Escherichia coli phage, phage composition and application thereof, and phage preparation

Abstract

The invention provides an Escherichia coli bacteriophage, a bacteriophage composition, application of the bacteriophage composition and a bacteriophage preparation, and relates to the technical field of microorganisms, the Escherichia coli bacteriophage is named as Escherichia coli bacteriophage GaoM7-14E, the preservation number is CGMCC NO.46188, the preservation time is September 20, 2024, another Escherichia coli bacteriophage is named as Escherichia coli bacteriophage JM3e, the preservation number is CGMCC NO.46186, the preservation time is CGMCC NO.46188, and the preservation time is CGMCC NO.46186. The preservation time is September 18, 2024. According to the technical scheme, the bacteriophage GaoM7-14E and the bacteriophage JM3e are adopted as the bacteriophage composition and can synergistically inhibit escherichia coli, so that pathogenic escherichia coli is inhibited, and colibacillosis is prevented and treated.

Description

Technical Field

[0001] The present invention relates to the field of microbial technology, and in particular to Escherichia coli phage, phage composition and application thereof, and phage preparation. Background Art

[0002] Avian colibacillosis is an infectious disease of poultry caused by avian pathogenic Escherichia coli (APEC). Avian pathogenic Escherichia coli is a type of extraintestinal pathogenic Escherichia coli (ExPEC), which is mainly transmitted through the respiratory tract. It can cause disease in chickens and other poultry through virulence factors such as pili, invasin, iron acquisition system, K1 capsule, temperature-sensitive hemagglutinin, etc., and manifests as peripheral hepatitis, air sac inflammation, pericarditis, peritonitis, salpingitis and other symptoms. In severe cases, it can lead to death of poultry.

[0003] Avian colibacillosis is one of the main causes of morbidity and mortality in poultry, causing irreversible economic losses to the poultry industry, especially the chicken industry, and becoming an economic threat to the global poultry industry. Chicken farms have been using antibiotics to prevent and treat infections caused by avian pathogenic Escherichia coli, but the widespread use and even abuse of antibiotics has led to the emergence and spread of multidrug-resistant strains (MDR), which not only poses a challenge to the treatment of avian colibacillosis, but also has adverse effects on human health. Summary of the invention

[0004] The main purpose of the present invention is to provide an Escherichia coli phage, a phage composition and its application, and a phage preparation, aiming to provide a phage that can prevent and treat avian Escherichia coli disease.

[0005] To achieve the above objectives, the present invention proposes an Escherichia coli phage, the Escherichia coli phage is taxonomically named Escherichia coli phage, named Escherichia coli phage GaoM7-14E, with a preservation number of CGMCC NO.46188 and a preservation time of September 20, 2024.

[0006] The present invention proposes an Escherichia coli phage, the Escherichia coli phage is taxonomically named Escherichia coli phage, named Escherichia coli phage JM3e, the preservation number is CGMCCNO.46186, and the preservation time is September 18, 2024.

[0007] The present invention provides a phage composition, comprising Escherichia coli phage GaoM7-14E and Escherichia coli phage JM3e;

[0008] The Escherichia coli phage GaoM7-14E is the aforementioned Escherichia coli phage GaoM7-14E, and the Escherichia coli phage JM3e is the aforementioned Escherichia coli phage JM3e.

[0009] In one embodiment, the titer of the E. coli phage GaoM7-14E and the titer of the E. coli phage JM3e are not less than 10 7 PFU / mL.

[0010] In one embodiment, the multiplicity of infection (MOI) is 0.001-10.

[0011] The present invention provides an application of a bacteriophage in preparing an antibacterial agent, wherein the bacteriophage comprises at least one of Escherichia coli phage GaoM7-14E and Escherichia coli phage JM3e;

[0012] The Escherichia coli phage GaoM7-14E is the aforementioned Escherichia coli phage GaoM7-14E, and the Escherichia coli phage JM3e is the aforementioned Escherichia coli phage JM3e.

