Staphylococcus aureus phage and application thereof

Abstract

The invention belongs to the technical field of bioengineering, and provides a staphylococcus aureus bacteriophage and application thereof. The staphylococcus aureus bacteriophage provided by the invention is XHX-SA-1P, is preserved in the China Center for Type Culture Collection, has the preservation number of CCTCC NO: M2025494, and is classified and named as the staphylococcus aureus bacteriophage, the bacteriophage is obtained by separating and purifying an infected sample, the lysis spectrum is wide, the lysis efficiency is high, and the staphylococcus aureus bacteriophage has good environmental stability and multiplication capacity; the bacteriophage can be used for preparing an oral preparation, a freeze-drying preparation or a microcapsule preparation, can also be used as an active ingredient of a feed additive, and is used for preventing or treating diseases related to staphylococcus aureus infection of poultry and improving the biosafety level and the prevention and control effect in the breeding process.

Description

Technical Field

[0001] This invention belongs to the field of bioengineering technology and relates to a Staphylococcus aureus bacteriophage and its applications. Background Technology

[0002] Staphylococcus aureus is an environmental pathogen widely distributed in soil, water, and air. Diseases caused by Staphylococcus aureus in poultry are known as avian staphylococcal disease, a zoonotic infectious disease. Chickens infected with Staphylococcus aureus often exhibit symptoms such as joint disease, omphalitis, skin hemorrhage, necrosis, and synovitis, as well as eyelid swelling and difficulty breathing. This disease is one of the most serious threats to intensive poultry farming, causing significant economic losses to the poultry industry.

[0003] Bacteriophages are viruses that use bacteria as hosts to replicate themselves, ultimately lysing and killing the bacteria. Due to their specific bactericidal properties, bacteriophages do not harm beneficial bacteria, produce no toxic side effects or drug residues, and are considered a super weapon against drug-resistant bacteria. Bacteriophages, with their high specificity for host bacteria, strong lytic ability, and ease of large-scale production, have shown a broader application prospect and value than antibiotics.

[0004] In recent years, bacteriophages have been widely used to prevent and treat bacterial infections. Some applications of Staphylococcus aureus bacteriophages have been disclosed in existing technologies, but many of these bacteriophages have limitations such as narrow host spectrum and poor temperature and pH stability. Summary of the Invention

[0005] To address the shortcomings of existing technologies, the present invention aims to provide a Staphylococcus aureus phage and its application. The present invention provides a Staphylococcus aureus phage XHX-SA-1P, with the accession number CCTCC NO: M2025494. This phage can be used to treat joint disease caused by Staphylococcus aureus infection in chickens, thereby meeting the needs of actual production.

[0006] To achieve this objective, the present invention adopts the following technical solution:

[0007] This invention provides a Staphylococcus aureus bacteriophage, specifically comprising: a Staphylococcus aureus bacteriophage XHX-SA-1P screened from wastewater from a chicken farm in Weifang City, Shandong Province. The phage, XHX-SA-1P, was deposited at the China Center for Type Culture Collection (CCTCC) on March 17, 2025. The address of the depository is Wuhan University, China, 430072, China, with accession number CCTCC NO: M2025494. It was classified and named Staphylococcus aureus bacteriophage. On March 24, 2025, the CCTCC identified phage XHX-SA-1P as viable.

[0008] The bacteriophage has an icosahedral head and a retractable tail; it forms clear plaques on 1.2% LB agar medium with no halo, clear and regular edges, and a diameter of 0.5-1 mm; the restriction enzyme digestion pattern of the genome shows that the bacteriophage's nucleic acid is double-stranded DNA (dsDNA); according to the International Committee on Taxonomy of Viruses (ICTV) 2005 report, XHX-SA-1P belongs to the Myoviridae family. The bacteriophage is stable at 30-70°C for 60 min, but inactivated at 80°C; its titer is not significantly different from the initial titer at pH 5.0-10.0.

[0009] The optimal multiple of infection (MOI) of the Staphylococcus aureus phage XHX-SA-1P provided by this invention is 0.001. Under these conditions, the incubation period is about 30 minutes, the outbreak period is about 90 minutes, and the outbreak dose is about 277 PFU / CFU. At the same time, it has a good lytic effect on clinical isolates of Staphylococcus aureus from chickens.

