Broad-spectrum bacteriophage composition for preventing and controlling atrophic rhinitis of pigs and application thereof

Abstract

This invention relates to the field of biomedical technology, disclosing a broad-spectrum phage composition for the prevention and control of porcine atrophic rhinitis and its applications, particularly involving Pasteurella multocida phage SD-PM1 and Bordetella bronchiseptica phage SD-Bb1, with accession numbers CCTCC NO: M20232599 and CCTCC NO: M20232589, respectively. The phages and their compositions of this invention exhibit strong broad-spectrum lytic activity against both Pasteurella multocida and Bordetella bronchiseptica. These phages can be used alone or in combination with other phages to prepare drugs for the prevention and treatment of porcine respiratory diseases caused by single or mixed infections of Pasteurella multocida and Bordetella bronchiseptica, with particularly significant effects against porcine atrophic rhinitis. Furthermore, the phages of this invention are all virulent phages with a broad lytic spectrum, good acid and heat resistance, and can be applied in various practical scenarios.

Description

Technical Field

[0001] This invention relates to the field of biomedical technology, and more specifically, to a broad-spectrum bacteriophage composition for the prevention and control of atrophic rhinitis in pigs and its application. Background Technology

[0002] Pasteurella multocida (PM) belongs to the family Pasteuraceae and the genus Pasteurella. It is a Gram-negative facultative anaerobic bacterium and a zoonotic pathogen, primarily causing various diseases, mainly respiratory infections. Bordetella bronchiseptica (Bb) often forms synergistic infections with Pasteurella multocida, enhancing its colonization ability. Simultaneously, Bb can also interact with other respiratory pathogens (including Streptococcus suis, Mycoplasma suis, Streptococcus parasuis, porcine reproductive and respiratory syndrome virus, and swine influenza virus) to lead to disease.

[0003] In swine herds, Pasteurella multocida primarily circulates capsular types A and D, mainly causing Pasteurella pneumonia and atrophic rhinitis (AR). Bordetella bronchiseptica infection alone can lead to non-progressive atrophic rhinitis in pigs. Pigs with atrophic rhinitis mainly exhibit facial distortion, nasal turbinate atrophy, and stunted growth. Furthermore, their weakened immune systems make them susceptible to secondary respiratory diseases, increasing mortality and causing significant economic losses to the swine industry. Therefore, developing a combination formulation that can simultaneously control Bordetella bronchiseptica and Pasteurella multocida will greatly solve current clinical challenges in swine farming.

[0004] In recent years, the drug resistance of Bordetella bronchiseptica and Pasteurella multocida isolated from production lines has continued to increase. The continuously decreasing antibiotic sensitivity has become a major obstacle to controlling this disease. Bacteriophages are viruses that specifically phagocytose bacteria, widely distributed in nature, including soil, sewage, and feces, exhibiting biodiversity. Based on their parasitic mode, bacteriophages can be divided into lytic phages and temperate phages. Bacteriophages that can cause lysis of the host cell and release progeny phage particles are called lytic phages, virulent phages, or highly virulent phages, i.e., phages with clinical application potential. Bacteriophages have significant advantages as a therapeutic and preventative measure: firstly, they are abundant and biologically active, and can co-evolve with bacteria; secondly, they have high specificity, targeting only the lysis of specific pathogens rather than all bacteria, thus avoiding microbial imbalance in animals; they have therapeutic effects on some clinically isolated multidrug-resistant bacteria; and they can synergistically work with antibiotics to "regain sensitivity" to bacteria. Studies have shown that bacteriophages are significantly more effective than antibiotics and other organic chemical additives, especially in the control of clinical infections, the prevention and control of veterinary pathogens, and the environmental contamination of food-related pathogens, demonstrating promising applications. Therefore, developing a bacteriophage with a broad host spectrum is of great significance. Summary of the Invention

[0005] In view of this, the present invention proposes a broad-spectrum phage composition for the prevention and control of atrophic rhinitis in pigs and its application, aiming to provide a broad-spectrum phage composition that can effectively prevent and control atrophic rhinitis in pigs caused by Pasteurella multocida and Bordetella bronchiseptica, and to achieve efficient, safe and environmentally friendly prevention and control of atrophic rhinitis in pigs through specific application methods.