[0013] In one embodiment, the bacteriostatic agent is used to inhibit Escherichia coli, including avian pathogenic Escherichia coli.

[0014] The present invention provides a phage preparation, which comprises the aforementioned phage composition.

[0015] In one embodiment, the phage preparation further comprises auxiliary materials acceptable in the poultry industry.

[0016] In one embodiment, the dosage form of the phage preparation includes at least one of a solution, a powder, a gel, a granule or a lyophilized agent.

[0017] In the technical solution of the present invention, by using Escherichia coli phage GaoM7-14E and Escherichia coli phage JM3e as a phage composition, the two phages can synergistically inhibit Escherichia coli, thereby inhibiting pathogenic Escherichia coli, and further preventing and treating Escherichia coli disease; at the same time, the phenomenon of Escherichia coli developing drug resistance due to the use of antibiotics is avoided. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0019] Figure 1 The plaque results of bacteriophage GaoM7-14E and bacteriophage JM3e in Example 1 of the present invention are shown;

[0020] Figure 2 2 are electron microscope images of bacteriophage GaoM7-14E and bacteriophage JM3e in Example 2 of the present invention;

[0021] Figure 3 This is a schematic diagram of the whole genome of bacteriophage GaoM7-14E in Example 3 of the present invention;

[0022] Figure 4 This is a schematic diagram of the whole genome of bacteriophage JM3e in Example 3 of the present invention;

[0023] Figure 5 This is a diagram showing the optimal MOI detection result of bacteriophage GaoM7-14E in Example 4 of the present invention;

[0024] Figure 6 This is a diagram showing the optimal MOI detection result of bacteriophage JM3e in Example 4 of the present invention;

[0025] Figure 7 is a one-step growth curve diagram of bacteriophage GaoM7-14E in Example 5 of the present invention;

[0026] Figure 8 is a one-step growth curve diagram of bacteriophage JM3e in Example 5 of the present invention;

[0027] Fig. 9 This is a graph showing the antibacterial effect experimental results of bacteriophage GaoM7-14E and bacteriophage JM3e in Example 7 of the present invention.

[0028] The realization of the purpose, functional features and advantages of the present invention will be further explained in conjunction with embodiments and with reference to the accompanying drawings. DETAILED DESCRIPTION

[0029] To make the purpose, technical solution and advantages of the embodiments of the present invention clearer, the technical solution in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of them.

[0030] It should be noted that, in the embodiments, those without specifying specific conditions are carried out according to normal conditions or conditions recommended by the manufacturer. Those without specifying the manufacturer of reagents or instruments used are conventional products that can be purchased commercially. In addition, the meaning of "and / or" appearing in the full text includes three parallel schemes, and "A and / or B" is taken as an example, including schemes A, B, or A and B that meet the same time. In addition, the technical schemes between the various embodiments can be combined with each other, but must be based on the ability of ordinary technicians in the field to achieve. When the combination of the technical schemes is contradictory or cannot be achieved, it should be considered that the combination of such technical schemes does not exist, and is not within the scope of protection required by the present invention. Based on the embodiments in the present invention, all other embodiments obtained by ordinary technicians in the field without making creative work, all belong to the scope of protection of the present invention.

[0031] Avian colibacillosis is an infectious disease of poultry caused by avian pathogenic Escherichia coli (APEC). Avian pathogenic Escherichia coli is a type of extraintestinal pathogenic Escherichia coli (ExPEC), which is mainly transmitted through the respiratory tract. It can cause disease in chickens and other poultry through virulence factors such as pili, invasin, iron acquisition system, K1 capsule, temperature-sensitive hemagglutinin, etc., and manifests as peripheral hepatitis, air sac inflammation, pericarditis, peritonitis, salpingitis and other symptoms. In severe cases, it can lead to death of poultry.