[0010] The method for preparing the Staphylococcus aureus phage is as follows: Staphylococcus aureus is used as the host bacterium to enrich and culture the sample to be tested, and the supernatant is collected and filtered after centrifugation; phage plaques are formed by separating them using the double-layer agar plate method; a single phage plaque is picked and purified repeatedly to obtain Staphylococcus aureus phage.

[0011] Preferably, the sample to be tested is a chicken farm wastewater sample.

[0012] Preferably, the step of picking a single plaque and repeating purification is to continuously pick a single plaque and repeat purification 4 to 5 times.

[0013] The present invention provides a phage composition comprising Staphylococcus aureus phage XHX-SA-1P as described above.

[0014] The present invention also provides the use of the Staphylococcus aureus phage XHX-SA-1P as described above or the phage composition as described above in the preparation of a medicament for the prevention or treatment of diseases caused by Staphylococcus aureus infection.

[0015] In this document, the term "prevention" refers to all actions that suppress or delay the disease by administering the phage; the term "treatment" refers to all actions that improve or alleviate the disease by administering the phage.

[0016] The above-mentioned drugs can be used to prevent or treat Staphylococcus aureus infections in animals (chickens, pigs, cattle, geese, ducks, etc.).

[0017] Furthermore, the present invention provides a phage drug formulation, wherein the active ingredient of the phage drug formulation includes Staphylococcus aureus phage XHX-SA-1P as described above or a phage composition as described above.

[0018] Furthermore, the phage drug formulation also includes a pharmaceutically acceptable carrier; the dosage form of the phage drug formulation includes one or more of the following: solution, powder, gel, granule, emulsion, suspension, and lyophilized agent.

[0019] As used in this article, the term "pharmaceutically acceptable carrier" refers to a carrier or diluent that does not cause significant irritation to the organism and does not eliminate the biological activity and properties of the given active ingredient.

[0020] Furthermore, the present invention also provides a feed additive comprising Staphylococcus aureus phage XHX-SA-1P as described above or a phage composition as described above. The feed additive, when mixed with feed and fed to the patient, achieves the effect of preventing or treating Riemerella anatipestifer infection.

[0021] In addition, the present invention provides a disinfectant comprising Staphylococcus aureus phage XHX-SA-1P as described above or a phage composition as described above.

[0022] Furthermore, the disinfectant also contains other active ingredients or other adjuvants for inhibiting or eliminating bacteria in the environment, such as adjuvants that can prolong the duration of bacteriophage activity.

[0023] Secondly, the present invention also provides the application of the disinfectant as described above, wherein the disinfectant is used to disinfect the breeding environment, feed, drinking water or the surface of poultry and livestock by spraying or soaking to kill Staphylococcus aureus.

[0024] The farm environment refers to the breeding equipment, ground, walls, manure, bedding, and other spatial environments.

[0025] Compared with the prior art, the beneficial effects of the present invention are as follows: (1) The Staphylococcus aureus phage XHX-SA-1P provided by the present invention has a clear source and stable characteristics. It can form clear plaques and belongs to the Myotailviridae family. Its nucleic acid is double-stranded DNA. The optimal multiplicity of infection of this phage is 0.001. The one-step growth curve shows that its incubation period is about 30 min, the outbreak period is about 90 min, and the outbreak amount is about 277 PFU / CFU. At the same time, it has a good lysis effect on the clinical isolates of Staphylococcus aureus from chickens, which can provide new biological resources for the prevention and control of joint diseases caused by Staphylococcus aureus infection in poultry; (2) It has good temperature and pH stability: its activity remains basically unchanged below 50℃, and it can maintain a relatively high titer at pH 5.0~11.0.

