Catechin-resistant vibrio alginolyticus bacteriophage and application thereof

Abstract

The invention provides a catechin-resistant vibrio alginolyticus bacteriophage and application thereof, and belongs to the technical field of microorganisms, the bacteriophage is preserved in China Center for Type Culture Collection on March 6, 2024, the preservation address is Wuhan University, Wuhan, China, and the preservation number is CCTCC NO: M 2024392. The vibrio alginolyticus bacteriophage VAP230405 has the characteristic of catechin resistance, after the bacteriophage is compounded with various catechins, the bacteriophage has excellent tolerance, the bacteriophage and the catechins have a synergistic effect, the bacteriophage also has the biological characteristics of high splitting rate, high fermentation titer and the like, and the vibrio alginolyticus bacteriophage VAP230405 has an obvious effect on preventing and treating trepang putrid-skin disease caused by vibrio alginolyticus. The effect is better than that of singly using bacteriophages or catechins. The method can be widely applied to the fields of aquaculture, food preservation, medical consumption and the like, a new thought and a high-value seed resource are provided for preventing and treating vibrio alginolyticus in the future, and effective parameters are provided for vibrio alginolyticus bacteriophage biological fermentation in the future.

Description

Technical Field

[0001] The invention relates to the technical field of microorganisms, in particular to a catechin-resistant Vibrio alginolyticus phage and application thereof. Background Art

[0002] Vibrio alginolyticus (VA) is an important pathogen in aquaculture that can infect a variety of fish, shrimp and shellfish, causing huge losses to aquaculture around the world and posing a huge threat to the aquaculture environment. Vibrio alginolyticus not only causes infection in a variety of fish, shrimp and shellfish, but also infects humans. Through various seafood contaminated by it, it causes various infections through the food chain. It is a pathogen that is shared by humans and aquatic animals, and poses a great potential threat to food and public health safety.

[0003] Catechins are a class of phenolic active substances extracted from natural plants such as tea. Catechins have a variety of pharmacological effects such as anti-tumor, anti-oxidation, anti-bacteria, and protection of heart and brain organs. These pharmacological activities are mainly determined by their polyhydroxy structure. However, the polyhydroxy structure also makes catechins unstable under neutral and alkaline conditions. After being ingested by the human body, catechins will quickly undergo methylation or glycosylation under the action of biological enzymes. Studies have found that introducing other groups into the structure of catechins can effectively improve their stability and bioavailability, and specifically enhance the pharmacological effects of catechins. Catechins mainly include eight monomers: catechin (C), epicatechin (EC), gallocatechin (GC), epigallocatechin (EGC), catechin gallate (CG), epicatechin gallate (ECG), gallocatechin gallate (GCG) and epigallocatechin gallate (EGCG). Catechins are widely used in antibacterial and antiviral agents. Researchers have shown in the application of tea polyphenols or their components in the preparation of Enterococcus faecalis phage passivators (application number CN201911034893.0) that GA and EGCC in tea polyphenols have an inhibitory effect on Enterococcus faecalis phages, and have a certain effect in inhibiting intestinal Enterococcus faecalis phages. The inhibitory effect on Escherichia coli phages is quite different from that on Enterococcus faecalis phages.

[0004] Bacteriophage is a very green, healthy, non-residue, sustainable and highly targeted bacterial virus. Based on this, screening out a catechin-resistant Vibrio alginolyticus phage for use in aquaculture, food preservation and medical consumption is of great significance. The present invention provides a catechin-resistant Vibrio alginolyticus phage and its application. Summary of the invention

[0005] In order to prevent the infection problems caused by Vibrio alginolyticus and multi-drug resistant Vibrio alginolyticus and reduce the health risks caused by the problems, one of the purposes of the present invention is to provide a catechin-resistant Vibrio alginolyticus phage.