[0032] Avian colibacillosis is one of the main causes of morbidity and mortality in poultry, causing irreversible economic losses to the poultry industry, especially the chicken industry, and becoming an economic threat to the global poultry industry. Chicken farms have been using antibiotics to prevent and treat infections caused by avian pathogenic Escherichia coli, but the widespread use and even abuse of antibiotics has led to the emergence and spread of multidrug-resistant strains (MDR), which not only poses a challenge to the treatment of avian colibacillosis, but also has adverse effects on human health. With the continuous increase in antibiotic resistance, it is urgent to find alternatives to antibiotics. In order to solve the problem of antibiotic resistance of avian pathogenic Escherichia coli in the poultry industry and to find new alternatives to antibiotics, bacteriophages have come into people's view.

[0033] In view of this, the present invention uses sludge collected from a chicken farm to screen and culture Escherichia coli phage from it. The Escherichia coli phage screened and cultured in the present invention has been deposited in the China General Microbiological Culture Collection Center, the deposit address is: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard No. 1, Beichen West Road, Chaoyang District, Beijing, taxonomically named Escherichia coli phage, named Escherichia coli phage GaoM7-14E, the deposit number is CGMCC NO.46188, and the deposit time is September 20, 2024.

[0034] The present invention also proposes an Escherichia coli phage, which has been deposited in the China General Microbiological Culture Collection Center, the deposit address is: Institute of Microbiology, Chinese Academy of Sciences, No. 3, Yard 1, Beichen West Road, Chaoyang District, Beijing, the taxonomic name is Escherichia coli phage, named Escherichia coli phage JM3e, the deposit number is CGMCCNO.46186, and the deposit time is September 18, 2024.

[0035] The present invention also provides a phage composition, comprising Escherichia coli phage GaoM7-14E and Escherichia coli phage JM3e; the Escherichia coli phage GaoM7-14E is the aforementioned Escherichia coli phage GaoM7-14E, and the Escherichia coli phage JM3e is the aforementioned Escherichia coli phage JM3e.

[0036] In the technical solution of the present invention, by using Escherichia coli phage GaoM7-14E and Escherichia coli phage JM3e as a phage composition, the two phages can synergistically inhibit Escherichia coli, thereby inhibiting pathogenic Escherichia coli, and further preventing and treating Escherichia coli disease; at the same time, the phenomenon of Escherichia coli developing drug resistance due to the use of antibiotics is avoided.

[0037] In one embodiment, the titer of the E. coli phage GaoM7-14E and the titer of the E. coli phage JM3e are not less than 10 7 PFU / mL.

[0038] In one embodiment, the MOI is 0.001 to 10. Preferably, the MOI is 0.01 to 0.1.

[0039] The present invention also proposes an application of a bacteriophage in the preparation of an antibacterial agent, wherein the bacteriophage includes at least one of Escherichia coli phage GaoM7-14E and Escherichia coli phage JM3e; the Escherichia coli phage GaoM7-14E is the aforementioned Escherichia coli phage GaoM7-14E, and the Escherichia coli phage JM3e is the aforementioned Escherichia coli phage JM3e.

[0040] In one embodiment, the bacteriostatic agent is used to inhibit Escherichia coli, including avian pathogenic Escherichia coli.

[0041] In the technical solution of the present invention, by adopting the antibacterial agent, avian pathogenic Escherichia coli can be specifically inhibited, thereby preventing and treating avian Escherichia coli disease.

[0042] The present invention also provides a phage preparation, which comprises the aforementioned phage composition.

[0043] In the technical solution of the present invention, the phage composition is prepared into a phage preparation, which can be used to inhibit the growth and development of Escherichia coli, while expanding the application scope of the phage composition. In particular, Escherichia coli phage GaoM7-14E and Escherichia coli phage JM3e can specifically inhibit avian pathogenic Escherichia coli, thereby preventing and treating avian Escherichia coli disease.

[0044] In one embodiment, the phage preparation further comprises auxiliary materials acceptable in the poultry industry.

[0045] It should be noted that the auxiliary material can be at least one of a dispersant, a stabilizer, a filler and a solvent, and the specific type is not limited here, as long as it is suitable for poultry farming.

[0046] In one embodiment, the dosage form of the phage preparation includes at least one of a solution, a powder, a gel, a granule or a lyophilized agent.