[0026] Biological Preservation Instructions:

[0027] A Staphylococcus aureus bacteriophage, XHX-SA-1P, was deposited at the China Center for Type Culture Collection (CCTCC) on March 17, 2025. The address of the depository is Wuhan University, China, 430072, China, and the accession number is CCTCC NO: M2025494. It is classified and named Staphylococcus aureus bacteriophage. Attached Figure Description

[0028] Figure 1 Photograph of plaques from bacteriophage XHX-SA-1P;

[0029] Figure 2 Transmission electron microscopy image of bacteriophage XHX-SA-1P;

[0030] Figure 3 Results of the thermal stability of bacteriophage XHX-SA-1P;

[0031] Figure 4 The pH stability results for bacteriophage XHX-SA-1P;

[0032] Figure 5 This represents the optimal multiplicity of infection result for bacteriophage XHX-SA-1P;

[0033] Figure 6 The results show the one-step growth curve of bacteriophage XHX-SA-1P.

[0034] Figure 7 A schematic diagram illustrating the efficacy of bacteriophage XHX-SA-1P in preventing and treating arthritis. Detailed Implementation

[0035] The technical solutions of the present invention will be described in detail below with reference to specific embodiments and accompanying drawings. The embodiments described herein are specific implementations of the present invention, used to illustrate the concept of the present invention; these descriptions are explanatory and exemplary, and should not be construed as limiting the implementation methods or the scope of protection of the present invention. In addition to the embodiments described herein, those skilled in the art can employ other obvious technical solutions based on the content disclosed in the claims and specification of this application. These technical solutions include those that make any obvious substitutions and modifications to the embodiments described herein.

[0036] Unless otherwise specified, the raw materials, reagents and equipment involved in the embodiments of this invention were all purchased from commercial channels.

[0037] The host bacterium involved in the example is Staphylococcus aureus XHX-SA-1, a clinical strain of broiler arthritis, which was isolated from the feces of chickens with leg disease in a chicken farm in Weifang and preserved by the Jiangsu Academy of Agricultural Sciences.

[0038] The whole genome of the Staphylococcus aureus phage XHX-SA-1P of this invention has been sequenced by Sangon Biotech (Shanghai) Co., Ltd. The sequence has been uploaded to the GenBank database with accession number 0R836606.1 and can be searched and downloaded from the website of the National Center for Biotechnology Information (NCBI).

[0039] LB liquid medium (1L): 10g peptone, 5g yeast extract, 10g sodium chloride, add ddH2O to 1L, adjust pH to 7.0, autoclave at 121℃ for 15min, and cool for later use.

[0040] 1.2% LB solid medium (1L): 10g peptone, 5g yeast extract, 10g sodium chloride, 12g agar powder, add ddH2O to 1L, adjust pH to 7.0, autoclave at 121℃ for 15min, cool to 50℃, pour into plates, cool and solidify, then invert for later use.

[0041] 0.6% LB semi-solid medium (1L): 10g peptone, 5g yeast extract, 10g sodium chloride, 6g agar powder, add ddH2O to 1L, adjust pH to 7.0, autoclave at 121℃ for 15min and use.

[0042] 1 mol / L sterile CaCl2 solution (1L): Weigh 111 g of CaCl2 solid using a balance, pour it into a beaker, add water to dissolve it, pour the solution into a 1L volumetric flask, rinse the beaker three times with distilled water, pour the rinsing solution into the volumetric flask, make up to volume, and autoclave for later use.

[0043] SM solution (1L): Weigh 6.055g Tris and dissolve it in 20mL of distilled water. Adjust the pH to 7.5 with concentrated hydrochloric acid and bring the volume to 50mL. Then add 5.8g NaCl and 2g MgSO4, dissolve them, and bring the volume to 1L. Autoclave at 121℃ for 15min.

[0044] DNase I, RNase A, PEG8000, and phosphotungstic acid (PTA, 2% w / v) were commercially available for cooling purposes.

[0045] Example 1: Isolation and preparation of Staphylococcus aureus bacteriophage XHX-SA-1P

[0046] The host bacterium XHX-SA-1 was streaked onto 1.2% LB solid medium and cultured overnight. Then, a single colony was picked and inoculated into 5 mL of LB liquid medium and cultured at 37°C with shaking for 8 h to serve as the host bacterium culture.