[0006] The second object of the present invention is to provide a Vibrio alginolyticus phage resistant to high concentrations of catechins and its application. The phage provided by the present invention has high concentration tolerance to one or a mixture of eight monomers including catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate and epigallocatechin gallate.

[0007] The third object of the present invention is to provide a formula of bacteriophage and catechins, comprising a formula of a single catechin of catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate and epigallocatechin gallate and bacteriophage; comprising a formula of a ratio of two or three of epicatechin gallate, gallocatechin gallate and epigallocatechin gallate and bacteriophage.

[0008] In order to achieve the above-mentioned purpose, the present invention is implemented through the following technical scheme: a catechin-resistant Vibrio alginolyticus phage, the classification name of which is Vibrio alginolyticus phage VAP230405. The applicant isolated a Vibrio alginolyticus phage VAP230405 from sewage in Qingdao City, Shandong Province. The phage was sent to the China Center for Type Culture Collection for preservation on March 6, 2024. The preservation address is: Wuhan University, Wuhan, China; the preservation number is CCTCC NO: M 2024392.

[0009] Furthermore, it also includes the complex of Vibrio alginolyticus phage VAP230405 and other phages, and the complex of catechins.

[0010] Furthermore, the compound of catechins includes Vibrio alginolyticus phage VAP230405, and the catechins are 8 monomers including catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate and epigallocatechin gallate.

[0011] Furthermore, the Vibrio alginolyticus phage VAP230405 is a phage resistant to high concentrations of catechins.

[0012] Furthermore, the catechins include one or a combination of different catechins.

[0013] An application of the above-mentioned bacteriophage, bacteriophage VAP230405 and other bacteriophage compounds, and catechin compounds to prepare a drug for treating or preventing Vibrio alginolyticus infection, wherein the Vibrio alginolyticus is drug-resistant Vibrio alginolyticus and common Vibrio alginolyticus.

[0014] Furthermore, it is also used in the fields of aquaculture, food preservation, and medical consumption for preparing antagonistic Vibrio alginolyticus.

[0015] Beneficial effects of the present invention:

[0016] 1. The alginolytic Vibrio phage VAP230405 showed excellent resistance to eight catechins (catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate and epigallocatechin gallate) at three concentrations (0.5, 1.0 and 1.5 mg / mL) and had certain resistance to high concentrations of catechins. Compared with the alginolytic Vibrio phage VAP231201, the comparative advantage was more obvious. Under the treatment of 0.5 mg / mL concentration for 24 hours, compared with the control group, the titer of the alginolytic Vibrio phage VAP230405 decreased by 0-0.065 (Log 10 A); When treated with 1.0 mg / mL for 24 h, the titer of Vibrio alginolyticus phage VAP230405 decreased by 0.046-0.155 (Log 10 A); When treated with 1.5 mg / mL for 24 h, the titer of Vibrio alginolyticus phage VAP230405 decreased by 0.167-0.744 (Log 10 A).

[0017] 2. In the tolerance test of Vibrio alginolyticus phage VAP230405 to various compound catechins, the potency of phage VAP230405 decreased in the range of 0.495-1.222 (Log 10A), among which the EGCG+GCG+ECG+VAP230405 group had the largest decrease in titer, which was 1.222 (Log 10 A), GCG+ECG+VAP230405 group decreased by 0.807 (Log 10 A), GCG+ECG+VAP230405 group decreased by 0.807 (Log 10 A), EGCG+ECG+VAP230405 group decreased by 0.585 (Log 10 A), EGCG+GCG+VAP230405 group decreased by 0.495 (Log 10 A), the tolerance of bacteriophage VAP230405 in the three groups of two catechins was good, and under the combination of three catechins, the titer decreased by 1 order of magnitude. The titer of EGCG+GCG+ECG+VAP231201 group decreased by 3.194 (Log 10 A), decreased by 3 orders of magnitude, indicating that compared with VAP231201, phage VAP230405 is more resistant to catechins and improves the titer by 2 orders of magnitude within 24 hours.