[0047] The technical solution of the present invention is further described in detail below in conjunction with specific embodiments. It should be understood that the following embodiments are only used to explain the present invention and are not used to limit the present invention.

[0048] The culture medium, reagents, equipment and materials used in the following examples are:

[0049] LB (Luria-Bertani) liquid medium (g / L): YEAST EXTRACT 5g, TRYPTONE 10g, NaCl 10g, distilled water 1000mL. Weigh the above reagents, dissolve in distilled water, sterilize at 121℃ for 20min, and set aside.

[0050] LB (Luria-Bertani) solid medium (g / L): YEASTE XTRACT 5g, TRYPTONE 10g, NaCl 10g, agar powder 20g, distilled water 1000mL. Weigh the above reagents, dissolve in distilled water, autoclave at 121℃ for 20min, pour into a disposable sterile culture dish under sterile environment, and set aside.

[0051] Phage buffer (200 mL): NaCl 1.75 g, Tris 1.21 g, MgCl2·6H2O 0.41 g, anhydrous CaCl2 0.04 g; weigh the above reagents, dissolve them in 200 mL of distilled water, adjust the pH to 7.5 with dilute hydrochloric acid (6 mol / L), and sterilize at 121°C for 20 min.

[0052] 0.5% water agar (g / L): 5 g agar powder, 1000 mL distilled water. Dissolve agar powder in distilled water and sterilize at 121°C for 20 min.

[0053] Equipment and instruments: clean bench (Suzhou Purification Equipment Co., Ltd.), full temperature shaking incubator (Suzhou Peiying Experimental Equipment Co., Ltd.), DNP-9052 electric constant temperature incubator (Shanghai Jinghong Experimental Equipment Co., Ltd.), ultra-low temperature refrigerator (Changhong Meiling Co., Ltd.), electric constant temperature blast drying oven (Shanghai Jinghong Experimental Equipment Co., Ltd.), METTLERAL204 electronic balance (Swiss Mettler-Toledo), magnetic stirrer MS100B (Shanghai Dam Industrial Co., Ltd.), MINIB-100 mini metal bath (Hangzhou Miou Instrument Co., Ltd.), MTC-100 constant temperature mixer (Hangzhou Miou Instrument Co., Ltd.), DYY-6C dual stable time electrophoresis instrument (Beijing Liuyi Biotechnology Co., Ltd.), Life Express gradient PCR amplifier (Hangzhou Biori Technology Co., Ltd.), portable bacterial turbidity meter (Hangzhou Qiwei Instrument Co., Ltd.), vertical pressure steam sterilizer LDZX-50KBS (Shanghai Shen'an Medical Machinery Factory), desktop high-speed refrigerated centrifuge TGL-16M (Hunan Xiangyi Laboratory Instrument Development Co., Ltd.), transmission electron microscope JEM-1400 (Japan Electron Corporation).

[0054] Example 1 Isolation and purification of Escherichia coli phage

[0055] Escherichia coli O157:H7 was used as the host bacteria to isolate bacteriophages. Chicken farm sludge was used to isolate bacteriophages and stored at 4°C until use.

[0056] Weigh 10g of sample into a sterilized conical flask containing 50mL of LB liquid medium, add 10mL of phage buffer and 1mL of Escherichia coli logarithmic phase suspension, mix well, and culture overnight at 30℃. Centrifuge the liquid in the flask at 5000g and 4℃ for 10min, and filter and sterilize the supernatant with a filter with a pore size of 0.22μm to obtain the phage stock solution.

[0057] Take 500 μL of Escherichia coli logarithmic phase suspension, 500 μL of phage buffer and 10 μL of phage stock solution and mix them into a test tube, then add 4 mL of water agar, mix well, spread it on a solid LB plate, and culture it upright at 30°C overnight.