[0047] Phage samples were collected from wastewater at a chicken farm in Weifang City, Shandong Province. The supernatant was filtered through double-layered filter paper and centrifuged at 12,000 rpm for 30 min. The supernatant was then filtered through 0.45 μm and 0.22 μm filter membranes for sterilization. 10 mL of the filtrate was taken, and 0.5 mL of the above-mentioned host bacterial culture was added. 10 mL of 2×LB liquid medium (2×LB liquid medium is double-concentration LB liquid medium) was added, and the mixture was incubated overnight at 37℃ and 180 rpm. The next day, the culture was centrifuged at 12,000 rpm and 4℃ for 30 min, and the supernatant was filtered through a 0.22 μm filter membrane for sterilization to obtain a phage suspension.

[0048] Take 10 mL of this supernatant, add 0.5 mL of overnight host culture, add sterile CaCl2 stock solution to a final concentration of 1.25 mM, mix well, add 20 mL of LB liquid medium, culture and centrifuge according to the above method to obtain enriched supernatant; enrich again according to the above experimental method, filter the supernatant enriched three times through a 0.22 μm filter membrane to form phage stock solution;

[0049] Divide a 1.2% LB solid medium plate into two regions. Take 0.1 mL of the above host bacterial culture and 5 mL of 0.6% LB semi-solid medium, mix them evenly, and spread them evenly on the 1.2% LB solid medium. After it dries, take 10 μL of the above phage stock solution and drop it into one of the regions. After it dries naturally, invert it in a 37℃ incubator overnight and observe whether there are any empty plaques in the region where the phage was dropped.

[0050] If plaque formation occurs, it indicates the presence of bacteriophages; take 0.1 mL of the above bacteriophage stock solution and perform a series of 10-fold dilutions; take 10 -2 10 -4 and 10-6 Mix 0.1 mL of each diluent with 0.1 mL of the host bacterial culture. After incubating at room temperature for 15 min, add 5 mL of 0.6% LB agar medium cooled to 45°C, mix well, and quickly spread evenly on a pre-prepared 1.2% LB agar medium plate. After solidification, invert the plate and incubate overnight at 37°C. Observe to obtain a double-layer plate with a single phage plaque.

[0051] Example 2: Amplification and purification of Staphylococcus aureus phage XHX-SA-1P

[0052] On the bilayer plate from which phage plaques were formed in Example 1, a single clear phage plaque was picked up with a pipette tip and inoculated into 5 mL of LB liquid medium. 0.1 mL of phage host culture was added and incubated overnight at 37°C. After centrifugation at 12000 rpm and 4°C for 10 min, the supernatant was collected. The bilayer experiment was repeated, and single phage plaques were picked up 4 to 5 times in this manner to purify the phage into phage plaques of the same size. The phage was named XHX-SA-1P and stored at 4°C for later use.

[0053] Take 0.1 mL of the above-mentioned phage XHX-SA-1P and 0.1 mL of the host bacterial culture prepared in Example 1, and incubate at 37°C for 15 min to allow the phage particles to adsorb onto the host bacteria; add 10 mL of LB liquid medium, and then add CaCl2 stock solution to a final concentration of 1.25 mM, and culture at 37°C with shaking for 12–16 h; centrifuge at 12000 rpm and 4°C for 10 min, and take the supernatant and filter it through a 0.22 μm filter membrane to remove bacteria, which is the phage lysate;

[0054] PEG purification: Add RNase A and DNase I to the phage lysis buffer to a final concentration of 1 μg / mL and incubate at 37°C for 30 min; add PEG8000 to a final concentration of 10% and NaCl to a final concentration of 1 M, shake well until dissolved, and incubate on ice for 1 h or at 4°C overnight; centrifuge at 10000 rpm for 10 min at 4°C and discard the supernatant; add 2 mL of SM solution, wash the precipitate thoroughly, and incubate at room temperature for 1 h; add an equal volume of chloroform for extraction and gently shake for 30 s; centrifuge at 5000 rpm for 10 min at 4°C to separate the organic and hydrophilic phases, recover the hydrophilic phase containing phage particles, and obtain purified phage;

[0055] The phage titer was determined using the double-layer agar plate method: The purified phage solution was serially diluted 10-fold. 0.1 mL of each of the corresponding phage dilutions was mixed thoroughly with 0.1 mL of the host culture from Example 1. 5 mL of 0.6% LB agar medium cooled to 45°C was added, and the mixture was quickly spread evenly on a pre-prepared 1.2% LB agar plate to prepare a double-layer agar plate. After solidification, the plate was inverted and incubated at 37°C for approximately 10 hours. Plaques were counted on each agar plate. Plates showing approximately 100-200 plaques were selected. The initial phage concentration calculated based on the dilution factor was used to determine the phage titer. The phage titer (PFU / mL) = dilution factor × number of plaques × 10. The purified phage... Figure 1 As shown, purified phages can form clear plaques in 1.2% LB agar medium, with no halo around them, clear and regular edges, and a diameter of 1-2 mm.

