated vaccine (1) Virus proliferation and harvesting: The isolated and identified goose-derived Muscovy duck reovirus JS001 was inoculated into well-grown LMH cells at an inoculation volume ratio of 1:100; adsorbed at 37°C for 30 min, and then cultured with DMEM containing 2% newborn calf serum at 37°C and 5% CO2. When 80% of the cells showed pathological changes, the cells were harvested to obtain the cell virus fluid. The obtained sufficient cell virus fluid was frozen at -20°C, and after two freeze-thaw cycles, the supernatant was collected by centrifugation to obtain the virus fluid. Calculate TCID50 The virus content in each 0.1ml virus liquid is 10 -6.2 TCID 50 .

[0050] (2) Virus purification: Use established PCR, RT-PCR and other detection methods to detect whether the obtained virus liquid contains other common viruses. The detection items include DRV, TMUV, DAStV, DuCV, DPV and DHAV, and purify the seed virus.

[0051] (3) Inactivation of virus fluid: The virus solution that passed the bacterial test was inactivated with formaldehyde. The best inactivation condition was to add formaldehyde to a final concentration of 0.2% and stir at 37°C for 16 hours.

[0052] (4) Vaccine preparation: ① Preparation of oil phase: Take No. 10 medicinal white oil and Span-80 in a ratio of 94:6 and mix them evenly. Then add 2% aluminum tristearate and stir until it becomes light yellow and clear. Sterilize with high-pressure steam at 121℃ for later use.

[0053] ② Preparation of aqueous phase: Mix the completely inactivated virus solution and sterile Tween-80 at a ratio of 96:4 by oscillation to completely dissolve Tween-80.

[0054] ③ Emulsification: The oil phase and the water phase are mixed in a ratio of 2:1. Add 2 parts of the oil phase into a tissue homogenizer in an ultra-clean bench, and slowly add 1 part of the water phase while stirring continuously. After all the water phase is added, mix at 6000 rpm for 10 min, then emulsify at 8000 r / min for 20 min, and divide into portions for use. The inactivated vaccine is prepared.

[0055] Example 4: Quality inspection of inactivated vaccines The inactivated vaccine prepared in Example 3 was subjected to quality inspections including dosage form, centrifugal stability, viscosity, sterility and shelf life. The specific methods refer to the Veterinary Pharmacopoeia of the People's Republic of China (2015 edition).

[0056] The results showed that the dosage form of the inactivated vaccine prepared by the present invention was water-in-oil (W / O); the centrifugal stability, viscosity and sterility tests were in compliance with the requirements of the Veterinary Pharmacopoeia of the People's Republic of China (2015 edition).

[0057] Example 5: Safety test of inactivated vaccine Twenty 5-day-old goslings were randomly divided into two groups, with 10 in each group. Group 1 was the experimental group, which was injected with the goose-derived Muscovy duck reovirus prepared in Example 3 into the leg muscle, 0.5 mL / goose, and Group 2 was the control group, which was injected with the same amount of sterilized white oil adjuvant into the leg muscle. After vaccination, the mental state of the animals in each group was observed every day, as well as whether local inflammatory reactions such as redness, swelling, heat and pain appeared at the injection site. The observation was continued for 2 weeks. After 2 weeks, the experimental animals were dissected to observe the absorption of the vaccine at the injection site; Results: The experimental group showed a brief mental depression, but recovered quickly. After two weeks of observation, the experimental and control groups grew and developed normally, and were in good mental state. The autopsy of the experimental group found that the vaccine was well absorbed at the injection site, without redness, swelling, tissue necrosis and other inflammatory reactions. The results proved that the trial vaccine was safe and harmless, and had no effect on animal growth.

[0058] Example 6: Protective testing of inactivated vaccines 40 5-day-old goslings were randomly divided into 2 groups, 20 in each group. Group 1 was the immunization group, and the inactivated vaccine prepared in Example 3 was injected into the leg muscle, 0.5 mL / goose; Group 2 was the control group, and the same amount of sterilized white oil adjuvant was injected into the leg muscle. Ten days after immunization, 0.2 mL of goose-derived Muscovy duck reovirus liquid was injected into the legs of the two groups of goslings, and the goslings were isolated and raised in groups to observe the mental state and death of the two groups of goslings.