[0018] 3. In the tolerance experiment of Vibrio alginolyticus phage VAP230405 to different concentrations of EGCG+GCG+ECG, the titer of phage VAP230405 in the 0.25 mg / mL group did not decrease, while the titer of phage VAP230405 in the 0.50 mg / mL group decreased by 0.018 (Log 10 A), the titer of phage VAP230405 in the 0.75 mg / mL group decreased by 0.119 (Log 10 A), the titer of bacteriophage VAP230405 in the 1.00 mg / mL group decreased by 1.208 (Log 10 A); This indicates that the phage was well tolerated in the 0.25-0.75 mg / mL EGCG+GCG+ECG group, and the titer only dropped to 0-0.119 (Log 10 A).

[0019] 4. The antibacterial effects of different concentrations of EGCG+GCG+ECG and phage complex groups were better than those of different concentrations of EGCG+GCG+ECG single groups. Among them, the 0.75 mg / mL EGCG+GCG+ECG complex phage group controlled the Vibrio concentration at an OD600 value of 0.005 after 48 hours.

[0020] 5. The phage has a good fermentation titer. At the optimal multiplicity of infection (MOI = 0.01), the fermentation titer can reach 5*10 12pfu / mL; bacteriophage VAP230405 could lyse 98 strains of Vibrio alginolyticus among 100 strains resistant to dual florfenicol and enrofloxacin, with a lysis rate of 98%. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 The plaques are of Vibrio alginolyticus phage VAP230405;

[0022] Figure 2 is the titer of Vibrio alginolyticus phage VAP230405 under different infection multiplicity conditions;

[0023] Figure 3 The figure shows the tolerance of Vibrio alginolyticus phage VAP230405 to eight catechins;

[0024] Figure 4 The figure shows the tolerance of Vibrio alginolyticus phage VAP231201 to eight catechins;

[0025] Figure 5 The figure shows the tolerance of Vibrio alginolyticus phage VAP230405 to various compound catechins;

[0026] Figure 6 The tolerance of Vibrio alginolyticus phage VAP230405 to different concentrations of EGCG+GCG+ECG mixtures;

[0027] Figure 7 This is the inhibitory effect of Vibrio alginolyticus phage VAP230405 and different concentrations of EGCG+GCG+ECG complex on Vibrio alginolyticus. DETAILED DESCRIPTION

[0028] In order to make the technical means, creative features, objectives and effects achieved by the present invention easy to understand, the present invention is further explained below in conjunction with specific implementation methods.

[0029] See also Figures 1 to 7 , the present invention provides the following technical solutions:

[0030] Embodiment 1:

[0031] Isolation and Purification of Vibrio alginolyticus Phage VAP230405

[0032] Thirty sewage samples were collected from a water body in Qingdao, Shandong Province. Each sample was centrifuged at 6000 rpm for 5 min. The supernatant was sterilized with a 0.22 μm filter. 20 mL of the filtrate was mixed with 1 mL of Vibrio alginolyticus (concentration of about 1×10 9CFU / mL) were mixed evenly, and after standing for 15 minutes, the culture was shaken at 200 rpm in a 37°C shaker for overnight fermentation. The fermentation broth was centrifuged at 6000 rpm for 10 minutes, the supernatant was sterilized with a 0.22 μm filter, and 100 μL of the filtrate was mixed with 300 μL of Vibrio alginolyticus (concentration was about 1×10 9 CFU / mL) and mix well, add 2216E semi-solid (containing 0.65% agar), gently invert and pour evenly on the nutrient agar bottom plate, and after solidification, place the culture dish in a 37°C incubator for overnight culture. Pick up the transparent and bright plaque spots, shake and desorb in 1mL SM liquid, and sterilize through a 0.22μm microporous filter to obtain a phage filtrate, inoculate it in 5mL 2216E liquid culture medium, add 500μL of the corresponding host Vibrio alginolyticus liquid and mix well, shake and culture at 200rpm overnight at 37°C, centrifuge at 6000rpm for 10min, take the supernatant and sterilize through a 0.22μm microporous filter to obtain a phage filtrate, and observe the plaque morphology using the double-layer plate method. After repeating the operation 3-5 times, plaques of consistent shape and size can be obtained.