[0056] The applicant named the purified bacteriophage XHX-SA-1P and deposited it at the China Center for Type Culture Collection (CCTCC). The address of the depository is Wuhan University, China, 430072, China. The accession number is CCTCC NO: M2025494. The classification name is Staphylococcus aureus bacteriophage. The deposit date is March 17, 2025.

[0057] Example 3: Transmission electron microscopy observation of Staphylococcus aureus bacteriophage XHX-SA-1P

[0058] The phage purified by PEG in Example 2 was observed under an electron microscope. The specific procedure was as follows: 10 μL of sample was added to a copper grid and allowed to precipitate for 15 min. Excess liquid was absorbed with filter paper, and the sample was stained with 2% phosphotungstic acid (PTA) for 1–2 min. After drying, the sample was observed using a transmission electron microscope (Hitachi H-7650). The observation results are as follows: Figure 2 As shown, the head is icosahedral, with a diameter of approximately 80 nm and a tail length of approximately 110 nm. According to the International Committee on Taxonomy of Viruses (ICTV) 2005 report, "Taxonomy of Viruses—Eighth Report of the International Committee on Taxonomy of Viruses," XHX-SA-1P belongs to the Myoviridae family.

[0059] Example 4: Temperature stability experiment of Staphylococcus aureus bacteriophage XHX-SA-1P

[0060] Take 6 sterile EP tubes and add 0.5 mL of the purified phage XHX-SA-1P (4.5 × 10⁻⁶) obtained in Example 2 to each tube. 9The PFU / mL values ​​were measured by incubating the tubes in water at 30℃, 40℃, 50℃, 60℃, 70℃, and 80℃ for 30 min, respectively. Immediately after the water bath, the EP tubes were placed at 37℃ for 30 s, and then the potency was determined using the double-layer plate method. The results are as follows: Figure 3 As shown, bacteriophage XHX-SA-1P can withstand high temperatures of 50℃; at 60℃, the bacteriophage titer is significantly reduced; and at 70℃ and 80℃, the bacteriophage is rapidly inactivated.

[0061] Example 5: Acid-base tolerance test of Staphylococcus aureus bacteriophage XHX-SA-1P

[0062] The pH of LB liquid medium was adjusted to 2.0, 3.0, 4.0, 5.0, 6.0, 7.0, 8.0, 9.0, 10.0, 11.0, 12.0, and 13.0 respectively using 1M HCl and 1M NaOH. 0.1 mL of the purified bacteriophage XHX-SA-1P (4.5 × 10⁻⁶) obtained in Example 2 was taken. 9 PFU / mL was added to 0.9 mL of LB liquid medium at different pH values, mixed thoroughly, and incubated at 37°C with shaking for 1 h. The potency was then determined using the double-layer plate method. pH results are shown below. Figure 4 As shown, bacteriophage XHX-SA-1P exhibits high activity in the pH range of 5.0 to 9.0; however, its biological activity decreases significantly when the pH is below 5.0 or above 11.0; and it becomes completely inactive and loses its ability to infect the host when the pH is 2.0, 3.0, 12.0, or 13.0.

