Bacteriophage capable of splitting salmonella bolidanae as well as composition and application of bacteriophage

Abstract

The invention relates to the technical field of salmonella bacteriophages, and in particular relates to a bacteriophage capable of splitting salmonella brassicae as well as a composition and application of the bacteriophage capable of splitting the salmonella brassicae. The bacteriophage is salmonella bacteriophage RDP-SA-22010, the preservation number of the bacteriophage is CGMCC (China General Microbiological Culture Collection Center) No.45274, and the bacteriophage is preserved in the China General Microbiological Culture Collection Center on September 21, 2022. The salmonella bacteriophage RDP-SA-22010 can also be used for cracking salmonella enteritidis, salmonella pullorum and salmonella kafenkii. The invention also relates to a composition, which comprises the salmonella bacteriophage RDP-SA-22010. The reagent or the kit comprises the composition. The invention also provides application of the salmonella bacteriophage RDP-SA-22010 to preparation of a biological bactericide, preparation of a medicine for treating diseases caused by salmonella and preparation of a feed additive. The salmonella bacteriophage RDP-SA-22010 disclosed by the invention provides a novel biological prevention and treatment means for the prevention and treatment of salmonella bulidan.

Description

Technical Field

[0001] The present invention relates to the technical field of Salmonella phage, and in particular to a phage capable of lysing Salmonella buridan, and a composition and application thereof. Background Art

[0002] Salmonella is a major pathogen causing food poisoning in livestock and humans, posing a serious threat to the livestock and poultry industry and human health. Traditional Salmonella control methods rely primarily on antibiotics and chemical fungicides, but these methods pose challenges such as drug residues, environmental pollution, and drug resistance. Bacteriophages, as naturally occurring bacterial viruses, possess the ability to specifically lyse host bacteria and are therefore widely used in biological control.

[0003] In recent years, food poisoning incidents caused by Salmonella buridanes have become frequent, with detection rates increasing annually. Clinical symptoms of poisoning include high fever, abdominal pain, diarrhea, nausea, and vomiting. Symptoms in poultry are similar to those of Salmonella enterica serovar Enteritidis, including lethargy, drooping of the head and eyes, drooping wings, ruffled feathers, significant anorexia, increased water intake, watery diarrhea, fecal matter sticking to the anus, and a fear of cold, resulting in proximity to heat sources or crowding. Due to the similar symptoms, misdiagnosis is highly likely, ultimately delaying optimal treatment and causing significant losses. Furthermore, Salmonella buridanes can be carried in animals, making cross-contamination during slaughter a common risk, leading to food poisoning. In addition to horizontal transmission, the pathogen can also be transmitted vertically throughout the entire breeding cycle, significantly impacting poultry farming and human food safety.

[0004] Currently, there are no phages specific to Salmonella buridan on the market, so effective phages against Salmonella buridan are still in urgent need of development. Summary of the Invention

[0005] To address the deficiencies in the prior art, the present invention provides a bacteriophage RDP-SA-22010 targeting Salmonella buridan. Furthermore, the Salmonella phage RDP-SA-22010 of the present invention can not only lyse Salmonella buridan, but also has a good lysis effect on Salmonella Enteritidis, Salmonella Pullorum and Salmonella Kentucky.

[0006] The technical solution of the present invention is:

[0007] A bacteriophage that can lyse Salmonella Blegdam bacteriophage, the phage being Salmonella phage RDP-SA-22010, with a deposit number of CGMCC No. 45274, deposited in the General Microbiology Center of the China Culture Collection Administration on September 21, 2022.

[0008] On the other hand, the Salmonella phage RDP-SA-22010 can also lyse Salmonella Enteritidis, Salmonella Pullorum and Salmonella Kentucky.

[0009] On the other hand, the full gene sequence of the Salmonella phage RDP-SA-22010 in the present invention is 43035 bp in length, with a total of 59 open reading frames, and no genes encoding lysogeny, antibacterial, virulence or toxin-antitoxin related genes were detected.