[0033] A strain of Vibrio alginolyticus phage VAP230405 was isolated from the water sample. Figure 1 As shown, the plaques formed by it and the host bacteria are relatively transparent, round, and have a diameter of 0.5 mm. The phage has been deposited in the China Center for Type Culture Collection on March 6, 2024, with classification name: Vibrio alginolyticus phage VAP230405, address: Wuhan University, Wuhan, China, and deposit number: CCTCC NO: M 2024392.

[0034] Embodiment 2:

[0035] Determination of the titer of Vibrio alginolyticus phage VAP230405 under different infection multiplicity conditions:

[0036] The host bacterium of Vibrio alginolyticus phage VAP230405, Vibrio alginolyticus QDRZ001, was inoculated into an EP tube with 3 mL of 2216E and cultured at 37°C for 5-8 hours to obtain a QDRZ001 bacterial solution. The bacterial solution was inoculated into 100 mL of 2216E medium at a 3% inoculum volume. When QDRZ001 grew to the initial logarithmic phase, phage VAP230405 was inoculated and the infection was carried out according to different multiplicity of infection (MOI; MOI = number of phages / number of bacteria, see Figure 2 ), each experiment was performed in triplicate. The cells were cultured in a 37°C shaker at 200 rpm for 12 h.

[0037] Results Figure 2When MOI = 0.01, the fermentation titer reached a maximum of 5 × 10 12 PFU / mL.

[0038] Embodiment 3:

[0039] Host range of lysis by Vibrio alginolyticus phage VAP230405

[0040] The experiment selected 100 strains of Vibrio alginolyticus from different sources, all of which were dual-resistant to enrofloxacin and florfenicol, including 20 strains in Qingdao, 20 strains in Wuhan, 20 strains in Shanghai, 20 strains in Beijing and 20 strains in Guangzhou; each strain of Vibrio alginolyticus was inoculated in a 3mL 2216E EP tube, and shaken at 37°C and 200rpm overnight to obtain a Vibrio alginolyticus liquid; prepare a sufficient amount of nutrient agar base plate, mix 0.5ml of Vibrio alginolyticus liquid with 6mL 2216E semi-solid culture medium (containing 0.65% agar) at about 50°C, and slowly spread it on the nutrient agar base plate; after the plate culture medium solidified to room temperature, take 1×10 8 5 μL of phage VAP230405 with a PFU / ml was dropped onto the plate, and after air drying, the plate was inverted and placed in a 37°C constant temperature biochemical incubator for about 8 hours, and the results were observed. Each group of experiments was repeated 3 times.

[0041] As shown in Table 1, bacteriophage VAP230405 can lyse 98 of 100 strains of Vibrio alginolyticus resistant to dual florfenicol and enrofloxacin, with a lysis rate of 98%. The experimental results confirmed that this strain of phage has a very outstanding effect in inhibiting Vibrio alginolyticus resistant to dual florfenicol and enrofloxacin, and has great value for the prevention, control and treatment of Vibrio alginolyticus in the future.

[0042] Table 1 Lysis effect of bacteriophage VAP230405 on dual-florfenicol- and enrofloxacin-resistant Vibrio alginolyticus

[0043]

[0044]

[0045] Note: “-” indicates no lysis, and “+” indicates lysis.