[0063] Example 6: Determination of the optimal multiple of infection (MOI) of Staphylococcus aureus bacteriophage XHX-SA-1P

[0064] Take 0.5 mL of the host bacterial culture prepared in Example 1 (adjust the concentration to 1 x 10⁻⁶). 7 Add 0.5 mL of 4.5 × 10⁻⁶ CFU / mL of the purified phage obtained in Example 2. 2 PFU / mL (MOI=0.00001), 4.5×10 3 PFU / mL (MOI=0.0001), 4.5×10 4 PFU / mL (MOI=0.001), 4.5×10 5 PFU / mL (MOI=0.01), 4.5×10 6 PFU / mL (MOI=0.1), 4.5×10 7 PFU / mL (MOI=1), 4.5×10 8 PFU / mL (MOI=10), 4.5×10 9PFU / mL (MOI=100) was added to 4 mL of LB liquid medium, and incubated at 37℃ with shaking at 180 rpm for 4 h. Afterwards, the culture was centrifuged at 8000 rpm for 5 min, filtered through a 0.22 μm microporous filter for sterilization, and then appropriately diluted. The phage titer was determined using the double-layer plate method. Results are as follows: Figure 5 The optimal multiplicity of infection for Staphylococcus aureus phage XHX-SA-1P is 0.001.

[0065] Example 7: Determination of the one-step growth curve of Staphylococcus aureus bacteriophage XHX-SA-1P

[0066] The host bacterial culture prepared in Example 1 was uniformly mixed with the purified phage obtained in Example 2 at the optimal MOI ratio, incubated at 37°C for 10 min, centrifuged at 8000 rpm for 5 min, the supernatant was discarded, and the precipitate was resuspended in 20 mL of preheated LB liquid medium. The mixture was then rapidly incubated at 37°C with shaking at 180 rpm. 500 μL samples were taken at 10-min intervals within the range of 0–150 min, and the phage titer was determined at each time point using the double-layer plate method. Each time point was measured three times, and the average value was taken. A one-step growth curve of the phage was plotted with phage titer as the ordinate and infection time as the abscissa to obtain the phage latency, outbreak period, and outbreak quantity. The results of the one-step growth curve are shown below. Figure 6 As shown, the incubation period for infection with the host bacteria is approximately 30 minutes, the outbreak period is 90 minutes, and the outbreak dose is 277 PFU / CFU.

[0067] Example 8: Determination of the lysis spectrum of Staphylococcus aureus bacteriophage XHX-SA-1P

[0068] Forty chicken-derived Staphylococcus aureus monoclonal strains isolated from clinical poultry joint diseases were selected and cultured in 5 mL LB liquid medium at 37°C and 180 rpm for 8 h to prepare bacterial suspensions. 0.1 mL of each suspension was added to 5 mL of 0.6% LB semi-solid medium at approximately 45°C, and evenly spread on pre-prepared 1.2% LB solid medium. Each plate was then divided into two equal areas. 5 μL of the purified phage obtained in Example 2 was added to one area, and 5 μL of physiological saline was added to the other area as a control. After the droplets dried, the plates were inverted and incubated at 37°C for 12 h. The presence or absence of phage plaques was observed; plaques were marked as "+" if present, and "-" otherwise. The results are shown in Table 1: Staphylococcus aureus phage XHX-SA-1P could lyse 35 of the 40 chicken-derived Staphylococcus aureus strains, with a lysis rate of 87.5%. The lysis spectrum analysis revealed that this bacteriophage has a broad lysis spectrum, indicating great potential for application in the prevention and control of poultry joint diseases caused by Staphylococcus aureus.

[0069] Table 1. Results of lysis spectrum determination of Staphylococcus aureus bacteriophage XHX-SA-1P

[0070]

[0071] Note: "+" indicates cleavage, "-" indicates no cleavage, and the cleavage plaque is blurred.

[0072] Example 9: Stability of Staphylococcus aureus bacteriophage XHX-SA-1P powder product

[0073] Staphylococcus aureus phage XHX-SA-1P stock solution was prepared, with a phage titer of 4.5 × 10⁻⁶. 9 PFU / mL. Trehalose and whey protein were selected as excipients in a mass ratio of 1:3. A high-temperature co-flow spray dryer (outlet temperature approximately 80℃) was used for phage powder preparation. The phage powder was placed in physiological saline, centrifuged, filtered, and serially diluted to determine its titer. The phage powder titer was 1.5 × 10⁻⁶ PFU / mL. 8 PFU / mL. The phage product, produced using a high-temperature spray-drying process, still maintains a high titer level. Stability of the phage powder during storage. The phage powder was stored at room temperature (25-26℃) and 45℃, with sampling points at 10, 20, and 30 days. The phage powder was placed in physiological saline, centrifuged, filtered, and serially diluted to determine the titer. The titer results are shown in Table 2. The phage powder, stored at room temperature and 45℃, showed almost no change in titer within 30 days, indicating that the phage of this invention maintains high stability and activity even after being prepared as powder.