[0058] Pick a single plaque with good growth and clear outline into 100μL phage buffer and dilute it in multiples. Take 10μL of each gradient phage solution and mix it with 500μL E. coli suspension, 500μL phage buffer and 4mL water agar, spread it on the LB solid plate, and culture it at 30℃ overnight. Repeat the above purification process 3-5 times until only a single plaque morphology appears on the same plate. The plaques formed by the two phage strains on the bacterial lawn are as follows: Figure 1 The phages were named GaoM7-14E and JM3e respectively.

[0059] Example 2 Morphological observation of bacteriophage

[0060] 20 μL of the purified phage stock solution in Example 1 was dripped onto the copper mesh and adsorbed for 10 minutes, and the excess liquid was removed with filter paper. Then 20 μL of 2% phosphotungstic acid was dripped onto the copper mesh, and after standing for 30 minutes, the excess liquid was removed with filter paper, and after drying, the phages were observed and photographed under a transmission electron microscope. The electron microscopic morphology of the two phage strains is shown in Figure 1. Figure 2 shown.

[0061] Example 3 Phage genome extraction, sequencing and genome comparative analysis

[0062] After filtering the phage stock solution in Example 1 with a 0.22μm filter, take 500μL and add 10μL DNaseⅠ, incubate in a 37℃ metal bath for 20min to remove free DNA. After the incubation, take 500μL phage, add 22μL EDTA to a final concentration of 20mmol / L (0.5M pH 8.0EDTA), and incubate at 65℃ for 10min. Add 27.5μL 10% SDS to a final concentration of 0.5%, add 2.5μL 10mg / L proteinase K to a final concentration of 50mg / L, and warm at 55℃ for 1.5h. Add 552μL of DNA extraction phenol reagent, mix well, and centrifuge at 4℃ 12000rpm for 10min. Take the supernatant to a new 1.5mL centrifuge tube, add an equal volume of DNA extraction phenol reagent, mix well, and centrifuge at 4℃ 12000rpm for 10min. Take the supernatant to a new 1.5mL centrifuge tube, add an equal volume of chloroform-isoamyl alcohol (v / v 24:1), and centrifuge at 4℃12000rpm for 10min. Take the supernatant to a new 1.5mL centrifuge tube, add 1 / 10 volume of 3M NaAc (pH 5.4), 2 times the volume of ice-cold anhydrous ethanol, mix well, and place at -20℃ for 2.5h. After taking it out from -20℃, centrifuge it at 4℃14000rpm for 20min, and discard the supernatant. Add 500μL of ice-cold 70% ethanol, wash the precipitate, centrifuge it at 4℃12000rpm for 3min, discard the supernatant, air-dry the precipitate in the clean bench for about 2h, and add 25μL ddH2O to dissolve it after air drying. 5μL of genomic sample was mixed with 2μL 6×Loading buffer and verified by agarose gel electrophoresis. The genomic sample with bands was sent to Chengdu Life Baseline Technology Co., Ltd. for sequencing.

[0063] The whole genome pattern of bacteriophage GaoM7-14E is as follows Figure 3 The whole genome pattern of phage JM3e is shown in Figure 4 The genome lengths of phage GaoM7-14E and JM3e are 169,421 bp and 50,578 bp, respectively, and no known drug resistance genes or virulence genes were predicted in the genomes.

[0064] Comparative genomics analysis was performed on the two phages. The phage most closely related to GaoM7-14E was Enterobacteria phage QL01 (KT176190.1), with an ANI of 98.05% and a coverage of 95%. The phage most closely related to JM3e was Escherichia phage Henu4_2 (PQ159479.1), with an ANI of 94.45% and a coverage of 89%, indicating that JM3e is a new type of Escherichia coli phage.

[0065] Example 4 Optimal MOI of phage

[0066] The phage was diluted and mixed with the host bacterial solution (10 8 CFU / mL), 1 mL of phage and 1 mL of bacterial solution, and the MOI after mixing was 10, 1, 0.1, 0.01, and 0.001, respectively. Then 8 mL of LB liquid culture medium was added to each mixed system, cultured at 37°C 220 rpm for 12 h, centrifuged at 4°C 8000 rpm for 10 min, and the supernatant was filtered with a 0.22 μm filter to measure the phage titer. The MOI corresponding to the highest phage titer was the optimal MOI of the phage. The optimal MOI results of the two phage strains are shown in Figure 1. Figure 5 and Figure 6 shown.