[0046] Embodiment 4:

[0047] Tolerance of Vibrio alginolyticus phage VAP230405 to eight catechins

[0048] The experiment selected two phages, Vibrio alginolyticus phage VAP230405 (deposit number: CCTCC NO: M2024392) and Vibrio alginolyticus phage VAP231201 (patent application number: CN202410528975.5; deposit number: CCTCC NO: M 2024391), for tolerance test of 8 catechins. Three concentrations of 0.5, 1.0, and 1.5 mg / mL were selected for each catechin. The final concentration of phage was 5*10 8 pfu / mL, the experiment was allowed to stand for 24 hours at a temperature of 8°C; after the treatment time was over, the mixture was mixed evenly and the titer of each group was determined, with 3 parallels in each group, and only phage was added to the blank group; the names and abbreviations of the catechin monomers are as follows (the same as in the following examples): catechin (C), epicatechin (EC), gallocatechin (GC), epigallocatechin (EGC), catechin gallate (CG), epicatechin gallate (ECG), gallocatechin gallate (GCG) and epigallocatechin gallate (EGCG).

[0049] The experimental results are as follows Figure 3 and Figure 4 As shown, at a concentration of 0.5 mg / mL for 24 h, the titer of Vibrio alginolyticus phage VAP230405 decreased by 0-0.065 (Log 10 A), the titer of Vibrio alginolyticus phage VAP231201 decreased from 0.155 to 0.585 (Log 10 A), EC and CG had a greater impact on the alginolytic Vibrio phage VAP231201, reaching a maximum value of 0.585 (Log 10 A); When treated with 1.0 mg / mL for 24 h, the titer of Vibrio alginolyticus phage VAP230405 decreased by 0.046-0.155 (Log 10 A), EGCG had a slight effect, with the maximum decrease in potency being 0.155 (Log 10 A), the titer of Vibrio alginolyticus phage VAP231201 decreased from 0.357 to 1.222 (Log 10 A), among which the catechins with the greatest impact on the potency of Vibrio algae phage VAP231201 were EC 1.222 (Log 10A), C's 1.097 (Log 10 A) and EGCG 0.921 (Log 10 A), all decreased by 1 order of magnitude; at 1.5 mg / mL concentration for 24 h, the titer of Vibrio alginolyticus phage VAP230405 decreased by 0.167-0.744 (Log 10 A), the titer of each group did not decrease by 10 times, only the EGCG group had the largest decrease of 0.745 (Log 10 A), the titer of Vibrio alginolyticus phage VAP231201 decreased from 1.046 to 2.398 (Log 10 A), among which the catechins with the greatest impact on the potency of Vibrio algae phage VAP231201 were EC 2.222 (Log 10 A), C's 2.097 (Log 10 A) and EGCG 2.398 (Log 10 A), both decreased by 2 orders of magnitude.

[0050] According to the analysis of the results, the Vibrio alginolyticus phage VAP230405 performed excellently in resistance to three concentrations of catechins and had certain resistance to high concentrations of catechins. Compared with the Vibrio alginolyticus phage VAP231201, its comparative advantage was more obvious. It will provide a new idea for making compound products of phage and monomer catechins in the future.

[0051] Embodiment 5:

[0052] Tolerance of Vibrio alginolyticus phage VAP230405 to multiple catechins

[0053] Through the comparison of various monomeric catechins in Example 4, among which EGCG, GCG, ECG and other three types of catechins have the greatest influence on phage VAP230405, the experiment sets up 2 and 3 monomeric catechins, the compounding ratios are 1:1 and 1:1:1 respectively, and the concentration of each catechin is 1.0 mg / mL. The experiment examines the effects of different formulas of catechins on the titer of phage VAP230405, and the experimental conditions are: standing for 24 hours, 8°C environment; the experiment also examines the effects of EGCG+GCG+ECG groups on the titers of phage VAP230405 and phage VAP231201, respectively, and each experimental group has 3 parallels; the settings are shown in Table 2.