[0074] Table 2. Potency changes of bacteriophage powder at different storage temperatures

[0075]

[0076] Example 10: Safety testing of Staphylococcus aureus bacteriophage XHX-SA-1P.

[0077] Mice were divided into three groups and treated as follows: a control group (normal feeding), group 1 (mammary gland perfusion with a 100-fold diluted purified phage solution), and group 2 (feeding with phage powder mixed with feed). After 24 hours, changes in mammary gland tissue were observed after dissection. There was no significant difference between the control group and the phage group; the mammary gland tissue was milky white, without hemorrhage or necrosis, and elastic. In the phage-perfused group, the acini were intact, the epithelium was tightly packed, and there was no lymphocyte infiltration in the acini and stroma; no pathological changes were observed. Compared with the control group, the TNF-α level in the phage group did not change significantly. This indicates that the phage product has no toxic side effects on mice and mouse mammary glands.

[0078] Example 11: Prevention and treatment effect of bacteriophage on Staphylococcus aureus-induced leg disease in broilers

[0079] In a broiler chicken house at a poultry farm in Weifang, Shandong Province, 10,000 chickens exhibited swollen, hot, and painful knee joints with palpable fluctuation. Necropsy revealed pale yellow, turbid exudate or caseous purulent material within the joint cavity. The synovial membrane was congested and thickened. Laboratory identification confirmed Staphylococcus aureus, confirming that the flock was infected with Staphylococcus aureus causing joint disease. The fermentation broth of bacteriophage XHX-SA-1P (effective concentration 10) was used. 9 The phage (PFU / mL) was added to the feed of this flock. After 24 hours of phage administration, knee swelling was significantly reduced; after 48 hours, the knee swelling had almost disappeared, feed intake increased, and the flock's overall condition improved; after 72 hours, the flock showed significant improvement. We tracked the proportion of lame chickens in this building over four months. Figure 7 It can be seen that the proportion of lame chickens decreased by 1.33% within 4 months compared to the same period last year, indicating a significant improvement in growth status and increased growth rate. This large-scale trial demonstrates that the bacteriophage of this invention can effectively treat Staphylococcus aureus-induced leg disease in broilers in practical applications, with significant results.

[0080] The above description is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Those skilled in the art should understand that any changes or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention fall within the protection and disclosure scope of the present invention.

Claims

1. A Staphylococcus aureus bacteriophage, characterized in that, The Staphylococcus aureus bacteriophage described is XHX-SA-1P, deposited at the China Center for Type Culture Collection (CCTCC) with accession number CCTCC NO:M2025494, and classified as Staphylococcus aureus bacteriophage.

2. A bacteriophage composition, characterized in that, Includes the Staphylococcus aureus phage as described in claim 1.

3. The use of the Staphylococcus aureus phage as described in claim 1 or the phage composition as described in claim 2 in the preparation of a medicament for the prevention or treatment of arthritis caused by Staphylococcus aureus infection.

4. A bacteriophage drug formulation, characterized in that, The active ingredient of the phage drug formulation includes the Staphylococcus aureus phage as described in claim 1 or the phage composition as described in claim 2.

5. The phage drug formulation according to claim 4, characterized in that, The phage drug formulation also contains a pharmaceutically acceptable carrier.

6. The phage drug formulation according to claim 4, characterized in that, The dosage forms of the bacteriophage drug formulation include one or more of the following: powder, solution, gel, granule, emulsion, suspension, and lyophilized agent.

7. A feed additive, characterized in that, The feed additive includes the Staphylococcus aureus bacteriophage as described in claim 1.

8. The feed additive as described in claim 7, characterized in that, The feed additive also includes the bacteriophage composition as described in claim 2.

9. A disinfectant, characterized in that, The disinfectant includes the Staphylococcus aureus bacteriophage as described in claim 1.

10. A disinfectant as described in claim 9, characterized in that, The disinfectant also includes the bacteriophage composition as described in claim 2.

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