[0067] Example 5 Phage one-step growth curve determination

[0068] The optimal MOI of the mixed bacterial solution (10 8 CFU / mL) and phage, incubate at 37℃ for 10min, centrifuge at 8000rpm for 5min, discard the supernatant, add 5mL LB to resuspend, incubate at 37℃ 200rpm for 120min, start sampling after 5min, sample 90μL each time, measure the phage titer after sampling, and calculate the phage latent time and burst volume. The latent time is the shortest time required for infected cells to release their progeny virus particles. The burst volume refers to the phage titer at the end of the outbreak divided by the concentration of host bacteria at the beginning of infection. The one-step growth curve results of the two phage strains are shown in Figure 2. Figure 7 and Figure 8 shown.

[0069] Example 6 Phage host spectrum test

[0070] The host range of phages was determined by the spot method. 500 μL of bacterial solution, 500 μL of phage buffer, and 5 mL of 0.5% water agar were mixed and poured onto the LB solid plate. After solidification, 10 μL of phage stock solution was dropped and cultured in a 37°C constant temperature incubator for 12 hours. The presence of plaques and the degree of transparency of the plaques were observed. The strains required for the host range experiment included 53 pathogenic Escherichia coli isolated from sick chickens, 8 pathogenic Salmonella, and laboratory-preserved E. coli O157:H7 (purchased from Qingdao High-tech Industrial Park Haibo Biotechnology Co., Ltd.).

[0071] The host spectrum test results of the two phages are shown in Table 1. Excluding the results of no plaques (-) and opaque plaques (+), the results of phages that are transparent (++) and have strong lysis are selected for statistics. It can be seen that the combination of phages GaoM7-14E and JM3e can lyse 85.48% (53 / 62) of the strains, indicating that the combination of these two phages can effectively lyse avian pathogenic Escherichia coli and pathogenic Salmonella in a broad spectrum.

[0072] Table 1 Results of lysis spectrum determination of Escherichia coli phage combination GaoM7-14E and JM3e

[0073]

[0074]

[0075]

[0076] Example 7 Evaluation of the inhibitory effect of bacteriophage on host bacteria

[0077] Mix 3mL of 10 8 CFU / ml of Escherichia coli O157:H7 strain and 3mL10 10 PFU / ml of phage (MOI=0.1) was cultured at 37℃ for 12h, samples were taken every 0.5h, and the absorbance at 600nm was measured by a spectrophotometer. The bacterial solution without phage addition was used as a control to evaluate the antibacterial effect of phage GaoM7-14E and JM3e on Escherichia coli O157:H7.

[0078] The results are as follows Fig. 9 As shown, bacteriophage GaoM7-14E and JM3e can kill Escherichia coli O157:H7 in a short time and have good antibacterial properties.

[0079] Example 8 Evaluation of the effect of phage composition in purifying avian Escherichia coli in the environment

[0080] In the biological laboratory, 9 points (each point is 20 cm × 20 cm) were randomly selected as the test area and marked. Three strains of avian pathogenic Escherichia coli were randomly selected from the laboratory collection. The bacteria were cultured to a concentration of 1×10 8 CFU / mL. Mix the bacterial suspensions of two strains of E. coli and spray them evenly over the test area in the biological laboratory. Culture bacteriophage GaoM7-14E and JM3e to obtain a concentration of 1×10 10PFU / mL of phage liquid. Mix two strains of E. coli phage and then spray the test area for disinfection. After 1 hour, wipe the test area with cotton balls and use the culture method to detect bacterial residues. The results showed that no E. coli strain residues were detected in the 9 test areas.