[0059] Results: The immunized group showed a short-term mental depression, but did not show "flower liver disease" (white necrotic spots on the surface of the liver and spleen) and joint cavity bleeding in the autopsy, and no goslings died; the goslings in the control group showed obvious clinical symptoms of joint cavity swelling after the virus challenge, and the autopsy showed a large number of white necrotic spots on the surface of the liver and spleen and bleeding symptoms in the joint cavity, and the number of deaths was 8. The results showed that the immune protection rate of the inactivated vaccine prepared by the present invention can reach 100%.

[0060] Example 7: Determination of the duration of immunity of inactivated vaccines 40 5-day-old goslings were randomly divided into 2 groups, each with 20. Group 1 was the immunization group, and the inactivated vaccine prepared in Example 3 was injected into the leg muscle of each gosling, 0.5 mL / gosling; Group 2 was the control group, and the same amount of sterilized white oil adjuvant was injected into the leg muscle; serum was collected every two days after immunization, and antibodies were detected by indirect ELISA.

[0061] The results showed that the antibody level of the immunized group began to increase significantly on the 4th day, reached a peak on the 8th day, and then slightly decreased within 45 days but still maintained a high level; while the antibody level of the control group was negative throughout the experiment. This shows that the inactivated vaccine of the present invention can quickly reach a high concentration of antibody levels in a short period of time, and the immunity lasts for a long time, and can provide rapid and long-term immune protection for goslings.

[0062] The above description is only a preferred embodiment of the present application and is not intended to limit the present application. For those skilled in the art, the present application may have various modifications and variations. Any modification made within the spirit and principle of the present application shall be deemed to be appropriate. Equivalent replacements, improvements, etc. should all be included in the protection scope of this application.

Claims

1. A goose-derived Muscovy duck reovirus, characterized in that: The goose-derived Muscovy duck reovirus was deposited in the China Center for Type Culture Collection on October 30, 2024, with the deposit number: CCTCC NO: V202491.

2. Use of the goose-derived Muscovy duck reovirus according to claim 1 in the preparation of a vaccine for preventing and treating "speckled liver disease" and joint cavity hemorrhage in goslings.

3. The use according to claim 2, characterized in that: The vaccine is any one of an inactivated vaccine, a live attenuated vaccine, a subunit vaccine or a genetically engineered vaccine.

4. The use according to claim 3, characterized in that: The vaccine is an inactivated vaccine.

5. An inactivated vaccine for preventing and treating goose "speckled liver disease" and joint cavity hemorrhage, characterized in that: The inactivated vaccine contains an effective amount of inactivated goose-derived Muscovy duck reovirus liquid for prevention or treatment; the deposit number of the goose-derived Muscovy duck reovirus is CCTCC NO: V202491.

6. The inactivated vaccine according to claim 5, characterized in that The method for preparing the inactivated goose-derived Muscovy duck reovirus liquid comprises the following steps: (1) The goose-derived Muscovy duck reovirus strain with a deposit number of CCTCC NO: V202491 was inoculated into LMH cells, the goose-derived Muscovy duck reovirus was proliferated and cultured, the cells were broken by freezing and thawing, the supernatant was collected, and purified to obtain the goose-derived Muscovy duck reovirus liquid; (2) Add formaldehyde with a final concentration of 0.2% to the goose-derived Muscovy duck reovirus solution obtained in step (1), and stir and inactivate the solution at 37° C. for 16 h to obtain an inactivated goose-derived Muscovy duck reovirus solution.

7. The inactivated vaccine according to claim 6, characterized in that The virus titer of the goose-derived Muscovy duck reovirus liquid is 10 -6.2 TCID 50 / 0.1 mL.

8. The inactivated vaccine according to claim 6, characterized in that The inactivated vaccine also contains a pharmaceutically acceptable adjuvant.

9. The inactivated vaccine according to any one of claims 5 to 8, characterized in that The method for preparing the inactivated vaccine comprises the following steps: Take inactivated goose-derived Muscovy duck reovirus liquid, add Tween-80 to mix as the water phase, mix white oil, aluminum stearate and Span-80 as the oil phase, mix the oil phase and the water phase in a ratio of 2:1, emulsify, and obtain an inactivated vaccine for preventing and treating goose-derived Muscovy duck reovirus.

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