[0010] On the other hand, the electron microscope photograph of the Salmonella phage RDP-SA-22010 of the present invention shows that the phage belongs to the family of Longicaudaceae, has a regular hexagonal head, a head diameter of about 65 nm, and a tail length of 105 nm.

[0011] On the other hand, the Salmonella phage RDP-SA-22010 of the present invention has good stability at a temperature of 50-70°C and a pH of 5-10. The Salmonella phage RDP-SA-22010 of the present invention maintains a titer of 10 at a temperature of 80°C for 5 minutes. 8 pfu / mL or above; it remains active when maintained at 80°C for 15 minutes.

[0012] On the other hand, the titer of the Salmonella phage RDP-SA-22010 of the present invention can reach 10 11 pfu / mL or above.

[0013] On the other hand, the Salmonella phage RDP-SA-22010 of the present invention has an incubation period of 5 minutes and an outbreak period of 50 minutes.

[0014] On the other hand, the Salmonella phage RDP-SA-22010 of the present invention can maintain a titer of 10 after being stored at 4°C without any treatment for 24 months. 9 pfu / mL, under -80℃ and freeze-dried conditions, the titer of Salmonella phage RDP-SA-22010 remained at the same order of magnitude.

[0015] On the other hand, the optimal multiplicity of infection of the Salmonella phage RDP-SA-22010 in the present invention is 0.01.

[0016] Based on the same inventive concept, the present invention provides a composition comprising Salmonella phage RDP-SA-22010.

[0017] Based on the same inventive concept, the present invention provides a reagent or kit comprising the above composition.

[0018] Based on the same inventive concept, the present invention provides an application of the above-mentioned Salmonella phage RDP-SA-22010. The Salmonella phage RDP-SA-22010 can be used in the preparation of biocides, the preparation of drugs for treating diseases caused by Salmonella, and the preparation of feed additives.

[0019] Based on the same inventive concept, the present invention provides that the Salmonella phage RDP-SA-22010 can be used to prepare a biofungicide against Salmonella buridan, a drug for treating diseases caused by Salmonella buridan, and a feed additive against Salmonella buridan.

[0020] Based on the same inventive concept, the present invention provides that the Salmonella phage RDP-SA-22010 can be used as a daily disinfectant to specifically kill Salmonella in the environment and improve the distribution of microorganisms there. It can also be used as a biofungicide in the breeding, transportation, and storage of livestock and poultry products to prevent and control pathogenic Salmonella contamination during the breeding, transportation, and storage of livestock and poultry products. It can also be used in combination with other disinfectants and sprayed in food production workshops to prevent and control Salmonella contamination during food processing.

[0021] Based on the same inventive concept, the present invention provides the Salmonella phage RDP-SA-22010, which can be added to feed to specifically and continuously prevent the survival and reproduction of Salmonella in feed, and prevent Salmonella contamination during feed storage and animal breeding.

[0022] Deposit information: Salmonella phage RDP-SA-22010, deposited with CGMCC No. 45274, was deposited in the General Microbiology Center of China Culture Collection Administration on September 21, 2022

[0023] The beneficial effects achieved by the present invention are:

[0024] 1. The Salmonella phage RDP-SA-22010 of the present invention can lyse Salmonella buridan, treat or prevent diseases and biological environmental pollution caused by Salmonella buridan. The titer of the Salmonella phage RDP-SA-22010 of the present invention can reach 10 11 pfu / mL or above, providing a reliable phage for biological control of Salmonella buridan.

[0025] 2. The Salmonella phage RDP-SA-22010 of the present invention can also be used to lyse Salmonella Enteritidis, Salmonella Pullorum and Salmonella Kentucky, and has a wide range of applications.

[0026] 3. The Salmonella phage RDP-SA-22010 of the present invention has good thermal stability and tolerance. The titer is maintained at 10 in a water bath at 70°C for 60 minutes. 4 pfu / mL, the titer was still high, and the titer was maintained at 10 at 80℃ for 5 minutes. 8 pfu / mL or above; it remains active when maintained at 80°C for 15 minutes.