[0006] This invention proposes a phage composition comprising Pasteurella multocida phage SD-PM1 and Bordetella bronchiseptica phage SD-Bb1;

[0007] The preservation number of Pasteurella multocida phage SD-PM1 is CCTCC NO: M20232589

[0008] The preservation number of the Bordetella bronchiseptica phage SD-Bb1 is CCTCC NO: M20232599.

[0009] The present invention also proposes an application of the above-described phage composition, the application comprising at least one of the following:

[0010] A1) The use of the above-mentioned phage composition in the preparation of products for the treatment of porcine atrophic rhinitis;

[0011] A2) The application of the above-mentioned bacteriophage composition in sterilization;

[0012] A3) Application of the above-mentioned bacteriophage composition in the preparation of bactericidal products.

[0013] Preferably, the sterilization is sterilization of the environment, equipment, and / or skin surface.

[0014] Preferably, the bacterium used for sterilization is Pasteurella multocida or Bordetella bronchiseptica.

[0015] The present invention also provides a medicament for treating atrophic rhinitis in pigs, the medicament comprising the above-described phage composition.

[0016] Preferably, the dosage form of the phage composition is a powder, a lyophilized agent, a granule, or a solution.

[0017] The present invention also proposes a bactericidal product comprising the above-described bacteriophage composition.

[0018] The present invention also proposes a feed additive comprising the above-described phage composition.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1. The bacteriophage involved in this invention is a lytic bacteriophage, which does not have a lysogen module and does not contain potential horizontal transfer elements such as drug resistance genes and virulence genes. Therefore, it has high safety in practical applications.

[0021] 2. The bacteriophage involved in this invention is specific to two major respiratory pathogens and can effectively treat single pathogen infections and mixed infections, thereby broadening its clinical application scope.

[0022] 3. The bacteriophage involved in this invention is a broad-spectrum bacteriophage that exhibits extremely strong lysis ability against porcine Pasteurella multocida, with a lysis rate as high as 100%, and also has a 100% lysis rate against Bordetella bronchiseptica.

[0023] 4. The two bacteriophages involved in this invention exhibit excellent biological characteristics. They can remain active after 120 minutes of treatment within a pH range of 3 to 12, showing a wide pH tolerance range. In particular, SD-Bb1 has excellent heat resistance. It can survive after being treated at 80°C for 60 minutes without heat protectant, making it suitable for various production and processing processes as well as extreme breeding environments.

[0024] 5. The bacteriophages involved in this invention are derived from the natural environment, are easy to obtain and can be directly applied to actual production transformation, which helps to reduce the cost of controlling specific bacterial pathogens; at the same time, multiple application scenarios can be selected according to different needs, including pig food slaughtering and processing, breeding environment, feed and other aspects, to achieve multi-dimensional and all-round prevention and control of important respiratory pathogens such as Bordetella bronchiseptica and Pasteurella multocida. Attached Figure Description

[0025] Various other advantages and benefits will become apparent to those skilled in the art upon reading the following detailed description of preferred embodiments. The accompanying drawings are for illustrative purposes only and are not intended to limit the invention. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0026] Figure 1 The morphology of phage SD-PM1 plaques on a double-layer agar plate;

[0027] Figure 2 The morphology of phage SD-Bb1 plaques on a double-layer agar plate;

[0028] Figure 3 The morphology of bacteriophage SD-PM1 under an electron microscope;

[0029] Figure 4 The morphology of bacteriophage SD-Bb1 under an electron microscope;

[0030] Figure 5 The results show the pH stability of bacteriophage SD-PM1.

[0031] Figure 6 The results show the pH stability of bacteriophage SD-Bb1.

[0032] Figure 7 The results of the thermal stability test for bacteriophage SD-PM1;

[0033] Figure 8 The results of the thermal stability test for bacteriophage SD-Bb1;

[0034] Figure 9 The optimal MOI detection results for bacteriophages SD-PM1 and SD-Bb1;

[0035] Figure 10 The results of the in vitro antibacterial test of bacteriophage SD-PM1;

[0036] Figure 11 The results of the in vitro antibacterial assay for bacteriophage SD-Bb1;

[0037] Figure 12The results of an experimental study on the treatment of porcine atrophic rhinitis with a combination of SD-PM1 and SD-Bb1 bacteriophages are shown in the figure.