[0054] Table 2 Experimental setup for the tolerance of Vibrio alginolyticus phage VAP230405 to various compound catechins

[0055]

[0056] The experimental results are as follows Figure 5 As shown, compared with the negative group, the titer of phage VAP230405 decreased in the range of 0.495-1.222 (Log 10 A), among which the EGCG+GCG+ECG+VAP230405 group had the largest decrease in titer, which was 1.222 (Log 10 A), GCG+ECG+VAP230405 group decreased by 0.807 (Log 10 A), GCG+ECG+VAP230405 group decreased by 0.807 (Log 10 A), EGCG+ECG+VAP230405 group decreased by 0.585 (Log 10 A), EGCG+GCG+VAP230405 group decreased by 0.495 (Log 10 A), the tolerance of bacteriophage VAP230405 in the three groups of two catechins was good, and under the combination of three catechins, the titer decreased by 1 order of magnitude. The titer of EGCG+GCG+ECG+VAP231201 group decreased by 3.194 (Log 10 A), decreased by 3 orders of magnitude, indicating that compared with VAP231201, phage VAP230405 is more resistant to catechins and has an effect of increasing the titer by 2 orders of magnitude within 24 hours.

[0057] Embodiment 6:

[0058] Tolerance of Vibrio alginolyticus phage VAP230405 to different concentrations of EGCG+GCG+ECG mixtures

[0059] After comparing the compounding of catechins in Example 5, this example investigates the tolerance of Vibrio alginolyticus phage VAP230405 to compounding of EGCG+GCG+ECG at different concentrations. The experimental setting is as follows: the ratio of EGCG+GCG+ECG in each group is 1:1:1, and the concentration of one catechin is set to 0.25, 0.50, 0.75 and 1.00 mg / mL for a total of 4 concentrations (i.e., the concentration of monomer catechins in each group is consistent, such as 0.25:0.25:0.25), and the concentration of each phage group is 5*10 8 pfu / mL, the experimental conditions were: standing for 24 hours at 8°C, setting the phage group as the negative control, and measuring the phage titer of each group after 24 hours, with 3 parallel experiments for each experimental group.

[0060] The experimental results are as follows Figure 6 As shown, the titer of phage VAP230405 in the 0.25 mg / mL group did not decrease, while the titer of phage VAP230405 in the 0.50 mg / mL group decreased by 0.018 (Log 10A), the titer of phage VAP230405 in the 0.75 mg / mL group decreased by 0.119 (Log 10 A), the titer of bacteriophage VAP230405 in the 1.00 mg / mL group decreased by 1.208 (Log 10 A); This indicates that the phage was well tolerated in the 0.25-0.75 mg / mL EGCG+GCG+ECG group, and the titer only dropped to 0-0.119 (Log 10 A).

[0061] Embodiment 7:

[0062] Inhibitory effect of Vibrio alginolyticus phage VAP230405 and different concentrations of EGCG+GCG+ECG complexes on Vibrio alginolyticus

[0063] This example investigates the antibacterial effect of Vibrio alginolyticus phage VAP230405 compounded with different concentrations of EGCG+GCG+ECG on Vibrio alginolyticus QDRZ001. The experimental steps of this example are as follows.

[0064] (1) Activate the host, take the glycerol-preserved QDRZ001 strain and add it to 30 mL of 2216E medium, and culture it at 37°C and 200 rpm overnight;

[0065] (2) Centrifuge the activated bacterial solution and resuspend it in 2216E to a concentration of 1*10 10 cfu / mL QDRZ001 bacterial solution.

[0066] (3) The experimental settings were as follows: the ratio of EGCG+GCG+ECG in each group was 1:1:1, the concentration of one catechin was set to 0.25, 0.50, 0.75 and 1.00 mg / mL, a total of four concentrations (i.e., the concentration of monomeric catechins in each group was consistent, such as 0.25:0.25:0.25), and the concentration of phage in each group was 5*10 8 pfu / mL, add 0.3mL of resuspended bacterial solution to new 30mL 2216E medium, and the host concentration in each group is controlled to 1*10 8 cfu / mL. 0, 2, 4, 6, 8, 10, 12, 18, 24, 36 and 48 h, cultured at 37 ° C, 200 rpm, set the phage + host bacteria group as the control group, and set 0.25, 0.50, 0.75 and 1.00 mg / mL EGCG + GCG + ECG groups as catechin control groups, the specific situation is shown in Table 3, each experimental group has 3 parallels.