[0027] 4. The Salmonella phage RDP-SA-22010 of the present invention has good pH stability and wide tolerance. It is relatively stable between pH 5 and 10 and is still active after being maintained at pH 2 for 2 hours.

[0028] 5. The Salmonella phage RDP-SA-22010 of the present invention can maintain a titer of 10 after being stored at 4°C without any treatment for 24 months. 9 pfu / mL, under -80℃ and freeze-dried conditions, the titer of Salmonella phage RDP-SA-22010 remained at the same order of magnitude.

[0029] 6. The optimal multiplicity of infection of the Salmonella phage RDP-SA-22010 of the present invention is 0.01.

[0030] 7. The incubation period of the bacteriophage RDP-SA-22010 in the present invention is short, at 5 minutes. The phage titer then increases sharply, remaining stable after 60 minutes. The phage burst period is 50 minutes, indicating rapid host cell lysis. The lysis yield, calculated as the ratio of the phage titer at the end of lysis to the host bacterial load at the beginning of infection, was 72 PFU / cell.

[0031] 8. The Salmonella phage RDP-SA-22010 of the present invention can be used in the preparation of biocides, the preparation of drugs for treating diseases caused by Salmonella, and the preparation of feed additives, to replace the use of antibiotics in the prevention and control of livestock and poultry breeding, and can be highly efficient and economical in practical applications. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 This is the plaque image of the Salmonella phage RDP-SA-22010 of the present invention.

[0033] Figure 2 This is an electron microscope image of the Salmonella phage RDP-SA-22010 of the present invention.

[0034] Figure 3 This is the one-step growth curve of the Salmonella phage RDP-SA-22010 of the present invention.

[0035] Figure 4 Graph showing the effect of temperature on the titer of the Salmonella phage RDP-SA-22010 of the present invention.

[0036] Figure 5 This figure shows the effect of a temperature of 80° C. on the potency of the Salmonella phage RDP-SA-22010 of the present invention.

[0037] Figure 6 This is the pH stability result of the Salmonella phage RDP-SA-22010 of the present invention.

[0038] Figure 7 This is the inhibition curve of the Salmonella phage RDP-SA-22010 of the present invention.

[0039] Figure 8 This is the genome map of the Salmonella phage RDP-SA-22010 of the present invention. DETAILED DESCRIPTION

[0040] The following will be combined with the contents of the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the embodiments described are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0041] Unless otherwise defined, all technical and scientific terms used in this specification have the same meanings as those commonly understood by those skilled in the art to which this invention pertains. The terms used in this specification are intended solely for the purpose of describing specific embodiments and are not intended to limit the invention. The term "and / or" as used in this specification includes any and all combinations of one or more of the associated listed items.

[0042] Unless otherwise specified, the experimental methods used in the following examples are conventional methods.

[0043] Unless otherwise specified, the materials and reagents used in the following examples can be obtained from commercial sources.

[0044] Hereinafter, Salmonella bacteriophage RDP-SA-22010 may be referred to as “bacteriophage RDP-SA-22010” or “RDP-SA-22010” for short.

[0045] Example 1: Isolation and Identification of Salmonella

[0046] Liver samples were collected from dead chickens and aseptically streaked onto SS agar (Salmonella Shigella agar). After incubation at 37°C for 20 hours, neat colonies with black centers and white edges, approximately 2-3 mm in diameter, appeared on the SS agar plate. Representative colonies were streaked onto LB (Luria-Bertani) agar plates and incubated at 37°C for 20 hours. Diffuse growth was observed on the LB agar plate. Representative colonies were streaked and purified three times. A single colony was then inoculated into 5 mL of LB liquid medium and incubated at 37°C with shaking at 200 rpm for 8 hours to obtain a uniform, turbid bacterial suspension. 16sRNA molecular identification confirmed the bacterial strain as Salmonella.