[0038] Figure 13 The results show the statistical comparison of pig mortality rates before and after nebulization treatment;

[0039] Figure 14 The results show the change in the proportion of pigs coughing before and after nebulization treatment. Detailed Implementation

[0040] Exemplary embodiments of the present disclosure will now be described in more detail with reference to the accompanying drawings. While exemplary embodiments of the present disclosure are shown in the drawings, it should be understood that the present disclosure may be implemented in various forms and should not be limited to the embodiments set forth herein. Rather, these embodiments are provided to enable a more thorough understanding of the present disclosure and to fully convey the scope of the disclosure to those skilled in the art. It should be noted that, unless otherwise specified, embodiments and features in the embodiments of the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0041] Example 1: Isolation and purification of Bordetella bronchiseptica bacteriophage and Pasteurella multocida bacteriophage

[0042] (1) Host bacterial resuscitation process: Strains PM23001 and Bb23001, frozen at -80℃, were streaked on TSA plates (containing 5% newborn calf serum) for resuscitation, and then incubated in a 37℃ incubator for 18-24 hours. Single colonies were selected and inoculated into 5 mL of TSB broth (containing 5% newborn calf serum) and placed in a 37℃ incubator with shaking at 180 rpm for 16 hours to harvest a single colony suspension.

[0043] (2) Pretreatment steps for environmental wastewater and other samples: The collected samples of pig farm feces, wastewater, respiratory secretions and other samples were mixed with SM solution and soaked. After standing for 4-6 hours, they were centrifuged at 6000 rpm for 10 minutes. The centrifugation was repeated until the liquid was clear. Then the original solution was filtered with a 0.22 μm filter to harvest the phage stock solution.

[0044] (3) Phage proliferation method: The phage stock solution and the host bacterial suspension were mixed at a volume ratio of 10:1, and TSB broth containing 5% newborn calf serum was added for co-enrichment. The mixture was then incubated at 180 rpm for 8-12 hours in a constant temperature shaker at 37°C. The mixture was then centrifuged at 8000 rpm for 20 minutes and filtered through a 0.22 μm filter to harvest the phage proliferation solution.

[0045] (4) Phage isolation technology: Phage isolation was performed using the double-layer plate method. The host bacteria and phage proliferation solution were mixed at a volume ratio of 1:1 and added to a 10ml centrifuge tube. The mixture was incubated at 37℃ for 5-10 minutes, followed by the addition of 5mL of the upper semi-solid culture medium. The mixture was then quickly poured onto the lower TSA solid plate (containing 5% newborn calf serum), and the plate was gently shaken to mix. After solidification, the plate was inverted and incubated overnight at 37℃. If phages are present, transparent, regular circular vacuoles will appear on the surface of the plate; otherwise, a uniform bacterial growth will appear on the surface of the culture medium.

[0046] (5) Phage purification procedure: Phages were purified using the single-spot dilution method. A single clear phage plaque was picked up with a sterile 10 μl pipette tip and added to a 1 ml centrifuge tube containing 900 μl PBS. After vortexing and mixing, the phages were serially diluted 10-fold to 10⁻⁶. -5 10 -6 10 -7 The host bacterial culture and different serial dilutions were mixed at a 1:1 volume ratio and added to a 10ml EP tube. 5ml of the upper semi-solid culture medium (containing 5% newborn calf serum) was added, and the mixture was quickly poured into a TSA agar plate. After solidification, the plate was inverted and incubated at 37℃ for 12-16 hours. The phages were purified by repeated single-spot dilutions 3-5 times until clear, uniform, and consistent phage plaques appeared. The morphologies of SD-PM1 and SD-Bb1 phages on double-layer agar plates are shown in the figures below. Figure 1 , Figure 2 .

[0047] (6) Phage enrichment strategy: Liquid proliferation method was used for enrichment. The host bacterial solution was inoculated into 100ml TSB broth (containing 5% newborn calf serum) in a conical flask at a ratio of 1:100. Then, 10μl of sterile pipette tip was added to pick up the purified single-spot phage. The phage was cultured in a constant temperature shaker at 37℃ until clear. After filtration through a 0.22μm filter, the phage enrichment solutions SD-PM1 and SD-Bb1 were harvested.

[0048] (7) Phage cryopreservation method: Take 750 μl each of the filtered enriched solutions SD-PM1 and SD-Bb1, mix them with 750 μl each of 50% sterile glycerol, add them to a 2 mL cryopreservation tube, and freeze at -80℃.