[0081] Example 9 Evaluation of the clinical efficacy of bacteriophage composition in treating Escherichia coli infection in chickens

[0082] 120 healthy, unvaccinated male broilers at one day of age were randomly divided into four groups, 30 in each group, and each group was further divided into three pens, with 10 in each pen as three parallel groups. Water and antibiotic-free broiler feed were randomly provided throughout the experiment. One group was the control group. All broilers were not challenged with E. coli and were not treated with phages. Only 2 mL of phagebuffer was injected. All broilers in the second group were not challenged with E. coli, and each broiler was injected with 2 ml of 1×10 10 In the third group, 0.5 mL of pathogenic Escherichia coli O157:H7 (10 9 All broilers were challenged with 2 mL of the combination of bacteriophage GaoM7-14E and JM3e (10 10 The fourth group was also treated with 0.5 mL of pathogenic Escherichia coli (10 9 CFU / mL) were used to challenge all broilers, and 2 mL of phage buffer was injected 2 hours after the challenge. Escherichia coli is mainly transmitted through the respiratory tract and to prevent gastric acid from destroying the phage, the bacterial liquid, phage suspension and phage buffer were inoculated into the trachea of ​​1-day-old chicks using a feeding needle. The mortality rate of the chicks and the protection rate of the phage composition for the chicks were observed and counted for about 2 weeks of treatment.

[0083] The results of the clinical effect evaluation test of using the phage composition to treat chicken E. coli infection are shown in Table 2. The results show that the combination of the two phage strains can effectively treat sick chickens infected with avian pathogenic E. coli, with a protection rate of 86.67%.

[0084] Table 2 Clinical effect of Escherichia coli phage composition in treating Escherichia coli infection in chickens

[0085]

[0086] The above description is only a preferred embodiment of the present invention, and does not limit the patent scope of the present invention. All equivalent structural changes made by using the contents of the present invention specification under the inventive concept of the present invention, or directly / indirectly applied in other related technical fields are included in the patent protection scope of the present invention.

Claims

1. An Escherichia coli phage, characterized in that The Escherichia coli phage is taxonomically named Escherichia coli phage, named Escherichia coli phage GaoM7-14E, with a preservation number of CGMCC NO.46188 and a preservation date of September 20, 2024.

2. An Escherichia coli phage, characterized in that The Escherichia coli phage is taxonomically named Escherichia coli phage, named Escherichia coli phage JM3e, with a preservation number of CGMCCNO.46186 and a preservation date of September 18, 2024.

3. A bacteriophage composition, characterized in that: These include E. coli phage GaoM7-14E and E. coli phage JM3e; The Escherichia coli phage GaoM7-14E is the Escherichia coli phage GaoM7-14E according to claim 1, and the Escherichia coli phage JM3e is the Escherichia coli phage JM3e according to claim 2.

4. The bacteriophage composition according to claim 3, wherein The titer of the E. coli phage GaoM7-14E and the titer of the E. coli phage JM3e are not less than 10 7 PFU / mL.

5. The bacteriophage composition according to claim 3, wherein The multiplicity of infection (MOI) was 0.001-10.

6. Use of a bacteriophage in the preparation of an antibacterial agent, characterized in that: The bacteriophage includes at least one of Escherichia coli phage GaoM7-14E and Escherichia coli phage JM3e; The Escherichia coli phage GaoM7-14E is the Escherichia coli phage GaoM7-14E according to claim 1, and the Escherichia coli phage JM3e is the Escherichia coli phage JM3e according to claim 2.

7. Use of the bacteriophage according to claim 6 in the preparation of an antibacterial agent, characterized in that: The bacteriostatic agent is used for inhibiting Escherichia coli, and the Escherichia coli includes avian pathogenic Escherichia coli.

8. A bacteriophage preparation, characterized in that: The phage preparation comprises the phage composition according to any one of claims 3 to 5.

9. The bacteriophage preparation according to claim 8, characterized in that The bacteriophage preparation also includes auxiliary materials acceptable in the poultry industry.

10. The bacteriophage preparation according to claim 8, characterized in that The dosage form of the phage preparation includes at least one of a solution, a powder, a gel, a granule or a lyophilized agent.

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