[0047] Biochemical identification was performed using a complete set of Salmonella biochemical identification tubes (Qingdao Haibo Biotechnology Co., Ltd.) according to the manufacturer's instructions, demonstrating positive reaction kinetics, acid production, gas production, and hydrogen sulfide production. Serological identification was performed using a Salmonella diagnostic serum kit (Ningbo Tianrun Biopharmaceutical Co., Ltd.) according to the manufacturer's instructions. The AF polyvalent serum agglutination test was positive (++++), and the bacterial O9 antigen (++++), O12 antigen (++++), and flagellar H antigen m and q were both positive (+++). These test results ultimately confirmed the infection as Salmonella buridan.

[0048] Example 2: Isolation and identification of bacteriophage

[0049] (1) Sampling

[0050] The test samples of the present invention were collected from sewage around farms in Liaoning Province in 2024 as water samples for phage separation. Take 10 mL of sewage, centrifuge at 10,000 rpm for 5 minutes, remove larger impurities and most of the bacteria, and then filter and sterilize with a 0.22 μm microporous filter membrane. Take 3 mL of filtrate and 3 mL of host bacterial suspension, add them together to 20 mL of LB broth liquid culture medium after high-pressure sterilization, and then place them in a 37°C incubator for overnight culture. After culture, take 5 mL, centrifuge at 10,000 rpm for 5 minutes, and then filter and sterilize with a 0.22 μm microporous filter. The filtrate is the original solution intended to contain phage. Then, the double plate method is used to identify whether there are phages. If there are plaques, there are phages. Otherwise, it means that the phages have not been isolated and need to be re-screened.

[0051] (2) Phage purification

[0052] The size and morphology of the initially isolated plaques are often inconsistent, so further purification is required. Pick a single, independent, uniform, clear and transparent plaque on the double-layer plate with plaques, place it in 1 mL of normal saline, soak it for 10 minutes, take the clear liquid, filter it with a 0.22 μm microporous filter, and then dilute the filtrate appropriately (there will be a single plaque when spreading the double plates), and spread the double plates with the host bacterial suspension. Repeat this step 3 to 4 times. When the size, morphology and clarity of the plaques on the double plates are consistent, the purified phage is obtained. Figure 1 As shown, the plaques have consistent morphology, size and clarity, and have typical lytic phage characteristics.

[0053] (3) Determination of phage titer

[0054] The purified phage was spread on a double-layer plate, and then a single phage plaque was taken and added to LB liquid medium. At the same time, the host bacterial suspension was added. After the phage was proliferated, the proliferated liquid was centrifuged at 10000 rpm for 5 minutes and then filtered with a 0.22 μm microporous filter. The filtrate was diluted 10 times to 10 8 Take 0.1 mL of the last three dilutions of phage dilution and 0.1 mL of host bacterial suspension, spread on double-layer plates, and determine the phage titer.

[0055] Phage titer (pfu / mL) = number of plaques * dilution factor ÷ 0.1

[0056] The titer of the phage can reach 10 11 pfu / mL or above.

[0057] Example 3: Morphological observation of Salmonella phage RDP-SA-22010

[0058] Using the phosphotungstic acid negative staining method: drop phage solution (titer 10) on the paraffin slide 10 pfu / mL) and placed the copper mesh with the membrane side on the phage droplet. After 10 minutes, remove the mesh and air dry for 2-3 minutes. Then, add a drop of 2% phosphotungstic acid (PTA) aqueous solution to the copper mesh for staining. After 10 minutes, remove the mesh and air dry for 10-15 minutes. Observe with an electron microscope and take a photo of the clear phage image. Figure 2 As shown in the electron microscope photo, it can be seen that the phage belongs to the family of Longicaudae phage, with a regular hexagonal head, a head diameter of about 65nm, and a tail length of 105nm.