[0049] Example 2: Determination of SD-PM1 and SD-Bb1 phage titers

[0050] The titers of phages SD-PM1 and SD-Bb1 were determined using the double-layer plate method. First, the phage enrichment solutions SD-PM1 and SD-Bb1 were serially diluted 10-fold with SM buffer, with a dilution gradient of 10-10. -1 -10 -7Subsequently, 2 to 3 suitable dilutions were selected. Using a sterile pipette tip, 100 μL of the diluent and 100 μL of the host bacterial suspension were mixed in 10 mL EP tubes and incubated at 37°C for 5 minutes. Then, 5 mL of the upper semi-solid medium was added and thoroughly mixed, then poured onto the lower TSA solid medium. Each dilution was repeated 3 times. After the plates solidified, they were incubated upside down at 37°C for 8-12 hours. The morphology of individual, uniform plaques was observed and recorded, and the number of effective plaques (30-300) was counted. Based on the formula: Phage titer = Average number of effective plaques × Dilution factor × 100 (PFU / mL), the titer of phage SD-PM1 was calculated to be 1.08 × 10⁻⁶. 9 PFU / mL, SD-Bb1 titer is 3.45 × 10⁻⁶. 9 PFU / mL.

[0051] Example 3: Electron microscopic observation of SD-PM1 and SD-Bb1 bacteriophages

[0052] Take 20 μl each of fresh phage enrichment solutions SD-PM1 and SD-Bb1, and drop them onto copper grids respectively. After covering with filter paper, dry under an incandescent lamp. Then stain the copper grids with tungstic phosphate (PTA, 2% w / v). After drying, observe the phage morphology using transmission electron microscopy. The results are shown in the figure. Figure 3 , Figure 4 .

[0053] PMPH001 as Figure 3 The results showed that the phage was Pasteurelia suispage SD-PM1, which was deposited at the China Center for Type Culture Collection on December 18, 2023, with accession number CCTCCNO: M20232589.

[0054] SD-Bb1 such Figure 4 The results showed that the phage was Brodetella bronchiseptica page SD-Bb1, which was deposited at the China Center for Type Culture Collection on December 19, 2023, with accession number CCTCC NO: M20232599.

[0055] Example 4: pH stability of SD-PM1 and SD-Bb1 bacteriophages

[0056] Take 100 μl each of fresh phage enrichment solutions SD-PM1 and SD-Bb1, and pre-adjust the phage titer to 1.5 × 10⁻⁶. 8 PFU / mL, 1.0×10 9PFU / mL. Eleven pH gradients of SM solution were established: 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, and 12. 100 μl of phage enrichment solution was added to each EP tube containing 900 μl of SM solution, with three replicates per pH group. Each tube was placed in a preheated 37°C water bath, and the phage titer was determined using the double-layer agar plate method at incubation times of 10 min, 30 min, 60 min, and 120 min. Detailed experimental results are available in [link to results]. Figure 5 , Figure 6 .

[0057] Experimental results showed that both SD-PM1 and SD-Bb1 bacteriophages could survive for extended periods within a pH range of 3-12. After one hour of exposure at pH 3, the titers of both phages did not decrease by more than two orders of magnitude. SD-PM1 showed minimal titer changes within a pH range of 4-11; SD-Bb1 showed an average titer change of one order of magnitude within a pH range of 3-12, indicating that both SD-PM1 and SD-Bb1 bacteriophages possess strong resistance to acidic and alkaline environments.

[0058] Example 5: Thermal stability of SD-PM1 and SD-Bb1 bacteriophages

[0059] Take 100 μl each of fresh phage enrichment solutions SD-PM1 and SD-Bb1, and pre-adjust the phage titer to 1.5 × 10⁻⁶. 8 PFU / mL. 100 μl of phage enrichment solution was added to an EP tube containing 900 μl of SM solution. Each EP tube was placed in a water bath at 40℃, 50℃, 60℃, 70℃, and 80℃, with three replicates for each temperature group. The phage titer was determined using the double-layer agar plate method at incubation times of 30 min, 60 min, 90 min, and 120 min. Results are shown below. Figure 7 , Figure 8 .

[0060] The results are as follows Figure 7 and Figure 8 As shown, PM1 exhibits high activity in the range of 4-50℃, but its activity is completely lost after 30 minutes of exposure at 60℃; BbPH001 shows good survival ability in the range of 4-70℃, but its activity is completely lost after 75 minutes of exposure at 80℃, demonstrating strong thermal stability.