[0067] (4) Determine the bacterial concentration OD of the experimental group 600 After the value is calculated, record the result.

[0068] Table 3 Experimental design of the inhibitory effect of bacteriophage VAP230405 and different concentrations of EGCG+GCG+ECG complexes on Vibrio alginolyticus

[0069]

[0070]

[0071] The experimental results are as follows Figure 7 As shown in the figure, the antibacterial effects of the EGCG+GCG+ECG and phage complex groups at different concentrations were better than those of the single EGCG+GCG+ECG groups at different concentrations. Among them, the 0.75 mg / mL EGCG+GCG+ECG complex phage group (Group 3) performed excellently. After 48 hours, the concentration of Vibrio was controlled at OD 600 The value was 0.005. In the group with only phage and host bacteria (group 7), at 48h, OD 600 The value was 0.105. In the group with only 0.75 mg / mL EGCG+GCG+ECG (Group 6), the OD 600 The value is 0.612, indicating that the phage compound EGCG+GCG+ECG has a better effect, providing a high-value parameter for the subsequent phage compound catechin formula

[0072] The above shows and describes the basic principles and main features of the present invention and the advantages of the present invention. It is obvious to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, no matter from which point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the attached claims rather than the above description, and it is intended that all changes falling within the meaning and scope of the equivalent elements of the claims are included in the present invention. Any figure mark in the claims should not be regarded as limiting the claims involved.

[0073] In addition, it should be understood that although the present specification is described according to implementation modes, not every implementation mode contains only one independent technical solution. This description of the specification is only for the sake of clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment may also be appropriately combined to form other implementation modes that can be understood by those skilled in the art.

Claims

1. A catechin-resistant Vibrio alginolyticus phage, characterized in that: The phage is classified and named as Vibrio alginolyticus phage VAP230405. The applicant isolated a strain of Vibrio alginolyticus phage VAP230405 from sewage in Qingdao City, Shandong Province. The phage was sent to the China Center for Type Culture Collection for preservation on March 6, 2024. The preservation address is: Wuhan University, Wuhan, China; the preservation number is CCTCC NO: M 2024392.

2. The bacteriophage according to claim 1, characterized in that: It also includes Vibrio alginolyticus phage VAP230405 and other phage complexes, and catechin complexes.

3. The bacteriophage according to claim 2, characterized in that: The compound of catechins includes Vibrio alginolyticus phage VAP230405, and the catechins are 8 monomers including catechin, epicatechin, gallocatechin, epigallocatechin, catechin gallate, epicatechin gallate, gallocatechin gallate and epigallocatechin gallate.

4. The bacteriophage according to claim 3, characterized in that: The Vibrio alginolyticus phage VAP230405 is a phage resistant to high concentrations of catechins.

5. The compound of catechins according to claim 3, characterized in that: Catechins include one or a combination of different catechins.

6. A use of the bacteriophage, bacteriophage VAP230405 and other bacteriophage compounds, and catechin compounds as claimed in claim 2, characterized in that: The invention is used for preparing a medicine for treating or preventing Vibrio alginolyticus infection, wherein the Vibrio alginolyticus includes drug-resistant Vibrio alginolyticus and common Vibrio alginolyticus.

7. The use of the bacteriophage, bacteriophage VAP230405 and other bacteriophage compounds, and catechin compounds according to claim 6, characterized in that: It is also used in the fields of aquaculture, food preservation, and medical consumption for preparing antagonistic Vibrio alginolyticus.

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