[0059] Example 4: One-step growth curve of Salmonella phage RDP-SA-22010

[0060] Salmonella phage RDP-SA-22010 was mixed with host bacteria at an optimal MOI and incubated at 37°C for 10 minutes to allow the phage to adsorb to the host bacteria. The mixture was then centrifuged at 10,000 rpm for 5 minutes, the supernatant discarded, and the mixture was resuspended in an equal volume of LB broth. This process was repeated twice to remove any unadsorbed phage. 10 mL of the above solution was added to 90 mL of LB broth. 1 mL samples were taken at regular intervals (i.e., at 0, 10, 20, 30, 40, 50, 60, 90, 120, 150, 180, and 240 minutes) and centrifuged at 10,000 rpm for 5 minutes. The supernatant was then collected and the phage titer was determined using the double-plate method.

[0061] Depend on Figure 3 As shown, the curve of phage RDP-SA-22010 remained stable for the first 5 minutes, indicating a relatively short incubation period of 5 minutes. The phage titer then increased dramatically, remaining stable after 60 minutes. The phage burst lasted 50 minutes, indicating rapid lysis of host cells. The lysis yield, calculated as the ratio of the phage titer at the end of lysis to the host bacterial load at the beginning of infection, was 72 PFU / cell.

[0062] Example 5: Thermal stability of Salmonella phage RDP-SA-22010

[0063] Adjust the phage titer to 10 9 pfu / mL, and then divided into 1.5mL centrifuge tubes, adding 1mL to each centrifuge tube, and then the divided phage liquid was water bathed at 50℃, 60℃, 70℃, and 80℃ for 30min. After the water bath, double-layer plates were spread to determine the phage titer.

[0064] Depend on Figure 4 As shown, the titer of bacteriophage RDP-SA-22010 was 10 at 70℃ for 60min in water bath. 4 pfu / mL, the titer is still high. Figure 5 As shown, the titer of phage RDP-SA-22010 was maintained at 10 at 80℃ for 5 minutes. 8 pfu / mL or more; it remained active at 80°C for 15 minutes. Therefore, the phage RDP-SA-22010 has good temperature tolerance.

[0065] Example 6: pH stability of Salmonella phage RDP-SA-22010

[0066] Take 100 μL of the titer of 10 9 The phage suspension of 100 pfu / mL was added to 900 μL of phosphate buffer with different pH values (2-13), placed in a 37°C water bath for 2 h, and then double-layered plates were spread to determine the titer of the phage in each centrifuge tube.

[0067] Depend on Figure 6 As shown, phage RDP-SA-22010 is relatively stable between pH 5 and 10, and is still active after being maintained at pH 2 for 2 hours. Therefore, the phage has a wide tolerance to pH.

[0068] Example 7: Storage of Salmonella phage RDP-SA-22010

[0069] Take the titer as 10 11 The phage solution containing 100 pfu / mL was centrifuged at 10,000 rpm for 5 minutes, sterilized with a 0.22 μm filter, and then stored using three methods: First, storage at 4°C: aliquot the sterile phage RDP-SA-22010 solution into 2 mL cryovials, 1 mL per cryovial, and stored in a 4°C refrigerator. Second, ultra-low temperature storage: mix the phage RDP-SA-22010 solution with 60% glycerol (60 g glycerol + 40 g LB broth) in a 1:1 ratio, aliquot the solution into 2 mL cryovials, 1 mL per cryovial, and store in a -80°C refrigerator. The third method involved mixing the bacteriophage RDP-SA-22010 solution with a lyoprotectant (5g skim milk powder, 2g mannitol, 100mL water) in a 1:1 ratio. The solution was dispensed into 400µL ampoules, dehydrated in a freeze dryer, sealed, and stored in a refrigerator at 4°C. The titer of the bacteriophage RDP-SA-22010 was measured every three months. The results are shown in the table below:

[0070] Table 1: Changes in the titer of bacteriophage RDP-SA-22010 under different storage conditions

[0071]

[0072] Note: The unit is *10 9 pfu / mL

[0073] As shown in Table 1, the phage RDP-SA-22010 is relatively stable. After being stored at 4°C for 24 months without any treatment, the phage titer can still be maintained at 10 9 pfu / mL, under ultra-low temperature and freeze-dried conditions, the phage titer remained at the same order of magnitude.