[0061] Example 6: Optimal Multiple of Infection for SD-PM1 and SD-Bb1 Bacteriophages

[0062] Pasteurella multocida and Bordetella bronchiseptica were used as liquid propagation host bacteria, and their corresponding bacteriophages PMPH001 and BbPH001 were inoculated at MOI (multiple of infection) ratios of 10, 1, 0.1, 0.01, 0.001, and 0.0001, respectively. Three replicates were set up for each MOI value. EP tubes were placed in a 37°C constant-temperature shaker and shaken at 180 rpm for 6-8 hours, followed by centrifugation at 8000 rpm for 15 minutes. The phage titer in the supernatant was determined using the double-layer plate method to determine the optimal MOI for the phage.

[0063] like Figure 9 As shown, the titer of bacteriophage PMPH001 exceeded 10 in the MOI range of 1 to 0.0001. 9 PFU / mL, the titer showed a slow upward trend as the MOI ratio decreased, with the optimal MOI being 0.0001; while phage BbPH001 had a titer exceeding 10 at an MOI of 0.1. 10 The optimal MOI for PFU / mL is 0.1.

[0064] Example 7: Lysis spectrum experiment of SD-PM1 and SD-Bb1 bacteriophages

[0065] Resuscitation experiments were conducted on Pasteurella multocida and Bordetella bronchiseptica, all strains of which were preserved in the laboratory cryopreservation facility. The resuscitated strains were placed in a 37°C constant-temperature shaker and cultured at 180 rpm for 6 hours until the logarithmic growth phase was reached. Subsequently, the lysis spectra of bacteriophages PMPH001 and BbPH001 were determined using the double-layer plate method. Table 1 shows the lysis spectra results of bacteriophages SD-PM1 and SD-Bb1.

[0066] Table 1

[0067]

[0068]

[0069] PMPH001 is a broad-spectrum phage with extensive lytic activity, capable of effectively lysing porcine Pasteurella A and D strains isolated from clinical settings, as well as Pasteurella strains for which capsular typing was not performed. SD-Bb1 phage also exhibits a broad lytic spectrum.

[0070] Example 8: In vitro antibacterial experiment of SD-PM1 and SD-Bb1 bacteriophages

[0071] Freshly prepared TSB proliferation broth of host bacteria PM23001 and Bb23001 was used, with the bacterial concentration pre-adjusted to 1×10⁻⁶. 8CFU / ml were used in in vitro host lysis experiments with phage enrichment solutions SD-PM1 (MOI = 0.01, 0.1, 1) and BbPH2300 (MOI = 0.1, 1) at different MOIs. The OD600 values ​​of bacteria were measured over a continuous period, with three replicates for each experiment. Detailed results are available in [link to results]. Figure 10 , 11 .

[0072] like Figure 10 As shown, under in vitro culture conditions, bacteriophage PMPH001 exhibited a significant inhibitory effect on the host bacteria in the treatment groups with MOI = 0.01 to 1, compared with the bacterial control group, with a duration of up to 8 hours; while bacteriophage BbPH001, under MOI = 0.1 conditions, had an inhibitory effect that lasted up to 13 hours; under MOI = 0.01 conditions, the long-term inhibitory effect of bacteriophage on the host bacteria was more significant.

[0073] Example 9: Experimental study on the treatment of swine atrophic rhinitis using SD-PM1 and SD-Bb1 bacteriophage compositions.

[0074] In a large-scale pig farm slaughterhouse, a high detection rate of Bordetella bronchiseptica was found in nasal swab tests of fattening pigs, indicating significant respiratory disease pressure on the farm. To assess nasal turbinate bone damage, nasal turbinate bone necropsy scoring was performed on slaughtered pigs, with a total of 50 samples collected. Results showed that all samples exhibited nasal turbinate bone damage, and the degree of damage was severe (score ≥ 3 points), with 100% of samples showing severe damage. Specifically, there were 0 samples with scores between 0 and 2, 1 sample with a score of 3 (2%), 48 samples with a score of 4 (96%), and 1 sample with a score of 5 (2%). Related results are as follows... Figure 12 As shown.