[0074] Example 8: Determination of the optimal multiplicity of infection

[0075] The multiplicity of infection (MOI) refers to the ratio of the number of phages to the number of host bacteria at the time of initial infection. Phages were mixed with host bacteria at various MOI values (0.001, 0.01, 0.1, 1, 10, 100, 1000) and incubated in a shaker at 37°C and 160 rpm for 6 hours. Following incubation, the supernatant was centrifuged at 10,000 rpm for 5 minutes. The phage titer in the supernatant was determined using the double-layer plate method at various MOI values.

[0076] Table 2: Phage titers of supernatants from samples at different MOI values:

[0077] MOI <![CDATA[Phage titer (*10 8 pfu / mL)]]> 0.001 351 0.01 1020 0.1 540 1 198 10 224 100 95 1000 71

[0078] As shown in Table 2, when the MOI of phage RDP-SA-22010 was 0.01, the phage titer was the highest at 1.02×10 11 PFU / mL, so the optimal MOI of bacteriophage RDP-SA-22010 is 0.01.

[0079] Example 9: Salmonella phage RDP-SA-22010 lysis spectrum experiment

[0080] The Salmonella phage RDP-SA-22010 of the present invention was used to conduct a lysis spectrum experiment on Salmonella Enteritidis, Salmonella Pullorum, Salmonella Kentucky, Salmonella Dublin, Salmonella Typhi, Salmonella Indiana and Salmonella Buridan. The experimental results are shown in the following table:

[0081] Table 3: Lysis spectrum of Salmonella phage RDP-SA-22010

[0082] salmonella Cracking capacity Salmonella Enteritidis + Salmonella pullorum + Salmonella Kentucky + Salmonella Dublin - Salmonella Typhi - Salmonella Indiana - Salmonella Buridan +

[0083] Note: “+” indicates cleavable, “-” indicates non-cleavable

[0084] As can be seen from the experimental results in Table 3, the Salmonella phage RDP-SA-22010 of the present invention can not only lyse Salmonella buridan, but also has a good lysis effect on other serotypes of Salmonella, such as Salmonella Enteritidis, Salmonella Pullorum and Salmonella Kentucky.

[0085] Example 10: Determination of the inhibition curve of Salmonella phage RDP-SA-22010

[0086] First, 100 μL of host bacteria and phage RDP-SA-22010 were added according to the optimal MOI, mixed, incubated at 37°C for 10 min, and then inoculated into 5 mL of LB broth medium. A total of 7 groups of samples were prepared and cultured in a shaker at 37°C and 160 rpm. The OD value at a wavelength of 600 nm was measured in one test tube every 1 h.

[0087] Depend on Figure 7 The experimental results show that compared with the positive control without phage RDP-SA-22010, phage RDP-SA-22010 inhibited the growth of different Salmonella species within 10 hours, with a particularly strong inhibitory effect on Salmonella buridan.

[0088] Example 11: Whole genome sequencing of Salmonella phage RDP-SA-22010

[0089] After enrichment and cultivation of a single phage, centrifuge at 8000g for 15 minutes at 4°C, add 10% PEG8000 and 0.5M NaCl and let it stand overnight, then add an equal amount of chloroform and mix well. After standing and stratification, centrifuge at 5000g for 10 minutes. After removing the chloroform layer and PEG layer, add restriction endonuclease for digestion, and suspend the phage under gradient density cesium chloride conditions. Later, dialyze 3 times with TM (Temperature Melting) buffer, each time for 30 minutes. Finally, a part of the dialyzed phage is reserved for electron microscopy observation, and a part is sent to BGI Biological Sequencing Company for whole genome sequencing. The phage sequence is shown in SEQ ID NO.1. The genome map is shown in Figure 8 As shown, the complete gene sequence of the phage RDP-SA-22010 is 43035bp, with a total of 59 open reading frames, and no genes encoding lysogeny, antibacterial, virulence or toxin-antitoxin related genes were detected.