[0075] Based on the situation at the group's pig farm slaughterhouse, two sow production lines were selected for study. Each line has 2,000 breeding sows, with a regional free-range scale of approximately 40,000 sows. The main disease problems faced by these sow lines include the instability of porcine reproductive and respiratory syndrome (PRRS) and the severity of secondary infections such as atrophic rhinitis and Haemophilus parasuis, leading to a free-range loss rate of up to 12-15%. This embodiment utilizes the phage composition of this invention (a 1:1 ratio of two phages), applied via nasal spray to sows 3 days before farrowing, during the nursing period for piglets, and within 3 days after weaning. The phage dosage used for nasal spraying is 1.0 ml per sow (containing a phage concentration of not less than 10). 8 The results (PFU / ml) were recorded, and the cough rate and tear stains and eye discharge in sows were also analyzed. The relevant results are detailed in Table 2.

[0076] Table 2

[0077]

[0078]

[0079] This shows that the proportion of respiratory symptoms in piglets in the experimental group after phage nasal spray was significantly lower than that in the control group.

[0080] Example 10: Experimental study on the treatment of porcine atrophic rhinitis using SD-PM1 and SD-Bb1 phage compositions.

[0081] In a large-scale pig farm, the phage composition of the present invention was applied to selected breeding line pigs for testing. The experimental groups were as follows: the nebulization group received phage nebulization treatment and enrofloxacin treatment for 2 days, followed by amoxicillin nebulization treatment for 2 days, for a total of 4 days of nebulization treatment; the control group maintained routine feed mixing and health care measures.

[0082] The test results are as follows:

[0083] 1. Changes in pig mortality rates before and after nebulization treatment

[0084] according to Figure 13 The data showed no significant difference in daily mortality rates between the nebulization group and the control group during the observation period. However, the overall trend indicated a lower mortality rate in the nebulization group compared to the control group. Even after discontinuation of nebulization treatment, the mortality rate in the nebulization group remained lower than that in the control group.

[0085] 2. Changes in the proportion of pigs coughing before and after nebulization therapy

[0086] according to Figure 14 Data showed that the cough rate in the nebulization group was significantly lower than that in the control group. Within two days of nebulization treatment with a combination of bacteriophage and enrofloxacin, the cough rate rapidly decreased from 4.42% to 2.14%. After continuing amoxicillin nebulization treatment for two more days, the cough situation in the nebulization group remained stable, and by the 19th, the cough rate in the nebulization group had decreased to 2.86%, while the control group's feed-mixing preventative measures only reduced the cough rate to 1.14%. The nebulization group experienced virtually no coughing from the 21st to the 22nd, while the control group's coughing persisted until the 27th, significantly shortening the coughing period. The results indicate that nebulization treatment with a combination of bacteriophage and antibiotics is significantly more effective than traditional feed-mixing preventative measures in improving respiratory symptoms in pigs.

[0087] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the specific implementation of the present invention. Any modifications or equivalent substitutions that do not depart from the spirit and scope of the present invention should be covered within the scope of protection of the claims of the present invention.

Claims

1. A bacteriophage composition, characterized in that, Including Pasteurella multocida phage SD-PM1 and Bordetella bronchiseptica phage SD-Bb1; The preservation number of Pasteurella multocida phage SD-PM1 is CCTCC NO: M20232589 The preservation number of the Bordetella bronchiseptica phage SD-Bb1 is CCTCC NO: M20232599.

2. The application of the phage composition according to claim 1, characterized in that, The application includes at least one of the following: A1) The use of the phage composition according to claim 1 in the preparation of a product for the treatment of porcine atrophic rhinitis; A2) The use of the bacteriophage composition according to claim 1 in the preparation of bactericidal products.

3. The application according to claim 2, characterized in that, The sterilization refers to the sterilization of the environment, equipment, and / or the skin surface.

4. The application according to claim 2 or 3, characterized in that, The bacteria used for sterilization are Pasteurella multocida or Bordetella bronchiseptica.

5. A drug for treating atrophic rhinitis in pigs, characterized in that, The drug comprises the bacteriophage composition of claim 1.

6. The drug for porcine atrophic rhinitis according to claim 5, characterized in that, The phage composition is available in the form of powder, lyophilized agent, granules, or solution.

7. A sterilization product, characterized in that, The bactericidal product includes the bacteriophage composition of claim 1.

8. A feed additive, characterized in that, The feed additive includes the bacteriophage composition of claim 1.

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