[0090] Example 12: Chicken embryo protection experiment

[0091] This experiment selected 1-week-old chicken embryos and was divided into 3 groups, each with 100 chicken embryos. One group was the blank control group, in which the chicken embryos were injected with 0.2mL LB broth; one group was the Salmonella Buridan challenge group, in which the chicken embryos were injected with 0.1mL Salmonella bacteria liquid and 0.1mL LB broth; and one group was the treatment group, in which the chicken embryos were injected with 0.1mL Salmonella bacteria liquid and 0.1mL phage liquid. After the treatment, the chickens were placed in an incubator and hatched, and the mortality rate and hatchability were recorded. Then, the 7-day-old chickens that were hatched were aseptically dissected and ground. The grinding liquid was inoculated into a selenite cystine enrichment solution (SC enrichment solution) at a ratio of 10% and cultivated at 37°C for 20h. Then, the culture solution was picked with an inoculating loop and inoculated on SS agar. After the inoculation, the flat plate was placed in a 37°C incubator and cultivated for 20h to observe whether there was Salmonella.

[0092] Table 4: Results of chicken embryo protection experiment

[0093] Number of deaths Hatching rate / piece Salmonella detection rate Blank group 20 80 0 Poison attack group 90 10 100％ Treatment group 30 70 0

[0094] As can be seen from the experimental results in Table 4 above, no Salmonella was detected in the chickens hatched in the treatment group, indicating that the Salmonella phage RDP-SA-22010 has a good therapeutic effect on diseases caused by Salmonella buridanum.

[0095] The above-described embodiments of the present invention do not limit the scope of protection of the present invention. Any modifications, equivalent substitutions, and improvements made within the spirit and principles of the present invention should be included in the scope of protection of the claims of the present invention.

Claims

1. A bacteriophage capable of lysing Salmonella Blegdam, characterized in that: The phage is Salmonella phage RDP-SA-22010, with a preservation number of CGMCC No. 45274, and was deposited in the General Microbiology Center of the China Culture Collection Administration on September 21, 2022.

2. The bacteriophage capable of lysing Salmonella buridan according to claim 1, characterized in that: The Salmonella phage RDP-SA-22010 can also lyse Salmonella Enteritidis, Salmonella Pullorum and Salmonella Kentucky.

3. The bacteriophage capable of lysing Salmonella buridan according to claim 1, characterized in that: The Salmonella phage RDP-SA-22010 was maintained at a titer of 10 at 80°C for 5 minutes. 8 pfu / mL or above; it remains active when maintained at 80°C for 15 minutes.

4. The bacteriophage capable of lysing Salmonella buridan according to claim 1, characterized in that: The Salmonella phage RDP-SA-22010 can maintain a titer of 10 after being stored at 4°C for 24 months without any treatment. 9 pfu / mL, under the conditions of -80°C and freeze-dried, the titer of the Salmonella phage RDP-SA-22010 remained unchanged at the same order of magnitude.

5. The bacteriophage capable of lysing Salmonella buridan according to claim 1, characterized in that: The titer of the Salmonella phage RDP-SA-22010 can reach 10 11 pfu / mL or above, the incubation period is 5 minutes and the outbreak period is 50 minutes.

6. The bacteriophage capable of lysing Salmonella buridan according to claim 1, characterized in that: The optimal multiplicity of infection of the Salmonella phage RDP-SA-22010 is 0.

01.

7. A bacteriophage capable of lysing Salmonella buridan according to claim 1, characterized in that: The Salmonella phage RDP-SA-22010 can be applied to the preparation of biological fungicides, the preparation of medicines for treating diseases caused by Salmonella, and the preparation of feed additives.

8. A bacteriophage capable of lysing Salmonella buridan according to claim 7, characterized in that: The Salmonella phage RDP-SA-22010 can be applied to the preparation of a biofungicide targeting Salmonella buridan, the preparation of a medicine for treating diseases caused by Salmonella buridan, and the preparation of a feed additive targeting Salmonella buridan.

9. A composition, characterized in that: The invention comprises the Salmonella phage RDP-SA-22010 according to claim 1 or 2.

10. A reagent or kit comprising the composition according to claim 9.

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